Merge branch 'akpm' (patches from Andrew)

Merge more updates from Andrew Morton:

 - a few misc things

 - kexec updates

 - DMA-mapping updates to better support networking DMA operations

 - IPC updates

 - various MM changes to improve DAX fault handling

 - lots of radix-tree changes, mainly to the test suite. All leading up
   to reimplementing the IDA/IDR code to be a wrapper layer over the
   radix-tree. However the final trigger-pulling patch is held off for
   4.11.

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (114 commits)
  radix tree test suite: delete unused rcupdate.c
  radix tree test suite: add new tag check
  radix-tree: ensure counts are initialised
  radix tree test suite: cache recently freed objects
  radix tree test suite: add some more functionality
  idr: reduce the number of bits per level from 8 to 6
  rxrpc: abstract away knowledge of IDR internals
  tpm: use idr_find(), not idr_find_slowpath()
  idr: add ida_is_empty
  radix tree test suite: check multiorder iteration
  radix-tree: fix replacement for multiorder entries
  radix-tree: add radix_tree_split_preload()
  radix-tree: add radix_tree_split
  radix-tree: add radix_tree_join
  radix-tree: delete radix_tree_range_tag_if_tagged()
  radix-tree: delete radix_tree_locate_item()
  radix-tree: improve multiorder iterators
  btrfs: fix race in btrfs_free_dummy_fs_info()
  radix-tree: improve dump output
  radix-tree: make radix_tree_find_next_bit more useful
  ...

Documentation/filesystems/Locking

@@ -556,7 +556,7 @@ till "end_pgoff". ->map_pages() is called with page table locked and must
 not block.  If it's not possible to reach a page without blocking,
 filesystem should skip it. Filesystem should use do_set_pte() to setup
 page table entry. Pointer to entry associated with the page is passed in
-"pte" field in fault_env structure. Pointers to entries for other offsets
+"pte" field in vm_fault structure. Pointers to entries for other offsets
 should be calculated relative to "pte".
 
 	->page_mkwrite() is called when a previously read-only pte is

arch/arc/mm/dma.c

@@ -158,7 +158,10 @@ static dma_addr_t arc_dma_map_page(struct device *dev, struct page *page,
 		unsigned long attrs)
 {
 	phys_addr_t paddr = page_to_phys(page) + offset;
-	_dma_cache_sync(paddr, size, dir);
+
+	if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC))
+		_dma_cache_sync(paddr, size, dir);
+
 	return plat_phys_to_dma(dev, paddr);
 }
 

arch/arm/common/dmabounce.c

@@ -243,7 +243,8 @@ static int needs_bounce(struct device *dev, dma_addr_t dma_addr, size_t size)
 }
 
 static inline dma_addr_t map_single(struct device *dev, void *ptr, size_t size,
-		enum dma_data_direction dir)
+				    enum dma_data_direction dir,
+				    unsigned long attrs)
 {
 	struct dmabounce_device_info *device_info = dev->archdata.dmabounce;
 	struct safe_buffer *buf;
@@ -262,7 +263,8 @@ static inline dma_addr_t map_single(struct device *dev, void *ptr, size_t size,
 		__func__, buf->ptr, virt_to_dma(dev, buf->ptr),
 		buf->safe, buf->safe_dma_addr);
 
-	if (dir == DMA_TO_DEVICE || dir == DMA_BIDIRECTIONAL) {
+	if ((dir == DMA_TO_DEVICE || dir == DMA_BIDIRECTIONAL) &&
+	    !(attrs & DMA_ATTR_SKIP_CPU_SYNC)) {
 		dev_dbg(dev, "%s: copy unsafe %p to safe %p, size %d\n",
 			__func__, ptr, buf->safe, size);
 		memcpy(buf->safe, ptr, size);
@@ -272,7 +274,8 @@ static inline dma_addr_t map_single(struct device *dev, void *ptr, size_t size,
 }
 
 static inline void unmap_single(struct device *dev, struct safe_buffer *buf,
-		size_t size, enum dma_data_direction dir)
+				size_t size, enum dma_data_direction dir,
+				unsigned long attrs)
 {
 	BUG_ON(buf->size != size);
 	BUG_ON(buf->direction != dir);
@@ -283,7 +286,8 @@ static inline void unmap_single(struct device *dev, struct safe_buffer *buf,
 
 	DO_STATS(dev->archdata.dmabounce->bounce_count++);
 
-	if (dir == DMA_FROM_DEVICE || dir == DMA_BIDIRECTIONAL) {
+	if ((dir == DMA_FROM_DEVICE || dir == DMA_BIDIRECTIONAL) &&
+	    !(attrs & DMA_ATTR_SKIP_CPU_SYNC)) {
 		void *ptr = buf->ptr;
 
 		dev_dbg(dev, "%s: copy back safe %p to unsafe %p size %d\n",
@@ -334,7 +338,7 @@ static dma_addr_t dmabounce_map_page(struct device *dev, struct page *page,
 		return DMA_ERROR_CODE;
 	}
 
-	return map_single(dev, page_address(page) + offset, size, dir);
+	return map_single(dev, page_address(page) + offset, size, dir, attrs);
 }
 
 /*
@@ -357,7 +361,7 @@ static void dmabounce_unmap_page(struct device *dev, dma_addr_t dma_addr, size_t
 		return;
 	}
 
-	unmap_single(dev, buf, size, dir);
+	unmap_single(dev, buf, size, dir, attrs);
 }
 
 static int __dmabounce_sync_for_cpu(struct device *dev, dma_addr_t addr,

arch/avr32/mm/dma-coherent.c

@@ -146,7 +146,8 @@ static dma_addr_t avr32_dma_map_page(struct device *dev, struct page *page,
 {
 	void *cpu_addr = page_address(page) + offset;
 
-	dma_cache_sync(dev, cpu_addr, size, direction);
+	if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC))
+		dma_cache_sync(dev, cpu_addr, size, direction);
 	return virt_to_bus(cpu_addr);
 }
 
@@ -162,6 +163,10 @@ static int avr32_dma_map_sg(struct device *dev, struct scatterlist *sglist,
 
 		sg->dma_address = page_to_bus(sg_page(sg)) + sg->offset;
 		virt = sg_virt(sg);
+
+		if (attrs & DMA_ATTR_SKIP_CPU_SYNC)
+			continue;
+
 		dma_cache_sync(dev, virt, sg->length, direction);
 	}
 

arch/blackfin/kernel/dma-mapping.c

@@ -118,6 +118,10 @@ static int bfin_dma_map_sg(struct device *dev, struct scatterlist *sg_list,
 
 	for_each_sg(sg_list, sg, nents, i) {
 		sg->dma_address = (dma_addr_t) sg_virt(sg);
+
+		if (attrs & DMA_ATTR_SKIP_CPU_SYNC)
+			continue;
+
 		__dma_sync(sg_dma_address(sg), sg_dma_len(sg), direction);
 	}
 
@@ -143,7 +147,9 @@ static dma_addr_t bfin_dma_map_page(struct device *dev, struct page *page,
 {
 	dma_addr_t handle = (dma_addr_t)(page_address(page) + offset);
 
-	_dma_sync(handle, size, dir);
+	if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC))
+		_dma_sync(handle, size, dir);
+
 	return handle;
 }
 

arch/c6x/kernel/dma.c

@@ -42,14 +42,17 @@ static dma_addr_t c6x_dma_map_page(struct device *dev, struct page *page,
 {
 	dma_addr_t handle = virt_to_phys(page_address(page) + offset);
 
-	c6x_dma_sync(handle, size, dir);
+	if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC))
+		c6x_dma_sync(handle, size, dir);
+
 	return handle;
 }
 
 static void c6x_dma_unmap_page(struct device *dev, dma_addr_t handle,
 		size_t size, enum dma_data_direction dir, unsigned long attrs)
 {
-	c6x_dma_sync(handle, size, dir);
+	if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC))
+		c6x_dma_sync(handle, size, dir);
 }
 
 static int c6x_dma_map_sg(struct device *dev, struct scatterlist *sglist,
@@ -60,7 +63,8 @@ static int c6x_dma_map_sg(struct device *dev, struct scatterlist *sglist,
 
 	for_each_sg(sglist, sg, nents, i) {
 		sg->dma_address = sg_phys(sg);
-		c6x_dma_sync(sg->dma_address, sg->length, dir);
+		if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC))
+			c6x_dma_sync(sg->dma_address, sg->length, dir);
 	}
 
 	return nents;
@@ -72,9 +76,11 @@ static void c6x_dma_unmap_sg(struct device *dev, struct scatterlist *sglist,
 	struct scatterlist *sg;
 	int i;
 
+	if (attrs & DMA_ATTR_SKIP_CPU_SYNC)
+		return;
+
 	for_each_sg(sglist, sg, nents, i)
 		c6x_dma_sync(sg_dma_address(sg), sg->length, dir);
-
 }
 
 static void c6x_dma_sync_single_for_cpu(struct device *dev, dma_addr_t handle,

arch/frv/mb93090-mb00/pci-dma-nommu.c

@@ -109,16 +109,19 @@ static int frv_dma_map_sg(struct device *dev, struct scatterlist *sglist,
 		int nents, enum dma_data_direction direction,
 		unsigned long attrs)
 {
-	int i;
 	struct scatterlist *sg;
+	int i;
+
+	BUG_ON(direction == DMA_NONE);
+
+	if (attrs & DMA_ATTR_SKIP_CPU_SYNC)
+		return nents;
 
 	for_each_sg(sglist, sg, nents, i) {
 		frv_cache_wback_inv(sg_dma_address(sg),
 				    sg_dma_address(sg) + sg_dma_len(sg));
 	}
 
-	BUG_ON(direction == DMA_NONE);
-
 	return nents;
 }
 
@@ -127,7 +130,10 @@ static dma_addr_t frv_dma_map_page(struct device *dev, struct page *page,
 		enum dma_data_direction direction, unsigned long attrs)
 {
 	BUG_ON(direction == DMA_NONE);
-	flush_dcache_page(page);
+
+	if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC))
+		flush_dcache_page(page);
+
 	return (dma_addr_t) page_to_phys(page) + offset;
 }
 

arch/frv/mb93090-mb00/pci-dma.c

@@ -40,13 +40,16 @@ static int frv_dma_map_sg(struct device *dev, struct scatterlist *sglist,
 		int nents, enum dma_data_direction direction,
 		unsigned long attrs)
 {
+	struct scatterlist *sg;
 	unsigned long dampr2;
 	void *vaddr;
 	int i;
-	struct scatterlist *sg;
 
 	BUG_ON(direction == DMA_NONE);
 
+	if (attrs & DMA_ATTR_SKIP_CPU_SYNC)
+		return nents;
+
 	dampr2 = __get_DAMPR(2);
 
 	for_each_sg(sglist, sg, nents, i) {
@@ -70,7 +73,9 @@ static dma_addr_t frv_dma_map_page(struct device *dev, struct page *page,
 		unsigned long offset, size_t size,
 		enum dma_data_direction direction, unsigned long attrs)
 {
-	flush_dcache_page(page);
+	if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC))
+		flush_dcache_page(page);
+
 	return (dma_addr_t) page_to_phys(page) + offset;
 }
 

arch/hexagon/kernel/dma.c

@@ -119,6 +119,9 @@ static int hexagon_map_sg(struct device *hwdev, struct scatterlist *sg,
 
 		s->dma_length = s->length;
 
+		if (attrs & DMA_ATTR_SKIP_CPU_SYNC)
+			continue;
+
 		flush_dcache_range(dma_addr_to_virt(s->dma_address),
 				   dma_addr_to_virt(s->dma_address + s->length));
 	}
@@ -180,7 +183,8 @@ static dma_addr_t hexagon_map_page(struct device *dev, struct page *page,
 	if (!check_addr("map_single", dev, bus, size))
 		return bad_dma_address;
 
-	dma_sync(dma_addr_to_virt(bus), size, dir);
+	if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC))
+		dma_sync(dma_addr_to_virt(bus), size, dir);
 
 	return bus;
 }

arch/m68k/kernel/dma.c

@@ -134,7 +134,9 @@ static dma_addr_t m68k_dma_map_page(struct device *dev, struct page *page,
 {
 	dma_addr_t handle = page_to_phys(page) + offset;
 
-	dma_sync_single_for_device(dev, handle, size, dir);
+	if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC))
+		dma_sync_single_for_device(dev, handle, size, dir);
+
 	return handle;
 }
 
@@ -146,6 +148,10 @@ static int m68k_dma_map_sg(struct device *dev, struct scatterlist *sglist,
 
 	for_each_sg(sglist, sg, nents, i) {
 		sg->dma_address = sg_phys(sg);
+
+		if (attrs & DMA_ATTR_SKIP_CPU_SYNC)
+			continue;
+
 		dma_sync_single_for_device(dev, sg->dma_address, sg->length,
 					   dir);
 	}

arch/metag/kernel/dma.c

@@ -484,8 +484,9 @@ static dma_addr_t metag_dma_map_page(struct device *dev, struct page *page,
 		unsigned long offset, size_t size,
 		enum dma_data_direction direction, unsigned long attrs)
 {
-	dma_sync_for_device((void *)(page_to_phys(page) + offset), size,
+	if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC))
-			    direction);
+		dma_sync_for_device((void *)(page_to_phys(page) + offset),
+				    size, direction);
 	return page_to_phys(page) + offset;
 }
 
@@ -493,7 +494,8 @@ static void metag_dma_unmap_page(struct device *dev, dma_addr_t dma_address,
 		size_t size, enum dma_data_direction direction,
 		unsigned long attrs)
 {
-	dma_sync_for_cpu(phys_to_virt(dma_address), size, direction);
+	if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC))
+		dma_sync_for_cpu(phys_to_virt(dma_address), size, direction);
 }
 
 static int metag_dma_map_sg(struct device *dev, struct scatterlist *sglist,
@@ -507,6 +509,10 @@ static int metag_dma_map_sg(struct device *dev, struct scatterlist *sglist,
 		BUG_ON(!sg_page(sg));
 
 		sg->dma_address = sg_phys(sg);
+
+		if (attrs & DMA_ATTR_SKIP_CPU_SYNC)
+			continue;
+
 		dma_sync_for_device(sg_virt(sg), sg->length, direction);
 	}
 
@@ -525,6 +531,10 @@ static void metag_dma_unmap_sg(struct device *dev, struct scatterlist *sglist,
 		BUG_ON(!sg_page(sg));
 
 		sg->dma_address = sg_phys(sg);
+
+		if (attrs & DMA_ATTR_SKIP_CPU_SYNC)
+			continue;
+
 		dma_sync_for_cpu(sg_virt(sg), sg->length, direction);
 	}
 }

arch/microblaze/kernel/dma.c

@@ -61,6 +61,10 @@ static int dma_direct_map_sg(struct device *dev, struct scatterlist *sgl,
 	/* FIXME this part of code is untested */
 	for_each_sg(sgl, sg, nents, i) {
 		sg->dma_address = sg_phys(sg);
+
+		if (attrs & DMA_ATTR_SKIP_CPU_SYNC)
+			continue;
+
 		__dma_sync(page_to_phys(sg_page(sg)) + sg->offset,
 							sg->length, direction);
 	}
@@ -80,7 +84,8 @@ static inline dma_addr_t dma_direct_map_page(struct device *dev,
 					     enum dma_data_direction direction,
 					     unsigned long attrs)
 {
-	__dma_sync(page_to_phys(page) + offset, size, direction);
+	if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC))
+		__dma_sync(page_to_phys(page) + offset, size, direction);
 	return page_to_phys(page) + offset;
 }
 
@@ -95,7 +100,8 @@ static inline void dma_direct_unmap_page(struct device *dev,
  * phys_to_virt is here because in __dma_sync_page is __virt_to_phys and
  * dma_address is physical address
  */
-	__dma_sync(dma_address, size, direction);
+	if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC))
+		__dma_sync(dma_address, size, direction);
 }
 
 static inline void

arch/mips/loongson64/common/dma-swiotlb.c

@@ -61,7 +61,7 @@ static int loongson_dma_map_sg(struct device *dev, struct scatterlist *sg,
 				int nents, enum dma_data_direction dir,
 				unsigned long attrs)
 {
-	int r = swiotlb_map_sg_attrs(dev, sg, nents, dir, 0);
+	int r = swiotlb_map_sg_attrs(dev, sg, nents, dir, attrs);
 	mb();
 
 	return r;

arch/mips/mm/dma-default.c

@@ -293,7 +293,7 @@ static inline void __dma_sync(struct page *page,
 static void mips_dma_unmap_page(struct device *dev, dma_addr_t dma_addr,
 	size_t size, enum dma_data_direction direction, unsigned long attrs)
 {
-	if (cpu_needs_post_dma_flush(dev))
+	if (cpu_needs_post_dma_flush(dev) && !(attrs & DMA_ATTR_SKIP_CPU_SYNC))
 		__dma_sync(dma_addr_to_page(dev, dma_addr),
 			   dma_addr & ~PAGE_MASK, size, direction);
 	plat_post_dma_flush(dev);
@@ -307,7 +307,8 @@ static int mips_dma_map_sg(struct device *dev, struct scatterlist *sglist,
 	struct scatterlist *sg;
 
 	for_each_sg(sglist, sg, nents, i) {
-		if (!plat_device_is_coherent(dev))
+		if (!plat_device_is_coherent(dev) &&
+		    !(attrs & DMA_ATTR_SKIP_CPU_SYNC))
 			__dma_sync(sg_page(sg), sg->offset, sg->length,
 				   direction);
 #ifdef CONFIG_NEED_SG_DMA_LENGTH
@@ -324,7 +325,7 @@ static dma_addr_t mips_dma_map_page(struct device *dev, struct page *page,
 	unsigned long offset, size_t size, enum dma_data_direction direction,
 	unsigned long attrs)
 {
-	if (!plat_device_is_coherent(dev))
+	if (!plat_device_is_coherent(dev) && !(attrs & DMA_ATTR_SKIP_CPU_SYNC))
 		__dma_sync(page, offset, size, direction);
 
 	return plat_map_dma_mem_page(dev, page) + offset;
@@ -339,6 +340,7 @@ static void mips_dma_unmap_sg(struct device *dev, struct scatterlist *sglist,
 
 	for_each_sg(sglist, sg, nhwentries, i) {
 		if (!plat_device_is_coherent(dev) &&
+		    !(attrs & DMA_ATTR_SKIP_CPU_SYNC) &&
 		    direction != DMA_TO_DEVICE)
 			__dma_sync(sg_page(sg), sg->offset, sg->length,
 				   direction);

arch/nios2/mm/dma-mapping.c

@@ -98,13 +98,17 @@ static int nios2_dma_map_sg(struct device *dev, struct scatterlist *sg,
 	int i;
 
 	for_each_sg(sg, sg, nents, i) {
-		void *addr;
+		void *addr = sg_virt(sg);
 
-		addr = sg_virt(sg);
+		if (!addr)
-		if (addr) {
+			continue;
-			__dma_sync_for_device(addr, sg->length, direction);
+
-			sg->dma_address = sg_phys(sg);
+		sg->dma_address = sg_phys(sg);
-		}
+
+		if (attrs & DMA_ATTR_SKIP_CPU_SYNC)
+			continue;
+
+		__dma_sync_for_device(addr, sg->length, direction);
 	}
 
 	return nents;
@@ -117,7 +121,9 @@ static dma_addr_t nios2_dma_map_page(struct device *dev, struct page *page,
 {
 	void *addr = page_address(page) + offset;
 
-	__dma_sync_for_device(addr, size, direction);
+	if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC))
+		__dma_sync_for_device(addr, size, direction);
+
 	return page_to_phys(page) + offset;
 }
 
@@ -125,7 +131,8 @@ static void nios2_dma_unmap_page(struct device *dev, dma_addr_t dma_address,
 		size_t size, enum dma_data_direction direction,
 		unsigned long attrs)
 {
-	__dma_sync_for_cpu(phys_to_virt(dma_address), size, direction);
+	if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC))
+		__dma_sync_for_cpu(phys_to_virt(dma_address), size, direction);
 }
 
 static void nios2_dma_unmap_sg(struct device *dev, struct scatterlist *sg,
@@ -138,6 +145,9 @@ static void nios2_dma_unmap_sg(struct device *dev, struct scatterlist *sg,
 	if (direction == DMA_TO_DEVICE)
 		return;
 
+	if (attrs & DMA_ATTR_SKIP_CPU_SYNC)
+		return;
+
 	for_each_sg(sg, sg, nhwentries, i) {
 		addr = sg_virt(sg);
 		if (addr)

arch/openrisc/kernel/dma.c

@@ -141,6 +141,9 @@ or1k_map_page(struct device *dev, struct page *page,
 	unsigned long cl;
 	dma_addr_t addr = page_to_phys(page) + offset;
 
+	if (attrs & DMA_ATTR_SKIP_CPU_SYNC)
+		return addr;
+
 	switch (dir) {
 	case DMA_TO_DEVICE:
 		/* Flush the dcache for the requested range */

arch/parisc/kernel/pci-dma.c

@@ -459,7 +459,9 @@ static dma_addr_t pa11_dma_map_page(struct device *dev, struct page *page,
 	void *addr = page_address(page) + offset;
 	BUG_ON(direction == DMA_NONE);
 
-	flush_kernel_dcache_range((unsigned long) addr, size);
+	if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC))
+		flush_kernel_dcache_range((unsigned long) addr, size);
+
 	return virt_to_phys(addr);
 }
 
@@ -469,8 +471,11 @@ static void pa11_dma_unmap_page(struct device *dev, dma_addr_t dma_handle,
 {
 	BUG_ON(direction == DMA_NONE);
 
+	if (attrs & DMA_ATTR_SKIP_CPU_SYNC)
+		return;
+
 	if (direction == DMA_TO_DEVICE)
-	    return;
+		return;
 
 	/*
 	 * For PCI_DMA_FROMDEVICE this flush is not necessary for the
@@ -479,7 +484,6 @@ static void pa11_dma_unmap_page(struct device *dev, dma_addr_t dma_handle,
 	 */
 
 	flush_kernel_dcache_range((unsigned long) phys_to_virt(dma_handle), size);
-	return;
 }
 
 static int pa11_dma_map_sg(struct device *dev, struct scatterlist *sglist,
@@ -496,6 +500,10 @@ static int pa11_dma_map_sg(struct device *dev, struct scatterlist *sglist,
 
 		sg_dma_address(sg) = (dma_addr_t) virt_to_phys(vaddr);
 		sg_dma_len(sg) = sg->length;
+
+		if (attrs & DMA_ATTR_SKIP_CPU_SYNC)
+			continue;
+
 		flush_kernel_dcache_range(vaddr, sg->length);
 	}
 	return nents;
@@ -510,14 +518,16 @@ static void pa11_dma_unmap_sg(struct device *dev, struct scatterlist *sglist,
 
 	BUG_ON(direction == DMA_NONE);
 
+	if (attrs & DMA_ATTR_SKIP_CPU_SYNC)
+		return;
+
 	if (direction == DMA_TO_DEVICE)
-	    return;
+		return;
 
 	/* once we do combining we'll need to use phys_to_virt(sg_dma_address(sglist)) */
 
 	for_each_sg(sglist, sg, nents, i)
 		flush_kernel_vmap_range(sg_virt(sg), sg->length);
-	return;
 }
 
 static void pa11_dma_sync_single_for_cpu(struct device *dev,

arch/powerpc/kernel/dma.c

@@ -203,6 +203,10 @@ static int dma_direct_map_sg(struct device *dev, struct scatterlist *sgl,
 	for_each_sg(sgl, sg, nents, i) {
 		sg->dma_address = sg_phys(sg) + get_dma_offset(dev);
 		sg->dma_length = sg->length;
+
+		if (attrs & DMA_ATTR_SKIP_CPU_SYNC)
+			continue;
+
 		__dma_sync_page(sg_page(sg), sg->offset, sg->length, direction);
 	}
 
@@ -235,7 +239,10 @@ static inline dma_addr_t dma_direct_map_page(struct device *dev,
 					     unsigned long attrs)
 {
 	BUG_ON(dir == DMA_NONE);
-	__dma_sync_page(page, offset, size, dir);
+
+	if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC))
+		__dma_sync_page(page, offset, size, dir);
+
 	return page_to_phys(page) + offset + get_dma_offset(dev);
 }
 

arch/powerpc/platforms/cell/spufs/file.c

@@ -236,7 +236,6 @@ static int
 spufs_mem_mmap_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 {
 	struct spu_context *ctx	= vma->vm_file->private_data;
-	unsigned long address = (unsigned long)vmf->virtual_address;
 	unsigned long pfn, offset;
 
 	offset = vmf->pgoff << PAGE_SHIFT;
@@ -244,7 +243,7 @@ spufs_mem_mmap_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 		return VM_FAULT_SIGBUS;
 
 	pr_debug("spufs_mem_mmap_fault address=0x%lx, offset=0x%lx\n",
-			address, offset);
+			vmf->address, offset);
 
 	if (spu_acquire(ctx))
 		return VM_FAULT_NOPAGE;
@@ -256,7 +255,7 @@ spufs_mem_mmap_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 		vma->vm_page_prot = pgprot_noncached_wc(vma->vm_page_prot);
 		pfn = (ctx->spu->local_store_phys + offset) >> PAGE_SHIFT;
 	}
-	vm_insert_pfn(vma, address, pfn);
+	vm_insert_pfn(vma, vmf->address, pfn);
 
 	spu_release(ctx);
 
