Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (123 commits)
  perf: Remove the nmi parameter from the oprofile_perf backend
  x86, perf: Make copy_from_user_nmi() a library function
  perf: Remove perf_event_attr::type check
  x86, perf: P4 PMU - Fix typos in comments and style cleanup
  perf tools: Make test use the preset debugfs path
  perf tools: Add automated tests for events parsing
  perf tools: De-opt the parse_events function
  perf script: Fix display of IP address for non-callchain path
  perf tools: Fix endian conversion reading event attr from file header
  perf tools: Add missing 'node' alias to the hw_cache[] array
  perf probe: Support adding probes on offline kernel modules
  perf probe: Add probed module in front of function
  perf probe: Introduce debuginfo to encapsulate dwarf information
  perf-probe: Move dwarf library routines to dwarf-aux.{c, h}
  perf probe: Remove redundant dwarf functions
  perf probe: Move strtailcmp to string.c
  perf probe: Rename DIE_FIND_CB_FOUND to DIE_FIND_CB_END
  tracing/kprobe: Update symbol reference when loading module
  tracing/kprobes: Support module init function probing
  kprobes: Return -ENOENT if probe point doesn't exist
  ...

kernel/async.c

@@ -49,12 +49,13 @@ asynchronous and synchronous parts of the kernel.
 */
 
 #include <linux/async.h>
+#include <linux/atomic.h>
+#include <linux/ktime.h>
 #include <linux/module.h>
 #include <linux/wait.h>
 #include <linux/sched.h>
 #include <linux/slab.h>
 #include <linux/workqueue.h>
-#include <asm/atomic.h>
 
 static async_cookie_t next_cookie = 1;
 
@@ -128,7 +129,8 @@ static void async_run_entry_fn(struct work_struct *work)
 
 	/* 2) run (and print duration) */
 	if (initcall_debug && system_state == SYSTEM_BOOTING) {
-		printk("calling  %lli_%pF @ %i\n", (long long)entry->cookie,
+		printk(KERN_DEBUG "calling  %lli_%pF @ %i\n",
+			(long long)entry->cookie,
 			entry->func, task_pid_nr(current));
 		calltime = ktime_get();
 	}
@@ -136,7 +138,7 @@ static void async_run_entry_fn(struct work_struct *work)
 	if (initcall_debug && system_state == SYSTEM_BOOTING) {
 		rettime = ktime_get();
 		delta = ktime_sub(rettime, calltime);
-		printk("initcall %lli_%pF returned 0 after %lld usecs\n",
+		printk(KERN_DEBUG "initcall %lli_%pF returned 0 after %lld usecs\n",
 			(long long)entry->cookie,
 			entry->func,
 			(long long)ktime_to_ns(delta) >> 10);
@@ -270,7 +272,7 @@ void async_synchronize_cookie_domain(async_cookie_t cookie,
 	ktime_t starttime, delta, endtime;
 
 	if (initcall_debug && system_state == SYSTEM_BOOTING) {
-		printk("async_waiting @ %i\n", task_pid_nr(current));
+		printk(KERN_DEBUG "async_waiting @ %i\n", task_pid_nr(current));
 		starttime = ktime_get();
 	}
 
@@ -280,7 +282,7 @@ void async_synchronize_cookie_domain(async_cookie_t cookie,
 		endtime = ktime_get();
 		delta = ktime_sub(endtime, starttime);
 
-		printk("async_continuing @ %i after %lli usec\n",
+		printk(KERN_DEBUG "async_continuing @ %i after %lli usec\n",
 			task_pid_nr(current),
 			(long long)ktime_to_ns(delta) >> 10);
 	}

kernel/events/Makefile

@@ -2,5 +2,5 @@ ifdef CONFIG_FUNCTION_TRACER
 CFLAGS_REMOVE_core.o = -pg
 endif
 
-obj-y := core.o
+obj-y := core.o ring_buffer.o
 obj-$(CONFIG_HAVE_HW_BREAKPOINT) += hw_breakpoint.o

kernel/events/hw_breakpoint.c

@@ -431,9 +431,11 @@ int register_perf_hw_breakpoint(struct perf_event *bp)
 struct perf_event *
 register_user_hw_breakpoint(struct perf_event_attr *attr,
 			    perf_overflow_handler_t triggered,
+			    void *context,
 			    struct task_struct *tsk)
 {
-	return perf_event_create_kernel_counter(attr, -1, tsk, triggered);
+	return perf_event_create_kernel_counter(attr, -1, tsk, triggered,
+						context);
 }
 EXPORT_SYMBOL_GPL(register_user_hw_breakpoint);
 
@@ -502,7 +504,8 @@ EXPORT_SYMBOL_GPL(unregister_hw_breakpoint);
  */
 struct perf_event * __percpu *
 register_wide_hw_breakpoint(struct perf_event_attr *attr,
-			    perf_overflow_handler_t triggered)
+			    perf_overflow_handler_t triggered,
+			    void *context)
 {
 	struct perf_event * __percpu *cpu_events, **pevent, *bp;
 	long err;
@@ -515,7 +518,8 @@ register_wide_hw_breakpoint(struct perf_event_attr *attr,
 	get_online_cpus();
 	for_each_online_cpu(cpu) {
 		pevent = per_cpu_ptr(cpu_events, cpu);
-		bp = perf_event_create_kernel_counter(attr, cpu, NULL, triggered);
+		bp = perf_event_create_kernel_counter(attr, cpu, NULL,
+						      triggered, context);
 
