Merge branch 'work.uaccess' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

Pull uaccess unification updates from Al Viro:
 "This is the uaccess unification pile. It's _not_ the end of uaccess
  work, but the next batch of that will go into the next cycle. This one
  mostly takes copy_from_user() and friends out of arch/* and gets the
  zero-padding behaviour in sync for all architectures.

  Dealing with the nocache/writethrough mess is for the next cycle;
  fortunately, that's x86-only. Same for cleanups in iov_iter.c (I am
  sold on access_ok() in there, BTW; just not in this pile), same for
  reducing __copy_... callsites, strn*... stuff, etc. - there will be a
  pile about as large as this one in the next merge window.

  This one sat in -next for weeks. -3KLoC"

* 'work.uaccess' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (96 commits)
  HAVE_ARCH_HARDENED_USERCOPY is unconditional now
  CONFIG_ARCH_HAS_RAW_COPY_USER is unconditional now
  m32r: switch to RAW_COPY_USER
  hexagon: switch to RAW_COPY_USER
  microblaze: switch to RAW_COPY_USER
  get rid of padding, switch to RAW_COPY_USER
  ia64: get rid of copy_in_user()
  ia64: sanitize __access_ok()
  ia64: get rid of 'segment' argument of __do_{get,put}_user()
  ia64: get rid of 'segment' argument of __{get,put}_user_check()
  ia64: add extable.h
  powerpc: get rid of zeroing, switch to RAW_COPY_USER
  esas2r: don't open-code memdup_user()
  alpha: fix stack smashing in old_adjtimex(2)
  don't open-code kernel_setsockopt()
  mips: switch to RAW_COPY_USER
  mips: get rid of tail-zeroing in primitives
  mips: make copy_from_user() zero tail explicitly
  mips: clean and reorder the forest of macros...
  mips: consolidate __invoke_... wrappers
  ...

arch/mips/include/asm/checksum.h

@@ -50,7 +50,7 @@ __wsum csum_partial_copy_from_user(const void __user *src, void *dst, int len,
 				   __wsum sum, int *err_ptr)
 {
 	might_fault();
-	if (segment_eq(get_fs(), get_ds()))
+	if (uaccess_kernel())
 		return __csum_partial_copy_kernel((__force void *)src, dst,
 						  len, sum, err_ptr);
 	else
@@ -82,7 +82,7 @@ __wsum csum_and_copy_to_user(const void *src, void __user *dst, int len,
 {
 	might_fault();
 	if (access_ok(VERIFY_WRITE, dst, len)) {
-		if (segment_eq(get_fs(), get_ds()))
+		if (uaccess_kernel())
 			return __csum_partial_copy_kernel(src,
 							  (__force void *)dst,
 							  len, sum, err_ptr);

arch/mips/include/asm/r4kcache.h

@@ -20,7 +20,7 @@
 #include <asm/cpu-features.h>
 #include <asm/cpu-type.h>
 #include <asm/mipsmtregs.h>
-#include <linux/uaccess.h> /* for segment_eq() */
+#include <linux/uaccess.h> /* for uaccess_kernel() */
 
 extern void (*r4k_blast_dcache)(void);
 extern void (*r4k_blast_icache)(void);
@@ -714,7 +714,7 @@ static inline void protected_blast_##pfx##cache##_range(unsigned long start,\
 									\
 	__##pfx##flush_prologue						\
 									\
-	if (segment_eq(get_fs(), USER_DS)) {				\
+	if (!uaccess_kernel()) {					\
 		while (1) {						\
 			protected_cachee_op(hitop, addr);		\
 			if (addr == aend)				\

arch/mips/include/asm/uaccess.h

@@ -12,8 +12,6 @@
 #define _ASM_UACCESS_H
 
 #include <linux/kernel.h>
-#include <linux/errno.h>
-#include <linux/thread_info.h>
 #include <linux/string.h>
 #include <asm/asm-eva.h>
 #include <asm/extable.h>
@@ -71,9 +69,6 @@ extern u64 __ua_limit;
 #define USER_DS		((mm_segment_t) { __UA_LIMIT })
 #endif
 