@@ -355,8 +354,7 @@ static int spufs_ps_fault(struct vm_area_struct *vma,
 		down_read(&current->mm->mmap_sem);
 	} else {
 		area = ctx->spu->problem_phys + ps_offs;
-		vm_insert_pfn(vma, (unsigned long)vmf->virtual_address,
+		vm_insert_pfn(vma, vmf->address, (area + offset) >> PAGE_SHIFT);
-					(area + offset) >> PAGE_SHIFT);
 		spu_context_trace(spufs_ps_fault__insert, ctx, ctx->spu);
 	}
 

arch/sh/kernel/dma-nommu.c

@@ -18,7 +18,9 @@ static dma_addr_t nommu_map_page(struct device *dev, struct page *page,
 	dma_addr_t addr = page_to_phys(page) + offset;
 
 	WARN_ON(size == 0);
-	dma_cache_sync(dev, page_address(page) + offset, size, dir);
+
+	if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC))
+		dma_cache_sync(dev, page_address(page) + offset, size, dir);
 
 	return addr;
 }
@@ -35,7 +37,8 @@ static int nommu_map_sg(struct device *dev, struct scatterlist *sg,
 	for_each_sg(sg, s, nents, i) {
 		BUG_ON(!sg_page(s));
 
-		dma_cache_sync(dev, sg_virt(s), s->length, dir);
+		if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC))
+			dma_cache_sync(dev, sg_virt(s), s->length, dir);
 
 		s->dma_address = sg_phys(s);
 		s->dma_length = s->length;

arch/sparc/kernel/iommu.c

@@ -415,7 +415,7 @@ static void dma_4u_unmap_page(struct device *dev, dma_addr_t bus_addr,
 		ctx = (iopte_val(*base) & IOPTE_CONTEXT) >> 47UL;
 
 	/* Step 1: Kick data out of streaming buffers if necessary. */
-	if (strbuf->strbuf_enabled)
+	if (strbuf->strbuf_enabled && !(attrs & DMA_ATTR_SKIP_CPU_SYNC))
 		strbuf_flush(strbuf, iommu, bus_addr, ctx,
 			     npages, direction);
 
@@ -640,7 +640,7 @@ static void dma_4u_unmap_sg(struct device *dev, struct scatterlist *sglist,
 		base = iommu->page_table + entry;
 
 		dma_handle &= IO_PAGE_MASK;
-		if (strbuf->strbuf_enabled)
+		if (strbuf->strbuf_enabled && !(attrs & DMA_ATTR_SKIP_CPU_SYNC))
 			strbuf_flush(strbuf, iommu, dma_handle, ctx,
 				     npages, direction);
 

arch/sparc/kernel/ioport.c

@@ -527,7 +527,7 @@ static dma_addr_t pci32_map_page(struct device *dev, struct page *page,
 static void pci32_unmap_page(struct device *dev, dma_addr_t ba, size_t size,
 			     enum dma_data_direction dir, unsigned long attrs)
 {
-	if (dir != PCI_DMA_TODEVICE)
+	if (dir != PCI_DMA_TODEVICE && !(attrs & DMA_ATTR_SKIP_CPU_SYNC))
 		dma_make_coherent(ba, PAGE_ALIGN(size));
 }
 
@@ -572,7 +572,7 @@ static void pci32_unmap_sg(struct device *dev, struct scatterlist *sgl,
 	struct scatterlist *sg;
 	int n;
 
-	if (dir != PCI_DMA_TODEVICE) {
+	if (dir != PCI_DMA_TODEVICE && !(attrs & DMA_ATTR_SKIP_CPU_SYNC)) {
 		for_each_sg(sgl, sg, nents, n) {
 			dma_make_coherent(sg_phys(sg), PAGE_ALIGN(sg->length));
 		}

arch/sparc/kernel/nmi.c

@@ -42,7 +42,7 @@ static int panic_on_timeout;
  */
 atomic_t nmi_active = ATOMIC_INIT(0);		/* oprofile uses this */
 EXPORT_SYMBOL(nmi_active);
-
+static int nmi_init_done;
 static unsigned int nmi_hz = HZ;
 static DEFINE_PER_CPU(short, wd_enabled);
 static int endflag __initdata;
@@ -153,6 +153,8 @@ static void report_broken_nmi(int cpu, int *prev_nmi_count)
 
 void stop_nmi_watchdog(void *unused)
 {
+	if (!__this_cpu_read(wd_enabled))
+		return;
 	pcr_ops->write_pcr(0, pcr_ops->pcr_nmi_disable);
 	__this_cpu_write(wd_enabled, 0);
 	atomic_dec(&nmi_active);
@@ -207,6 +209,9 @@ error:
 
 void start_nmi_watchdog(void *unused)
 {
+	if (__this_cpu_read(wd_enabled))
+		return;
+
 	__this_cpu_write(wd_enabled, 1);
 	atomic_inc(&nmi_active);
 
@@ -259,6 +264,8 @@ int __init nmi_init(void)
 		}
 	}
 
+	nmi_init_done = 1;
+
 	return err;
 }
 
@@ -270,3 +277,38 @@ static int __init setup_nmi_watchdog(char *str)
 	return 0;
 }
 __setup("nmi_watchdog=", setup_nmi_watchdog);
+
+/*
+ * sparc specific NMI watchdog enable function.
+ * Enables watchdog if it is not enabled already.
+ */
+int watchdog_nmi_enable(unsigned int cpu)
+{
+	if (atomic_read(&nmi_active) == -1) {
+		pr_warn("NMI watchdog cannot be enabled or disabled\n");
+		return -1;
+	}
+
+	/*
+	 * watchdog thread could start even before nmi_init is called.
+	 * Just Return in that case. Let nmi_init finish the init
+	 * process first.
+	 */
+	if (!nmi_init_done)
+		return 0;
+
+	smp_call_function_single(cpu, start_nmi_watchdog, NULL, 1);
+
+	return 0;
+}
+/*
+ * sparc specific NMI watchdog disable function.
+ * Disables watchdog if it is not disabled already.
+ */
+void watchdog_nmi_disable(unsigned int cpu)
+{
+	if (atomic_read(&nmi_active) == -1)
+		pr_warn_once("NMI watchdog cannot be enabled or disabled\n");
+	else
+		smp_call_function_single(cpu, stop_nmi_watchdog, NULL, 1);
+}

arch/tile/kernel/pci-dma.c

@@ -213,10 +213,12 @@ static int tile_dma_map_sg(struct device *dev, struct scatterlist *sglist,
 
 	for_each_sg(sglist, sg, nents, i) {
 		sg->dma_address = sg_phys(sg);
-		__dma_prep_pa_range(sg->dma_address, sg->length, direction);
 #ifdef CONFIG_NEED_SG_DMA_LENGTH
 		sg->dma_length = sg->length;
 #endif
+		if (attrs & DMA_ATTR_SKIP_CPU_SYNC)
+			continue;
+		__dma_prep_pa_range(sg->dma_address, sg->length, direction);
 	}
 
 	return nents;
@@ -232,6 +234,8 @@ static void tile_dma_unmap_sg(struct device *dev, struct scatterlist *sglist,
 	BUG_ON(!valid_dma_direction(direction));
 	for_each_sg(sglist, sg, nents, i) {
 		sg->dma_address = sg_phys(sg);
+		if (attrs & DMA_ATTR_SKIP_CPU_SYNC)
+			continue;
 		__dma_complete_pa_range(sg->dma_address, sg->length,
 					direction);
 	}
@@ -245,7 +249,8 @@ static dma_addr_t tile_dma_map_page(struct device *dev, struct page *page,
 	BUG_ON(!valid_dma_direction(direction));
 
 	BUG_ON(offset + size > PAGE_SIZE);
-	__dma_prep_page(page, offset, size, direction);
+	if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC))
+		__dma_prep_page(page, offset, size, direction);
 
 	return page_to_pa(page) + offset;
 }
@@ -256,6 +261,9 @@ static void tile_dma_unmap_page(struct device *dev, dma_addr_t dma_address,
 {
 	BUG_ON(!valid_dma_direction(direction));
 
+	if (attrs & DMA_ATTR_SKIP_CPU_SYNC)
+		return;
+
 	__dma_complete_page(pfn_to_page(PFN_DOWN(dma_address)),
 			    dma_address & (PAGE_SIZE - 1), size, direction);
 }

arch/x86/entry/vdso/vma.c

@@ -109,7 +109,7 @@ static int vvar_fault(const struct vm_special_mapping *sm,
 		return VM_FAULT_SIGBUS;
 
 	if (sym_offset == image->sym_vvar_page) {
-		ret = vm_insert_pfn(vma, (unsigned long)vmf->virtual_address,
+		ret = vm_insert_pfn(vma, vmf->address,
 				    __pa_symbol(&__vvar_page) >> PAGE_SHIFT);
 	} else if (sym_offset == image->sym_pvclock_page) {
 		struct pvclock_vsyscall_time_info *pvti =
@@ -117,7 +117,7 @@ static int vvar_fault(const struct vm_special_mapping *sm,
 		if (pvti && vclock_was_used(VCLOCK_PVCLOCK)) {
 			ret = vm_insert_pfn(
 				vma,
-				(unsigned long)vmf->virtual_address,
+				vmf->address,
 				__pa(pvti) >> PAGE_SHIFT);
 		}
 	}

arch/x86/kernel/machine_kexec_64.c

@@ -328,7 +328,7 @@ void machine_kexec(struct kimage *image)
 
 void arch_crash_save_vmcoreinfo(void)
 {
-	VMCOREINFO_SYMBOL(phys_base);
+	VMCOREINFO_NUMBER(phys_base);
 	VMCOREINFO_SYMBOL(init_level4_pgt);
 
 #ifdef CONFIG_NUMA
@@ -337,9 +337,7 @@ void arch_crash_save_vmcoreinfo(void)
 #endif
 	vmcoreinfo_append_str("KERNELOFFSET=%lx\n",
 			      kaslr_offset());
-	VMCOREINFO_PAGE_OFFSET(PAGE_OFFSET);
+	VMCOREINFO_NUMBER(KERNEL_IMAGE_SIZE);
-	VMCOREINFO_VMALLOC_START(VMALLOC_START);
-	VMCOREINFO_VMEMMAP_START(VMEMMAP_START);
 }
 
 /* arch-dependent functionality related to kexec file-based syscall */

arch/xtensa/kernel/pci-dma.c

@@ -189,7 +189,9 @@ static dma_addr_t xtensa_map_page(struct device *dev, struct page *page,
 {
 	dma_addr_t dma_handle = page_to_phys(page) + offset;
 
-	xtensa_sync_single_for_device(dev, dma_handle, size, dir);
+	if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC))
+		xtensa_sync_single_for_device(dev, dma_handle, size, dir);
+
 	return dma_handle;
 }
 
@@ -197,7 +199,8 @@ static void xtensa_unmap_page(struct device *dev, dma_addr_t dma_handle,
 			      size_t size, enum dma_data_direction dir,
 			      unsigned long attrs)
 {
-	xtensa_sync_single_for_cpu(dev, dma_handle, size, dir);
+	if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC))
+		xtensa_sync_single_for_cpu(dev, dma_handle, size, dir);
 }
 
 static int xtensa_map_sg(struct device *dev, struct scatterlist *sg,

drivers/char/agp/alpha-agp.c

@@ -19,8 +19,7 @@ static int alpha_core_agp_vm_fault(struct vm_area_struct *vma,
 	unsigned long pa;
 	struct page *page;
 
-	dma_addr = (unsigned long)vmf->virtual_address - vma->vm_start
+	dma_addr = vmf->address - vma->vm_start + agp->aperture.bus_base;
-						+ agp->aperture.bus_base;
 	pa = agp->ops->translate(agp, dma_addr);
 
 	if (pa == (unsigned long)-EINVAL)

drivers/char/mspec.c

@@ -227,7 +227,7 @@ mspec_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 	 * be because another thread has installed the pte first, so it
 	 * is no problem.
 	 */
-	vm_insert_pfn(vma, (unsigned long)vmf->virtual_address, pfn);
+	vm_insert_pfn(vma, vmf->address, pfn);
 
 	return VM_FAULT_NOPAGE;
 }

drivers/char/tpm/tpm-chip.c

@@ -84,7 +84,7 @@ EXPORT_SYMBOL_GPL(tpm_put_ops);
  *
  * The return'd chip has been tpm_try_get_ops'd and must be released via
  * tpm_put_ops
-  */
+ */
 struct tpm_chip *tpm_chip_find_get(int chip_num)
 {
 	struct tpm_chip *chip, *res = NULL;
@@ -103,7 +103,7 @@ struct tpm_chip *tpm_chip_find_get(int chip_num)
 			}
 		} while (chip_prev != chip_num);
 	} else {
-		chip = idr_find_slowpath(&dev_nums_idr, chip_num);
+		chip = idr_find(&dev_nums_idr, chip_num);
 		if (chip && !tpm_try_get_ops(chip))
 			res = chip;
 	}

drivers/dax/dax.c

@@ -328,7 +328,6 @@ static phys_addr_t pgoff_to_phys(struct dax_dev *dax_dev, pgoff_t pgoff,
 static int __dax_dev_fault(struct dax_dev *dax_dev, struct vm_area_struct *vma,
 		struct vm_fault *vmf)
 {
-	unsigned long vaddr = (unsigned long) vmf->virtual_address;
 	struct device *dev = &dax_dev->dev;
 	struct dax_region *dax_region;
 	int rc = VM_FAULT_SIGBUS;
@@ -353,7 +352,7 @@ static int __dax_dev_fault(struct dax_dev *dax_dev, struct vm_area_struct *vma,
 
 	pfn = phys_to_pfn_t(phys, dax_region->pfn_flags);
 
-	rc = vm_insert_mixed(vma, vaddr, pfn);
+	rc = vm_insert_mixed(vma, vmf->address, pfn);
 
 	if (rc == -ENOMEM)
 		return VM_FAULT_OOM;

drivers/gpu/drm/armada/armada_gem.c

@@ -17,12 +17,11 @@
 static int armada_gem_vm_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 {
 	struct armada_gem_object *obj = drm_to_armada_gem(vma->vm_private_data);
-	unsigned long addr = (unsigned long)vmf->virtual_address;
 	unsigned long pfn = obj->phys_addr >> PAGE_SHIFT;
 	int ret;
 
-	pfn += (addr - vma->vm_start) >> PAGE_SHIFT;
+	pfn += (vmf->address - vma->vm_start) >> PAGE_SHIFT;
-	ret = vm_insert_pfn(vma, addr, pfn);
+	ret = vm_insert_pfn(vma, vmf->address, pfn);
 
 	switch (ret) {
 	case 0:

drivers/gpu/drm/drm_vm.c

@@ -124,8 +124,7 @@ static int drm_do_vm_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 		 * Using vm_pgoff as a selector forces us to use this unusual
 		 * addressing scheme.
 		 */
-		resource_size_t offset = (unsigned long)vmf->virtual_address -
+		resource_size_t offset = vmf->address - vma->vm_start;
-			vma->vm_start;
 		resource_size_t baddr = map->offset + offset;
 		struct drm_agp_mem *agpmem;
 		struct page *page;
@@ -195,7 +194,7 @@ static int drm_do_vm_shm_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 	if (!map)
 		return VM_FAULT_SIGBUS;	/* Nothing allocated */
 
-	offset = (unsigned long)vmf->virtual_address - vma->vm_start;
+	offset = vmf->address - vma->vm_start;
 	i = (unsigned long)map->handle + offset;
 	page = vmalloc_to_page((void *)i);
 	if (!page)
@@ -301,7 +300,8 @@ static int drm_do_vm_dma_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 	if (!dma->pagelist)
 		return VM_FAULT_SIGBUS;	/* Nothing allocated */
 
-	offset = (unsigned long)vmf->virtual_address - vma->vm_start;	/* vm_[pg]off[set] should be 0 */
+	offset = vmf->address - vma->vm_start;
+					/* vm_[pg]off[set] should be 0 */
 	page_nr = offset >> PAGE_SHIFT; /* page_nr could just be vmf->pgoff */
 	page = virt_to_page((void *)dma->pagelist[page_nr]);
 
@@ -337,7 +337,7 @@ static int drm_do_vm_sg_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 	if (!entry->pagelist)
 		return VM_FAULT_SIGBUS;	/* Nothing allocated */
 
-	offset = (unsigned long)vmf->virtual_address - vma->vm_start;
+	offset = vmf->address - vma->vm_start;
 	map_offset = map->offset - (unsigned long)dev->sg->virtual;
 	page_offset = (offset >> PAGE_SHIFT) + (map_offset >> PAGE_SHIFT);
 	page = entry->pagelist[page_offset];

drivers/gpu/drm/etnaviv/etnaviv_gem.c

@@ -202,15 +202,14 @@ int etnaviv_gem_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 	}
 
 	/* We don't use vmf->pgoff since that has the fake offset: */
-	pgoff = ((unsigned long)vmf->virtual_address -
+	pgoff = (vmf->address - vma->vm_start) >> PAGE_SHIFT;
-			vma->vm_start) >> PAGE_SHIFT;
 
 	page = pages[pgoff];
 
-	VERB("Inserting %p pfn %lx, pa %lx", vmf->virtual_address,
+	VERB("Inserting %p pfn %lx, pa %lx", (void *)vmf->address,
 	     page_to_pfn(page), page_to_pfn(page) << PAGE_SHIFT);
 
-	ret = vm_insert_page(vma, (unsigned long)vmf->virtual_address, page);
+	ret = vm_insert_page(vma, vmf->address, page);
 
 out:
 	switch (ret) {
@@ -759,7 +758,7 @@ static struct page **etnaviv_gem_userptr_do_get_pages(
 	down_read(&mm->mmap_sem);
 	while (pinned < npages) {
 		ret = get_user_pages_remote(task, mm, ptr, npages - pinned,
-					    flags, pvec + pinned, NULL);
+					    flags, pvec + pinned, NULL, NULL);
 		if (ret < 0)
 			break;
 

drivers/gpu/drm/exynos/exynos_drm_gem.c

@@ -455,8 +455,7 @@ int exynos_drm_gem_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 	pgoff_t page_offset;
 	int ret;
 
-	page_offset = ((unsigned long)vmf->virtual_address -
+	page_offset = (vmf->address - vma->vm_start) >> PAGE_SHIFT;
-			vma->vm_start) >> PAGE_SHIFT;
 
 	if (page_offset >= (exynos_gem->size >> PAGE_SHIFT)) {
 		DRM_ERROR("invalid page offset\n");
@@ -465,8 +464,7 @@ int exynos_drm_gem_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 	}
 
 	pfn = page_to_pfn(exynos_gem->pages[page_offset]);
-	ret = vm_insert_mixed(vma, (unsigned long)vmf->virtual_address,
+	ret = vm_insert_mixed(vma, vmf->address, __pfn_to_pfn_t(pfn, PFN_DEV));
-			__pfn_to_pfn_t(pfn, PFN_DEV));
 
 out:
 	switch (ret) {

drivers/gpu/drm/gma500/framebuffer.c

@@ -125,7 +125,7 @@ static int psbfb_vm_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 				  psbfb->gtt->offset;
 
 	page_num = vma_pages(vma);
-	address = (unsigned long)vmf->virtual_address - (vmf->pgoff << PAGE_SHIFT);
+	address = vmf->address - (vmf->pgoff << PAGE_SHIFT);
 
 	vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
 

drivers/gpu/drm/gma500/gem.c

@@ -197,15 +197,14 @@ int psb_gem_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 
 	/* Page relative to the VMA start - we must calculate this ourselves
 	   because vmf->pgoff is the fake GEM offset */
-	page_offset = ((unsigned long) vmf->virtual_address - vma->vm_start)
+	page_offset = (vmf->address - vma->vm_start) >> PAGE_SHIFT;
-				>> PAGE_SHIFT;
 
 	/* CPU view of the page, don't go via the GART for CPU writes */
 	if (r->stolen)
 		pfn = (dev_priv->stolen_base + r->offset) >> PAGE_SHIFT;
 	else
 		pfn = page_to_pfn(r->pages[page_offset]);
-	ret = vm_insert_pfn(vma, (unsigned long)vmf->virtual_address, pfn);
+	ret = vm_insert_pfn(vma, vmf->address, pfn);
 
 fail:
 	mutex_unlock(&dev_priv->mmap_mutex);

drivers/gpu/drm/i915/i915_gem.c

@@ -1796,8 +1796,7 @@ int i915_gem_fault(struct vm_area_struct *area, struct vm_fault *vmf)
 	int ret;
 
 	/* We don't use vmf->pgoff since that has the fake offset */
-	page_offset = ((unsigned long)vmf->virtual_address - area->vm_start) >>
+	page_offset = (vmf->address - area->vm_start) >> PAGE_SHIFT;
-		PAGE_SHIFT;
 
 	trace_i915_gem_object_fault(obj, page_offset, true, write);
 

drivers/gpu/drm/i915/i915_gem_userptr.c

@@ -515,7 +515,7 @@ __i915_gem_userptr_get_pages_worker(struct work_struct *_work)
 					 obj->userptr.ptr + pinned * PAGE_SIZE,
 					 npages - pinned,
 					 flags,
-					 pvec + pinned, NULL);
+					 pvec + pinned, NULL, NULL);
 				if (ret < 0)
 					break;
 

drivers/gpu/drm/msm/msm_gem.c

@@ -225,16 +225,14 @@ int msm_gem_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 	}
 
 	/* We don't use vmf->pgoff since that has the fake offset: */
-	pgoff = ((unsigned long)vmf->virtual_address -
+	pgoff = (vmf->address - vma->vm_start) >> PAGE_SHIFT;
-			vma->vm_start) >> PAGE_SHIFT;
 
 	pfn = page_to_pfn(pages[pgoff]);
 
-	VERB("Inserting %p pfn %lx, pa %lx", vmf->virtual_address,
+	VERB("Inserting %p pfn %lx, pa %lx", (void *)vmf->address,
 			pfn, pfn << PAGE_SHIFT);
 
-	ret = vm_insert_mixed(vma, (unsigned long)vmf->virtual_address,
+	ret = vm_insert_mixed(vma, vmf->address, __pfn_to_pfn_t(pfn, PFN_DEV));
-			__pfn_to_pfn_t(pfn, PFN_DEV));
 
 out_unlock:
 	mutex_unlock(&dev->struct_mutex);

drivers/gpu/drm/omapdrm/omap_gem.c

@@ -398,8 +398,7 @@ static int fault_1d(struct drm_gem_object *obj,
 	pgoff_t pgoff;
 
 	/* We don't use vmf->pgoff since that has the fake offset: */
-	pgoff = ((unsigned long)vmf->virtual_address -
+	pgoff = (vmf->address - vma->vm_start) >> PAGE_SHIFT;
-			vma->vm_start) >> PAGE_SHIFT;
 
 	if (omap_obj->pages) {
 		omap_gem_cpu_sync(obj, pgoff);
@@ -409,11 +408,10 @@ static int fault_1d(struct drm_gem_object *obj,
 		pfn = (omap_obj->paddr >> PAGE_SHIFT) + pgoff;
 	}
 
-	VERB("Inserting %p pfn %lx, pa %lx", vmf->virtual_address,
+	VERB("Inserting %p pfn %lx, pa %lx", (void *)vmf->address,
 			pfn, pfn << PAGE_SHIFT);
 
-	return vm_insert_mixed(vma, (unsigned long)vmf->virtual_address,
+	return vm_insert_mixed(vma, vmf->address, __pfn_to_pfn_t(pfn, PFN_DEV));
-			__pfn_to_pfn_t(pfn, PFN_DEV));
 }
 
 /* Special handling for the case of faulting in 2d tiled buffers */
@@ -427,7 +425,7 @@ static int fault_2d(struct drm_gem_object *obj,
 	struct page *pages[64];  /* XXX is this too much to have on stack? */
 	unsigned long pfn;
 	pgoff_t pgoff, base_pgoff;
-	void __user *vaddr;
+	unsigned long vaddr;
 	int i, ret, slots;
 
 	/*
@@ -447,8 +445,7 @@ static int fault_2d(struct drm_gem_object *obj,
 	const int m = 1 + ((omap_obj->width << fmt) / PAGE_SIZE);
 
 	/* We don't use vmf->pgoff since that has the fake offset: */
-	pgoff = ((unsigned long)vmf->virtual_address -
+	pgoff = (vmf->address - vma->vm_start) >> PAGE_SHIFT;
-			vma->vm_start) >> PAGE_SHIFT;
 
 	/*
 	 * Actual address we start mapping at is rounded down to previous slot
@@ -459,7 +456,7 @@ static int fault_2d(struct drm_gem_object *obj,
 	/* figure out buffer width in slots */
 	slots = omap_obj->width >> priv->usergart[fmt].slot_shift;
 