 		*pevent = bp;
 

kernel/events/internal.h

@@ -0,0 +1,96 @@
+#ifndef _KERNEL_EVENTS_INTERNAL_H
+#define _KERNEL_EVENTS_INTERNAL_H
+
+#define RING_BUFFER_WRITABLE		0x01
+
+struct ring_buffer {
+	atomic_t			refcount;
+	struct rcu_head			rcu_head;
+#ifdef CONFIG_PERF_USE_VMALLOC
+	struct work_struct		work;
+	int				page_order;	/* allocation order  */
+#endif
+	int				nr_pages;	/* nr of data pages  */
+	int				writable;	/* are we writable   */
+
+	atomic_t			poll;		/* POLL_ for wakeups */
+
+	local_t				head;		/* write position    */
+	local_t				nest;		/* nested writers    */
+	local_t				events;		/* event limit       */
+	local_t				wakeup;		/* wakeup stamp      */
+	local_t				lost;		/* nr records lost   */
+
+	long				watermark;	/* wakeup watermark  */
+
+	struct perf_event_mmap_page	*user_page;
+	void				*data_pages[0];
+};
+
+extern void rb_free(struct ring_buffer *rb);
+extern struct ring_buffer *
+rb_alloc(int nr_pages, long watermark, int cpu, int flags);
+extern void perf_event_wakeup(struct perf_event *event);
+
+extern void
+perf_event_header__init_id(struct perf_event_header *header,
+			   struct perf_sample_data *data,
+			   struct perf_event *event);
+extern void
+perf_event__output_id_sample(struct perf_event *event,
+			     struct perf_output_handle *handle,
+			     struct perf_sample_data *sample);
+
+extern struct page *
+perf_mmap_to_page(struct ring_buffer *rb, unsigned long pgoff);
+
+#ifdef CONFIG_PERF_USE_VMALLOC
+/*
+ * Back perf_mmap() with vmalloc memory.
+ *
+ * Required for architectures that have d-cache aliasing issues.
+ */
+
+static inline int page_order(struct ring_buffer *rb)
+{
+	return rb->page_order;
+}
+
+#else
+
+static inline int page_order(struct ring_buffer *rb)
+{
+	return 0;
+}
+#endif
+
+static unsigned long perf_data_size(struct ring_buffer *rb)
+{
+	return rb->nr_pages << (PAGE_SHIFT + page_order(rb));
+}
+
+static inline void
+__output_copy(struct perf_output_handle *handle,
+		   const void *buf, unsigned int len)
+{
+	do {
+		unsigned long size = min_t(unsigned long, handle->size, len);
+
+		memcpy(handle->addr, buf, size);
+
+		len -= size;
+		handle->addr += size;
+		buf += size;
+		handle->size -= size;
+		if (!handle->size) {
+			struct ring_buffer *rb = handle->rb;
+
+			handle->page++;
+			handle->page &= rb->nr_pages - 1;
+			handle->addr = rb->data_pages[handle->page];
+			handle->size = PAGE_SIZE << page_order(rb);
+		}
+	} while (len);
+}
+
+#endif /* _KERNEL_EVENTS_INTERNAL_H */