-#define VERIFY_READ    0
-#define VERIFY_WRITE   1
-
 #define get_ds()	(KERNEL_DS)
 #define get_fs()	(current_thread_info()->addr_limit)
 #define set_fs(x)	(current_thread_info()->addr_limit = (x))
@@ -93,7 +88,7 @@ static inline bool eva_kernel_access(void)
 	if (!IS_ENABLED(CONFIG_EVA))
 		return false;
 
-	return segment_eq(get_fs(), get_ds());
+	return uaccess_kernel();
 }
 
 /*
@@ -133,23 +128,14 @@ static inline bool eva_kernel_access(void)
  * this function, memory access functions may still return -EFAULT.
  */
 
-#define __access_mask get_fs().seg
-
-#define __access_ok(addr, size, mask)					\
-({									\
-	unsigned long __addr = (unsigned long) (addr);			\
-	unsigned long __size = size;					\
-	unsigned long __mask = mask;					\
-	unsigned long __ok;						\
-									\
-	__chk_user_ptr(addr);						\
-	__ok = (signed long)(__mask & (__addr | (__addr + __size) |	\
-		__ua_size(__size)));					\
-	__ok == 0;							\
-})
+static inline int __access_ok(const void __user *p, unsigned long size)
+{
+	unsigned long addr = (unsigned long)p;
+	return (get_fs().seg & (addr | (addr + size) | __ua_size(size))) == 0;
+}
 
 #define access_ok(type, addr, size)					\
-	likely(__access_ok((addr), (size), __access_mask))
+	likely(__access_ok((addr), (size)))
 
 /*
  * put_user: - Write a simple value into user space.
@@ -811,8 +797,30 @@ extern void __put_user_unaligned_unknown(void);
 
 extern size_t __copy_user(void *__to, const void *__from, size_t __n);
 