-	vaddr = vmf->virtual_address - ((pgoff - base_pgoff) << PAGE_SHIFT);
+	vaddr = vmf->address - ((pgoff - base_pgoff) << PAGE_SHIFT);
 
 	entry = &priv->usergart[fmt].entry[priv->usergart[fmt].last];
 
@@ -503,12 +500,11 @@ static int fault_2d(struct drm_gem_object *obj,
 
 	pfn = entry->paddr >> PAGE_SHIFT;
 
-	VERB("Inserting %p pfn %lx, pa %lx", vmf->virtual_address,
+	VERB("Inserting %p pfn %lx, pa %lx", (void *)vmf->address,
 			pfn, pfn << PAGE_SHIFT);
 
 	for (i = n; i > 0; i--) {
-		vm_insert_mixed(vma, (unsigned long)vaddr,
+		vm_insert_mixed(vma, vaddr, __pfn_to_pfn_t(pfn, PFN_DEV));
-				__pfn_to_pfn_t(pfn, PFN_DEV));
 		pfn += priv->usergart[fmt].stride_pfn;
 		vaddr += PAGE_SIZE * m;
 	}

drivers/gpu/drm/tegra/gem.c

@@ -452,10 +452,10 @@ static int tegra_bo_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 	if (!bo->pages)
 		return VM_FAULT_SIGBUS;
 
-	offset = ((unsigned long)vmf->virtual_address - vma->vm_start) >> PAGE_SHIFT;
+	offset = (vmf->address - vma->vm_start) >> PAGE_SHIFT;
 	page = bo->pages[offset];
 
-	err = vm_insert_page(vma, (unsigned long)vmf->virtual_address, page);
+	err = vm_insert_page(vma, vmf->address, page);
 	switch (err) {
 	case -EAGAIN:
 	case 0:

drivers/gpu/drm/ttm/ttm_bo_vm.c

@@ -101,7 +101,7 @@ static int ttm_bo_vm_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 	struct page *page;
 	int ret;
 	int i;
-	unsigned long address = (unsigned long)vmf->virtual_address;
+	unsigned long address = vmf->address;
 	int retval = VM_FAULT_NOPAGE;
 	struct ttm_mem_type_manager *man =
 		&bdev->man[bo->mem.mem_type];

drivers/gpu/drm/udl/udl_gem.c

@@ -107,14 +107,13 @@ int udl_gem_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 	unsigned int page_offset;
 	int ret = 0;
 
-	page_offset = ((unsigned long)vmf->virtual_address - vma->vm_start) >>
+	page_offset = (vmf->address - vma->vm_start) >> PAGE_SHIFT;
-		PAGE_SHIFT;
 
 	if (!obj->pages)
 		return VM_FAULT_SIGBUS;
 
 	page = obj->pages[page_offset];
-	ret = vm_insert_page(vma, (unsigned long)vmf->virtual_address, page);
+	ret = vm_insert_page(vma, vmf->address, page);
 	switch (ret) {
 	case -EAGAIN:
 	case 0:

drivers/gpu/drm/vgem/vgem_drv.c

@@ -54,7 +54,7 @@ static int vgem_gem_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 {
 	struct drm_vgem_gem_object *obj = vma->vm_private_data;
 	/* We don't use vmf->pgoff since that has the fake offset */
-	unsigned long vaddr = (unsigned long)vmf->virtual_address;
+	unsigned long vaddr = vmf->address;
 	struct page *page;
 
 	page = shmem_read_mapping_page(file_inode(obj->base.filp)->i_mapping,

drivers/infiniband/core/umem_odp.c

@@ -578,7 +578,7 @@ int ib_umem_odp_map_dma_pages(struct ib_umem *umem, u64 user_virt, u64 bcnt,
 		 */
 		npages = get_user_pages_remote(owning_process, owning_mm,
 				user_virt, gup_num_pages,
-				flags, local_page_list, NULL);
+				flags, local_page_list, NULL, NULL);
 		up_read(&owning_mm->mmap_sem);
 
 		if (npages < 0)

drivers/media/v4l2-core/videobuf-dma-sg.c

@@ -439,13 +439,12 @@ static int videobuf_vm_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 	struct page *page;
 
 	dprintk(3, "fault: fault @ %08lx [vma %08lx-%08lx]\n",
-		(unsigned long)vmf->virtual_address,
+		vmf->address, vma->vm_start, vma->vm_end);
-		vma->vm_start, vma->vm_end);
 
 	page = alloc_page(GFP_USER | __GFP_DMA32);
 	if (!page)
 		return VM_FAULT_OOM;
-	clear_user_highpage(page, (unsigned long)vmf->virtual_address);
+	clear_user_highpage(page, vmf->address);
 	vmf->page = page;
 
 	return 0;

drivers/misc/cxl/context.c

@@ -117,13 +117,12 @@ int cxl_context_init(struct cxl_context *ctx, struct cxl_afu *afu, bool master,
 static int cxl_mmap_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 {
 	struct cxl_context *ctx = vma->vm_file->private_data;
-	unsigned long address = (unsigned long)vmf->virtual_address;
 	u64 area, offset;
 
 	offset = vmf->pgoff << PAGE_SHIFT;
 
 	pr_devel("%s: pe: %i address: 0x%lx offset: 0x%llx\n",
-			__func__, ctx->pe, address, offset);
+			__func__, ctx->pe, vmf->address, offset);
 
 	if (ctx->afu->current_mode == CXL_MODE_DEDICATED) {
 		area = ctx->afu->psn_phys;
@@ -155,7 +154,7 @@ static int cxl_mmap_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 		return VM_FAULT_SIGBUS;
 	}
 
-	vm_insert_pfn(vma, address, (area + offset) >> PAGE_SHIFT);
+	vm_insert_pfn(vma, vmf->address, (area + offset) >> PAGE_SHIFT);
 
 	mutex_unlock(&ctx->status_mutex);
 

drivers/misc/sgi-gru/grumain.c

@@ -932,7 +932,7 @@ int gru_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 	unsigned long paddr, vaddr;
 	unsigned long expires;
 
-	vaddr = (unsigned long)vmf->virtual_address;
+	vaddr = vmf->address;
 	gru_dbg(grudev, "vma %p, vaddr 0x%lx (0x%lx)\n",
 		vma, vaddr, GSEG_BASE(vaddr));
 	STAT(nopfn);

drivers/net/ethernet/intel/igb/igb.h

@@ -210,7 +210,12 @@ struct igb_tx_buffer {
 struct igb_rx_buffer {
 	dma_addr_t dma;
 	struct page *page;
-	unsigned int page_offset;
+#if (BITS_PER_LONG > 32) || (PAGE_SIZE >= 65536)
+	__u32 page_offset;
+#else
+	__u16 page_offset;
+#endif
+	__u16 pagecnt_bias;
 };
 
 struct igb_tx_queue_stats {

drivers/net/ethernet/intel/igb/igb_main.c

@@ -3947,11 +3947,23 @@ static void igb_clean_rx_ring(struct igb_ring *rx_ring)
 		if (!buffer_info->page)
 			continue;
 
-		dma_unmap_page(rx_ring->dev,
+		/* Invalidate cache lines that may have been written to by
-			       buffer_info->dma,
+		 * device so that we avoid corrupting memory.
-			       PAGE_SIZE,
+		 */
-			       DMA_FROM_DEVICE);
+		dma_sync_single_range_for_cpu(rx_ring->dev,
-		__free_page(buffer_info->page);
+					      buffer_info->dma,
+					      buffer_info->page_offset,
+					      IGB_RX_BUFSZ,
+					      DMA_FROM_DEVICE);
+
+		/* free resources associated with mapping */
+		dma_unmap_page_attrs(rx_ring->dev,
+				     buffer_info->dma,
+				     PAGE_SIZE,
+				     DMA_FROM_DEVICE,
+				     DMA_ATTR_SKIP_CPU_SYNC);
+		__page_frag_drain(buffer_info->page, 0,
+				  buffer_info->pagecnt_bias);
 
 		buffer_info->page = NULL;
 	}
@@ -6812,12 +6824,6 @@ static void igb_reuse_rx_page(struct igb_ring *rx_ring,
 
 	/* transfer page from old buffer to new buffer */
 	*new_buff = *old_buff;
-
-	/* sync the buffer for use by the device */
-	dma_sync_single_range_for_device(rx_ring->dev, old_buff->dma,
-					 old_buff->page_offset,
-					 IGB_RX_BUFSZ,
-					 DMA_FROM_DEVICE);
 }
 
 static inline bool igb_page_is_reserved(struct page *page)
@@ -6829,13 +6835,15 @@ static bool igb_can_reuse_rx_page(struct igb_rx_buffer *rx_buffer,
 				  struct page *page,
 				  unsigned int truesize)
 {
+	unsigned int pagecnt_bias = rx_buffer->pagecnt_bias--;
+
 	/* avoid re-using remote pages */
 	if (unlikely(igb_page_is_reserved(page)))
 		return false;
 
 #if (PAGE_SIZE < 8192)
 	/* if we are only owner of page we can reuse it */
-	if (unlikely(page_count(page) != 1))
+	if (unlikely(page_ref_count(page) != pagecnt_bias))
 		return false;
 
 	/* flip page offset to other buffer */
@@ -6848,10 +6856,14 @@ static bool igb_can_reuse_rx_page(struct igb_rx_buffer *rx_buffer,
 		return false;
 #endif
 
-	/* Even if we own the page, we are not allowed to use atomic_set()
+	/* If we have drained the page fragment pool we need to update
-	 * This would break get_page_unless_zero() users.
+	 * the pagecnt_bias and page count so that we fully restock the
+	 * number of references the driver holds.
 	 */
-	page_ref_inc(page);
+	if (unlikely(pagecnt_bias == 1)) {
+		page_ref_add(page, USHRT_MAX);
+		rx_buffer->pagecnt_bias = USHRT_MAX;
+	}
 
 	return true;
 }
@@ -6903,7 +6915,6 @@ static bool igb_add_rx_frag(struct igb_ring *rx_ring,
 			return true;
 
 		/* this page cannot be reused so discard it */
-		__free_page(page);
 		return false;
 	}
 
@@ -6938,6 +6949,13 @@ static struct sk_buff *igb_fetch_rx_buffer(struct igb_ring *rx_ring,
 	page = rx_buffer->page;
 	prefetchw(page);
 
+	/* we are reusing so sync this buffer for CPU use */
+	dma_sync_single_range_for_cpu(rx_ring->dev,
+				      rx_buffer->dma,
+				      rx_buffer->page_offset,
+				      size,
+				      DMA_FROM_DEVICE);
+
 	if (likely(!skb)) {
 		void *page_addr = page_address(page) +
 				  rx_buffer->page_offset;
@@ -6962,21 +6980,18 @@ static struct sk_buff *igb_fetch_rx_buffer(struct igb_ring *rx_ring,
 		prefetchw(skb->data);
 	}
 
-	/* we are reusing so sync this buffer for CPU use */
-	dma_sync_single_range_for_cpu(rx_ring->dev,
-				      rx_buffer->dma,
-				      rx_buffer->page_offset,
-				      size,
-				      DMA_FROM_DEVICE);
-
 	/* pull page into skb */
 	if (igb_add_rx_frag(rx_ring, rx_buffer, size, rx_desc, skb)) {
 		/* hand second half of page back to the ring */
 		igb_reuse_rx_page(rx_ring, rx_buffer);
 	} else {
-		/* we are not reusing the buffer so unmap it */
+		/* We are not reusing the buffer so unmap it and free
-		dma_unmap_page(rx_ring->dev, rx_buffer->dma,
+		 * any references we are holding to it
-			       PAGE_SIZE, DMA_FROM_DEVICE);
+		 */
+		dma_unmap_page_attrs(rx_ring->dev, rx_buffer->dma,
+				     PAGE_SIZE, DMA_FROM_DEVICE,
+				     DMA_ATTR_SKIP_CPU_SYNC);
+		__page_frag_drain(page, 0, rx_buffer->pagecnt_bias);
 	}
 
 	/* clear contents of rx_buffer */
@@ -7234,7 +7249,8 @@ static bool igb_alloc_mapped_page(struct igb_ring *rx_ring,
 	}
 
 	/* map page for use */
-	dma = dma_map_page(rx_ring->dev, page, 0, PAGE_SIZE, DMA_FROM_DEVICE);
+	dma = dma_map_page_attrs(rx_ring->dev, page, 0, PAGE_SIZE,
+				 DMA_FROM_DEVICE, DMA_ATTR_SKIP_CPU_SYNC);
 
 	/* if mapping failed free memory back to system since
 	 * there isn't much point in holding memory we can't use
@@ -7249,6 +7265,7 @@ static bool igb_alloc_mapped_page(struct igb_ring *rx_ring,
 	bi->dma = dma;
 	bi->page = page;
 	bi->page_offset = 0;
+	bi->pagecnt_bias = 1;
 
 	return true;
 }
@@ -7275,6 +7292,12 @@ void igb_alloc_rx_buffers(struct igb_ring *rx_ring, u16 cleaned_count)
 		if (!igb_alloc_mapped_page(rx_ring, bi))
 			break;
 
+		/* sync the buffer for use by the device */
+		dma_sync_single_range_for_device(rx_ring->dev, bi->dma,
+						 bi->page_offset,
+						 IGB_RX_BUFSZ,
+						 DMA_FROM_DEVICE);
+
 		/* Refresh the desc even if buffer_addrs didn't change
 		 * because each write-back erases this info.
 		 */

drivers/net/wireless/intel/iwlwifi/dvm/calib.c

@@ -900,8 +900,7 @@ static void iwlagn_gain_computation(struct iwl_priv *priv,
 
 		/* bound gain by 2 bits value max, 3rd bit is sign */
 		data->delta_gain_code[i] =
-			min(abs(delta_g),
+			min(abs(delta_g), CHAIN_NOISE_MAX_DELTA_GAIN_CODE);
-			(s32) CHAIN_NOISE_MAX_DELTA_GAIN_CODE);
 
 		if (delta_g < 0)
 			/*

drivers/staging/android/ion/ion.c

@@ -882,7 +882,7 @@ static int ion_vm_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 	BUG_ON(!buffer->pages || !buffer->pages[vmf->pgoff]);
 
 	pfn = page_to_pfn(ion_buffer_page(buffer->pages[vmf->pgoff]));
-	ret = vm_insert_pfn(vma, (unsigned long)vmf->virtual_address, pfn);
+	ret = vm_insert_pfn(vma, vmf->address, pfn);
 	mutex_unlock(&buffer->lock);
 	if (ret)
 		return VM_FAULT_ERROR;

drivers/staging/lustre/lustre/llite/vvp_io.c

@@ -1014,7 +1014,7 @@ static int vvp_io_kernel_fault(struct vvp_fault_io *cfio)
 		       "page %p map %p index %lu flags %lx count %u priv %0lx: got addr %p type NOPAGE\n",
 		       vmf->page, vmf->page->mapping, vmf->page->index,
 		       (long)vmf->page->flags, page_count(vmf->page),
-		       page_private(vmf->page), vmf->virtual_address);
+		       page_private(vmf->page), (void *)vmf->address);
 		if (unlikely(!(cfio->ft_flags & VM_FAULT_LOCKED))) {
 			lock_page(vmf->page);
 			cfio->ft_flags |= VM_FAULT_LOCKED;
@@ -1025,12 +1025,12 @@ static int vvp_io_kernel_fault(struct vvp_fault_io *cfio)
 	}
 
 	if (cfio->ft_flags & (VM_FAULT_SIGBUS | VM_FAULT_SIGSEGV)) {
-		CDEBUG(D_PAGE, "got addr %p - SIGBUS\n", vmf->virtual_address);
+		CDEBUG(D_PAGE, "got addr %p - SIGBUS\n", (void *)vmf->address);
 		return -EFAULT;
 	}
 
 	if (cfio->ft_flags & VM_FAULT_OOM) {
-		CDEBUG(D_PAGE, "got addr %p - OOM\n", vmf->virtual_address);
+		CDEBUG(D_PAGE, "got addr %p - OOM\n", (void *)vmf->address);
 		return -ENOMEM;
 	}
 

drivers/usb/gadget/function/f_hid.c

@@ -905,7 +905,7 @@ static void hidg_free_inst(struct usb_function_instance *f)
 	mutex_lock(&hidg_ida_lock);
 
 	hidg_put_minor(opts->minor);
-	if (idr_is_empty(&hidg_ida.idr))
+	if (ida_is_empty(&hidg_ida))
 		ghid_cleanup();
 
 	mutex_unlock(&hidg_ida_lock);
@@ -931,7 +931,7 @@ static struct usb_function_instance *hidg_alloc_inst(void)
 
 	mutex_lock(&hidg_ida_lock);
 
-	if (idr_is_empty(&hidg_ida.idr)) {
+	if (ida_is_empty(&hidg_ida)) {
 		status = ghid_setup(NULL, HIDG_MINORS);
 		if (status)  {
 			ret = ERR_PTR(status);
@@ -944,7 +944,7 @@ static struct usb_function_instance *hidg_alloc_inst(void)
 	if (opts->minor < 0) {
 		ret = ERR_PTR(opts->minor);
 		kfree(opts);
-		if (idr_is_empty(&hidg_ida.idr))
+		if (ida_is_empty(&hidg_ida))
 			ghid_cleanup();
 		goto unlock;
 	}

drivers/usb/gadget/function/f_printer.c

@@ -1265,7 +1265,7 @@ static void gprinter_free_inst(struct usb_function_instance *f)
 	mutex_lock(&printer_ida_lock);
 
 	gprinter_put_minor(opts->minor);
-	if (idr_is_empty(&printer_ida.idr))
+	if (ida_is_empty(&printer_ida))
 		gprinter_cleanup();
 
 	mutex_unlock(&printer_ida_lock);
@@ -1289,7 +1289,7 @@ static struct usb_function_instance *gprinter_alloc_inst(void)
 
 	mutex_lock(&printer_ida_lock);
 
-	if (idr_is_empty(&printer_ida.idr)) {
+	if (ida_is_empty(&printer_ida)) {
 		status = gprinter_setup(PRINTER_MINORS);
 		if (status) {
 			ret = ERR_PTR(status);
@@ -1302,7 +1302,7 @@ static struct usb_function_instance *gprinter_alloc_inst(void)
 	if (opts->minor < 0) {
 		ret = ERR_PTR(opts->minor);
 		kfree(opts);
-		if (idr_is_empty(&printer_ida.idr))
+		if (ida_is_empty(&printer_ida))
 			gprinter_cleanup();
 		goto unlock;
 	}

drivers/vfio/vfio_iommu_type1.c

@@ -362,7 +362,7 @@ static int vaddr_get_pfn(struct mm_struct *mm, unsigned long vaddr,
 
 		down_read(&mm->mmap_sem);
 		ret = get_user_pages_remote(NULL, mm, vaddr, 1, flags, page,
-					    NULL);
+					    NULL, NULL);
 		up_read(&mm->mmap_sem);
 	}
 

drivers/xen/privcmd.c

@@ -602,7 +602,7 @@ static int privcmd_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 {
 	printk(KERN_DEBUG "privcmd_fault: vma=%p %lx-%lx, pgoff=%lx, uv=%p\n",
 	       vma, vma->vm_start, vma->vm_end,
-	       vmf->pgoff, vmf->virtual_address);
+	       vmf->pgoff, (void *)vmf->address);
 
 	return VM_FAULT_SIGBUS;
 }

fs/btrfs/super.c

@@ -202,12 +202,12 @@ static struct ratelimit_state printk_limits[] = {
 void btrfs_printk(const struct btrfs_fs_info *fs_info, const char *fmt, ...)
 {
 	struct super_block *sb = fs_info->sb;
-	char lvl[PRINTK_MAX_SINGLE_HEADER_LEN + 1];
+	char lvl[PRINTK_MAX_SINGLE_HEADER_LEN + 1] = "\0";
 	struct va_format vaf;
 	va_list args;
-	const char *type = NULL;
 	int kern_level;
-	struct ratelimit_state *ratelimit;
+	const char *type = logtypes[4];
+	struct ratelimit_state *ratelimit = &printk_limits[4];
 
 	va_start(args, fmt);
 
@@ -223,12 +223,6 @@ void btrfs_printk(const struct btrfs_fs_info *fs_info, const char *fmt, ...)
 		fmt += size;
 	}
 
-	if (!type) {
-		*lvl = '\0';
-		type = logtypes[4];
-		ratelimit = &printk_limits[4];
-	}
-
 	vaf.fmt = fmt;
 	vaf.va = &args;
 

fs/btrfs/tests/btrfs-tests.c

@@ -162,6 +162,7 @@ void btrfs_free_dummy_fs_info(struct btrfs_fs_info *fs_info)
 				slot = radix_tree_iter_retry(&iter);
 			continue;
 		}
+		slot = radix_tree_iter_resume(slot, &iter);
 		spin_unlock(&fs_info->buffer_lock);
 		free_extent_buffer_stale(eb);
 		spin_lock(&fs_info->buffer_lock);

fs/dax.c

@@ -31,6 +31,7 @@
 #include <linux/vmstat.h>
 #include <linux/pfn_t.h>
 #include <linux/sizes.h>
+#include <linux/mmu_notifier.h>
 #include <linux/iomap.h>
 #include "internal.h"
 
@@ -240,6 +241,23 @@ static void *get_unlocked_mapping_entry(struct address_space *mapping,
 	}
 }
 
+static void dax_unlock_mapping_entry(struct address_space *mapping,
+				     pgoff_t index)
+{
+	void *entry, **slot;
+
+	spin_lock_irq(&mapping->tree_lock);
+	entry = __radix_tree_lookup(&mapping->page_tree, index, NULL, &slot);
+	if (WARN_ON_ONCE(!entry || !radix_tree_exceptional_entry(entry) ||
+			 !slot_locked(mapping, slot))) {
+		spin_unlock_irq(&mapping->tree_lock);
+		return;
+	}
+	unlock_slot(mapping, slot);
+	spin_unlock_irq(&mapping->tree_lock);
+	dax_wake_mapping_entry_waiter(mapping, index, entry, false);
+}
+
 static void put_locked_mapping_entry(struct address_space *mapping,
 				     pgoff_t index, void *entry)
 {
@@ -433,22 +451,6 @@ void dax_wake_mapping_entry_waiter(struct address_space *mapping,
 		__wake_up(wq, TASK_NORMAL, wake_all ? 0 : 1, &key);
 }
 
-void dax_unlock_mapping_entry(struct address_space *mapping, pgoff_t index)
-{
-	void *entry, **slot;
-
-	spin_lock_irq(&mapping->tree_lock);
-	entry = __radix_tree_lookup(&mapping->page_tree, index, NULL, &slot);
-	if (WARN_ON_ONCE(!entry || !radix_tree_exceptional_entry(entry) ||
-			 !slot_locked(mapping, slot))) {
-		spin_unlock_irq(&mapping->tree_lock);
-		return;
-	}
-	unlock_slot(mapping, slot);
-	spin_unlock_irq(&mapping->tree_lock);
-	dax_wake_mapping_entry_waiter(mapping, index, entry, false);
-}
-
 /*
  * Delete exceptional DAX entry at @index from @mapping. Wait for radix tree
  * entry to get unlocked before deleting it.
@@ -500,10 +502,8 @@ static int dax_load_hole(struct address_space *mapping, void *entry,
 	/* This will replace locked radix tree entry with a hole page */
 	page = find_or_create_page(mapping, vmf->pgoff,
 				   vmf->gfp_mask | __GFP_ZERO);
-	if (!page) {
+	if (!page)
-		put_locked_mapping_entry(mapping, vmf->pgoff, entry);
 		return VM_FAULT_OOM;
-	}
 	vmf->page = page;
 	return VM_FAULT_LOCKED;
 }
@@ -615,36 +615,107 @@ static void *dax_insert_mapping_entry(struct address_space *mapping,
 	return new_entry;
 }
 
+static inline unsigned long
+pgoff_address(pgoff_t pgoff, struct vm_area_struct *vma)
+{
+	unsigned long address;
+
+	address = vma->vm_start + ((pgoff - vma->vm_pgoff) << PAGE_SHIFT);
+	VM_BUG_ON_VMA(address < vma->vm_start || address >= vma->vm_end, vma);
+	return address;
+}
+
+/* Walk all mappings of a given index of a file and writeprotect them */
+static void dax_mapping_entry_mkclean(struct address_space *mapping,
+				      pgoff_t index, unsigned long pfn)
+{
+	struct vm_area_struct *vma;
+	pte_t *ptep;
+	pte_t pte;
+	spinlock_t *ptl;
+	bool changed;
+
+	i_mmap_lock_read(mapping);
+	vma_interval_tree_foreach(vma, &mapping->i_mmap, index, index) {
+		unsigned long address;
+
+		cond_resched();
+
+		if (!(vma->vm_flags & VM_SHARED))
+			continue;
+
+		address = pgoff_address(index, vma);
+		changed = false;
+		if (follow_pte(vma->vm_mm, address, &ptep, &ptl))
+			continue;
+		if (pfn != pte_pfn(*ptep))
+			goto unlock;
+		if (!pte_dirty(*ptep) && !pte_write(*ptep))
+			goto unlock;
+
+		flush_cache_page(vma, address, pfn);
+		pte = ptep_clear_flush(vma, address, ptep);
+		pte = pte_wrprotect(pte);
+		pte = pte_mkclean(pte);
+		set_pte_at(vma->vm_mm, address, ptep, pte);
+		changed = true;
+unlock:
+		pte_unmap_unlock(ptep, ptl);
+
+		if (changed)
+			mmu_notifier_invalidate_page(vma->vm_mm, address);
+	}
+	i_mmap_unlock_read(mapping);
+}
+
 static int dax_writeback_one(struct block_device *bdev,
 		struct address_space *mapping, pgoff_t index, void *entry)
 {
 	struct radix_tree_root *page_tree = &mapping->page_tree;
-	struct radix_tree_node *node;
 	struct blk_dax_ctl dax;
-	void **slot;
+	void *entry2, **slot;
 	int ret = 0;
 