kernel/events/ring_buffer.c

@@ -0,0 +1,380 @@
+/*
+ * Performance events ring-buffer code:
+ *
+ *  Copyright (C) 2008 Thomas Gleixner <tglx@linutronix.de>
+ *  Copyright (C) 2008-2011 Red Hat, Inc., Ingo Molnar
+ *  Copyright (C) 2008-2011 Red Hat, Inc., Peter Zijlstra <pzijlstr@redhat.com>
+ *  Copyright  <20>  2009 Paul Mackerras, IBM Corp. <paulus@au1.ibm.com>
+ *
+ * For licensing details see kernel-base/COPYING
+ */
+
+#include <linux/perf_event.h>
+#include <linux/vmalloc.h>
+#include <linux/slab.h>
+
+#include "internal.h"
+
+static bool perf_output_space(struct ring_buffer *rb, unsigned long tail,
+			      unsigned long offset, unsigned long head)
+{
+	unsigned long mask;
+
+	if (!rb->writable)
+		return true;
+
+	mask = perf_data_size(rb) - 1;
+
+	offset = (offset - tail) & mask;
+	head   = (head   - tail) & mask;
+
+	if ((int)(head - offset) < 0)
+		return false;
+
+	return true;
+}
+
+static void perf_output_wakeup(struct perf_output_handle *handle)
+{
+	atomic_set(&handle->rb->poll, POLL_IN);
+
+	handle->event->pending_wakeup = 1;
+	irq_work_queue(&handle->event->pending);
+}
+
+/*
+ * We need to ensure a later event_id doesn't publish a head when a former
+ * event isn't done writing. However since we need to deal with NMIs we
+ * cannot fully serialize things.
+ *
+ * We only publish the head (and generate a wakeup) when the outer-most
+ * event completes.
+ */
+static void perf_output_get_handle(struct perf_output_handle *handle)
+{
+	struct ring_buffer *rb = handle->rb;
+
+	preempt_disable();
+	local_inc(&rb->nest);
+	handle->wakeup = local_read(&rb->wakeup);
+}
+
+static void perf_output_put_handle(struct perf_output_handle *handle)
+{
+	struct ring_buffer *rb = handle->rb;
+	unsigned long head;
+
+again:
+	head = local_read(&rb->head);
+
+	/*
+	 * IRQ/NMI can happen here, which means we can miss a head update.
+	 */
+
+	if (!local_dec_and_test(&rb->nest))
+		goto out;
+
+	/*
+	 * Publish the known good head. Rely on the full barrier implied
+	 * by atomic_dec_and_test() order the rb->head read and this
+	 * write.
+	 */
+	rb->user_page->data_head = head;
+
+	/*
+	 * Now check if we missed an update, rely on the (compiler)
+	 * barrier in atomic_dec_and_test() to re-read rb->head.
+	 */
+	if (unlikely(head != local_read(&rb->head))) {
+		local_inc(&rb->nest);
+		goto again;
+	}
+
+	if (handle->wakeup != local_read(&rb->wakeup))
+		perf_output_wakeup(handle);
+
+out:
+	preempt_enable();
+}
+
+int perf_output_begin(struct perf_output_handle *handle,
+		      struct perf_event *event, unsigned int size)
+{
+	struct ring_buffer *rb;
+	unsigned long tail, offset, head;
+	int have_lost;
+	struct perf_sample_data sample_data;
+	struct {
+		struct perf_event_header header;
+		u64			 id;
+		u64			 lost;
+	} lost_event;
+
+	rcu_read_lock();
+	/*
+	 * For inherited events we send all the output towards the parent.
+	 */
+	if (event->parent)
+		event = event->parent;
+
+	rb = rcu_dereference(event->rb);
+	if (!rb)
+		goto out;
+
+	handle->rb	= rb;
+	handle->event	= event;
+
+	if (!rb->nr_pages)
+		goto out;
+
+	have_lost = local_read(&rb->lost);
+	if (have_lost) {
+		lost_event.header.size = sizeof(lost_event);
+		perf_event_header__init_id(&lost_event.header, &sample_data,
+					   event);
+		size += lost_event.header.size;
+	}
+
+	perf_output_get_handle(handle);
+
+	do {
+		/*
+		 * Userspace could choose to issue a mb() before updating the
+		 * tail pointer. So that all reads will be completed before the
+		 * write is issued.
+		 */
+		tail = ACCESS_ONCE(rb->user_page->data_tail);
+		smp_rmb();
+		offset = head = local_read(&rb->head);
+		head += size;
+		if (unlikely(!perf_output_space(rb, tail, offset, head)))
+			goto fail;
+	} while (local_cmpxchg(&rb->head, offset, head) != offset);
+
+	if (head - local_read(&rb->wakeup) > rb->watermark)
+		local_add(rb->watermark, &rb->wakeup);
+
+	handle->page = offset >> (PAGE_SHIFT + page_order(rb));
+	handle->page &= rb->nr_pages - 1;
+	handle->size = offset & ((PAGE_SIZE << page_order(rb)) - 1);
+	handle->addr = rb->data_pages[handle->page];
+	handle->addr += handle->size;
+	handle->size = (PAGE_SIZE << page_order(rb)) - handle->size;
+
+	if (have_lost) {