-#ifndef CONFIG_EVA
-#define __invoke_copy_to_user(to, from, n)				\
+#define __invoke_copy_from(func, to, from, n)				\
+({									\
+	register void *__cu_to_r __asm__("$4");				\
+	register const void __user *__cu_from_r __asm__("$5");		\
+	register long __cu_len_r __asm__("$6");				\
+									\
+	__cu_to_r = (to);						\
+	__cu_from_r = (from);						\
+	__cu_len_r = (n);						\
+	__asm__ __volatile__(						\
+	".set\tnoreorder\n\t"						\
+	__MODULE_JAL(func)						\
+	".set\tnoat\n\t"						\
+	__UA_ADDU "\t$1, %1, %2\n\t"					\
+	".set\tat\n\t"							\
+	".set\treorder"							\
+	: "+r" (__cu_to_r), "+r" (__cu_from_r), "+r" (__cu_len_r)	\
+	:								\
+	: "$8", "$9", "$10", "$11", "$12", "$14", "$15", "$24", "$31",	\
+	  DADDI_SCRATCH, "memory");					\
+	__cu_len_r;							\
+})
+
+#define __invoke_copy_to(func, to, from, n)				\
 ({									\
 	register void __user *__cu_to_r __asm__("$4");			\
 	register const void *__cu_from_r __asm__("$5");			\
@@ -822,161 +830,7 @@ extern size_t __copy_user(void *__to, const void *__from, size_t __n);
 	__cu_from_r = (from);						\
 	__cu_len_r = (n);						\
 	__asm__ __volatile__(						\
-	__MODULE_JAL(__copy_user)					\
-	: "+r" (__cu_to_r), "+r" (__cu_from_r), "+r" (__cu_len_r)	\
-	:								\
-	: "$8", "$9", "$10", "$11", "$12", "$14", "$15", "$24", "$31",	\
-	  DADDI_SCRATCH, "memory");					\
-	__cu_len_r;							\
-})
-
-#define __invoke_copy_to_kernel(to, from, n)				\
-	__invoke_copy_to_user(to, from, n)
-
-#endif
-
-/*
- * __copy_to_user: - Copy a block of data into user space, with less checking.
- * @to:	  Destination address, in user space.
- * @from: Source address, in kernel space.
- * @n:	  Number of bytes to copy.
- *
- * Context: User context only. This function may sleep if pagefaults are
- *          enabled.
- *
- * Copy data from kernel space to user space.  Caller must check
- * the specified block with access_ok() before calling this function.
- *
- * Returns number of bytes that could not be copied.
- * On success, this will be zero.
- */
-#define __copy_to_user(to, from, n)					\
-({									\
-	void __user *__cu_to;						\
-	const void *__cu_from;						\
-	long __cu_len;							\
-									\
-	__cu_to = (to);							\
-	__cu_from = (from);						\
-	__cu_len = (n);							\
-									\
-	check_object_size(__cu_from, __cu_len, true);			\
-	might_fault();							\
-									\
-	if (eva_kernel_access())					\
-		__cu_len = __invoke_copy_to_kernel(__cu_to, __cu_from,	\
-						   __cu_len);		\
-	else								\
-		__cu_len = __invoke_copy_to_user(__cu_to, __cu_from,	\
-						 __cu_len);		\
-	__cu_len;							\
-})
-
-extern size_t __copy_user_inatomic(void *__to, const void *__from, size_t __n);
-
-#define __copy_to_user_inatomic(to, from, n)				\
-({									\
-	void __user *__cu_to;						\
-	const void *__cu_from;						\
-	long __cu_len;							\
-									\
-	__cu_to = (to);							\
-	__cu_from = (from);						\
-	__cu_len = (n);							\
-									\
-	check_object_size(__cu_from, __cu_len, true);			\
-									\
-	if (eva_kernel_access())					\
-		__cu_len = __invoke_copy_to_kernel(__cu_to, __cu_from,	\
-						   __cu_len);		\
-	else								\
-		__cu_len = __invoke_copy_to_user(__cu_to, __cu_from,	\
-						 __cu_len);		\
-	__cu_len;							\
-})
-
-#define __copy_from_user_inatomic(to, from, n)				\
-({									\
-	void *__cu_to;							\
-	const void __user *__cu_from;					\
-	long __cu_len;							\
-									\
-	__cu_to = (to);							\
-	__cu_from = (from);						\
-	__cu_len = (n);							\
-									\
-	check_object_size(__cu_to, __cu_len, false);			\
-									\
-	if (eva_kernel_access())					\
-		__cu_len = __invoke_copy_from_kernel_inatomic(__cu_to,	\
-							      __cu_from,\
-							      __cu_len);\
-	else								\
-		__cu_len = __invoke_copy_from_user_inatomic(__cu_to,	\
-							    __cu_from,	\
-							    __cu_len);	\
-	__cu_len;							\
-})
-
-/*
- * copy_to_user: - Copy a block of data into user space.
- * @to:	  Destination address, in user space.
- * @from: Source address, in kernel space.
- * @n:	  Number of bytes to copy.
- *
- * Context: User context only. This function may sleep if pagefaults are
- *          enabled.
- *
- * Copy data from kernel space to user space.
- *
- * Returns number of bytes that could not be copied.
- * On success, this will be zero.
- */
-#define copy_to_user(to, from, n)					\
-({									\
-	void __user *__cu_to;						\
-	const void *__cu_from;						\
-	long __cu_len;							\
-									\
-	__cu_to = (to);							\
-	__cu_from = (from);						\
-	__cu_len = (n);							\
-									\
-	check_object_size(__cu_from, __cu_len, true);			\
-									\
-	if (eva_kernel_access()) {					\
-		__cu_len = __invoke_copy_to_kernel(__cu_to,		\
-						   __cu_from,		\
-						   __cu_len);		\
-	} else {							\
-		if (access_ok(VERIFY_WRITE, __cu_to, __cu_len)) {       \
-			might_fault();                                  \
-			__cu_len = __invoke_copy_to_user(__cu_to,	\
-							 __cu_from,	\
-							 __cu_len);     \
-		}							\
-	}								\
-	__cu_len;							\
-})
-
-#ifndef CONFIG_EVA
-
-#define __invoke_copy_from_user(to, from, n)				\
-({									\
-	register void *__cu_to_r __asm__("$4");				\
-	register const void __user *__cu_from_r __asm__("$5");		\
-	register long __cu_len_r __asm__("$6");				\
-									\
-	__cu_to_r = (to);						\
-	__cu_from_r = (from);						\
-	__cu_len_r = (n);						\
-	__asm__ __volatile__(						\
-	".set\tnoreorder\n\t"						\
-	__MODULE_JAL(__copy_user)					\
-	".set\tnoat\n\t"						\
-	__UA_ADDU "\t$1, %1, %2\n\t"					\
-	".set\tat\n\t"							\
-	".set\treorder"							\
+	__MODULE_JAL(func)						\
 	: "+r" (__cu_to_r), "+r" (__cu_from_r), "+r" (__cu_len_r)	\
 	:								\
 	: "$8", "$9", "$10", "$11", "$12", "$14", "$15", "$24", "$31",	\
@@ -985,261 +839,78 @@ extern size_t __copy_user_inatomic(void *__to, const void *__from, size_t __n);
 })
 