-	spin_lock_irq(&mapping->tree_lock);
 	/*
-	 * Regular page slots are stabilized by the page lock even
+	 * A page got tagged dirty in DAX mapping? Something is seriously
-	 * without the tree itself locked.  These unlocked entries
+	 * wrong.
-	 * need verification under the tree lock.
 	 */
-	if (!__radix_tree_lookup(page_tree, index, &node, &slot))
+	if (WARN_ON(!radix_tree_exceptional_entry(entry)))
-		goto unlock;
+		return -EIO;
-	if (*slot != entry)
-		goto unlock;
-
-	/* another fsync thread may have already written back this entry */
-	if (!radix_tree_tag_get(page_tree, index, PAGECACHE_TAG_TOWRITE))
-		goto unlock;
 
+	spin_lock_irq(&mapping->tree_lock);
+	entry2 = get_unlocked_mapping_entry(mapping, index, &slot);
+	/* Entry got punched out / reallocated? */
+	if (!entry2 || !radix_tree_exceptional_entry(entry2))
+		goto put_unlocked;
+	/*
+	 * Entry got reallocated elsewhere? No need to writeback. We have to
+	 * compare sectors as we must not bail out due to difference in lockbit
+	 * or entry type.
+	 */
+	if (dax_radix_sector(entry2) != dax_radix_sector(entry))
+		goto put_unlocked;
 	if (WARN_ON_ONCE(dax_is_empty_entry(entry) ||
 				dax_is_zero_entry(entry))) {
 		ret = -EIO;
-		goto unlock;
+		goto put_unlocked;
 	}
 
+	/* Another fsync thread may have already written back this entry */
+	if (!radix_tree_tag_get(page_tree, index, PAGECACHE_TAG_TOWRITE))
+		goto put_unlocked;
+	/* Lock the entry to serialize with page faults */
+	entry = lock_slot(mapping, slot);
+	/*
+	 * We can clear the tag now but we have to be careful so that concurrent
+	 * dax_writeback_one() calls for the same index cannot finish before we
+	 * actually flush the caches. This is achieved as the calls will look
+	 * at the entry only under tree_lock and once they do that they will
+	 * see the entry locked and wait for it to unlock.
+	 */
+	radix_tree_tag_clear(page_tree, index, PAGECACHE_TAG_TOWRITE);
+	spin_unlock_irq(&mapping->tree_lock);
+
 	/*
 	 * Even if dax_writeback_mapping_range() was given a wbc->range_start
 	 * in the middle of a PMD, the 'index' we are given will be aligned to
@@ -654,31 +725,40 @@ static int dax_writeback_one(struct block_device *bdev,
 	 */
 	dax.sector = dax_radix_sector(entry);
 	dax.size = PAGE_SIZE << dax_radix_order(entry);
-	spin_unlock_irq(&mapping->tree_lock);
 
 	/*
 	 * We cannot hold tree_lock while calling dax_map_atomic() because it
 	 * eventually calls cond_resched().
 	 */
 	ret = dax_map_atomic(bdev, &dax);
-	if (ret < 0)
+	if (ret < 0) {
+		put_locked_mapping_entry(mapping, index, entry);
 		return ret;
+	}
 
 	if (WARN_ON_ONCE(ret < dax.size)) {
 		ret = -EIO;
 		goto unmap;
 	}
 
+	dax_mapping_entry_mkclean(mapping, index, pfn_t_to_pfn(dax.pfn));
 	wb_cache_pmem(dax.addr, dax.size);
-
+	/*
+	 * After we have flushed the cache, we can clear the dirty tag. There
+	 * cannot be new dirty data in the pfn after the flush has completed as
+	 * the pfn mappings are writeprotected and fault waits for mapping
+	 * entry lock.
+	 */
 	spin_lock_irq(&mapping->tree_lock);
-	radix_tree_tag_clear(page_tree, index, PAGECACHE_TAG_TOWRITE);
+	radix_tree_tag_clear(page_tree, index, PAGECACHE_TAG_DIRTY);
 	spin_unlock_irq(&mapping->tree_lock);
  unmap:
 	dax_unmap_atomic(bdev, &dax);
+	put_locked_mapping_entry(mapping, index, entry);
 	return ret;
 
- unlock:
+ put_unlocked:
+	put_unlocked_mapping_entry(mapping, index, entry2);
 	spin_unlock_irq(&mapping->tree_lock);
 	return ret;
 }
@@ -738,7 +818,7 @@ static int dax_insert_mapping(struct address_space *mapping,
 		struct block_device *bdev, sector_t sector, size_t size,
 		void **entryp, struct vm_area_struct *vma, struct vm_fault *vmf)
 {
-	unsigned long vaddr = (unsigned long)vmf->virtual_address;
+	unsigned long vaddr = vmf->address;
 	struct blk_dax_ctl dax = {
 		.sector = sector,
 		.size = size,
@@ -767,17 +847,27 @@ int dax_pfn_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
 {
 	struct file *file = vma->vm_file;
 	struct address_space *mapping = file->f_mapping;
-	void *entry;
+	void *entry, **slot;
 	pgoff_t index = vmf->pgoff;
 
 	spin_lock_irq(&mapping->tree_lock);
-	entry = get_unlocked_mapping_entry(mapping, index, NULL);
+	entry = get_unlocked_mapping_entry(mapping, index, &slot);
-	if (!entry || !radix_tree_exceptional_entry(entry))
+	if (!entry || !radix_tree_exceptional_entry(entry)) {
-		goto out;
+		if (entry)
+			put_unlocked_mapping_entry(mapping, index, entry);
+		spin_unlock_irq(&mapping->tree_lock);
+		return VM_FAULT_NOPAGE;
+	}
 	radix_tree_tag_set(&mapping->page_tree, index, PAGECACHE_TAG_DIRTY);
-	put_unlocked_mapping_entry(mapping, index, entry);
+	entry = lock_slot(mapping, slot);
-out:
 	spin_unlock_irq(&mapping->tree_lock);
+	/*
+	 * If we race with somebody updating the PTE and finish_mkwrite_fault()
+	 * fails, we don't care. We need to return VM_FAULT_NOPAGE and retry
+	 * the fault in either case.
+	 */
+	finish_mkwrite_fault(vmf);
+	put_locked_mapping_entry(mapping, index, entry);
 	return VM_FAULT_NOPAGE;
 }
 EXPORT_SYMBOL_GPL(dax_pfn_mkwrite);
@@ -948,13 +1038,13 @@ int dax_iomap_fault(struct vm_area_struct *vma, struct vm_fault *vmf,
 {
 	struct address_space *mapping = vma->vm_file->f_mapping;
 	struct inode *inode = mapping->host;
-	unsigned long vaddr = (unsigned long)vmf->virtual_address;
+	unsigned long vaddr = vmf->address;
 	loff_t pos = (loff_t)vmf->pgoff << PAGE_SHIFT;
 	sector_t sector;
 	struct iomap iomap = { 0 };
 	unsigned flags = IOMAP_FAULT;
 	int error, major = 0;
-	int locked_status = 0;
+	int vmf_ret = 0;
 	void *entry;
 
 	/*
@@ -1007,13 +1097,11 @@ int dax_iomap_fault(struct vm_area_struct *vma, struct vm_fault *vmf,
 
 		if (error)
 			goto finish_iomap;
-		if (!radix_tree_exceptional_entry(entry)) {
+
-			vmf->page = entry;
+		__SetPageUptodate(vmf->cow_page);
-			locked_status = VM_FAULT_LOCKED;
+		vmf_ret = finish_fault(vmf);
-		} else {
+		if (!vmf_ret)
-			vmf->entry = entry;
+			vmf_ret = VM_FAULT_DONE_COW;
-			locked_status = VM_FAULT_DAX_LOCKED;
-		}
 		goto finish_iomap;
 	}
 
@@ -1030,7 +1118,7 @@ int dax_iomap_fault(struct vm_area_struct *vma, struct vm_fault *vmf,
 	case IOMAP_UNWRITTEN:
 	case IOMAP_HOLE:
 		if (!(vmf->flags & FAULT_FLAG_WRITE)) {
-			locked_status = dax_load_hole(mapping, entry, vmf);
+			vmf_ret = dax_load_hole(mapping, entry, vmf);
 			break;
 		}
 		/*FALLTHRU*/
@@ -1042,7 +1130,7 @@ int dax_iomap_fault(struct vm_area_struct *vma, struct vm_fault *vmf,
 
  finish_iomap:
 	if (ops->iomap_end) {
-		if (error) {
+		if (error || (vmf_ret & VM_FAULT_ERROR)) {
 			/* keep previous error */
 			ops->iomap_end(inode, pos, PAGE_SIZE, 0, flags,
 					&iomap);
@@ -1052,7 +1140,7 @@ int dax_iomap_fault(struct vm_area_struct *vma, struct vm_fault *vmf,
 		}
 	}
  unlock_entry:
-	if (!locked_status || error)
+	if (vmf_ret != VM_FAULT_LOCKED || error)
 		put_locked_mapping_entry(mapping, vmf->pgoff, entry);
  out:
 	if (error == -ENOMEM)
@@ -1060,9 +1148,9 @@ int dax_iomap_fault(struct vm_area_struct *vma, struct vm_fault *vmf,
 	/* -EBUSY is fine, somebody else faulted on the same PTE */
 	if (error < 0 && error != -EBUSY)
 		return VM_FAULT_SIGBUS | major;
-	if (locked_status) {
+	if (vmf_ret) {
 		WARN_ON_ONCE(error); /* -EBUSY from ops->iomap_end? */
-		return locked_status;
+		return vmf_ret;
 	}
 	return VM_FAULT_NOPAGE | major;
 }

fs/exec.c

@@ -209,7 +209,7 @@ static struct page *get_arg_page(struct linux_binprm *bprm, unsigned long pos,
 	 * doing the exec and bprm->mm is the new process's mm.
 	 */
 	ret = get_user_pages_remote(current, bprm->mm, pos, 1, gup_flags,
-			&page, NULL);
+			&page, NULL, NULL);
 	if (ret <= 0)
 		return NULL;
 

fs/userfaultfd.c

@@ -257,9 +257,9 @@ out:
  * fatal_signal_pending()s, and the mmap_sem must be released before
  * returning it.
  */
-int handle_userfault(struct fault_env *fe, unsigned long reason)
+int handle_userfault(struct vm_fault *vmf, unsigned long reason)
 {
-	struct mm_struct *mm = fe->vma->vm_mm;
+	struct mm_struct *mm = vmf->vma->vm_mm;
 	struct userfaultfd_ctx *ctx;
 	struct userfaultfd_wait_queue uwq;
 	int ret;
@@ -268,7 +268,7 @@ int handle_userfault(struct fault_env *fe, unsigned long reason)
 	BUG_ON(!rwsem_is_locked(&mm->mmap_sem));
 
 	ret = VM_FAULT_SIGBUS;
-	ctx = fe->vma->vm_userfaultfd_ctx.ctx;
+	ctx = vmf->vma->vm_userfaultfd_ctx.ctx;
 	if (!ctx)
 		goto out;
 
@@ -301,17 +301,18 @@ int handle_userfault(struct fault_env *fe, unsigned long reason)
 	 * without first stopping userland access to the memory. For
 	 * VM_UFFD_MISSING userfaults this is enough for now.
 	 */
-	if (unlikely(!(fe->flags & FAULT_FLAG_ALLOW_RETRY))) {
+	if (unlikely(!(vmf->flags & FAULT_FLAG_ALLOW_RETRY))) {
 		/*
 		 * Validate the invariant that nowait must allow retry
 		 * to be sure not to return SIGBUS erroneously on
 		 * nowait invocations.
 		 */
-		BUG_ON(fe->flags & FAULT_FLAG_RETRY_NOWAIT);
+		BUG_ON(vmf->flags & FAULT_FLAG_RETRY_NOWAIT);
 #ifdef CONFIG_DEBUG_VM
 		if (printk_ratelimit()) {
 			printk(KERN_WARNING
-			       "FAULT_FLAG_ALLOW_RETRY missing %x\n", fe->flags);
+			       "FAULT_FLAG_ALLOW_RETRY missing %x\n",
+			       vmf->flags);
 			dump_stack();
 		}
 #endif
@@ -323,7 +324,7 @@ int handle_userfault(struct fault_env *fe, unsigned long reason)
 	 * and wait.
 	 */
 	ret = VM_FAULT_RETRY;
-	if (fe->flags & FAULT_FLAG_RETRY_NOWAIT)
+	if (vmf->flags & FAULT_FLAG_RETRY_NOWAIT)
 		goto out;
 
 	/* take the reference before dropping the mmap_sem */
@@ -331,11 +332,11 @@ int handle_userfault(struct fault_env *fe, unsigned long reason)
 
 	init_waitqueue_func_entry(&uwq.wq, userfaultfd_wake_function);
 	uwq.wq.private = current;
-	uwq.msg = userfault_msg(fe->address, fe->flags, reason);
+	uwq.msg = userfault_msg(vmf->address, vmf->flags, reason);
 	uwq.ctx = ctx;
 
 	return_to_userland =
-		(fe->flags & (FAULT_FLAG_USER|FAULT_FLAG_KILLABLE)) ==
+		(vmf->flags & (FAULT_FLAG_USER|FAULT_FLAG_KILLABLE)) ==
 		(FAULT_FLAG_USER|FAULT_FLAG_KILLABLE);
 
 	spin_lock(&ctx->fault_pending_wqh.lock);
@@ -353,7 +354,8 @@ int handle_userfault(struct fault_env *fe, unsigned long reason)
 			  TASK_KILLABLE);
 	spin_unlock(&ctx->fault_pending_wqh.lock);
 
-	must_wait = userfaultfd_must_wait(ctx, fe->address, fe->flags, reason);
+	must_wait = userfaultfd_must_wait(ctx, vmf->address, vmf->flags,
+					  reason);
 	up_read(&mm->mmap_sem);
 
 	if (likely(must_wait && !ACCESS_ONCE(ctx->released) &&

include/linux/dax.h

@@ -46,7 +46,6 @@ void dax_wake_mapping_entry_waiter(struct address_space *mapping,
 
 #ifdef CONFIG_FS_DAX
 struct page *read_dax_sector(struct block_device *bdev, sector_t n);
-void dax_unlock_mapping_entry(struct address_space *mapping, pgoff_t index);
 int __dax_zero_page_range(struct block_device *bdev, sector_t sector,
 		unsigned int offset, unsigned int length);
 #else
@@ -55,12 +54,6 @@ static inline struct page *read_dax_sector(struct block_device *bdev,
 {
 	return ERR_PTR(-ENXIO);
 }
-/* Shouldn't ever be called when dax is disabled. */
-static inline void dax_unlock_mapping_entry(struct address_space *mapping,
-					    pgoff_t index)
-{
-	BUG();
-}
 static inline int __dax_zero_page_range(struct block_device *bdev,
 		sector_t sector, unsigned int offset, unsigned int length)
 {

include/linux/dma-mapping.h

@@ -243,29 +243,33 @@ static inline void dma_unmap_sg_attrs(struct device *dev, struct scatterlist *sg
 		ops->unmap_sg(dev, sg, nents, dir, attrs);
 }
 
-static inline dma_addr_t dma_map_page(struct device *dev, struct page *page,
+static inline dma_addr_t dma_map_page_attrs(struct device *dev,
-				      size_t offset, size_t size,
+					    struct page *page,
-				      enum dma_data_direction dir)
+					    size_t offset, size_t size,
+					    enum dma_data_direction dir,
+					    unsigned long attrs)
 {
 	struct dma_map_ops *ops = get_dma_ops(dev);
 	dma_addr_t addr;
 
 	kmemcheck_mark_initialized(page_address(page) + offset, size);
 	BUG_ON(!valid_dma_direction(dir));
-	addr = ops->map_page(dev, page, offset, size, dir, 0);
+	addr = ops->map_page(dev, page, offset, size, dir, attrs);
 	debug_dma_map_page(dev, page, offset, size, dir, addr, false);
 
 	return addr;
 }
 
-static inline void dma_unmap_page(struct device *dev, dma_addr_t addr,
+static inline void dma_unmap_page_attrs(struct device *dev,
-				  size_t size, enum dma_data_direction dir)
+					dma_addr_t addr, size_t size,
+					enum dma_data_direction dir,
+					unsigned long attrs)
 {
 	struct dma_map_ops *ops = get_dma_ops(dev);
 
 	BUG_ON(!valid_dma_direction(dir));
 	if (ops->unmap_page)
-		ops->unmap_page(dev, addr, size, dir, 0);
+		ops->unmap_page(dev, addr, size, dir, attrs);
 	debug_dma_unmap_page(dev, addr, size, dir, false);
 }
 
@@ -385,6 +389,8 @@ dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg,
 #define dma_unmap_single(d, a, s, r) dma_unmap_single_attrs(d, a, s, r, 0)
 #define dma_map_sg(d, s, n, r) dma_map_sg_attrs(d, s, n, r, 0)
 #define dma_unmap_sg(d, s, n, r) dma_unmap_sg_attrs(d, s, n, r, 0)
+#define dma_map_page(d, p, o, s, r) dma_map_page_attrs(d, p, o, s, r, 0)
+#define dma_unmap_page(d, a, s, r) dma_unmap_page_attrs(d, a, s, r, 0)
 
 extern int dma_common_mmap(struct device *dev, struct vm_area_struct *vma,
 			   void *cpu_addr, dma_addr_t dma_addr, size_t size);

include/linux/gfp.h

@@ -506,6 +506,8 @@ extern void free_hot_cold_page(struct page *page, bool cold);
 extern void free_hot_cold_page_list(struct list_head *list, bool cold);
 
 struct page_frag_cache;
+extern void __page_frag_drain(struct page *page, unsigned int order,
+			      unsigned int count);
 extern void *__alloc_page_frag(struct page_frag_cache *nc,
 			       unsigned int fragsz, gfp_t gfp_mask);
 extern void __free_page_frag(void *addr);

include/linux/huge_mm.h

@@ -1,12 +1,12 @@
 #ifndef _LINUX_HUGE_MM_H
 #define _LINUX_HUGE_MM_H
 
-extern int do_huge_pmd_anonymous_page(struct fault_env *fe);
+extern int do_huge_pmd_anonymous_page(struct vm_fault *vmf);
 extern int copy_huge_pmd(struct mm_struct *dst_mm, struct mm_struct *src_mm,
 			 pmd_t *dst_pmd, pmd_t *src_pmd, unsigned long addr,
 			 struct vm_area_struct *vma);
-extern void huge_pmd_set_accessed(struct fault_env *fe, pmd_t orig_pmd);
+extern void huge_pmd_set_accessed(struct vm_fault *vmf, pmd_t orig_pmd);
-extern int do_huge_pmd_wp_page(struct fault_env *fe, pmd_t orig_pmd);
+extern int do_huge_pmd_wp_page(struct vm_fault *vmf, pmd_t orig_pmd);
 extern struct page *follow_trans_huge_pmd(struct vm_area_struct *vma,
 					  unsigned long addr,
 					  pmd_t *pmd,
@@ -142,7 +142,7 @@ static inline int hpage_nr_pages(struct page *page)
 	return 1;
 }
 
-extern int do_huge_pmd_numa_page(struct fault_env *fe, pmd_t orig_pmd);
+extern int do_huge_pmd_numa_page(struct vm_fault *vmf, pmd_t orig_pmd);
 
 extern struct page *huge_zero_page;
 
@@ -212,7 +212,7 @@ static inline spinlock_t *pmd_trans_huge_lock(pmd_t *pmd,
 	return NULL;
 }
 
-static inline int do_huge_pmd_numa_page(struct fault_env *fe, pmd_t orig_pmd)
+static inline int do_huge_pmd_numa_page(struct vm_fault *vmf, pmd_t orig_pmd)
 {
 	return 0;
 }

include/linux/idr.h

@@ -18,12 +18,11 @@
 #include <linux/rcupdate.h>
 
 /*
- * We want shallower trees and thus more bits covered at each layer.  8
+ * Using 6 bits at each layer allows us to allocate 7 layers out of each page.
- * bits gives us large enough first layer for most use cases and maximum
+ * 8 bits only gave us 3 layers out of every pair of pages, which is less
- * tree depth of 4.  Each idr_layer is slightly larger than 2k on 64bit and
+ * efficient except for trees with a largest element between 192-255 inclusive.
- * 1k on 32bit.
  */
-#define IDR_BITS 8
+#define IDR_BITS 6
 #define IDR_SIZE (1 << IDR_BITS)
 #define IDR_MASK ((1 << IDR_BITS)-1)
 
@@ -55,6 +54,32 @@ struct idr {
 }
 #define DEFINE_IDR(name)	struct idr name = IDR_INIT(name)
 
+/**
+ * idr_get_cursor - Return the current position of the cyclic allocator
+ * @idr: idr handle
+ *
+ * The value returned is the value that will be next returned from
+ * idr_alloc_cyclic() if it is free (otherwise the search will start from
+ * this position).
+ */
+static inline unsigned int idr_get_cursor(struct idr *idr)
+{
+	return READ_ONCE(idr->cur);
+}
+
+/**
+ * idr_set_cursor - Set the current position of the cyclic allocator
+ * @idr: idr handle
+ * @val: new position
+ *
+ * The next call to idr_alloc_cyclic() will return @val if it is free
+ * (otherwise the search will start from this position).
+ */
+static inline void idr_set_cursor(struct idr *idr, unsigned int val)
+{
+	WRITE_ONCE(idr->cur, val);
+}
+
 /**
  * DOC: idr sync
  * idr synchronization (stolen from radix-tree.h)
@@ -195,6 +220,11 @@ static inline int ida_get_new(struct ida *ida, int *p_id)
 	return ida_get_new_above(ida, 0, p_id);
 }
 
+static inline bool ida_is_empty(struct ida *ida)
+{
+	return idr_is_empty(&ida->idr);
+}
+
 void __init idr_init_cache(void);
 
 #endif /* __IDR_H__ */

include/linux/kdb.h

@@ -77,7 +77,6 @@ extern int kdb_poll_idx;
  * number whenever the kernel debugger is entered.
  */
 extern int kdb_initial_cpu;
-extern atomic_t kdb_event;
 
 /* Types and messages used for dynamically added kdb shell commands */
 
@@ -162,6 +161,7 @@ enum kdb_msgsrc {
 };
 
 extern int kdb_trap_printk;
+extern int kdb_printf_cpu;
 extern __printf(2, 0) int vkdb_printf(enum kdb_msgsrc src, const char *fmt,
 				      va_list args);
 extern __printf(1, 2) int kdb_printf(const char *, ...);

include/linux/kexec.h

@@ -259,12 +259,6 @@ phys_addr_t paddr_vmcoreinfo_note(void);
 	vmcoreinfo_append_str("NUMBER(%s)=%ld\n", #name, (long)name)
 #define VMCOREINFO_CONFIG(name) \
 	vmcoreinfo_append_str("CONFIG_%s=y\n", #name)
-#define VMCOREINFO_PAGE_OFFSET(value) \
-	vmcoreinfo_append_str("PAGE_OFFSET=%lx\n", (unsigned long)value)
-#define VMCOREINFO_VMALLOC_START(value) \
-	vmcoreinfo_append_str("VMALLOC_START=%lx\n", (unsigned long)value)
-#define VMCOREINFO_VMEMMAP_START(value) \
-	vmcoreinfo_append_str("VMEMMAP_START=%lx\n", (unsigned long)value)
 
 extern struct kimage *kexec_image;
 extern struct kimage *kexec_crash_image;

include/linux/mm.h

@@ -292,36 +292,23 @@ extern pgprot_t protection_map[16];
  * pgoff should be used in favour of virtual_address, if possible.
  */
 struct vm_fault {
+	struct vm_area_struct *vma;	/* Target VMA */
 	unsigned int flags;		/* FAULT_FLAG_xxx flags */
 	gfp_t gfp_mask;			/* gfp mask to be used for allocations */
 	pgoff_t pgoff;			/* Logical page offset based on vma */
-	void __user *virtual_address;	/* Faulting virtual address */
+	unsigned long address;		/* Faulting virtual address */
+	pmd_t *pmd;			/* Pointer to pmd entry matching
+					 * the 'address' */
+	pte_t orig_pte;			/* Value of PTE at the time of fault */
 