+		lost_event.header.type = PERF_RECORD_LOST;
+		lost_event.header.misc = 0;
+		lost_event.id          = event->id;
+		lost_event.lost        = local_xchg(&rb->lost, 0);
+
+		perf_output_put(handle, lost_event);
+		perf_event__output_id_sample(event, handle, &sample_data);
+	}
+
+	return 0;
+
+fail:
+	local_inc(&rb->lost);
+	perf_output_put_handle(handle);
+out:
+	rcu_read_unlock();
+
+	return -ENOSPC;
+}
+
+void perf_output_copy(struct perf_output_handle *handle,
+		      const void *buf, unsigned int len)
+{
+	__output_copy(handle, buf, len);
+}
+
+void perf_output_end(struct perf_output_handle *handle)
+{
+	perf_output_put_handle(handle);
+	rcu_read_unlock();
+}
+
+static void
+ring_buffer_init(struct ring_buffer *rb, long watermark, int flags)
+{
+	long max_size = perf_data_size(rb);
+
+	if (watermark)
+		rb->watermark = min(max_size, watermark);
+
+	if (!rb->watermark)
+		rb->watermark = max_size / 2;
+
+	if (flags & RING_BUFFER_WRITABLE)
+		rb->writable = 1;
+
+	atomic_set(&rb->refcount, 1);
+}
+
+#ifndef CONFIG_PERF_USE_VMALLOC
+
+/*
+ * Back perf_mmap() with regular GFP_KERNEL-0 pages.
+ */
+
+struct page *
+perf_mmap_to_page(struct ring_buffer *rb, unsigned long pgoff)
+{
+	if (pgoff > rb->nr_pages)
+		return NULL;
+
+	if (pgoff == 0)
+		return virt_to_page(rb->user_page);
+
+	return virt_to_page(rb->data_pages[pgoff - 1]);
+}
+
+static void *perf_mmap_alloc_page(int cpu)
+{
+	struct page *page;
+	int node;
+
+	node = (cpu == -1) ? cpu : cpu_to_node(cpu);
+	page = alloc_pages_node(node, GFP_KERNEL | __GFP_ZERO, 0);
+	if (!page)
+		return NULL;
+
+	return page_address(page);
+}
+
+struct ring_buffer *rb_alloc(int nr_pages, long watermark, int cpu, int flags)
+{
+	struct ring_buffer *rb;
+	unsigned long size;
+	int i;
+
+	size = sizeof(struct ring_buffer);
+	size += nr_pages * sizeof(void *);
+
+	rb = kzalloc(size, GFP_KERNEL);
+	if (!rb)
+		goto fail;
+
+	rb->user_page = perf_mmap_alloc_page(cpu);
+	if (!rb->user_page)
+		goto fail_user_page;
+
+	for (i = 0; i < nr_pages; i++) {
+		rb->data_pages[i] = perf_mmap_alloc_page(cpu);
+		if (!rb->data_pages[i])
+			goto fail_data_pages;
+	}
+
+	rb->nr_pages = nr_pages;
+
+	ring_buffer_init(rb, watermark, flags);
+
+	return rb;
+
+fail_data_pages:
+	for (i--; i >= 0; i--)
+		free_page((unsigned long)rb->data_pages[i]);
+
+	free_page((unsigned long)rb->user_page);
+
+fail_user_page:
+	kfree(rb);
+
+fail:
+	return NULL;
+}
+
+static void perf_mmap_free_page(unsigned long addr)
+{
+	struct page *page = virt_to_page((void *)addr);
+
+	page->mapping = NULL;
+	__free_page(page);
+}
+
+void rb_free(struct ring_buffer *rb)
+{
+	int i;
+
+	perf_mmap_free_page((unsigned long)rb->user_page);
+	for (i = 0; i < rb->nr_pages; i++)
+		perf_mmap_free_page((unsigned long)rb->data_pages[i]);
+	kfree(rb);
+}
+
+#else
+
+struct page *
+perf_mmap_to_page(struct ring_buffer *rb, unsigned long pgoff)
+{
+	if (pgoff > (1UL << page_order(rb)))
+		return NULL;
+
+	return vmalloc_to_page((void *)rb->user_page + pgoff * PAGE_SIZE);
+}
+
+static void perf_mmap_unmark_page(void *addr)
+{
+	struct page *page = vmalloc_to_page(addr);
+
+	page->mapping = NULL;
+}
+
+static void rb_free_work(struct work_struct *work)
+{
+	struct ring_buffer *rb;
+	void *base;
+	int i, nr;
+
+	rb = container_of(work, struct ring_buffer, work);
+	nr = 1 << page_order(rb);
+
+	base = rb->user_page;
+	for (i = 0; i < nr + 1; i++)
+		perf_mmap_unmark_page(base + (i * PAGE_SIZE));
+
+	vfree(base);
+	kfree(rb);
+}
+
+void rb_free(struct ring_buffer *rb)
+{
+	schedule_work(&rb->work);
+}
+
+struct ring_buffer *rb_alloc(int nr_pages, long watermark, int cpu, int flags)
+{
+	struct ring_buffer *rb;
+	unsigned long size;
+	void *all_buf;
+
+	size = sizeof(struct ring_buffer);
+	size += sizeof(void *);
+
+	rb = kzalloc(size, GFP_KERNEL);
+	if (!rb)
+		goto fail;
+
+	INIT_WORK(&rb->work, rb_free_work);
+
+	all_buf = vmalloc_user((nr_pages + 1) * PAGE_SIZE);
+	if (!all_buf)
+		goto fail_all_buf;
+
+	rb->user_page = all_buf;
+	rb->data_pages[0] = all_buf + PAGE_SIZE;
+	rb->page_order = ilog2(nr_pages);
+	rb->nr_pages = 1;
+
+	ring_buffer_init(rb, watermark, flags);
+
+	return rb;
+
+fail_all_buf:
+	kfree(rb);
+
+fail:
+	return NULL;
+}
+
+#endif