 #define __invoke_copy_from_kernel(to, from, n)				\
-	__invoke_copy_from_user(to, from, n)
+	__invoke_copy_from(__copy_user, to, from, n)
 
-/* For userland <-> userland operations */
-#define ___invoke_copy_in_user(to, from, n)				\
-	__invoke_copy_from_user(to, from, n)
+#define __invoke_copy_to_kernel(to, from, n)				\
+	__invoke_copy_to(__copy_user, to, from, n)
 
-/* For kernel <-> kernel operations */
 #define ___invoke_copy_in_kernel(to, from, n)				\
-	__invoke_copy_from_user(to, from, n)
+	__invoke_copy_from(__copy_user, to, from, n)
 
-#define __invoke_copy_from_user_inatomic(to, from, n)			\
-({									\
-	register void *__cu_to_r __asm__("$4");				\
-	register const void __user *__cu_from_r __asm__("$5");		\
-	register long __cu_len_r __asm__("$6");				\
-									\
-	__cu_to_r = (to);						\
-	__cu_from_r = (from);						\
-	__cu_len_r = (n);						\
-	__asm__ __volatile__(						\
-	".set\tnoreorder\n\t"						\
-	__MODULE_JAL(__copy_user_inatomic)				\
-	".set\tnoat\n\t"						\
-	__UA_ADDU "\t$1, %1, %2\n\t"					\
-	".set\tat\n\t"							\
-	".set\treorder"							\
-	: "+r" (__cu_to_r), "+r" (__cu_from_r), "+r" (__cu_len_r)	\
-	:								\
-	: "$8", "$9", "$10", "$11", "$12", "$14", "$15", "$24", "$31",	\
-	  DADDI_SCRATCH, "memory");					\
-	__cu_len_r;							\
-})
+#ifndef CONFIG_EVA
+#define __invoke_copy_from_user(to, from, n)				\
+	__invoke_copy_from(__copy_user, to, from, n)
 
-#define __invoke_copy_from_kernel_inatomic(to, from, n)			\
-	__invoke_copy_from_user_inatomic(to, from, n)			\
+#define __invoke_copy_to_user(to, from, n)				\
+	__invoke_copy_to(__copy_user, to, from, n)
+
+#define ___invoke_copy_in_user(to, from, n)				\
+	__invoke_copy_from(__copy_user, to, from, n)
 
 #else
 
 /* EVA specific functions */
 
-extern size_t __copy_user_inatomic_eva(void *__to, const void *__from,
-				       size_t __n);
 extern size_t __copy_from_user_eva(void *__to, const void *__from,
 				   size_t __n);
 extern size_t __copy_to_user_eva(void *__to, const void *__from,
 				 size_t __n);
 extern size_t __copy_in_user_eva(void *__to, const void *__from, size_t __n);
 