-	struct page *cow_page;		/* Handler may choose to COW */
+	struct page *cow_page;		/* Page handler may use for COW fault */
+	struct mem_cgroup *memcg;	/* Cgroup cow_page belongs to */
 	struct page *page;		/* ->fault handlers should return a
 					 * page here, unless VM_FAULT_NOPAGE
 					 * is set (which is also implied by
 					 * VM_FAULT_ERROR).
 					 */
-	void *entry;			/* ->fault handler can alternatively
+	/* These three entries are valid only while holding ptl lock */
-					 * return locked DAX entry. In that
-					 * case handler should return
-					 * VM_FAULT_DAX_LOCKED and fill in
-					 * entry here.
-					 */
-};
-
-/*
- * Page fault context: passes though page fault handler instead of endless list
- * of function arguments.
- */
-struct fault_env {
-	struct vm_area_struct *vma;	/* Target VMA */
-	unsigned long address;		/* Faulting virtual address */
-	unsigned int flags;		/* FAULT_FLAG_xxx flags */
-	pmd_t *pmd;			/* Pointer to pmd entry matching
-					 * the 'address'
-					 */
 	pte_t *pte;			/* Pointer to pte entry matching
 					 * the 'address'. NULL if the page
 					 * table hasn't been allocated.
@@ -351,7 +338,7 @@ struct vm_operations_struct {
 	int (*fault)(struct vm_area_struct *vma, struct vm_fault *vmf);
 	int (*pmd_fault)(struct vm_area_struct *, unsigned long address,
 						pmd_t *, unsigned int flags);
-	void (*map_pages)(struct fault_env *fe,
+	void (*map_pages)(struct vm_fault *vmf,
 			pgoff_t start_pgoff, pgoff_t end_pgoff);
 
 	/* notification that a previously read-only page is about to become
@@ -625,8 +612,10 @@ static inline pte_t maybe_mkwrite(pte_t pte, struct vm_area_struct *vma)
 	return pte;
 }
 
-int alloc_set_pte(struct fault_env *fe, struct mem_cgroup *memcg,
+int alloc_set_pte(struct vm_fault *vmf, struct mem_cgroup *memcg,
 		struct page *page);
+int finish_fault(struct vm_fault *vmf);
+int finish_mkwrite_fault(struct vm_fault *vmf);
 #endif
 
 /*
@@ -1110,7 +1099,7 @@ static inline void clear_page_pfmemalloc(struct page *page)
 #define VM_FAULT_LOCKED	0x0200	/* ->fault locked the returned page */
 #define VM_FAULT_RETRY	0x0400	/* ->fault blocked, must retry */
 #define VM_FAULT_FALLBACK 0x0800	/* huge page fault failed, fall back to small */
-#define VM_FAULT_DAX_LOCKED 0x1000	/* ->fault has locked DAX entry */
+#define VM_FAULT_DONE_COW   0x1000	/* ->fault has fully handled COW */
 
 #define VM_FAULT_HWPOISON_LARGE_MASK 0xf000 /* encodes hpage index for large hwpoison */
 
@@ -1221,6 +1210,8 @@ int copy_page_range(struct mm_struct *dst, struct mm_struct *src,
 			struct vm_area_struct *vma);
 void unmap_mapping_range(struct address_space *mapping,
 		loff_t const holebegin, loff_t const holelen, int even_cows);
+int follow_pte(struct mm_struct *mm, unsigned long address, pte_t **ptepp,
+	       spinlock_t **ptlp);
 int follow_pfn(struct vm_area_struct *vma, unsigned long address,
 	unsigned long *pfn);
 int follow_phys(struct vm_area_struct *vma, unsigned long address,
@@ -1276,15 +1267,12 @@ extern int __access_remote_vm(struct task_struct *tsk, struct mm_struct *mm,
 long get_user_pages_remote(struct task_struct *tsk, struct mm_struct *mm,
 			    unsigned long start, unsigned long nr_pages,
 			    unsigned int gup_flags, struct page **pages,
-			    struct vm_area_struct **vmas);
+			    struct vm_area_struct **vmas, int *locked);
 long get_user_pages(unsigned long start, unsigned long nr_pages,
 			    unsigned int gup_flags, struct page **pages,
 			    struct vm_area_struct **vmas);
 long get_user_pages_locked(unsigned long start, unsigned long nr_pages,
 		    unsigned int gup_flags, struct page **pages, int *locked);
-long __get_user_pages_unlocked(struct task_struct *tsk, struct mm_struct *mm,
-			       unsigned long start, unsigned long nr_pages,
-			       struct page **pages, unsigned int gup_flags);
 long get_user_pages_unlocked(unsigned long start, unsigned long nr_pages,
 		    struct page **pages, unsigned int gup_flags);
 int get_user_pages_fast(unsigned long start, int nr_pages, int write,
@@ -2099,7 +2087,7 @@ extern void truncate_inode_pages_final(struct address_space *);
 
 /* generic vm_area_ops exported for stackable file systems */
 extern int filemap_fault(struct vm_area_struct *, struct vm_fault *);
-extern void filemap_map_pages(struct fault_env *fe,
+extern void filemap_map_pages(struct vm_fault *vmf,
 		pgoff_t start_pgoff, pgoff_t end_pgoff);
 extern int filemap_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf);
 

include/linux/nmi.h

@@ -7,6 +7,23 @@
 #include <linux/sched.h>
 #include <asm/irq.h>
 
+/*
+ * The run state of the lockup detectors is controlled by the content of the
+ * 'watchdog_enabled' variable. Each lockup detector has its dedicated bit -
+ * bit 0 for the hard lockup detector and bit 1 for the soft lockup detector.
+ *
+ * 'watchdog_user_enabled', 'nmi_watchdog_enabled' and 'soft_watchdog_enabled'
+ * are variables that are only used as an 'interface' between the parameters
+ * in /proc/sys/kernel and the internal state bits in 'watchdog_enabled'. The
+ * 'watchdog_thresh' variable is handled differently because its value is not
+ * boolean, and the lockup detectors are 'suspended' while 'watchdog_thresh'
+ * is equal zero.
+ */
+#define NMI_WATCHDOG_ENABLED_BIT   0
+#define SOFT_WATCHDOG_ENABLED_BIT  1
+#define NMI_WATCHDOG_ENABLED      (1 << NMI_WATCHDOG_ENABLED_BIT)
+#define SOFT_WATCHDOG_ENABLED     (1 << SOFT_WATCHDOG_ENABLED_BIT)
+
 /**
  * touch_nmi_watchdog - restart NMI watchdog timeout.
  * 
@@ -91,9 +108,16 @@ extern int nmi_watchdog_enabled;
 extern int soft_watchdog_enabled;
 extern int watchdog_user_enabled;
 extern int watchdog_thresh;
+extern unsigned long watchdog_enabled;
 extern unsigned long *watchdog_cpumask_bits;
+#ifdef CONFIG_SMP
 extern int sysctl_softlockup_all_cpu_backtrace;
 extern int sysctl_hardlockup_all_cpu_backtrace;
+#else
+#define sysctl_softlockup_all_cpu_backtrace 0
+#define sysctl_hardlockup_all_cpu_backtrace 0
+#endif
+extern bool is_hardlockup(void);
 struct ctl_table;
 extern int proc_watchdog(struct ctl_table *, int ,
 			 void __user *, size_t *, loff_t *);

include/linux/radix-tree.h

@@ -80,23 +80,25 @@ static inline bool radix_tree_is_internal_node(void *ptr)
 #define RADIX_TREE_MAX_PATH (DIV_ROUND_UP(RADIX_TREE_INDEX_BITS, \
 					  RADIX_TREE_MAP_SHIFT))
 
+/*
+ * @count is the count of every non-NULL element in the ->slots array
+ * whether that is an exceptional entry, a retry entry, a user pointer,
+ * a sibling entry or a pointer to the next level of the tree.
+ * @exceptional is the count of every element in ->slots which is
+ * either radix_tree_exceptional_entry() or is a sibling entry for an
+ * exceptional entry.
+ */
 struct radix_tree_node {
 	unsigned char	shift;		/* Bits remaining in each slot */
 	unsigned char	offset;		/* Slot offset in parent */
 	unsigned char	count;		/* Total entry count */
 	unsigned char	exceptional;	/* Exceptional entry count */
+	struct radix_tree_node *parent;		/* Used when ascending tree */
+	void *private_data;			/* For tree user */
 	union {
-		struct {
+		struct list_head private_list;	/* For tree user */
-			/* Used when ascending tree */
+		struct rcu_head	rcu_head;	/* Used when freeing node */
-			struct radix_tree_node *parent;
-			/* For tree user */
-			void *private_data;
-		};
-		/* Used when freeing node */
-		struct rcu_head	rcu_head;
 	};
-	/* For tree user */
-	struct list_head private_list;
 	void __rcu	*slots[RADIX_TREE_MAP_SIZE];
 	unsigned long	tags[RADIX_TREE_MAX_TAGS][RADIX_TREE_TAG_LONGS];
 };
@@ -126,6 +128,41 @@ static inline bool radix_tree_empty(struct radix_tree_root *root)
 	return root->rnode == NULL;
 }
 
+/**
+ * struct radix_tree_iter - radix tree iterator state
+ *
+ * @index:	index of current slot
+ * @next_index:	one beyond the last index for this chunk
+ * @tags:	bit-mask for tag-iterating
+ * @node:	node that contains current slot
+ * @shift:	shift for the node that holds our slots
+ *
+ * This radix tree iterator works in terms of "chunks" of slots.  A chunk is a
+ * subinterval of slots contained within one radix tree leaf node.  It is
+ * described by a pointer to its first slot and a struct radix_tree_iter
+ * which holds the chunk's position in the tree and its size.  For tagged
+ * iteration radix_tree_iter also holds the slots' bit-mask for one chosen
+ * radix tree tag.
+ */
+struct radix_tree_iter {
+	unsigned long	index;
+	unsigned long	next_index;
+	unsigned long	tags;
+	struct radix_tree_node *node;
+#ifdef CONFIG_RADIX_TREE_MULTIORDER
+	unsigned int	shift;
+#endif
+};
+
+static inline unsigned int iter_shift(const struct radix_tree_iter *iter)
+{
+#ifdef CONFIG_RADIX_TREE_MULTIORDER
+	return iter->shift;
+#else
+	return 0;
+#endif
+}
+
 /**
  * Radix-tree synchronization
  *
@@ -264,6 +301,8 @@ void __radix_tree_replace(struct radix_tree_root *root,
 			  struct radix_tree_node *node,
 			  void **slot, void *item,
 			  radix_tree_update_node_t update_node, void *private);
+void radix_tree_iter_replace(struct radix_tree_root *,
+		const struct radix_tree_iter *, void **slot, void *item);
 void radix_tree_replace_slot(struct radix_tree_root *root,
 			     void **slot, void *item);
 void __radix_tree_delete_node(struct radix_tree_root *root,
@@ -289,6 +328,8 @@ void *radix_tree_tag_clear(struct radix_tree_root *root,
 			unsigned long index, unsigned int tag);
 int radix_tree_tag_get(struct radix_tree_root *root,
 			unsigned long index, unsigned int tag);
+void radix_tree_iter_tag_set(struct radix_tree_root *root,
+		const struct radix_tree_iter *iter, unsigned int tag);
 unsigned int
 radix_tree_gang_lookup_tag(struct radix_tree_root *root, void **results,
 		unsigned long first_index, unsigned int max_items,
@@ -297,50 +338,18 @@ unsigned int
 radix_tree_gang_lookup_tag_slot(struct radix_tree_root *root, void ***results,
 		unsigned long first_index, unsigned int max_items,
 		unsigned int tag);
-unsigned long radix_tree_range_tag_if_tagged(struct radix_tree_root *root,
-		unsigned long *first_indexp, unsigned long last_index,
-		unsigned long nr_to_tag,
-		unsigned int fromtag, unsigned int totag);
 int radix_tree_tagged(struct radix_tree_root *root, unsigned int tag);
-unsigned long radix_tree_locate_item(struct radix_tree_root *root, void *item);
 
 static inline void radix_tree_preload_end(void)
 {
 	preempt_enable();
 }
 
-/**
+int radix_tree_split_preload(unsigned old_order, unsigned new_order, gfp_t);
- * struct radix_tree_iter - radix tree iterator state
+int radix_tree_split(struct radix_tree_root *, unsigned long index,
- *
+			unsigned new_order);
- * @index:	index of current slot
+int radix_tree_join(struct radix_tree_root *, unsigned long index,
- * @next_index:	one beyond the last index for this chunk
+			unsigned new_order, void *);
- * @tags:	bit-mask for tag-iterating
- * @shift:	shift for the node that holds our slots
- *
- * This radix tree iterator works in terms of "chunks" of slots.  A chunk is a
- * subinterval of slots contained within one radix tree leaf node.  It is
- * described by a pointer to its first slot and a struct radix_tree_iter
- * which holds the chunk's position in the tree and its size.  For tagged
- * iteration radix_tree_iter also holds the slots' bit-mask for one chosen
- * radix tree tag.
- */
-struct radix_tree_iter {
-	unsigned long	index;
-	unsigned long	next_index;
-	unsigned long	tags;
-#ifdef CONFIG_RADIX_TREE_MULTIORDER
-	unsigned int	shift;
-#endif
-};
-
-static inline unsigned int iter_shift(struct radix_tree_iter *iter)
-{
-#ifdef CONFIG_RADIX_TREE_MULTIORDER
-	return iter->shift;
-#else
-	return 0;
-#endif
-}
 
 #define RADIX_TREE_ITER_TAG_MASK	0x00FF	/* tag index in lower byte */
 #define RADIX_TREE_ITER_TAGGED		0x0100	/* lookup tagged slots */
@@ -409,20 +418,17 @@ __radix_tree_iter_add(struct radix_tree_iter *iter, unsigned long slots)
 }
 
 /**
- * radix_tree_iter_next - resume iterating when the chunk may be invalid
+ * radix_tree_iter_resume - resume iterating when the chunk may be invalid
- * @iter:	iterator state
+ * @slot: pointer to current slot
+ * @iter: iterator state
+ * Returns: New slot pointer
  *
  * If the iterator needs to release then reacquire a lock, the chunk may
  * have been invalidated by an insertion or deletion.  Call this function
- * to continue the iteration from the next index.
+ * before releasing the lock to continue the iteration from the next index.
  */
-static inline __must_check
+void **__must_check radix_tree_iter_resume(void **slot,
-void **radix_tree_iter_next(struct radix_tree_iter *iter)
+					struct radix_tree_iter *iter);
-{
-	iter->next_index = __radix_tree_iter_add(iter, 1);
-	iter->tags = 0;
-	return NULL;
-}
 
 /**
  * radix_tree_chunk_size - get current chunk size
@@ -436,10 +442,17 @@ radix_tree_chunk_size(struct radix_tree_iter *iter)
 	return (iter->next_index - iter->index) >> iter_shift(iter);
 }
 
-static inline struct radix_tree_node *entry_to_node(void *ptr)
+#ifdef CONFIG_RADIX_TREE_MULTIORDER
+void ** __radix_tree_next_slot(void **slot, struct radix_tree_iter *iter,
+				unsigned flags);
+#else
+/* Can't happen without sibling entries, but the compiler can't tell that */
+static inline void ** __radix_tree_next_slot(void **slot,
+				struct radix_tree_iter *iter, unsigned flags)
 {
-	return (void *)((unsigned long)ptr & ~RADIX_TREE_INTERNAL_NODE);
+	return slot;
 }
+#endif
 
 /**
  * radix_tree_next_slot - find next slot in chunk
@@ -453,7 +466,7 @@ static inline struct radix_tree_node *entry_to_node(void *ptr)
  * For tagged lookup it also eats @iter->tags.
  *
  * There are several cases where 'slot' can be passed in as NULL to this
- * function.  These cases result from the use of radix_tree_iter_next() or
+ * function.  These cases result from the use of radix_tree_iter_resume() or
  * radix_tree_iter_retry().  In these cases we don't end up dereferencing
  * 'slot' because either:
  * a) we are doing tagged iteration and iter->tags has been set to 0, or
@@ -464,51 +477,31 @@ static __always_inline void **
 radix_tree_next_slot(void **slot, struct radix_tree_iter *iter, unsigned flags)
 {
 	if (flags & RADIX_TREE_ITER_TAGGED) {
-		void *canon = slot;
-
 		iter->tags >>= 1;
 		if (unlikely(!iter->tags))
 			return NULL;
-		while (IS_ENABLED(CONFIG_RADIX_TREE_MULTIORDER) &&
-					radix_tree_is_internal_node(slot[1])) {
-			if (entry_to_node(slot[1]) == canon) {
-				iter->tags >>= 1;
-				iter->index = __radix_tree_iter_add(iter, 1);
-				slot++;
-				continue;
-			}
-			iter->next_index = __radix_tree_iter_add(iter, 1);
-			return NULL;
-		}
 		if (likely(iter->tags & 1ul)) {
 			iter->index = __radix_tree_iter_add(iter, 1);
-			return slot + 1;
+			slot++;
+			goto found;
 		}
 		if (!(flags & RADIX_TREE_ITER_CONTIG)) {
 			unsigned offset = __ffs(iter->tags);
 
-			iter->tags >>= offset;
+			iter->tags >>= offset++;
-			iter->index = __radix_tree_iter_add(iter, offset + 1);
+			iter->index = __radix_tree_iter_add(iter, offset);
-			return slot + offset + 1;
+			slot += offset;
+			goto found;
 		}
 	} else {
 		long count = radix_tree_chunk_size(iter);
-		void *canon = slot;
 
 		while (--count > 0) {
 			slot++;
 			iter->index = __radix_tree_iter_add(iter, 1);
 
-			if (IS_ENABLED(CONFIG_RADIX_TREE_MULTIORDER) &&
-			    radix_tree_is_internal_node(*slot)) {
-				if (entry_to_node(*slot) == canon)
-					continue;
-				iter->next_index = iter->index;
-				break;
-			}
-
 			if (likely(*slot))
-				return slot;
+				goto found;
 			if (flags & RADIX_TREE_ITER_CONTIG) {
 				/* forbid switching to the next chunk */
 				iter->next_index = 0;
@@ -517,6 +510,11 @@ radix_tree_next_slot(void **slot, struct radix_tree_iter *iter, unsigned flags)
 		}
 	}
 	return NULL;
+
+ found:
+	if (unlikely(radix_tree_is_internal_node(*slot)))
+		return __radix_tree_next_slot(slot, iter, flags);
+	return slot;
 }
 
 /**
@@ -567,6 +565,6 @@ radix_tree_next_slot(void **slot, struct radix_tree_iter *iter, unsigned flags)
 	     slot || (slot = radix_tree_next_chunk(root, iter,		\
 			      RADIX_TREE_ITER_TAGGED | tag)) ;		\
 	     slot = radix_tree_next_slot(slot, iter,			\
-				RADIX_TREE_ITER_TAGGED))
+				RADIX_TREE_ITER_TAGGED | tag))
 
 #endif /* _LINUX_RADIX_TREE_H */

include/linux/signal.h

@@ -97,6 +97,23 @@ static inline int sigisemptyset(sigset_t *set)
 	}
 }
 
+static inline int sigequalsets(const sigset_t *set1, const sigset_t *set2)
+{
+	switch (_NSIG_WORDS) {
+	case 4:
+		return	(set1->sig[3] == set2->sig[3]) &&
+			(set1->sig[2] == set2->sig[2]) &&
+			(set1->sig[1] == set2->sig[1]) &&
+			(set1->sig[0] == set2->sig[0]);
+	case 2:
+		return	(set1->sig[1] == set2->sig[1]) &&
+			(set1->sig[0] == set2->sig[0]);
+	case 1:
+		return	set1->sig[0] == set2->sig[0];
+	}
+	return 0;
+}
+
 #define sigmask(sig)	(1UL << ((sig) - 1))
 
 #ifndef __HAVE_ARCH_SIG_SETOPS

include/linux/userfaultfd_k.h

@@ -27,7 +27,7 @@
 #define UFFD_SHARED_FCNTL_FLAGS (O_CLOEXEC | O_NONBLOCK)
 #define UFFD_FLAGS_SET (EFD_SHARED_FCNTL_FLAGS)
 
-extern int handle_userfault(struct fault_env *fe, unsigned long reason);
+extern int handle_userfault(struct vm_fault *vmf, unsigned long reason);
 
 extern ssize_t mcopy_atomic(struct mm_struct *dst_mm, unsigned long dst_start,
 			    unsigned long src_start, unsigned long len);
@@ -55,7 +55,7 @@ static inline bool userfaultfd_armed(struct vm_area_struct *vma)
 #else /* CONFIG_USERFAULTFD */
 
 /* mm helpers */
-static inline int handle_userfault(struct fault_env *fe, unsigned long reason)
+static inline int handle_userfault(struct vm_fault *vmf, unsigned long reason)
 {
 	return VM_FAULT_SIGBUS;
 }

ipc/msg.c

@@ -763,7 +763,10 @@ static inline int convert_mode(long *msgtyp, int msgflg)
 	if (*msgtyp == 0)
 		return SEARCH_ANY;
 	if (*msgtyp < 0) {
-		*msgtyp = -*msgtyp;
+		if (*msgtyp == LONG_MIN) /* -LONG_MIN is undefined */
+			*msgtyp = LONG_MAX;
+		else
+			*msgtyp = -*msgtyp;
 		return SEARCH_LESSEQUAL;
 	}
 	if (msgflg & MSG_EXCEPT)

ipc/sem.c

@@ -11,6 +11,7 @@
  * (c) 2001 Red Hat Inc
  * Lockless wakeup
  * (c) 2003 Manfred Spraul <manfred@colorfullife.com>
+ * (c) 2016 Davidlohr Bueso <dave@stgolabs.net>
  * Further wakeup optimizations, documentation
  * (c) 2010 Manfred Spraul <manfred@colorfullife.com>
  *
@@ -53,15 +54,11 @@
  *   Semaphores are actively given to waiting tasks (necessary for FIFO).
  *   (see update_queue())
  * - To improve the scalability, the actual wake-up calls are performed after
- *   dropping all locks. (see wake_up_sem_queue_prepare(),
+ *   dropping all locks. (see wake_up_sem_queue_prepare())
- *   wake_up_sem_queue_do())
  * - All work is done by the waker, the woken up task does not have to do
  *   anything - not even acquiring a lock or dropping a refcount.
  * - A woken up task may not even touch the semaphore array anymore, it may
  *   have been destroyed already by a semctl(RMID).
- * - The synchronizations between wake-ups due to a timeout/signal and a
- *   wake-up due to a completed semaphore operation is achieved by using an
- *   intermediate state (IN_WAKEUP).
  * - UNDO values are stored in an array (one per process and per
  *   semaphore array, lazily allocated). For backwards compatibility, multiple
  *   modes for the UNDO variables are supported (per process, per thread)
@@ -118,7 +115,8 @@ struct sem_queue {
 	struct sembuf		*sops;	 /* array of pending operations */
 	struct sembuf		*blocking; /* the operation that blocked */
 	int			nsops;	 /* number of operations */
-	int			alter;	 /* does *sops alter the array? */
+	bool			alter;	 /* does *sops alter the array? */
+	bool                    dupsop;	 /* sops on more than one sem_num */
 };
 
 /* Each task has a list of undo requests. They are executed automatically
@@ -416,29 +414,6 @@ static inline void sem_unlock(struct sem_array *sma, int locknum)
  *
  * The caller holds the RCU read lock.
  */
-static inline struct sem_array *sem_obtain_lock(struct ipc_namespace *ns,
-			int id, struct sembuf *sops, int nsops, int *locknum)
-{
-	struct kern_ipc_perm *ipcp;
-	struct sem_array *sma;
-
-	ipcp = ipc_obtain_object_idr(&sem_ids(ns), id);
-	if (IS_ERR(ipcp))
-		return ERR_CAST(ipcp);
-
-	sma = container_of(ipcp, struct sem_array, sem_perm);
-	*locknum = sem_lock(sma, sops, nsops);
-
-	/* ipc_rmid() may have already freed the ID while sem_lock
-	 * was spinning: verify that the structure is still valid
-	 */
-	if (ipc_valid_object(ipcp))
-		return container_of(ipcp, struct sem_array, sem_perm);
-
-	sem_unlock(sma, *locknum);
-	return ERR_PTR(-EINVAL);
-}
-
 static inline struct sem_array *sem_obtain_object(struct ipc_namespace *ns, int id)
 {
 	struct kern_ipc_perm *ipcp = ipc_obtain_object_idr(&sem_ids(ns), id);
@@ -471,40 +446,6 @@ static inline void sem_rmid(struct ipc_namespace *ns, struct sem_array *s)
 	ipc_rmid(&sem_ids(ns), &s->sem_perm);
 }
 