kernel/kprobes.c

@@ -1255,19 +1255,29 @@ static int __kprobes in_kprobes_functions(unsigned long addr)
 /*
  * If we have a symbol_name argument, look it up and add the offset field
  * to it. This way, we can specify a relative address to a symbol.
+ * This returns encoded errors if it fails to look up symbol or invalid
+ * combination of parameters.
  */
 static kprobe_opcode_t __kprobes *kprobe_addr(struct kprobe *p)
 {
 	kprobe_opcode_t *addr = p->addr;
+
+	if ((p->symbol_name && p->addr) ||
+	    (!p->symbol_name && !p->addr))
+		goto invalid;
+
 	if (p->symbol_name) {
-		if (addr)
-			return NULL;
 		kprobe_lookup_name(p->symbol_name, addr);
+		if (!addr)
+			return ERR_PTR(-ENOENT);
 	}
 
-	if (!addr)
-		return NULL;
-	return (kprobe_opcode_t *)(((char *)addr) + p->offset);
+	addr = (kprobe_opcode_t *)(((char *)addr) + p->offset);
+	if (addr)
+		return addr;
+
+invalid:
+	return ERR_PTR(-EINVAL);
 }
 
 /* Check passed kprobe is valid and return kprobe in kprobe_table. */
@@ -1311,8 +1321,8 @@ int __kprobes register_kprobe(struct kprobe *p)
 	kprobe_opcode_t *addr;
 
 	addr = kprobe_addr(p);
-	if (!addr)
-		return -EINVAL;
+	if (IS_ERR(addr))
+		return PTR_ERR(addr);
 	p->addr = addr;
 
 	ret = check_kprobe_rereg(p);
@@ -1335,6 +1345,8 @@ int __kprobes register_kprobe(struct kprobe *p)
 	 */
 	probed_mod = __module_text_address((unsigned long) p->addr);
 	if (probed_mod) {
+		/* Return -ENOENT if fail. */
+		ret = -ENOENT;
 		/*
 		 * We must hold a refcount of the probed module while updating
 		 * its code to prohibit unexpected unloading.
@@ -1351,6 +1363,7 @@ int __kprobes register_kprobe(struct kprobe *p)
 			module_put(probed_mod);
 			goto fail_with_jump_label;
 		}
+		/* ret will be updated by following code */
 	}
 	preempt_enable();
 	jump_label_unlock();
@@ -1399,7 +1412,7 @@ out:
 fail_with_jump_label:
 	preempt_enable();
 	jump_label_unlock();
-	return -EINVAL;
+	return ret;
 }
 EXPORT_SYMBOL_GPL(register_kprobe);
 
@@ -1686,8 +1699,8 @@ int __kprobes register_kretprobe(struct kretprobe *rp)
 
 	if (kretprobe_blacklist_size) {
 		addr = kprobe_addr(&rp->kp);
-		if (!addr)
-			return -EINVAL;
+		if (IS_ERR(addr))
+			return PTR_ERR(addr);
 
 		for (i = 0; kretprobe_blacklist[i].name != NULL; i++) {
 			if (kretprobe_blacklist[i].addr == addr)

kernel/sched.c

@@ -2220,7 +2220,7 @@ void set_task_cpu(struct task_struct *p, unsigned int new_cpu)
 
 	if (task_cpu(p) != new_cpu) {
 		p->se.nr_migrations++;
-		perf_sw_event(PERF_COUNT_SW_CPU_MIGRATIONS, 1, 1, NULL, 0);
+		perf_sw_event(PERF_COUNT_SW_CPU_MIGRATIONS, 1, NULL, 0);
 	}
 
 	__set_task_cpu(p, new_cpu);

kernel/stacktrace.c

@@ -26,12 +26,18 @@ void print_stack_trace(struct stack_trace *trace, int spaces)
 EXPORT_SYMBOL_GPL(print_stack_trace);
 
 /*
- * Architectures that do not implement save_stack_trace_tsk get this
- * weak alias and a once-per-bootup warning (whenever this facility
- * is utilized - for example by procfs):
+ * Architectures that do not implement save_stack_trace_tsk or
+ * save_stack_trace_regs get this weak alias and a once-per-bootup warning
+ * (whenever this facility is utilized - for example by procfs):
  */
 __weak void
 save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace)
 {
 	WARN_ONCE(1, KERN_INFO "save_stack_trace_tsk() not implemented yet.\n");
 }
+
+__weak void
+save_stack_trace_regs(struct pt_regs *regs, struct stack_trace *trace)
+{
+	WARN_ONCE(1, KERN_INFO "save_stack_trace_regs() not implemented yet.\n");
+}

kernel/trace/ftrace.c

@@ -32,7 +32,6 @@
 
 #include <trace/events/sched.h>
 
-#include <asm/ftrace.h>
 #include <asm/setup.h>
 
 #include "trace_output.h"
@@ -82,14 +81,14 @@ static int ftrace_disabled __read_mostly;
 
 static DEFINE_MUTEX(ftrace_lock);
 
-static struct ftrace_ops ftrace_list_end __read_mostly =
-{
+static struct ftrace_ops ftrace_list_end __read_mostly = {
 	.func		= ftrace_stub,
 };
 
 static struct ftrace_ops *ftrace_global_list __read_mostly = &ftrace_list_end;
 static struct ftrace_ops *ftrace_ops_list __read_mostly = &ftrace_list_end;
 ftrace_func_t ftrace_trace_function __read_mostly = ftrace_stub;
+static ftrace_func_t __ftrace_trace_function_delay __read_mostly = ftrace_stub;
 ftrace_func_t __ftrace_trace_function __read_mostly = ftrace_stub;
 ftrace_func_t ftrace_pid_function __read_mostly = ftrace_stub;
 static struct ftrace_ops global_ops;
@@ -148,9 +147,11 @@ void clear_ftrace_function(void)
 {
 	ftrace_trace_function = ftrace_stub;
 	__ftrace_trace_function = ftrace_stub;
+	__ftrace_trace_function_delay = ftrace_stub;
 	ftrace_pid_function = ftrace_stub;
 }
 
+#undef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST
 #ifndef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST
 /*
  * For those archs that do not test ftrace_trace_stop in their
@@ -209,8 +210,13 @@ static void update_ftrace_function(void)
 
 #ifdef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST
 	ftrace_trace_function = func;
+#else
+#ifdef CONFIG_DYNAMIC_FTRACE
+	/* do not update till all functions have been modified */
+	__ftrace_trace_function_delay = func;
 #else
 	__ftrace_trace_function = func;
+#endif
 	ftrace_trace_function = ftrace_test_stop_func;
 #endif
 }
@@ -785,8 +791,7 @@ static void unregister_ftrace_profiler(void)
 	unregister_ftrace_graph();
 }
 #else
-static struct ftrace_ops ftrace_profile_ops __read_mostly =
-{
+static struct ftrace_ops ftrace_profile_ops __read_mostly = {
 	.func		= function_profile_call,
 };
 