-#define __invoke_copy_from_user_eva_generic(to, from, n, func_ptr)	\
-({									\
-	register void *__cu_to_r __asm__("$4");				\
-	register const void __user *__cu_from_r __asm__("$5");		\
-	register long __cu_len_r __asm__("$6");				\
-									\
-	__cu_to_r = (to);						\
-	__cu_from_r = (from);						\
-	__cu_len_r = (n);						\
-	__asm__ __volatile__(						\
-	".set\tnoreorder\n\t"						\
-	__MODULE_JAL(func_ptr)						\
-	".set\tnoat\n\t"						\
-	__UA_ADDU "\t$1, %1, %2\n\t"					\
-	".set\tat\n\t"							\
-	".set\treorder"							\
-	: "+r" (__cu_to_r), "+r" (__cu_from_r), "+r" (__cu_len_r)	\
-	:								\
-	: "$8", "$9", "$10", "$11", "$12", "$14", "$15", "$24", "$31",	\
-	  DADDI_SCRATCH, "memory");					\
-	__cu_len_r;							\
-})
-
-#define __invoke_copy_to_user_eva_generic(to, from, n, func_ptr)	\
-({									\
-	register void *__cu_to_r __asm__("$4");				\
-	register const void __user *__cu_from_r __asm__("$5");		\
-	register long __cu_len_r __asm__("$6");				\
-									\
-	__cu_to_r = (to);						\
-	__cu_from_r = (from);						\
-	__cu_len_r = (n);						\
-	__asm__ __volatile__(						\
-	__MODULE_JAL(func_ptr)						\
-	: "+r" (__cu_to_r), "+r" (__cu_from_r), "+r" (__cu_len_r)	\
-	:								\
-	: "$8", "$9", "$10", "$11", "$12", "$14", "$15", "$24", "$31",	\
-	  DADDI_SCRATCH, "memory");					\
-	__cu_len_r;							\
-})
-
 /*
  * Source or destination address is in userland. We need to go through
  * the TLB
  */
 #define __invoke_copy_from_user(to, from, n)				\
-	__invoke_copy_from_user_eva_generic(to, from, n, __copy_from_user_eva)
-
-#define __invoke_copy_from_user_inatomic(to, from, n)			\
-	__invoke_copy_from_user_eva_generic(to, from, n,		\
-					    __copy_user_inatomic_eva)
+	__invoke_copy_from(__copy_from_user_eva, to, from, n)
 
 #define __invoke_copy_to_user(to, from, n)				\
-	__invoke_copy_to_user_eva_generic(to, from, n, __copy_to_user_eva)
+	__invoke_copy_to(__copy_to_user_eva, to, from, n)
 
 #define ___invoke_copy_in_user(to, from, n)				\
-	__invoke_copy_from_user_eva_generic(to, from, n, __copy_in_user_eva)
-
-/*
- * Source or destination address in the kernel. We are not going through
- * the TLB
- */
-#define __invoke_copy_from_kernel(to, from, n)				\
-	__invoke_copy_from_user_eva_generic(to, from, n, __copy_user)
-
-#define __invoke_copy_from_kernel_inatomic(to, from, n)			\
-	__invoke_copy_from_user_eva_generic(to, from, n, __copy_user_inatomic)
-
-#define __invoke_copy_to_kernel(to, from, n)				\
-	__invoke_copy_to_user_eva_generic(to, from, n, __copy_user)
-
-#define ___invoke_copy_in_kernel(to, from, n)				\
-	__invoke_copy_from_user_eva_generic(to, from, n, __copy_user)
+	__invoke_copy_from(__copy_in_user_eva, to, from, n)
 
 #endif /* CONFIG_EVA */
 
-/*
- * __copy_from_user: - Copy a block of data from user space, with less checking.
- * @to:	  Destination address, in kernel space.
- * @from: Source address, in user space.
- * @n:	  Number of bytes to copy.
- *
- * Context: User context only. This function may sleep if pagefaults are
- *          enabled.
- *
- * Copy data from user space to kernel space.  Caller must check
- * the specified block with access_ok() before calling this function.
- *
- * Returns number of bytes that could not be copied.
- * On success, this will be zero.
- *
- * If some data could not be copied, this function will pad the copied
- * data to the requested size using zero bytes.
- */
-#define __copy_from_user(to, from, n)					\
-({									\
-	void *__cu_to;							\
-	const void __user *__cu_from;					\
-	long __cu_len;							\
-									\
-	__cu_to = (to);							\
-	__cu_from = (from);						\
-	__cu_len = (n);							\
-									\
-	check_object_size(__cu_to, __cu_len, false);			\
-									\
-	if (eva_kernel_access()) {					\
-		__cu_len = __invoke_copy_from_kernel(__cu_to,		\
-						     __cu_from,		\
-						     __cu_len);		\
-	} else {							\
-		might_fault();						\
-		__cu_len = __invoke_copy_from_user(__cu_to, __cu_from,	\
-						   __cu_len);		\
-	}								\
-	__cu_len;							\
-})
+static inline unsigned long
+raw_copy_to_user(void __user *to, const void *from, unsigned long n)
+{
+	if (eva_kernel_access())
+		return __invoke_copy_to_kernel(to, from, n);
+	else
+		return __invoke_copy_to_user(to, from, n);
+}
 