-/*
- * Lockless wakeup algorithm:
- * Without the check/retry algorithm a lockless wakeup is possible:
- * - queue.status is initialized to -EINTR before blocking.
- * - wakeup is performed by
- *	* unlinking the queue entry from the pending list
- *	* setting queue.status to IN_WAKEUP
- *	  This is the notification for the blocked thread that a
- *	  result value is imminent.
- *	* call wake_up_process
- *	* set queue.status to the final value.
- * - the previously blocked thread checks queue.status:
- *	* if it's IN_WAKEUP, then it must wait until the value changes
- *	* if it's not -EINTR, then the operation was completed by
- *	  update_queue. semtimedop can return queue.status without
- *	  performing any operation on the sem array.
- *	* otherwise it must acquire the spinlock and check what's up.
- *
- * The two-stage algorithm is necessary to protect against the following
- * races:
- * - if queue.status is set after wake_up_process, then the woken up idle
- *   thread could race forward and try (and fail) to acquire sma->lock
- *   before update_queue had a chance to set queue.status
- * - if queue.status is written before wake_up_process and if the
- *   blocked process is woken up by a signal between writing
- *   queue.status and the wake_up_process, then the woken up
- *   process could return from semtimedop and die by calling
- *   sys_exit before wake_up_process is called. Then wake_up_process
- *   will oops, because the task structure is already invalid.
- *   (yes, this happened on s390 with sysv msg).
- *
- */
-#define IN_WAKEUP	1
-
 /**
  * newary - Create a new semaphore set
  * @ns: namespace
@@ -624,15 +565,23 @@ SYSCALL_DEFINE3(semget, key_t, key, int, nsems, int, semflg)
 }
 
 /**
- * perform_atomic_semop - Perform (if possible) a semaphore operation
+ * perform_atomic_semop[_slow] - Attempt to perform semaphore
+ *                               operations on a given array.
  * @sma: semaphore array
  * @q: struct sem_queue that describes the operation
  *
+ * Caller blocking are as follows, based the value
+ * indicated by the semaphore operation (sem_op):
+ *
+ *  (1) >0 never blocks.
+ *  (2)  0 (wait-for-zero operation): semval is non-zero.
+ *  (3) <0 attempting to decrement semval to a value smaller than zero.
+ *
  * Returns 0 if the operation was possible.
  * Returns 1 if the operation is impossible, the caller must sleep.
- * Negative values are error codes.
+ * Returns <0 for error codes.
  */
-static int perform_atomic_semop(struct sem_array *sma, struct sem_queue *q)
+static int perform_atomic_semop_slow(struct sem_array *sma, struct sem_queue *q)
 {
 	int result, sem_op, nsops, pid;
 	struct sembuf *sop;
@@ -703,51 +652,84 @@ undo:
 	return result;
 }
 
-/** wake_up_sem_queue_prepare(q, error): Prepare wake-up
+static int perform_atomic_semop(struct sem_array *sma, struct sem_queue *q)
- * @q: queue entry that must be signaled
- * @error: Error value for the signal
- *
- * Prepare the wake-up of the queue entry q.
- */
-static void wake_up_sem_queue_prepare(struct list_head *pt,
-				struct sem_queue *q, int error)
 {
-	if (list_empty(pt)) {
+	int result, sem_op, nsops;
-		/*
+	struct sembuf *sop;
-		 * Hold preempt off so that we don't get preempted and have the
+	struct sem *curr;
-		 * wakee busy-wait until we're scheduled back on.
+	struct sembuf *sops;
-		 */
+	struct sem_undo *un;
-		preempt_disable();
-	}
-	q->status = IN_WAKEUP;
-	q->pid = error;
 
-	list_add_tail(&q->list, pt);
+	sops = q->sops;
+	nsops = q->nsops;
+	un = q->undo;
+
+	if (unlikely(q->dupsop))
+		return perform_atomic_semop_slow(sma, q);
+
+	/*
+	 * We scan the semaphore set twice, first to ensure that the entire
+	 * operation can succeed, therefore avoiding any pointless writes
+	 * to shared memory and having to undo such changes in order to block
+	 * until the operations can go through.
+	 */
+	for (sop = sops; sop < sops + nsops; sop++) {
+		curr = sma->sem_base + sop->sem_num;
+		sem_op = sop->sem_op;
+		result = curr->semval;
+
+		if (!sem_op && result)
+			goto would_block; /* wait-for-zero */
+
+		result += sem_op;
+		if (result < 0)
+			goto would_block;
+
+		if (result > SEMVMX)
+			return -ERANGE;
+
+		if (sop->sem_flg & SEM_UNDO) {
+			int undo = un->semadj[sop->sem_num] - sem_op;
+
+			/* Exceeding the undo range is an error. */
+			if (undo < (-SEMAEM - 1) || undo > SEMAEM)
+				return -ERANGE;
+		}
+	}
+
+	for (sop = sops; sop < sops + nsops; sop++) {
+		curr = sma->sem_base + sop->sem_num;
+		sem_op = sop->sem_op;
+		result = curr->semval;
+
+		if (sop->sem_flg & SEM_UNDO) {
+			int undo = un->semadj[sop->sem_num] - sem_op;
+
+			un->semadj[sop->sem_num] = undo;
+		}
+		curr->semval += sem_op;
+		curr->sempid = q->pid;
+	}
+
+	return 0;
+
+would_block:
+	q->blocking = sop;
+	return sop->sem_flg & IPC_NOWAIT ? -EAGAIN : 1;
 }
 
-/**
+static inline void wake_up_sem_queue_prepare(struct sem_queue *q, int error,
- * wake_up_sem_queue_do - do the actual wake-up
+					     struct wake_q_head *wake_q)
- * @pt: list of tasks to be woken up
- *
- * Do the actual wake-up.
- * The function is called without any locks held, thus the semaphore array
- * could be destroyed already and the tasks can disappear as soon as the
- * status is set to the actual return code.
- */
-static void wake_up_sem_queue_do(struct list_head *pt)
 {
-	struct sem_queue *q, *t;
+	wake_q_add(wake_q, q->sleeper);
-	int did_something;
+	/*
-
+	 * Rely on the above implicit barrier, such that we can
-	did_something = !list_empty(pt);
+	 * ensure that we hold reference to the task before setting
-	list_for_each_entry_safe(q, t, pt, list) {
+	 * q->status. Otherwise we could race with do_exit if the
-		wake_up_process(q->sleeper);
+	 * task is awoken by an external event before calling
-		/* q can disappear immediately after writing q->status. */
+	 * wake_up_process().
-		smp_wmb();
+	 */
-		q->status = q->pid;
+	WRITE_ONCE(q->status, error);
-	}
-	if (did_something)
-		preempt_enable();
 }
 
 static void unlink_queue(struct sem_array *sma, struct sem_queue *q)
@@ -767,7 +749,7 @@ static void unlink_queue(struct sem_array *sma, struct sem_queue *q)
  * modified the array.
  * Note that wait-for-zero operations are handled without restart.
  */
-static int check_restart(struct sem_array *sma, struct sem_queue *q)
+static inline int check_restart(struct sem_array *sma, struct sem_queue *q)
 {
 	/* pending complex alter operations are too difficult to analyse */
 	if (!list_empty(&sma->pending_alter))
@@ -795,21 +777,20 @@ static int check_restart(struct sem_array *sma, struct sem_queue *q)
  * wake_const_ops - wake up non-alter tasks
  * @sma: semaphore array.
  * @semnum: semaphore that was modified.
- * @pt: list head for the tasks that must be woken up.
+ * @wake_q: lockless wake-queue head.
  *
  * wake_const_ops must be called after a semaphore in a semaphore array
  * was set to 0. If complex const operations are pending, wake_const_ops must
  * be called with semnum = -1, as well as with the number of each modified
  * semaphore.
- * The tasks that must be woken up are added to @pt. The return code
+ * The tasks that must be woken up are added to @wake_q. The return code
  * is stored in q->pid.
  * The function returns 1 if at least one operation was completed successfully.
  */
 static int wake_const_ops(struct sem_array *sma, int semnum,
-				struct list_head *pt)
+			  struct wake_q_head *wake_q)
 {
-	struct sem_queue *q;
+	struct sem_queue *q, *tmp;
-	struct list_head *walk;
 	struct list_head *pending_list;
 	int semop_completed = 0;
 
@@ -818,25 +799,19 @@ static int wake_const_ops(struct sem_array *sma, int semnum,
 	else
 		pending_list = &sma->sem_base[semnum].pending_const;
 
-	walk = pending_list->next;
+	list_for_each_entry_safe(q, tmp, pending_list, list) {
-	while (walk != pending_list) {
+		int error = perform_atomic_semop(sma, q);
-		int error;
 
-		q = container_of(walk, struct sem_queue, list);
+		if (error > 0)
-		walk = walk->next;
+			continue;
+		/* operation completed, remove from queue & wakeup */
+		unlink_queue(sma, q);
 
-		error = perform_atomic_semop(sma, q);
+		wake_up_sem_queue_prepare(q, error, wake_q);
-
+		if (error == 0)
-		if (error <= 0) {
+			semop_completed = 1;
-			/* operation completed, remove from queue & wakeup */
-
-			unlink_queue(sma, q);
-
-			wake_up_sem_queue_prepare(pt, q, error);
-			if (error == 0)
-				semop_completed = 1;
-		}
 	}
+
 	return semop_completed;
 }
 
@@ -845,14 +820,14 @@ static int wake_const_ops(struct sem_array *sma, int semnum,
  * @sma: semaphore array
  * @sops: operations that were performed
  * @nsops: number of operations
- * @pt: list head of the tasks that must be woken up.
+ * @wake_q: lockless wake-queue head
  *
  * Checks all required queue for wait-for-zero operations, based
  * on the actual changes that were performed on the semaphore array.
  * The function returns 1 if at least one operation was completed successfully.
  */
 static int do_smart_wakeup_zero(struct sem_array *sma, struct sembuf *sops,
-					int nsops, struct list_head *pt)
+				int nsops, struct wake_q_head *wake_q)
 {
 	int i;
 	int semop_completed = 0;
@@ -865,7 +840,7 @@ static int do_smart_wakeup_zero(struct sem_array *sma, struct sembuf *sops,
 
 			if (sma->sem_base[num].semval == 0) {
 				got_zero = 1;
-				semop_completed |= wake_const_ops(sma, num, pt);
+				semop_completed |= wake_const_ops(sma, num, wake_q);
 			}
 		}
 	} else {
@@ -876,7 +851,7 @@ static int do_smart_wakeup_zero(struct sem_array *sma, struct sembuf *sops,
 		for (i = 0; i < sma->sem_nsems; i++) {
 			if (sma->sem_base[i].semval == 0) {
 				got_zero = 1;
-				semop_completed |= wake_const_ops(sma, i, pt);
+				semop_completed |= wake_const_ops(sma, i, wake_q);
 			}
 		}
 	}
@@ -885,7 +860,7 @@ static int do_smart_wakeup_zero(struct sem_array *sma, struct sembuf *sops,
 	 * then check the global queue, too.
 	 */
 	if (got_zero)
-		semop_completed |= wake_const_ops(sma, -1, pt);
+		semop_completed |= wake_const_ops(sma, -1, wake_q);
 
 	return semop_completed;
 }
@@ -895,22 +870,21 @@ static int do_smart_wakeup_zero(struct sem_array *sma, struct sembuf *sops,
  * update_queue - look for tasks that can be completed.
  * @sma: semaphore array.
  * @semnum: semaphore that was modified.
- * @pt: list head for the tasks that must be woken up.
+ * @wake_q: lockless wake-queue head.
  *
  * update_queue must be called after a semaphore in a semaphore array
  * was modified. If multiple semaphores were modified, update_queue must
  * be called with semnum = -1, as well as with the number of each modified
  * semaphore.
- * The tasks that must be woken up are added to @pt. The return code
+ * The tasks that must be woken up are added to @wake_q. The return code
  * is stored in q->pid.
  * The function internally checks if const operations can now succeed.
  *
  * The function return 1 if at least one semop was completed successfully.
  */
-static int update_queue(struct sem_array *sma, int semnum, struct list_head *pt)
+static int update_queue(struct sem_array *sma, int semnum, struct wake_q_head *wake_q)
 {
-	struct sem_queue *q;
+	struct sem_queue *q, *tmp;
-	struct list_head *walk;
 	struct list_head *pending_list;
 	int semop_completed = 0;
 
@@ -920,13 +894,9 @@ static int update_queue(struct sem_array *sma, int semnum, struct list_head *pt)
 		pending_list = &sma->sem_base[semnum].pending_alter;
 
 again:
-	walk = pending_list->next;
+	list_for_each_entry_safe(q, tmp, pending_list, list) {
-	while (walk != pending_list) {
 		int error, restart;
 
-		q = container_of(walk, struct sem_queue, list);
-		walk = walk->next;
-
 		/* If we are scanning the single sop, per-semaphore list of
 		 * one semaphore and that semaphore is 0, then it is not
 		 * necessary to scan further: simple increments
@@ -949,11 +919,11 @@ again:
 			restart = 0;
 		} else {
 			semop_completed = 1;
-			do_smart_wakeup_zero(sma, q->sops, q->nsops, pt);
+			do_smart_wakeup_zero(sma, q->sops, q->nsops, wake_q);
 			restart = check_restart(sma, q);
 		}
 
-		wake_up_sem_queue_prepare(pt, q, error);
+		wake_up_sem_queue_prepare(q, error, wake_q);
 		if (restart)
 			goto again;
 	}
@@ -984,24 +954,24 @@ static void set_semotime(struct sem_array *sma, struct sembuf *sops)
  * @sops: operations that were performed
  * @nsops: number of operations
  * @otime: force setting otime
- * @pt: list head of the tasks that must be woken up.
+ * @wake_q: lockless wake-queue head
  *
  * do_smart_update() does the required calls to update_queue and wakeup_zero,
  * based on the actual changes that were performed on the semaphore array.
  * Note that the function does not do the actual wake-up: the caller is
- * responsible for calling wake_up_sem_queue_do(@pt).
+ * responsible for calling wake_up_q().
  * It is safe to perform this call after dropping all locks.
  */
 static void do_smart_update(struct sem_array *sma, struct sembuf *sops, int nsops,
-			int otime, struct list_head *pt)
+			    int otime, struct wake_q_head *wake_q)
 {
 	int i;
 
-	otime |= do_smart_wakeup_zero(sma, sops, nsops, pt);
+	otime |= do_smart_wakeup_zero(sma, sops, nsops, wake_q);
 
 	if (!list_empty(&sma->pending_alter)) {
 		/* semaphore array uses the global queue - just process it. */
-		otime |= update_queue(sma, -1, pt);
+		otime |= update_queue(sma, -1, wake_q);
 	} else {
 		if (!sops) {
 			/*
@@ -1009,7 +979,7 @@ static void do_smart_update(struct sem_array *sma, struct sembuf *sops, int nsop
 			 * known. Check all.
 			 */
 			for (i = 0; i < sma->sem_nsems; i++)
-				otime |= update_queue(sma, i, pt);
+				otime |= update_queue(sma, i, wake_q);
 		} else {
 			/*
 			 * Check the semaphores that were increased:
@@ -1023,7 +993,7 @@ static void do_smart_update(struct sem_array *sma, struct sembuf *sops, int nsop
 			for (i = 0; i < nsops; i++) {
 				if (sops[i].sem_op > 0) {
 					otime |= update_queue(sma,
-							sops[i].sem_num, pt);
+							      sops[i].sem_num, wake_q);
 				}
 			}
 		}
@@ -1111,8 +1081,8 @@ static void freeary(struct ipc_namespace *ns, struct kern_ipc_perm *ipcp)
 	struct sem_undo *un, *tu;
 	struct sem_queue *q, *tq;
 	struct sem_array *sma = container_of(ipcp, struct sem_array, sem_perm);
-	struct list_head tasks;
 	int i;
+	DEFINE_WAKE_Q(wake_q);
 
 	/* Free the existing undo structures for this semaphore set.  */
 	ipc_assert_locked_object(&sma->sem_perm);
@@ -1126,25 +1096,24 @@ static void freeary(struct ipc_namespace *ns, struct kern_ipc_perm *ipcp)
 	}
 
 	/* Wake up all pending processes and let them fail with EIDRM. */
-	INIT_LIST_HEAD(&tasks);
 	list_for_each_entry_safe(q, tq, &sma->pending_const, list) {
 		unlink_queue(sma, q);
-		wake_up_sem_queue_prepare(&tasks, q, -EIDRM);
+		wake_up_sem_queue_prepare(q, -EIDRM, &wake_q);
 	}
 
 	list_for_each_entry_safe(q, tq, &sma->pending_alter, list) {
 		unlink_queue(sma, q);
-		wake_up_sem_queue_prepare(&tasks, q, -EIDRM);
+		wake_up_sem_queue_prepare(q, -EIDRM, &wake_q);
 	}
 	for (i = 0; i < sma->sem_nsems; i++) {
 		struct sem *sem = sma->sem_base + i;
 		list_for_each_entry_safe(q, tq, &sem->pending_const, list) {
 			unlink_queue(sma, q);
-			wake_up_sem_queue_prepare(&tasks, q, -EIDRM);
+			wake_up_sem_queue_prepare(q, -EIDRM, &wake_q);
 		}
 		list_for_each_entry_safe(q, tq, &sem->pending_alter, list) {
 			unlink_queue(sma, q);
-			wake_up_sem_queue_prepare(&tasks, q, -EIDRM);
+			wake_up_sem_queue_prepare(q, -EIDRM, &wake_q);
 		}
 	}
 
@@ -1153,7 +1122,7 @@ static void freeary(struct ipc_namespace *ns, struct kern_ipc_perm *ipcp)
 	sem_unlock(sma, -1);
 	rcu_read_unlock();
 
-	wake_up_sem_queue_do(&tasks);
+	wake_up_q(&wake_q);
 	ns->used_sems -= sma->sem_nsems;
 	ipc_rcu_putref(sma, sem_rcu_free);
 }
@@ -1292,9 +1261,9 @@ static int semctl_setval(struct ipc_namespace *ns, int semid, int semnum,
 	struct sem_undo *un;
 	struct sem_array *sma;
 	struct sem *curr;
-	int err;
+	int err, val;
-	struct list_head tasks;
+	DEFINE_WAKE_Q(wake_q);
-	int val;
+
 #if defined(CONFIG_64BIT) && defined(__BIG_ENDIAN)
 	/* big-endian 64bit */
 	val = arg >> 32;
@@ -1306,8 +1275,6 @@ static int semctl_setval(struct ipc_namespace *ns, int semid, int semnum,
 	if (val > SEMVMX || val < 0)
 		return -ERANGE;
 
-	INIT_LIST_HEAD(&tasks);
-
 	rcu_read_lock();
 	sma = sem_obtain_object_check(ns, semid);
 	if (IS_ERR(sma)) {
@@ -1350,10 +1317,10 @@ static int semctl_setval(struct ipc_namespace *ns, int semid, int semnum,
 	curr->sempid = task_tgid_vnr(current);
 	sma->sem_ctime = get_seconds();
 	/* maybe some queued-up processes were waiting for this */
-	do_smart_update(sma, NULL, 0, 0, &tasks);
+	do_smart_update(sma, NULL, 0, 0, &wake_q);
 	sem_unlock(sma, -1);
 	rcu_read_unlock();
-	wake_up_sem_queue_do(&tasks);
+	wake_up_q(&wake_q);
 	return 0;
 }
 
@@ -1365,9 +1332,7 @@ static int semctl_main(struct ipc_namespace *ns, int semid, int semnum,
 	int err, nsems;
 	ushort fast_sem_io[SEMMSL_FAST];
 	ushort *sem_io = fast_sem_io;
-	struct list_head tasks;
+	DEFINE_WAKE_Q(wake_q);
-
-	INIT_LIST_HEAD(&tasks);
 
 	rcu_read_lock();
 	sma = sem_obtain_object_check(ns, semid);
@@ -1478,7 +1443,7 @@ static int semctl_main(struct ipc_namespace *ns, int semid, int semnum,
 		}
 		sma->sem_ctime = get_seconds();
 		/* maybe some queued-up processes were waiting for this */
-		do_smart_update(sma, NULL, 0, 0, &tasks);
+		do_smart_update(sma, NULL, 0, 0, &wake_q);
 		err = 0;
 		goto out_unlock;
 	}
@@ -1514,7 +1479,7 @@ out_unlock:
 	sem_unlock(sma, -1);
 out_rcu_wakeup:
 	rcu_read_unlock();
-	wake_up_sem_queue_do(&tasks);
+	wake_up_q(&wake_q);
 out_free:
 	if (sem_io != fast_sem_io)
 		ipc_free(sem_io);
@@ -1787,32 +1752,6 @@ out:
 	return un;
 }
 
-
-/**
- * get_queue_result - retrieve the result code from sem_queue
- * @q: Pointer to queue structure
- *
- * Retrieve the return code from the pending queue. If IN_WAKEUP is found in
- * q->status, then we must loop until the value is replaced with the final
- * value: This may happen if a task is woken up by an unrelated event (e.g.
- * signal) and in parallel the task is woken up by another task because it got
- * the requested semaphores.
- *
- * The function can be called with or without holding the semaphore spinlock.
- */
-static int get_queue_result(struct sem_queue *q)
-{
-	int error;
-
-	error = q->status;
-	while (unlikely(error == IN_WAKEUP)) {
-		cpu_relax();
-		error = q->status;
-	}
-
-	return error;
-}
-
 SYSCALL_DEFINE4(semtimedop, int, semid, struct sembuf __user *, tsops,
 		unsigned, nsops, const struct timespec __user *, timeout)
 {
@@ -1821,11 +1760,11 @@ SYSCALL_DEFINE4(semtimedop, int, semid, struct sembuf __user *, tsops,
 	struct sembuf fast_sops[SEMOPM_FAST];
 	struct sembuf *sops = fast_sops, *sop;
 	struct sem_undo *un;
-	int undos = 0, alter = 0, max, locknum;
+	int max, locknum;
+	bool undos = false, alter = false, dupsop = false;
 	struct sem_queue queue;
-	unsigned long jiffies_left = 0;
+	unsigned long dup = 0, jiffies_left = 0;
 	struct ipc_namespace *ns;
-	struct list_head tasks;
 
 	ns = current->nsproxy->ipc_ns;
 
@@ -1838,10 +1777,12 @@ SYSCALL_DEFINE4(semtimedop, int, semid, struct sembuf __user *, tsops,
 		if (sops == NULL)
 			return -ENOMEM;
 	}
+
 	if (copy_from_user(sops, tsops, nsops * sizeof(*tsops))) {
 		error =  -EFAULT;
 		goto out_free;
 	}
+
 	if (timeout) {
 		struct timespec _timeout;
 		if (copy_from_user(&_timeout, timeout, sizeof(*timeout))) {
@@ -1855,18 +1796,30 @@ SYSCALL_DEFINE4(semtimedop, int, semid, struct sembuf __user *, tsops,
 		}
 		jiffies_left = timespec_to_jiffies(&_timeout);
 	}
+
 	max = 0;
 	for (sop = sops; sop < sops + nsops; sop++) {
+		unsigned long mask = 1ULL << ((sop->sem_num) % BITS_PER_LONG);
+
 		if (sop->sem_num >= max)
 			max = sop->sem_num;
 		if (sop->sem_flg & SEM_UNDO)
-			undos = 1;
+			undos = true;
-		if (sop->sem_op != 0)
+		if (dup & mask) {
-			alter = 1;
+			/*
+			 * There was a previous alter access that appears
+			 * to have accessed the same semaphore, thus use
+			 * the dupsop logic. "appears", because the detection
+			 * can only check % BITS_PER_LONG.
+			 */
+			dupsop = true;
+		}
+		if (sop->sem_op != 0) {
+			alter = true;
+			dup |= mask;
+		}
 	}
 
-	INIT_LIST_HEAD(&tasks);
-
 	if (undos) {
 		/* On success, find_alloc_undo takes the rcu_read_lock */
 		un = find_alloc_undo(ns, semid);
@@ -1887,16 +1840,22 @@ SYSCALL_DEFINE4(semtimedop, int, semid, struct sembuf __user *, tsops,
 	}
 
 	error = -EFBIG;
-	if (max >= sma->sem_nsems)
+	if (max >= sma->sem_nsems) {
-		goto out_rcu_wakeup;
+		rcu_read_unlock();
+		goto out_free;
+	}
 
 	error = -EACCES;
-	if (ipcperms(ns, &sma->sem_perm, alter ? S_IWUGO : S_IRUGO))
+	if (ipcperms(ns, &sma->sem_perm, alter ? S_IWUGO : S_IRUGO)) {
-		goto out_rcu_wakeup;
+		rcu_read_unlock();
+		goto out_free;
+	}
 
 	error = security_sem_semop(sma, sops, nsops, alter);
-	if (error)
+	if (error) {
-		goto out_rcu_wakeup;
+		rcu_read_unlock();
+		goto out_free;
+	}
 
 	error = -EIDRM;
 	locknum = sem_lock(sma, sops, nsops);
@@ -1925,24 +1884,34 @@ SYSCALL_DEFINE4(semtimedop, int, semid, struct sembuf __user *, tsops,
 	queue.undo = un;
 	queue.pid = task_tgid_vnr(current);
 	queue.alter = alter;
+	queue.dupsop = dupsop;
 
 	error = perform_atomic_semop(sma, &queue);
-	if (error == 0) {
+	if (error == 0) { /* non-blocking succesfull path */
-		/* If the operation was successful, then do
+		DEFINE_WAKE_Q(wake_q);
+
+		/*
+		 * If the operation was successful, then do
 		 * the required updates.
 		 */
 		if (alter)
-			do_smart_update(sma, sops, nsops, 1, &tasks);
+			do_smart_update(sma, sops, nsops, 1, &wake_q);
 		else
 			set_semotime(sma, sops);
+
+		sem_unlock(sma, locknum);
+		rcu_read_unlock();
+		wake_up_q(&wake_q);
+
+		goto out_free;
 	}
-	if (error <= 0)
+	if (error < 0) /* non-blocking error path */
 		goto out_unlock_free;
 