@@ -806,19 +811,10 @@ ftrace_profile_write(struct file *filp, const char __user *ubuf,
 		     size_t cnt, loff_t *ppos)
 {
 	unsigned long val;
-	char buf[64];		/* big enough to hold a number */
 	int ret;
 
-	if (cnt >= sizeof(buf))
-		return -EINVAL;
-
-	if (copy_from_user(&buf, ubuf, cnt))
-		return -EFAULT;
-
-	buf[cnt] = 0;
-
-	ret = strict_strtoul(buf, 10, &val);
-	if (ret < 0)
+	ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
+	if (ret)
 		return ret;
 
 	val = !!val;
@@ -1182,8 +1178,14 @@ alloc_and_copy_ftrace_hash(int size_bits, struct ftrace_hash *hash)
 	return NULL;
 }
 
+static void
+ftrace_hash_rec_disable(struct ftrace_ops *ops, int filter_hash);
+static void
+ftrace_hash_rec_enable(struct ftrace_ops *ops, int filter_hash);
+
 static int
-ftrace_hash_move(struct ftrace_hash **dst, struct ftrace_hash *src)
+ftrace_hash_move(struct ftrace_ops *ops, int enable,
+		 struct ftrace_hash **dst, struct ftrace_hash *src)
 {
 	struct ftrace_func_entry *entry;
 	struct hlist_node *tp, *tn;
@@ -1193,8 +1195,15 @@ ftrace_hash_move(struct ftrace_hash **dst, struct ftrace_hash *src)
 	unsigned long key;
 	int size = src->count;
 	int bits = 0;
+	int ret;
 	int i;
 
+	/*
+	 * Remove the current set, update the hash and add
+	 * them back.
+	 */
+	ftrace_hash_rec_disable(ops, enable);
+
 	/*
 	 * If the new source is empty, just free dst and assign it
 	 * the empty_hash.
@@ -1215,9 +1224,10 @@ ftrace_hash_move(struct ftrace_hash **dst, struct ftrace_hash *src)
 	if (bits > FTRACE_HASH_MAX_BITS)
 		bits = FTRACE_HASH_MAX_BITS;
 
+	ret = -ENOMEM;
 	new_hash = alloc_ftrace_hash(bits);
 	if (!new_hash)
-		return -ENOMEM;
+		goto out;
 
 	size = 1 << src->size_bits;
 	for (i = 0; i < size; i++) {
@@ -1236,7 +1246,16 @@ ftrace_hash_move(struct ftrace_hash **dst, struct ftrace_hash *src)
 	rcu_assign_pointer(*dst, new_hash);
 	free_ftrace_hash_rcu(old_hash);
 
-	return 0;
+	ret = 0;
+ out:
+	/*
+	 * Enable regardless of ret:
+	 *  On success, we enable the new hash.
+	 *  On failure, we re-enable the original hash.
+	 */
+	ftrace_hash_rec_enable(ops, enable);
+
+	return ret;
 }
 
 /*
@@ -1596,6 +1615,12 @@ static int __ftrace_modify_code(void *data)
 {
 	int *command = data;
 
+	/*
+	 * Do not call function tracer while we update the code.
+	 * We are in stop machine, no worrying about races.
+	 */
+	function_trace_stop++;
+
 	if (*command & FTRACE_ENABLE_CALLS)
 		ftrace_replace_code(1);
 	else if (*command & FTRACE_DISABLE_CALLS)
@@ -1609,6 +1634,18 @@ static int __ftrace_modify_code(void *data)
 	else if (*command & FTRACE_STOP_FUNC_RET)
 		ftrace_disable_ftrace_graph_caller();
 
+#ifndef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST
+	/*
+	 * For archs that call ftrace_test_stop_func(), we must
+	 * wait till after we update all the function callers
+	 * before we update the callback. This keeps different
+	 * ops that record different functions from corrupting
+	 * each other.
+	 */
+	__ftrace_trace_function = __ftrace_trace_function_delay;
+#endif
+	function_trace_stop--;
+
 	return 0;
 }
 
@@ -1744,10 +1781,36 @@ static cycle_t		ftrace_update_time;
 static unsigned long	ftrace_update_cnt;
 unsigned long		ftrace_update_tot_cnt;
 
+static int ops_traces_mod(struct ftrace_ops *ops)
+{
+	struct ftrace_hash *hash;
+
+	hash = ops->filter_hash;
+	return !!(!hash || !hash->count);
+}
+
 static int ftrace_update_code(struct module *mod)
 {
 	struct dyn_ftrace *p;
 	cycle_t start, stop;
+	unsigned long ref = 0;
+
+	/*
+	 * When adding a module, we need to check if tracers are
+	 * currently enabled and if they are set to trace all functions.
+	 * If they are, we need to enable the module functions as well
+	 * as update the reference counts for those function records.
+	 */
+	if (mod) {
+		struct ftrace_ops *ops;
+
+		for (ops = ftrace_ops_list;
+		     ops != &ftrace_list_end; ops = ops->next) {
+			if (ops->flags & FTRACE_OPS_FL_ENABLED &&
+			    ops_traces_mod(ops))
+				ref++;
+		}
+	}
 
 	start = ftrace_now(raw_smp_processor_id());
 	ftrace_update_cnt = 0;
@@ -1760,7 +1823,7 @@ static int ftrace_update_code(struct module *mod)
 
 		p = ftrace_new_addrs;
 		ftrace_new_addrs = p->newlist;
-		p->flags = 0L;
+		p->flags = ref;
 