-/*
- * copy_from_user: - Copy a block of data from user space.
- * @to:	  Destination address, in kernel space.
- * @from: Source address, in user space.
- * @n:	  Number of bytes to copy.
- *
- * Context: User context only. This function may sleep if pagefaults are
- *          enabled.
- *
- * Copy data from user space to kernel space.
- *
- * Returns number of bytes that could not be copied.
- * On success, this will be zero.
- *
- * If some data could not be copied, this function will pad the copied
- * data to the requested size using zero bytes.
- */
-#define copy_from_user(to, from, n)					\
-({									\
-	void *__cu_to;							\
-	const void __user *__cu_from;					\
-	long __cu_len;							\
-									\
-	__cu_to = (to);							\
-	__cu_from = (from);						\
-	__cu_len = (n);							\
-									\
-	check_object_size(__cu_to, __cu_len, false);			\
-									\
-	if (eva_kernel_access()) {					\
-		__cu_len = __invoke_copy_from_kernel(__cu_to,		\
-						     __cu_from,		\
-						     __cu_len);		\
-	} else {							\
-		if (access_ok(VERIFY_READ, __cu_from, __cu_len)) {	\
-			might_fault();                                  \
-			__cu_len = __invoke_copy_from_user(__cu_to,	\
-							   __cu_from,	\
-							   __cu_len);   \
-		} else {						\
-			memset(__cu_to, 0, __cu_len);			\
-		}							\
-	}								\
-	__cu_len;							\
-})
+static inline unsigned long
+raw_copy_from_user(void *to, const void __user *from, unsigned long n)
+{
+	if (eva_kernel_access())
+		return __invoke_copy_from_kernel(to, from, n);
+	else
+		return __invoke_copy_from_user(to, from, n);
+}
 
-#define __copy_in_user(to, from, n)					\
-({									\
-	void __user *__cu_to;						\
-	const void __user *__cu_from;					\
-	long __cu_len;							\
-									\
-	__cu_to = (to);							\
-	__cu_from = (from);						\
-	__cu_len = (n);							\
-	if (eva_kernel_access()) {					\
-		__cu_len = ___invoke_copy_in_kernel(__cu_to, __cu_from,	\
-						    __cu_len);		\
-	} else {							\
-		might_fault();						\
-		__cu_len = ___invoke_copy_in_user(__cu_to, __cu_from,	\
-						  __cu_len);		\
-	}								\
-	__cu_len;							\
-})
+#define INLINE_COPY_FROM_USER
+#define INLINE_COPY_TO_USER
 
-#define copy_in_user(to, from, n)					\
-({									\
-	void __user *__cu_to;						\
-	const void __user *__cu_from;					\
-	long __cu_len;							\
-									\
-	__cu_to = (to);							\
-	__cu_from = (from);						\
-	__cu_len = (n);							\
-	if (eva_kernel_access()) {					\
-		__cu_len = ___invoke_copy_in_kernel(__cu_to,__cu_from,	\
-						    __cu_len);		\
-	} else {							\
-		if (likely(access_ok(VERIFY_READ, __cu_from, __cu_len) &&\
-			   access_ok(VERIFY_WRITE, __cu_to, __cu_len))) {\
-			might_fault();					\
-			__cu_len = ___invoke_copy_in_user(__cu_to,	\
-							  __cu_from,	\
-							  __cu_len);	\
-		}							\
-	}								\
-	__cu_len;							\
-})
+static inline unsigned long
+raw_copy_in_user(void __user*to, const void __user *from, unsigned long n)
+{
+	if (eva_kernel_access())
+		return ___invoke_copy_in_kernel(to, from, n);
+	else
+		return ___invoke_copy_in_user(to, from,	n);
+}
 
 extern __kernel_size_t __bzero_kernel(void __user *addr, __kernel_size_t size);
 extern __kernel_size_t __bzero(void __user *addr, __kernel_size_t size);