-	/* We need to sleep on this operation, so we put the current
+	/*
+	 * We need to sleep on this operation, so we put the current
 	 * task into the pending queue and go to sleep.
 	 */
-
 	if (nsops == 1) {
 		struct sem *curr;
 		curr = &sma->sem_base[sops->sem_num];
@@ -1971,77 +1940,69 @@ SYSCALL_DEFINE4(semtimedop, int, semid, struct sembuf __user *, tsops,
 		sma->complex_count++;
 	}
 
-	queue.status = -EINTR;
+	do {
-	queue.sleeper = current;
+		queue.status = -EINTR;
+		queue.sleeper = current;
 
-sleep_again:
+		__set_current_state(TASK_INTERRUPTIBLE);
-	__set_current_state(TASK_INTERRUPTIBLE);
+		sem_unlock(sma, locknum);
-	sem_unlock(sma, locknum);
-	rcu_read_unlock();
-
-	if (timeout)
-		jiffies_left = schedule_timeout(jiffies_left);
-	else
-		schedule();
-
-	error = get_queue_result(&queue);
-
-	if (error != -EINTR) {
-		/* fast path: update_queue already obtained all requested
-		 * resources.
-		 * Perform a smp_mb(): User space could assume that semop()
-		 * is a memory barrier: Without the mb(), the cpu could
-		 * speculatively read in user space stale data that was
-		 * overwritten by the previous owner of the semaphore.
-		 */
-		smp_mb();
-
-		goto out_free;
-	}
-
-	rcu_read_lock();
-	sma = sem_obtain_lock(ns, semid, sops, nsops, &locknum);
-
-	/*
-	 * Wait until it's guaranteed that no wakeup_sem_queue_do() is ongoing.
-	 */
-	error = get_queue_result(&queue);
-
-	/*
-	 * Array removed? If yes, leave without sem_unlock().
-	 */
-	if (IS_ERR(sma)) {
 		rcu_read_unlock();
-		goto out_free;
-	}
 
+		if (timeout)
+			jiffies_left = schedule_timeout(jiffies_left);
+		else
+			schedule();
 
-	/*
+		/*
-	 * If queue.status != -EINTR we are woken up by another process.
+		 * fastpath: the semop has completed, either successfully or
-	 * Leave without unlink_queue(), but with sem_unlock().
+		 * not, from the syscall pov, is quite irrelevant to us at this
-	 */
+		 * point; we're done.
-	if (error != -EINTR)
+		 *
-		goto out_unlock_free;
+		 * We _do_ care, nonetheless, about being awoken by a signal or
+		 * spuriously.  The queue.status is checked again in the
+		 * slowpath (aka after taking sem_lock), such that we can detect
+		 * scenarios where we were awakened externally, during the
+		 * window between wake_q_add() and wake_up_q().
+		 */
+		error = READ_ONCE(queue.status);
+		if (error != -EINTR) {
+			/*
+			 * User space could assume that semop() is a memory
+			 * barrier: Without the mb(), the cpu could
+			 * speculatively read in userspace stale data that was
+			 * overwritten by the previous owner of the semaphore.
+			 */
+			smp_mb();
+			goto out_free;
+		}
 
-	/*
+		rcu_read_lock();
-	 * If an interrupt occurred we have to clean up the queue
+		sem_lock(sma, sops, nsops);
-	 */
-	if (timeout && jiffies_left == 0)
-		error = -EAGAIN;
 
-	/*
+		if (!ipc_valid_object(&sma->sem_perm))
-	 * If the wakeup was spurious, just retry
+			goto out_unlock_free;
-	 */
+
-	if (error == -EINTR && !signal_pending(current))
+		error = READ_ONCE(queue.status);
-		goto sleep_again;
+
+		/*
+		 * If queue.status != -EINTR we are woken up by another process.
+		 * Leave without unlink_queue(), but with sem_unlock().
+		 */
+		if (error != -EINTR)
+			goto out_unlock_free;
+
+		/*
+		 * If an interrupt occurred we have to clean up the queue.
+		 */
+		if (timeout && jiffies_left == 0)
+			error = -EAGAIN;
+	} while (error == -EINTR && !signal_pending(current)); /* spurious */
 
 	unlink_queue(sma, &queue);
 
 out_unlock_free:
 	sem_unlock(sma, locknum);
-out_rcu_wakeup:
 	rcu_read_unlock();
-	wake_up_sem_queue_do(&tasks);
 out_free:
 	if (sops != fast_sops)
 		kfree(sops);
@@ -2102,8 +2063,8 @@ void exit_sem(struct task_struct *tsk)
 	for (;;) {
 		struct sem_array *sma;
 		struct sem_undo *un;
-		struct list_head tasks;
 		int semid, i;
+		DEFINE_WAKE_Q(wake_q);
 
 		cond_resched();
 
@@ -2191,11 +2152,10 @@ void exit_sem(struct task_struct *tsk)
 			}
 		}
 		/* maybe some queued-up processes were waiting for this */
-		INIT_LIST_HEAD(&tasks);
+		do_smart_update(sma, NULL, 0, 1, &wake_q);
-		do_smart_update(sma, NULL, 0, 1, &tasks);
 		sem_unlock(sma, -1);
 		rcu_read_unlock();
-		wake_up_sem_queue_do(&tasks);
+		wake_up_q(&wake_q);
 
 		kfree_rcu(un, rcu);
 	}

ipc/shm.c

@@ -89,6 +89,7 @@ void shm_init_ns(struct ipc_namespace *ns)
 static void do_shm_rmid(struct ipc_namespace *ns, struct kern_ipc_perm *ipcp)
 {
 	struct shmid_kernel *shp;
+
 	shp = container_of(ipcp, struct shmid_kernel, shm_perm);
 
 	if (shp->shm_nattch) {
@@ -387,6 +388,7 @@ static int shm_set_policy(struct vm_area_struct *vma, struct mempolicy *new)
 	struct file *file = vma->vm_file;
 	struct shm_file_data *sfd = shm_file_data(file);
 	int err = 0;
+
 	if (sfd->vm_ops->set_policy)
 		err = sfd->vm_ops->set_policy(vma, new);
 	return err;
@@ -417,7 +419,7 @@ static int shm_mmap(struct file *file, struct vm_area_struct *vma)
 	 * In case of remap_file_pages() emulation, the file can represent
 	 * removed IPC ID: propogate shm_lock() error to caller.
 	 */
-	ret =__shm_open(vma);
+	ret = __shm_open(vma);
 	if (ret)
 		return ret;
 
@@ -468,6 +470,7 @@ static unsigned long shm_get_unmapped_area(struct file *file,
 	unsigned long flags)
 {
 	struct shm_file_data *sfd = shm_file_data(file);
+
 	return sfd->file->f_op->get_unmapped_area(sfd->file, addr, len,
 						pgoff, flags);
 }
@@ -766,6 +769,7 @@ static void shm_add_rss_swap(struct shmid_kernel *shp,
 	} else {
 #ifdef CONFIG_SHMEM
 		struct shmem_inode_info *info = SHMEM_I(inode);
+
 		spin_lock_irq(&info->lock);
 		*rss_add += inode->i_mapping->nrpages;
 		*swp_add += info->swapped;
@@ -1028,6 +1032,7 @@ SYSCALL_DEFINE3(shmctl, int, shmid, int, cmd, struct shmid_ds __user *, buf)
 
 		if (!ns_capable(ns->user_ns, CAP_IPC_LOCK)) {
 			kuid_t euid = current_euid();
+
 			if (!uid_eq(euid, shp->shm_perm.uid) &&
 			    !uid_eq(euid, shp->shm_perm.cuid)) {
 				err = -EPERM;
@@ -1045,6 +1050,7 @@ SYSCALL_DEFINE3(shmctl, int, shmid, int, cmd, struct shmid_ds __user *, buf)
 
 		if (cmd == SHM_LOCK) {
 			struct user_struct *user = current_user();
+
 			err = shmem_lock(shm_file, 1, user);
 			if (!err && !(shp->shm_perm.mode & SHM_LOCKED)) {
 				shp->shm_perm.mode |= SHM_LOCKED;
@@ -1354,9 +1360,10 @@ SYSCALL_DEFINE1(shmdt, char __user *, shmaddr)
 		vma = next;
 	}
 
-#else /* CONFIG_MMU */
+#else	/* CONFIG_MMU */
 	/* under NOMMU conditions, the exact address to be destroyed must be
-	 * given */
+	 * given
+	 */
 	if (vma && vma->vm_start == addr && vma->vm_ops == &shm_vm_ops) {
 		do_munmap(mm, vma->vm_start, vma->vm_end - vma->vm_start);
 		retval = 0;

kernel/Makefile

@@ -84,6 +84,7 @@ obj-$(CONFIG_KPROBES) += kprobes.o
 obj-$(CONFIG_KGDB) += debug/
 obj-$(CONFIG_DETECT_HUNG_TASK) += hung_task.o
 obj-$(CONFIG_LOCKUP_DETECTOR) += watchdog.o
+obj-$(CONFIG_HARDLOCKUP_DETECTOR) += watchdog_hld.o
 obj-$(CONFIG_SECCOMP) += seccomp.o
 obj-$(CONFIG_RELAY) += relay.o
 obj-$(CONFIG_SYSCTL) += utsname_sysctl.o

kernel/debug/debug_core.c

@@ -598,11 +598,11 @@ return_normal:
 	/*
 	 * Wait for the other CPUs to be notified and be waiting for us:
 	 */
-	time_left = loops_per_jiffy * HZ;
+	time_left = MSEC_PER_SEC;
 	while (kgdb_do_roundup && --time_left &&
 	       (atomic_read(&masters_in_kgdb) + atomic_read(&slaves_in_kgdb)) !=
 		   online_cpus)
-		cpu_relax();
+		udelay(1000);
 	if (!time_left)
 		pr_crit("Timed out waiting for secondary CPUs.\n");
 

kernel/debug/kdb/kdb_io.c

@@ -30,6 +30,7 @@
 char kdb_prompt_str[CMD_BUFLEN];
 
 int kdb_trap_printk;
+int kdb_printf_cpu = -1;
 
 static int kgdb_transition_check(char *buffer)
 {
@@ -554,31 +555,26 @@ int vkdb_printf(enum kdb_msgsrc src, const char *fmt, va_list ap)
 	int linecount;
 	int colcount;
 	int logging, saved_loglevel = 0;
-	int saved_trap_printk;
-	int got_printf_lock = 0;
 	int retlen = 0;
 	int fnd, len;
+	int this_cpu, old_cpu;
 	char *cp, *cp2, *cphold = NULL, replaced_byte = ' ';
 	char *moreprompt = "more> ";
 	struct console *c = console_drivers;
-	static DEFINE_SPINLOCK(kdb_printf_lock);
 	unsigned long uninitialized_var(flags);
 
-	preempt_disable();
-	saved_trap_printk = kdb_trap_printk;
-	kdb_trap_printk = 0;
-
 	/* Serialize kdb_printf if multiple cpus try to write at once.
 	 * But if any cpu goes recursive in kdb, just print the output,
 	 * even if it is interleaved with any other text.
 	 */
-	if (!KDB_STATE(PRINTF_LOCK)) {
+	local_irq_save(flags);
-		KDB_STATE_SET(PRINTF_LOCK);
+	this_cpu = smp_processor_id();
-		spin_lock_irqsave(&kdb_printf_lock, flags);
+	for (;;) {
-		got_printf_lock = 1;
+		old_cpu = cmpxchg(&kdb_printf_cpu, -1, this_cpu);
-		atomic_inc(&kdb_event);
+		if (old_cpu == -1 || old_cpu == this_cpu)
-	} else {
+			break;
-		__acquire(kdb_printf_lock);
+
+		cpu_relax();
 	}
 
 	diag = kdbgetintenv("LINES", &linecount);
@@ -847,16 +843,9 @@ kdb_print_out:
 	suspend_grep = 0; /* end of what may have been a recursive call */
 	if (logging)
 		console_loglevel = saved_loglevel;
-	if (KDB_STATE(PRINTF_LOCK) && got_printf_lock) {
+	/* kdb_printf_cpu locked the code above. */
-		got_printf_lock = 0;
+	smp_store_release(&kdb_printf_cpu, old_cpu);
-		spin_unlock_irqrestore(&kdb_printf_lock, flags);
+	local_irq_restore(flags);
-		KDB_STATE_CLEAR(PRINTF_LOCK);
-		atomic_dec(&kdb_event);
-	} else {
-		__release(kdb_printf_lock);
-	}
-	kdb_trap_printk = saved_trap_printk;
-	preempt_enable();
 	return retlen;
 }
 

kernel/debug/kdb/kdb_main.c

@@ -60,7 +60,6 @@ int kdb_grep_trailing;
  * Kernel debugger state flags
  */
 int kdb_flags;
-atomic_t kdb_event;
 
 /*
  * kdb_lock protects updates to kdb_initial_cpu.  Used to

kernel/debug/kdb/kdb_private.h

@@ -132,7 +132,6 @@ extern int kdb_state;
 #define KDB_STATE_PAGER		0x00000400	/* pager is available */
 #define KDB_STATE_GO_SWITCH	0x00000800	/* go is switching
 						 * back to initial cpu */
-#define KDB_STATE_PRINTF_LOCK	0x00001000	/* Holds kdb_printf lock */
 #define KDB_STATE_WAIT_IPI	0x00002000	/* Waiting for kdb_ipi() NMI */
 #define KDB_STATE_RECURSE	0x00004000	/* Recursive entry to kdb */
 #define KDB_STATE_IP_ADJUSTED	0x00008000	/* Restart IP has been

kernel/events/uprobes.c

@@ -301,7 +301,7 @@ int uprobe_write_opcode(struct mm_struct *mm, unsigned long vaddr,
 retry:
 	/* Read the page with vaddr into memory */
 	ret = get_user_pages_remote(NULL, mm, vaddr, 1, FOLL_FORCE, &old_page,
-			&vma);
+			&vma, NULL);
 	if (ret <= 0)
 		return ret;
 
@@ -1712,7 +1712,7 @@ static int is_trap_at_addr(struct mm_struct *mm, unsigned long vaddr)
 	 * essentially a kernel access to the memory.
 	 */
 	result = get_user_pages_remote(NULL, mm, vaddr, 1, FOLL_FORCE, &page,
-			NULL);
+			NULL, NULL);
 	if (result < 0)
 		return result;
 

kernel/kcov.c

@@ -1,11 +1,16 @@
 #define pr_fmt(fmt) "kcov: " fmt
 
 #define DISABLE_BRANCH_PROFILING
+#include <linux/atomic.h>
 #include <linux/compiler.h>
+#include <linux/errno.h>
+#include <linux/export.h>
 #include <linux/types.h>
 #include <linux/file.h>
 #include <linux/fs.h>
+#include <linux/init.h>
 #include <linux/mm.h>
+#include <linux/preempt.h>
 #include <linux/printk.h>
 #include <linux/sched.h>
 #include <linux/slab.h>

kernel/kexec_core.c

@@ -441,6 +441,8 @@ static struct page *kimage_alloc_crash_control_pages(struct kimage *image,
 	while (hole_end <= crashk_res.end) {
 		unsigned long i;
 
+		cond_resched();
+
 		if (hole_end > KEXEC_CRASH_CONTROL_MEMORY_LIMIT)
 			break;
 		/* See if I overlap any of the segments */
@@ -1467,9 +1469,6 @@ static int __init crash_save_vmcoreinfo_init(void)
 #endif
 	VMCOREINFO_NUMBER(PG_head_mask);
 	VMCOREINFO_NUMBER(PAGE_BUDDY_MAPCOUNT_VALUE);
-#ifdef CONFIG_X86
-	VMCOREINFO_NUMBER(KERNEL_IMAGE_SIZE);
-#endif
 #ifdef CONFIG_HUGETLB_PAGE
 	VMCOREINFO_NUMBER(HUGETLB_PAGE_DTOR);
 #endif

kernel/printk/printk.c

@@ -1926,7 +1926,8 @@ int vprintk_default(const char *fmt, va_list args)
 	int r;
 
 #ifdef CONFIG_KGDB_KDB
-	if (unlikely(kdb_trap_printk)) {
+	/* Allow to pass printk() to kdb but avoid a recursion. */
+	if (unlikely(kdb_trap_printk && kdb_printf_cpu < 0)) {
 		r = vkdb_printf(KDB_MSGSRC_PRINTK, fmt, args);
 		return r;
 	}

kernel/relay.c

@@ -809,11 +809,11 @@ void relay_subbufs_consumed(struct rchan *chan,
 {
 	struct rchan_buf *buf;
 
-	if (!chan)
+	if (!chan || cpu >= NR_CPUS)
 		return;
 
 	buf = *per_cpu_ptr(chan->buf, cpu);
-	if (cpu >= NR_CPUS || !buf || subbufs_consumed > chan->n_subbufs)
+	if (!buf || subbufs_consumed > chan->n_subbufs)
 		return;
 
 	if (subbufs_consumed > buf->subbufs_produced - buf->subbufs_consumed)

kernel/signal.c

@@ -2491,6 +2491,13 @@ void __set_current_blocked(const sigset_t *newset)
 {
 	struct task_struct *tsk = current;
 
+	/*
+	 * In case the signal mask hasn't changed, there is nothing we need
+	 * to do. The current->blocked shouldn't be modified by other task.
+	 */
+	if (sigequalsets(&tsk->blocked, newset))
+		return;
+
 	spin_lock_irq(&tsk->sighand->siglock);
 	__set_task_blocked(tsk, newset);
 	spin_unlock_irq(&tsk->sighand->siglock);

kernel/sysctl.c

@@ -2389,9 +2389,11 @@ static void validate_coredump_safety(void)
 #ifdef CONFIG_COREDUMP
 	if (suid_dumpable == SUID_DUMP_ROOT &&
 	    core_pattern[0] != '/' && core_pattern[0] != '|') {
-		printk(KERN_WARNING "Unsafe core_pattern used with "\
+		printk(KERN_WARNING
-			"suid_dumpable=2. Pipe handler or fully qualified "\
+"Unsafe core_pattern used with fs.suid_dumpable=2.\n"
-			"core dump path required.\n");
+"Pipe handler or fully qualified core dump path required.\n"
+"Set kernel.core_pattern before fs.suid_dumpable.\n"
+		);
 	}
 #endif
 }

kernel/sysctl_binary.c

@@ -1354,8 +1354,8 @@ static void deprecated_sysctl_warning(const int *name, int nlen)
 			"warning: process `%s' used the deprecated sysctl "
 			"system call with ", current->comm);
 		for (i = 0; i < nlen; i++)
-			printk("%d.", name[i]);
+			printk(KERN_CONT "%d.", name[i]);
-		printk("\n");
+		printk(KERN_CONT "\n");
 	}
 	return;
 }

kernel/time/alarmtimer.c

@@ -516,7 +516,8 @@ static enum alarmtimer_restart alarm_handle_timer(struct alarm *alarm,
 
 	spin_lock_irqsave(&ptr->it_lock, flags);
 	if ((ptr->it_sigev_notify & ~SIGEV_THREAD_ID) != SIGEV_NONE) {
-		if (posix_timer_event(ptr, 0) != 0)
+		if (IS_ENABLED(CONFIG_POSIX_TIMERS) &&
+		    posix_timer_event(ptr, 0) != 0)
 			ptr->it_overrun++;
 	}
 

kernel/watchdog.c

@@ -24,32 +24,14 @@
 
 #include <asm/irq_regs.h>
 #include <linux/kvm_para.h>
-#include <linux/perf_event.h>
 #include <linux/kthread.h>
 
-/*
- * The run state of the lockup detectors is controlled by the content of the
- * 'watchdog_enabled' variable. Each lockup detector has its dedicated bit -
- * bit 0 for the hard lockup detector and bit 1 for the soft lockup detector.
- *
- * 'watchdog_user_enabled', 'nmi_watchdog_enabled' and 'soft_watchdog_enabled'
- * are variables that are only used as an 'interface' between the parameters
- * in /proc/sys/kernel and the internal state bits in 'watchdog_enabled'. The
- * 'watchdog_thresh' variable is handled differently because its value is not
- * boolean, and the lockup detectors are 'suspended' while 'watchdog_thresh'
- * is equal zero.
- */
-#define NMI_WATCHDOG_ENABLED_BIT   0
-#define SOFT_WATCHDOG_ENABLED_BIT  1
-#define NMI_WATCHDOG_ENABLED      (1 << NMI_WATCHDOG_ENABLED_BIT)
-#define SOFT_WATCHDOG_ENABLED     (1 << SOFT_WATCHDOG_ENABLED_BIT)
-
 static DEFINE_MUTEX(watchdog_proc_mutex);
 
-#ifdef CONFIG_HARDLOCKUP_DETECTOR
+#if defined(CONFIG_HAVE_NMI_WATCHDOG) || defined(CONFIG_HARDLOCKUP_DETECTOR)
-static unsigned long __read_mostly watchdog_enabled = SOFT_WATCHDOG_ENABLED|NMI_WATCHDOG_ENABLED;
+unsigned long __read_mostly watchdog_enabled = SOFT_WATCHDOG_ENABLED|NMI_WATCHDOG_ENABLED;
 #else
-static unsigned long __read_mostly watchdog_enabled = SOFT_WATCHDOG_ENABLED;
+unsigned long __read_mostly watchdog_enabled = SOFT_WATCHDOG_ENABLED;
 #endif
 int __read_mostly nmi_watchdog_enabled;
 int __read_mostly soft_watchdog_enabled;
@@ -59,9 +41,6 @@ int __read_mostly watchdog_thresh = 10;
 #ifdef CONFIG_SMP
 int __read_mostly sysctl_softlockup_all_cpu_backtrace;
 int __read_mostly sysctl_hardlockup_all_cpu_backtrace;
-#else
-#define sysctl_softlockup_all_cpu_backtrace 0
-#define sysctl_hardlockup_all_cpu_backtrace 0
 #endif
 static struct cpumask watchdog_cpumask __read_mostly;
 unsigned long *watchdog_cpumask_bits = cpumask_bits(&watchdog_cpumask);
@@ -100,50 +79,9 @@ static DEFINE_PER_CPU(bool, soft_watchdog_warn);
 static DEFINE_PER_CPU(unsigned long, hrtimer_interrupts);
 static DEFINE_PER_CPU(unsigned long, soft_lockup_hrtimer_cnt);
 static DEFINE_PER_CPU(struct task_struct *, softlockup_task_ptr_saved);
-#ifdef CONFIG_HARDLOCKUP_DETECTOR
-static DEFINE_PER_CPU(bool, hard_watchdog_warn);
-static DEFINE_PER_CPU(bool, watchdog_nmi_touch);
 static DEFINE_PER_CPU(unsigned long, hrtimer_interrupts_saved);
-static DEFINE_PER_CPU(struct perf_event *, watchdog_ev);
-#endif
 static unsigned long soft_lockup_nmi_warn;
 
-/* boot commands */
-/*
- * Should we panic when a soft-lockup or hard-lockup occurs:
- */
-#ifdef CONFIG_HARDLOCKUP_DETECTOR
-unsigned int __read_mostly hardlockup_panic =
-			CONFIG_BOOTPARAM_HARDLOCKUP_PANIC_VALUE;
-static unsigned long hardlockup_allcpu_dumped;
-/*
- * We may not want to enable hard lockup detection by default in all cases,
- * for example when running the kernel as a guest on a hypervisor. In these
- * cases this function can be called to disable hard lockup detection. This
- * function should only be executed once by the boot processor before the
- * kernel command line parameters are parsed, because otherwise it is not
- * possible to override this in hardlockup_panic_setup().
- */
-void hardlockup_detector_disable(void)
-{
-	watchdog_enabled &= ~NMI_WATCHDOG_ENABLED;
-}
-
-static int __init hardlockup_panic_setup(char *str)
-{
-	if (!strncmp(str, "panic", 5))
-		hardlockup_panic = 1;
-	else if (!strncmp(str, "nopanic", 7))
-		hardlockup_panic = 0;
-	else if (!strncmp(str, "0", 1))
-		watchdog_enabled &= ~NMI_WATCHDOG_ENABLED;
-	else if (!strncmp(str, "1", 1))
-		watchdog_enabled |= NMI_WATCHDOG_ENABLED;
-	return 1;
-}
-__setup("nmi_watchdog=", hardlockup_panic_setup);
-#endif
-
 unsigned int __read_mostly softlockup_panic =
 			CONFIG_BOOTPARAM_SOFTLOCKUP_PANIC_VALUE;
 
@@ -264,32 +202,14 @@ void touch_all_softlockup_watchdogs(void)
 	wq_watchdog_touch(-1);
 }
 