 		/*
 		 * Do the initial record conversion from mcount jump
@@ -1783,7 +1846,7 @@ static int ftrace_update_code(struct module *mod)
 		 * conversion puts the module to the correct state, thus
 		 * passing the ftrace_make_call check.
 		 */
-		if (ftrace_start_up) {
+		if (ftrace_start_up && ref) {
 			int failed = __ftrace_replace_code(p, 1);
 			if (failed) {
 				ftrace_bug(failed, p->ip);
@@ -2407,10 +2470,9 @@ ftrace_match_module_records(struct ftrace_hash *hash, char *buff, char *mod)
  */
 
 static int
-ftrace_mod_callback(char *func, char *cmd, char *param, int enable)
+ftrace_mod_callback(struct ftrace_hash *hash,
+		    char *func, char *cmd, char *param, int enable)
 {
-	struct ftrace_ops *ops = &global_ops;
-	struct ftrace_hash *hash;
 	char *mod;
 	int ret = -EINVAL;
 
@@ -2430,11 +2492,6 @@ ftrace_mod_callback(char *func, char *cmd, char *param, int enable)
 	if (!strlen(mod))
 		return ret;
 
-	if (enable)
-		hash = ops->filter_hash;
-	else
-		hash = ops->notrace_hash;
-
 	ret = ftrace_match_module_records(hash, func, mod);
 	if (!ret)
 		ret = -EINVAL;
@@ -2760,7 +2817,7 @@ static int ftrace_process_regex(struct ftrace_hash *hash,
 	mutex_lock(&ftrace_cmd_mutex);
 	list_for_each_entry(p, &ftrace_commands, list) {
 		if (strcmp(p->name, command) == 0) {
-			ret = p->func(func, command, next, enable);
+			ret = p->func(hash, func, command, next, enable);
 			goto out_unlock;
 		}
 	}
@@ -2857,7 +2914,11 @@ ftrace_set_regex(struct ftrace_ops *ops, unsigned char *buf, int len,
 		ftrace_match_records(hash, buf, len);
 
 	mutex_lock(&ftrace_lock);
-	ret = ftrace_hash_move(orig_hash, hash);
+	ret = ftrace_hash_move(ops, enable, orig_hash, hash);
+	if (!ret && ops->flags & FTRACE_OPS_FL_ENABLED
+	    && ftrace_enabled)
+		ftrace_run_update_code(FTRACE_ENABLE_CALLS);
+
 	mutex_unlock(&ftrace_lock);
 
 	mutex_unlock(&ftrace_regex_lock);
@@ -3040,18 +3101,12 @@ ftrace_regex_release(struct inode *inode, struct file *file)
 			orig_hash = &iter->ops->notrace_hash;
 
 		mutex_lock(&ftrace_lock);
-		/*
-		 * Remove the current set, update the hash and add
-		 * them back.
-		 */
-		ftrace_hash_rec_disable(iter->ops, filter_hash);
-		ret = ftrace_hash_move(orig_hash, iter->hash);
-		if (!ret) {
-			ftrace_hash_rec_enable(iter->ops, filter_hash);
-			if (iter->ops->flags & FTRACE_OPS_FL_ENABLED
-			    && ftrace_enabled)
-				ftrace_run_update_code(FTRACE_ENABLE_CALLS);
-		}
+		ret = ftrace_hash_move(iter->ops, filter_hash,
+				       orig_hash, iter->hash);
+		if (!ret && (iter->ops->flags & FTRACE_OPS_FL_ENABLED)
+		    && ftrace_enabled)
+			ftrace_run_update_code(FTRACE_ENABLE_CALLS);
+
 		mutex_unlock(&ftrace_lock);
 	}
 	free_ftrace_hash(iter->hash);
@@ -3330,7 +3385,7 @@ static int ftrace_process_locs(struct module *mod,
 {
 	unsigned long *p;
 	unsigned long addr;
-	unsigned long flags;
+	unsigned long flags = 0; /* Shut up gcc */
 
 	mutex_lock(&ftrace_lock);
 	p = start;
@@ -3348,12 +3403,18 @@ static int ftrace_process_locs(struct module *mod,
 	}
 
 	/*
-	 * Disable interrupts to prevent interrupts from executing
-	 * code that is being modified.
+	 * We only need to disable interrupts on start up
+	 * because we are modifying code that an interrupt
+	 * may execute, and the modification is not atomic.
+	 * But for modules, nothing runs the code we modify
+	 * until we are finished with it, and there's no
+	 * reason to cause large interrupt latencies while we do it.
 	 */
-	local_irq_save(flags);
+	if (!mod)
+		local_irq_save(flags);
 	ftrace_update_code(mod);
-	local_irq_restore(flags);
+	if (!mod)
+		local_irq_restore(flags);
 	mutex_unlock(&ftrace_lock);
 
 	return 0;

kernel/trace/ring_buffer.c

@@ -997,15 +997,21 @@ static int rb_allocate_pages(struct ring_buffer_per_cpu *cpu_buffer,
 			     unsigned nr_pages)
 {
 	struct buffer_page *bpage, *tmp;
-	unsigned long addr;
 	LIST_HEAD(pages);
 	unsigned i;
 