-#ifdef CONFIG_HARDLOCKUP_DETECTOR
-void touch_nmi_watchdog(void)
-{
-	/*
-	 * Using __raw here because some code paths have
-	 * preemption enabled.  If preemption is enabled
-	 * then interrupts should be enabled too, in which
-	 * case we shouldn't have to worry about the watchdog
-	 * going off.
-	 */
-	raw_cpu_write(watchdog_nmi_touch, true);
-	touch_softlockup_watchdog();
-}
-EXPORT_SYMBOL(touch_nmi_watchdog);
-
-#endif
-
 void touch_softlockup_watchdog_sync(void)
 {
 	__this_cpu_write(softlockup_touch_sync, true);
 	__this_cpu_write(watchdog_touch_ts, 0);
 }
 
-#ifdef CONFIG_HARDLOCKUP_DETECTOR
 /* watchdog detector functions */
-static bool is_hardlockup(void)
+bool is_hardlockup(void)
 {
 	unsigned long hrint = __this_cpu_read(hrtimer_interrupts);
 
@@ -299,7 +219,6 @@ static bool is_hardlockup(void)
 	__this_cpu_write(hrtimer_interrupts_saved, hrint);
 	return false;
 }
-#endif
 
 static int is_softlockup(unsigned long touch_ts)
 {
@@ -313,78 +232,22 @@ static int is_softlockup(unsigned long touch_ts)
 	return 0;
 }
 
-#ifdef CONFIG_HARDLOCKUP_DETECTOR
-
-static struct perf_event_attr wd_hw_attr = {
-	.type		= PERF_TYPE_HARDWARE,
-	.config		= PERF_COUNT_HW_CPU_CYCLES,
-	.size		= sizeof(struct perf_event_attr),
-	.pinned		= 1,
-	.disabled	= 1,
-};
-
-/* Callback function for perf event subsystem */
-static void watchdog_overflow_callback(struct perf_event *event,
-		 struct perf_sample_data *data,
-		 struct pt_regs *regs)
-{
-	/* Ensure the watchdog never gets throttled */
-	event->hw.interrupts = 0;
-
-	if (__this_cpu_read(watchdog_nmi_touch) == true) {
-		__this_cpu_write(watchdog_nmi_touch, false);
-		return;
-	}
-
-	/* check for a hardlockup
-	 * This is done by making sure our timer interrupt
-	 * is incrementing.  The timer interrupt should have
-	 * fired multiple times before we overflow'd.  If it hasn't
-	 * then this is a good indication the cpu is stuck
-	 */
-	if (is_hardlockup()) {
-		int this_cpu = smp_processor_id();
-		struct pt_regs *regs = get_irq_regs();
-
-		/* only print hardlockups once */
-		if (__this_cpu_read(hard_watchdog_warn) == true)
-			return;
-
-		pr_emerg("Watchdog detected hard LOCKUP on cpu %d", this_cpu);
-		print_modules();
-		print_irqtrace_events(current);
-		if (regs)
-			show_regs(regs);
-		else
-			dump_stack();
-
-		/*
-		 * Perform all-CPU dump only once to avoid multiple hardlockups
-		 * generating interleaving traces
-		 */
-		if (sysctl_hardlockup_all_cpu_backtrace &&
-				!test_and_set_bit(0, &hardlockup_allcpu_dumped))
-			trigger_allbutself_cpu_backtrace();
-
-		if (hardlockup_panic)
-			nmi_panic(regs, "Hard LOCKUP");
-
-		__this_cpu_write(hard_watchdog_warn, true);
-		return;
-	}
-
-	__this_cpu_write(hard_watchdog_warn, false);
-	return;
-}
-#endif /* CONFIG_HARDLOCKUP_DETECTOR */
-
 static void watchdog_interrupt_count(void)
 {
 	__this_cpu_inc(hrtimer_interrupts);
 }
 
-static int watchdog_nmi_enable(unsigned int cpu);
+/*
-static void watchdog_nmi_disable(unsigned int cpu);
+ * These two functions are mostly architecture specific
+ * defining them as weak here.
+ */
+int __weak watchdog_nmi_enable(unsigned int cpu)
+{
+	return 0;
+}
+void __weak watchdog_nmi_disable(unsigned int cpu)
+{
+}
 
 static int watchdog_enable_all_cpus(void);
 static void watchdog_disable_all_cpus(void);
@@ -577,109 +440,6 @@ static void watchdog(unsigned int cpu)
 		watchdog_nmi_disable(cpu);
 }
 
-#ifdef CONFIG_HARDLOCKUP_DETECTOR
-/*
- * People like the simple clean cpu node info on boot.
- * Reduce the watchdog noise by only printing messages
- * that are different from what cpu0 displayed.
- */
-static unsigned long cpu0_err;
-
-static int watchdog_nmi_enable(unsigned int cpu)
-{
-	struct perf_event_attr *wd_attr;
-	struct perf_event *event = per_cpu(watchdog_ev, cpu);
-
-	/* nothing to do if the hard lockup detector is disabled */
-	if (!(watchdog_enabled & NMI_WATCHDOG_ENABLED))
-		goto out;
-
-	/* is it already setup and enabled? */
-	if (event && event->state > PERF_EVENT_STATE_OFF)
-		goto out;
-
-	/* it is setup but not enabled */
-	if (event != NULL)
-		goto out_enable;
-
-	wd_attr = &wd_hw_attr;
-	wd_attr->sample_period = hw_nmi_get_sample_period(watchdog_thresh);
-
-	/* Try to register using hardware perf events */
-	event = perf_event_create_kernel_counter(wd_attr, cpu, NULL, watchdog_overflow_callback, NULL);
-
-	/* save cpu0 error for future comparision */
-	if (cpu == 0 && IS_ERR(event))
-		cpu0_err = PTR_ERR(event);
-
-	if (!IS_ERR(event)) {
-		/* only print for cpu0 or different than cpu0 */
-		if (cpu == 0 || cpu0_err)
-			pr_info("enabled on all CPUs, permanently consumes one hw-PMU counter.\n");
-		goto out_save;
-	}
-
-	/*
-	 * Disable the hard lockup detector if _any_ CPU fails to set up
-	 * set up the hardware perf event. The watchdog() function checks
-	 * the NMI_WATCHDOG_ENABLED bit periodically.
-	 *
-	 * The barriers are for syncing up watchdog_enabled across all the
-	 * cpus, as clear_bit() does not use barriers.
-	 */
-	smp_mb__before_atomic();
-	clear_bit(NMI_WATCHDOG_ENABLED_BIT, &watchdog_enabled);
-	smp_mb__after_atomic();
-
-	/* skip displaying the same error again */
-	if (cpu > 0 && (PTR_ERR(event) == cpu0_err))
-		return PTR_ERR(event);
-
-	/* vary the KERN level based on the returned errno */
-	if (PTR_ERR(event) == -EOPNOTSUPP)
-		pr_info("disabled (cpu%i): not supported (no LAPIC?)\n", cpu);
-	else if (PTR_ERR(event) == -ENOENT)
-		pr_warn("disabled (cpu%i): hardware events not enabled\n",
-			 cpu);
-	else
-		pr_err("disabled (cpu%i): unable to create perf event: %ld\n",
-			cpu, PTR_ERR(event));
-
-	pr_info("Shutting down hard lockup detector on all cpus\n");
-
-	return PTR_ERR(event);
-
-	/* success path */
-out_save:
-	per_cpu(watchdog_ev, cpu) = event;
-out_enable:
-	perf_event_enable(per_cpu(watchdog_ev, cpu));
-out:
-	return 0;
-}
-
-static void watchdog_nmi_disable(unsigned int cpu)
-{
-	struct perf_event *event = per_cpu(watchdog_ev, cpu);
-
-	if (event) {
-		perf_event_disable(event);
-		per_cpu(watchdog_ev, cpu) = NULL;
-
-		/* should be in cleanup, but blocks oprofile */
-		perf_event_release_kernel(event);
-	}
-	if (cpu == 0) {
-		/* watchdog_nmi_enable() expects this to be zero initially. */
-		cpu0_err = 0;
-	}
-}
-
-#else
-static int watchdog_nmi_enable(unsigned int cpu) { return 0; }
-static void watchdog_nmi_disable(unsigned int cpu) { return; }
-#endif /* CONFIG_HARDLOCKUP_DETECTOR */
-
 static struct smp_hotplug_thread watchdog_threads = {
 	.store			= &softlockup_watchdog,
 	.thread_should_run	= watchdog_should_run,

kernel/watchdog_hld.c

@@ -0,0 +1,227 @@
+/*
+ * Detect hard lockups on a system
+ *
+ * started by Don Zickus, Copyright (C) 2010 Red Hat, Inc.
+ *
+ * Note: Most of this code is borrowed heavily from the original softlockup
+ * detector, so thanks to Ingo for the initial implementation.
+ * Some chunks also taken from the old x86-specific nmi watchdog code, thanks
+ * to those contributors as well.
+ */
+
+#define pr_fmt(fmt) "NMI watchdog: " fmt
+
+#include <linux/nmi.h>
+#include <linux/module.h>
+#include <asm/irq_regs.h>
+#include <linux/perf_event.h>
+
+static DEFINE_PER_CPU(bool, hard_watchdog_warn);
+static DEFINE_PER_CPU(bool, watchdog_nmi_touch);
+static DEFINE_PER_CPU(struct perf_event *, watchdog_ev);
+
+/* boot commands */
+/*
+ * Should we panic when a soft-lockup or hard-lockup occurs:
+ */
+unsigned int __read_mostly hardlockup_panic =
+			CONFIG_BOOTPARAM_HARDLOCKUP_PANIC_VALUE;
+static unsigned long hardlockup_allcpu_dumped;
+/*
+ * We may not want to enable hard lockup detection by default in all cases,
+ * for example when running the kernel as a guest on a hypervisor. In these
+ * cases this function can be called to disable hard lockup detection. This
+ * function should only be executed once by the boot processor before the
+ * kernel command line parameters are parsed, because otherwise it is not
+ * possible to override this in hardlockup_panic_setup().
+ */
+void hardlockup_detector_disable(void)
+{
+	watchdog_enabled &= ~NMI_WATCHDOG_ENABLED;
+}
+
+static int __init hardlockup_panic_setup(char *str)
+{
+	if (!strncmp(str, "panic", 5))
+		hardlockup_panic = 1;
+	else if (!strncmp(str, "nopanic", 7))
+		hardlockup_panic = 0;
+	else if (!strncmp(str, "0", 1))
+		watchdog_enabled &= ~NMI_WATCHDOG_ENABLED;
+	else if (!strncmp(str, "1", 1))
+		watchdog_enabled |= NMI_WATCHDOG_ENABLED;
+	return 1;
+}
+__setup("nmi_watchdog=", hardlockup_panic_setup);
+
+void touch_nmi_watchdog(void)
+{
+	/*
+	 * Using __raw here because some code paths have
+	 * preemption enabled.  If preemption is enabled
+	 * then interrupts should be enabled too, in which
+	 * case we shouldn't have to worry about the watchdog
+	 * going off.
+	 */
+	raw_cpu_write(watchdog_nmi_touch, true);
+	touch_softlockup_watchdog();
+}
+EXPORT_SYMBOL(touch_nmi_watchdog);
+
+static struct perf_event_attr wd_hw_attr = {
+	.type		= PERF_TYPE_HARDWARE,
+	.config		= PERF_COUNT_HW_CPU_CYCLES,
+	.size		= sizeof(struct perf_event_attr),
+	.pinned		= 1,
+	.disabled	= 1,
+};
+
+/* Callback function for perf event subsystem */
+static void watchdog_overflow_callback(struct perf_event *event,
+		 struct perf_sample_data *data,
+		 struct pt_regs *regs)
+{
+	/* Ensure the watchdog never gets throttled */
+	event->hw.interrupts = 0;
+
+	if (__this_cpu_read(watchdog_nmi_touch) == true) {
+		__this_cpu_write(watchdog_nmi_touch, false);
+		return;
+	}
+
+	/* check for a hardlockup
+	 * This is done by making sure our timer interrupt
+	 * is incrementing.  The timer interrupt should have
+	 * fired multiple times before we overflow'd.  If it hasn't
+	 * then this is a good indication the cpu is stuck
+	 */
+	if (is_hardlockup()) {
+		int this_cpu = smp_processor_id();
+
+		/* only print hardlockups once */
+		if (__this_cpu_read(hard_watchdog_warn) == true)
+			return;
+
+		pr_emerg("Watchdog detected hard LOCKUP on cpu %d", this_cpu);
+		print_modules();
+		print_irqtrace_events(current);
+		if (regs)
+			show_regs(regs);
+		else
+			dump_stack();
+
+		/*
+		 * Perform all-CPU dump only once to avoid multiple hardlockups
+		 * generating interleaving traces
+		 */
+		if (sysctl_hardlockup_all_cpu_backtrace &&
+				!test_and_set_bit(0, &hardlockup_allcpu_dumped))
+			trigger_allbutself_cpu_backtrace();
+
+		if (hardlockup_panic)
+			nmi_panic(regs, "Hard LOCKUP");
+
+		__this_cpu_write(hard_watchdog_warn, true);
+		return;
+	}
+
+	__this_cpu_write(hard_watchdog_warn, false);
+	return;
+}
+
+/*
+ * People like the simple clean cpu node info on boot.
+ * Reduce the watchdog noise by only printing messages
+ * that are different from what cpu0 displayed.
+ */
+static unsigned long cpu0_err;
+
+int watchdog_nmi_enable(unsigned int cpu)
+{
+	struct perf_event_attr *wd_attr;
+	struct perf_event *event = per_cpu(watchdog_ev, cpu);
+
+	/* nothing to do if the hard lockup detector is disabled */
+	if (!(watchdog_enabled & NMI_WATCHDOG_ENABLED))
+		goto out;
+
+	/* is it already setup and enabled? */
+	if (event && event->state > PERF_EVENT_STATE_OFF)
+		goto out;
+
+	/* it is setup but not enabled */
+	if (event != NULL)
+		goto out_enable;
+
+	wd_attr = &wd_hw_attr;
+	wd_attr->sample_period = hw_nmi_get_sample_period(watchdog_thresh);
+
+	/* Try to register using hardware perf events */
+	event = perf_event_create_kernel_counter(wd_attr, cpu, NULL, watchdog_overflow_callback, NULL);
+
+	/* save cpu0 error for future comparision */
+	if (cpu == 0 && IS_ERR(event))
+		cpu0_err = PTR_ERR(event);
+
+	if (!IS_ERR(event)) {
+		/* only print for cpu0 or different than cpu0 */
+		if (cpu == 0 || cpu0_err)
+			pr_info("enabled on all CPUs, permanently consumes one hw-PMU counter.\n");
+		goto out_save;
+	}
+
+	/*
+	 * Disable the hard lockup detector if _any_ CPU fails to set up
+	 * set up the hardware perf event. The watchdog() function checks
+	 * the NMI_WATCHDOG_ENABLED bit periodically.
+	 *
+	 * The barriers are for syncing up watchdog_enabled across all the
+	 * cpus, as clear_bit() does not use barriers.
+	 */
+	smp_mb__before_atomic();
+	clear_bit(NMI_WATCHDOG_ENABLED_BIT, &watchdog_enabled);
+	smp_mb__after_atomic();
+
+	/* skip displaying the same error again */
+	if (cpu > 0 && (PTR_ERR(event) == cpu0_err))
+		return PTR_ERR(event);
+
+	/* vary the KERN level based on the returned errno */
+	if (PTR_ERR(event) == -EOPNOTSUPP)
+		pr_info("disabled (cpu%i): not supported (no LAPIC?)\n", cpu);
+	else if (PTR_ERR(event) == -ENOENT)
+		pr_warn("disabled (cpu%i): hardware events not enabled\n",
+			 cpu);
+	else
+		pr_err("disabled (cpu%i): unable to create perf event: %ld\n",
+			cpu, PTR_ERR(event));
+
+	pr_info("Shutting down hard lockup detector on all cpus\n");
+
+	return PTR_ERR(event);
+
+	/* success path */
+out_save:
+	per_cpu(watchdog_ev, cpu) = event;
+out_enable:
+	perf_event_enable(per_cpu(watchdog_ev, cpu));
+out:
+	return 0;
+}
+
+void watchdog_nmi_disable(unsigned int cpu)
+{
+	struct perf_event *event = per_cpu(watchdog_ev, cpu);
+
+	if (event) {
+		perf_event_disable(event);
+		per_cpu(watchdog_ev, cpu) = NULL;
+
+		/* should be in cleanup, but blocks oprofile */
+		perf_event_release_kernel(event);
+	}
+	if (cpu == 0) {
+		/* watchdog_nmi_enable() expects this to be zero initially. */
+		cpu0_err = 0;
+	}
+}

lib/Kconfig.debug

@@ -194,8 +194,8 @@ config GDB_SCRIPTS
 	  build directory. If you load vmlinux into gdb, the helper
 	  scripts will be automatically imported by gdb as well, and
 	  additional functions are available to analyze a Linux kernel
-	  instance. See Documentation/gdb-kernel-debugging.txt for further
+	  instance. See Documentation/dev-tools/gdb-kernel-debugging.rst
-	  details.
+	  for further details.
 
 config ENABLE_WARN_DEPRECATED
 	bool "Enable __deprecated logic"
@@ -542,7 +542,7 @@ config DEBUG_KMEMLEAK
 	  difference being that the orphan objects are not freed but
 	  only shown in /sys/kernel/debug/kmemleak. Enabling this
 	  feature will introduce an overhead to memory
-	  allocations. See Documentation/kmemleak.txt for more
+	  allocations. See Documentation/dev-tools/kmemleak.rst for more
 	  details.
 
 	  Enabling DEBUG_SLAB or SLUB_DEBUG may increase the chances
@@ -739,7 +739,7 @@ config KCOV
 	  different machines and across reboots. If you need stable PC values,
 	  disable RANDOMIZE_BASE.
 
-	  For more details, see Documentation/kcov.txt.
+	  For more details, see Documentation/dev-tools/kcov.rst.
 
 config KCOV_INSTRUMENT_ALL
 	bool "Instrument all code by default"

lib/Kconfig.ubsan

@@ -10,7 +10,8 @@ config UBSAN
 	  This option enables undefined behaviour sanity checker
 	  Compile-time instrumentation is used to detect various undefined
 	  behaviours in runtime. Various types of checks may be enabled
-	  via boot parameter ubsan_handle (see: Documentation/ubsan.txt).
+	  via boot parameter ubsan_handle
+	  (see: Documentation/dev-tools/ubsan.rst).
 
 config UBSAN_SANITIZE_ALL
 	bool "Enable instrumentation for the entire kernel"

mm/compaction.c

@@ -818,6 +818,13 @@ isolate_migratepages_block(struct compact_control *cc, unsigned long low_pfn,
 		    page_count(page) > page_mapcount(page))
 			goto isolate_fail;
 
+		/*
+		 * Only allow to migrate anonymous pages in GFP_NOFS context
+		 * because those do not depend on fs locks.
+		 */
+		if (!(cc->gfp_mask & __GFP_FS) && page_mapping(page))
+			goto isolate_fail;
+
 		/* If we already hold the lock, we can skip some rechecking */
 		if (!locked) {
 			locked = compact_trylock_irqsave(zone_lru_lock(zone),
@@ -1677,14 +1684,16 @@ enum compact_result try_to_compact_pages(gfp_t gfp_mask, unsigned int order,
 		unsigned int alloc_flags, const struct alloc_context *ac,
 		enum compact_priority prio)
 {
-	int may_enter_fs = gfp_mask & __GFP_FS;
 	int may_perform_io = gfp_mask & __GFP_IO;
 	struct zoneref *z;
 	struct zone *zone;
 	enum compact_result rc = COMPACT_SKIPPED;
 
-	/* Check if the GFP flags allow compaction */
+	/*
-	if (!may_enter_fs || !may_perform_io)
+	 * Check if the GFP flags allow compaction - GFP_NOIO is really
+	 * tricky context because the migration might require IO
+	 */
+	if (!may_perform_io)
 		return COMPACT_SKIPPED;
 
 	trace_mm_compaction_try_to_compact_pages(order, gfp_mask, prio);
@@ -1751,6 +1760,7 @@ static void compact_node(int nid)
 		.mode = MIGRATE_SYNC,
 		.ignore_skip_hint = true,
 		.whole_zone = true,
+		.gfp_mask = GFP_KERNEL,
 	};
 
 
@@ -1876,6 +1886,7 @@ static void kcompactd_do_work(pg_data_t *pgdat)
 		.classzone_idx = pgdat->kcompactd_classzone_idx,
 		.mode = MIGRATE_SYNC_LIGHT,
 		.ignore_skip_hint = true,
+		.gfp_mask = GFP_KERNEL,
 
 	};
 	trace_mm_compaction_kcompactd_wake(pgdat->node_id, cc.order,

mm/filemap.c

@@ -2164,12 +2164,12 @@ page_not_uptodate:
 }
 EXPORT_SYMBOL(filemap_fault);
 
-void filemap_map_pages(struct fault_env *fe,
+void filemap_map_pages(struct vm_fault *vmf,
 		pgoff_t start_pgoff, pgoff_t end_pgoff)
 {
 	struct radix_tree_iter iter;
 	void **slot;
-	struct file *file = fe->vma->vm_file;
+	struct file *file = vmf->vma->vm_file;
 	struct address_space *mapping = file->f_mapping;
 	pgoff_t last_pgoff = start_pgoff;
 	loff_t size;
@@ -2225,11 +2225,11 @@ repeat:
 		if (file->f_ra.mmap_miss > 0)
 			file->f_ra.mmap_miss--;
 
-		fe->address += (iter.index - last_pgoff) << PAGE_SHIFT;
+		vmf->address += (iter.index - last_pgoff) << PAGE_SHIFT;
-		if (fe->pte)
+		if (vmf->pte)
-			fe->pte += iter.index - last_pgoff;
+			vmf->pte += iter.index - last_pgoff;
 		last_pgoff = iter.index;
-		if (alloc_set_pte(fe, NULL, page))
+		if (alloc_set_pte(vmf, NULL, page))
 			goto unlock;
 		unlock_page(page);
 		goto next;
@@ -2239,7 +2239,7 @@ skip:
 		put_page(page);
 next:
 		/* Huge page is mapped? No need to proceed. */
-		if (pmd_trans_huge(*fe->pmd))
+		if (pmd_trans_huge(*vmf->pmd))
 			break;
 		if (iter.index == end_pgoff)
 			break;

mm/gup.c

@@ -865,9 +865,10 @@ EXPORT_SYMBOL(get_user_pages_locked);
  * caller if required (just like with __get_user_pages). "FOLL_GET"
  * is set implicitly if "pages" is non-NULL.
  */
-__always_inline long __get_user_pages_unlocked(struct task_struct *tsk, struct mm_struct *mm,
+static __always_inline long __get_user_pages_unlocked(struct task_struct *tsk,
-					       unsigned long start, unsigned long nr_pages,
+		struct mm_struct *mm, unsigned long start,
-					       struct page **pages, unsigned int gup_flags)
+		unsigned long nr_pages, struct page **pages,
+		unsigned int gup_flags)
 {
 	long ret;
 	int locked = 1;
@@ -879,7 +880,6 @@ __always_inline long __get_user_pages_unlocked(struct task_struct *tsk, struct m
 		up_read(&mm->mmap_sem);
 	return ret;
 }
-EXPORT_SYMBOL(__get_user_pages_unlocked);
 
 /*
  * get_user_pages_unlocked() is suitable to replace the form:
@@ -917,6 +917,9 @@ EXPORT_SYMBOL(get_user_pages_unlocked);
  *		only intends to ensure the pages are faulted in.
  * @vmas:	array of pointers to vmas corresponding to each page.
  *		Or NULL if the caller does not require them.
+ * @locked:	pointer to lock flag indicating whether lock is held and
+ *		subsequently whether VM_FAULT_RETRY functionality can be
+ *		utilised. Lock must initially be held.
  *
  * Returns number of pages pinned. This may be fewer than the number
  * requested. If nr_pages is 0 or negative, returns 0. If no pages
@@ -960,10 +963,10 @@ EXPORT_SYMBOL(get_user_pages_unlocked);
 long get_user_pages_remote(struct task_struct *tsk, struct mm_struct *mm,
 		unsigned long start, unsigned long nr_pages,
 		unsigned int gup_flags, struct page **pages,
-		struct vm_area_struct **vmas)
+		struct vm_area_struct **vmas, int *locked)
 {
 	return __get_user_pages_locked(tsk, mm, start, nr_pages, pages, vmas,
-				       NULL, false,
+				       locked, true,
 				       gup_flags | FOLL_TOUCH | FOLL_REMOTE);
 }
 EXPORT_SYMBOL(get_user_pages_remote);
@@ -971,8 +974,9 @@ EXPORT_SYMBOL(get_user_pages_remote);
 /*
  * This is the same as get_user_pages_remote(), just with a
  * less-flexible calling convention where we assume that the task
- * and mm being operated on are the current task's.  We also
+ * and mm being operated on are the current task's and don't allow
- * obviously don't pass FOLL_REMOTE in here.
+ * passing of a locked parameter.  We also obviously don't pass
+ * FOLL_REMOTE in here.
  */
 long get_user_pages(unsigned long start, unsigned long nr_pages,
 		unsigned int gup_flags, struct page **pages,