 	WARN_ON(!nr_pages);
 
 	for (i = 0; i < nr_pages; i++) {
+		struct page *page;
+		/*
+		 * __GFP_NORETRY flag makes sure that the allocation fails
+		 * gracefully without invoking oom-killer and the system is
+		 * not destabilized.
+		 */
 		bpage = kzalloc_node(ALIGN(sizeof(*bpage), cache_line_size()),
-				    GFP_KERNEL, cpu_to_node(cpu_buffer->cpu));
+				    GFP_KERNEL | __GFP_NORETRY,
+				    cpu_to_node(cpu_buffer->cpu));
 		if (!bpage)
 			goto free_pages;
 
@@ -1013,10 +1019,11 @@ static int rb_allocate_pages(struct ring_buffer_per_cpu *cpu_buffer,
 
 		list_add(&bpage->list, &pages);
 
-		addr = __get_free_page(GFP_KERNEL);
-		if (!addr)
+		page = alloc_pages_node(cpu_to_node(cpu_buffer->cpu),
+					GFP_KERNEL | __GFP_NORETRY, 0);
+		if (!page)
 			goto free_pages;
-		bpage->page = (void *)addr;
+		bpage->page = page_address(page);
 		rb_init_page(bpage->page);
 	}
 
@@ -1045,7 +1052,7 @@ rb_allocate_cpu_buffer(struct ring_buffer *buffer, int cpu)
 {
 	struct ring_buffer_per_cpu *cpu_buffer;
 	struct buffer_page *bpage;
-	unsigned long addr;
+	struct page *page;
 	int ret;
 
 	cpu_buffer = kzalloc_node(ALIGN(sizeof(*cpu_buffer), cache_line_size()),
@@ -1067,10 +1074,10 @@ rb_allocate_cpu_buffer(struct ring_buffer *buffer, int cpu)
 	rb_check_bpage(cpu_buffer, bpage);
 
 	cpu_buffer->reader_page = bpage;
-	addr = __get_free_page(GFP_KERNEL);
-	if (!addr)
+	page = alloc_pages_node(cpu_to_node(cpu), GFP_KERNEL, 0);
+	if (!page)
 		goto fail_free_reader;
-	bpage->page = (void *)addr;
+	bpage->page = page_address(page);
 	rb_init_page(bpage->page);
 
 	INIT_LIST_HEAD(&cpu_buffer->reader_page->list);
@@ -1314,7 +1321,6 @@ int ring_buffer_resize(struct ring_buffer *buffer, unsigned long size)
 	unsigned nr_pages, rm_pages, new_pages;
 	struct buffer_page *bpage, *tmp;
 	unsigned long buffer_size;
-	unsigned long addr;
 	LIST_HEAD(pages);
 	int i, cpu;
 
@@ -1375,16 +1381,24 @@ int ring_buffer_resize(struct ring_buffer *buffer, unsigned long size)
 
 	for_each_buffer_cpu(buffer, cpu) {
 		for (i = 0; i < new_pages; i++) {
+			struct page *page;
+			/*
+			 * __GFP_NORETRY flag makes sure that the allocation
+			 * fails gracefully without invoking oom-killer and
+			 * the system is not destabilized.
+			 */
 			bpage = kzalloc_node(ALIGN(sizeof(*bpage),
 						  cache_line_size()),
-					    GFP_KERNEL, cpu_to_node(cpu));
+					    GFP_KERNEL | __GFP_NORETRY,
+					    cpu_to_node(cpu));
 			if (!bpage)
 				goto free_pages;
 			list_add(&bpage->list, &pages);
-			addr = __get_free_page(GFP_KERNEL);
-			if (!addr)
+			page = alloc_pages_node(cpu_to_node(cpu),
+						GFP_KERNEL | __GFP_NORETRY, 0);
+			if (!page)
 				goto free_pages;
-			bpage->page = (void *)addr;
+			bpage->page = page_address(page);
 			rb_init_page(bpage->page);
 		}
 	}
@@ -3730,16 +3744,17 @@ EXPORT_SYMBOL_GPL(ring_buffer_swap_cpu);
  * Returns:
  *  The page allocated, or NULL on error.
  */
-void *ring_buffer_alloc_read_page(struct ring_buffer *buffer)
+void *ring_buffer_alloc_read_page(struct ring_buffer *buffer, int cpu)
 {
 	struct buffer_data_page *bpage;
-	unsigned long addr;
+	struct page *page;
 
-	addr = __get_free_page(GFP_KERNEL);
-	if (!addr)
+	page = alloc_pages_node(cpu_to_node(cpu),
+				GFP_KERNEL | __GFP_NORETRY, 0);
+	if (!page)
 		return NULL;
 
-	bpage = (void *)addr;
+	bpage = page_address(page);
 
 	rb_init_page(bpage);
 
@@ -3978,20 +3993,11 @@ rb_simple_write(struct file *filp, const char __user *ubuf,
 		size_t cnt, loff_t *ppos)
 {
 	unsigned long *p = filp->private_data;
-	char buf[64];
 	unsigned long val;
 	int ret;
 
-	if (cnt >= sizeof(buf))
-		return -EINVAL;
-
-	if (copy_from_user(&buf, ubuf, cnt))
-		return -EFAULT;
-
-	buf[cnt] = 0;
-
-	ret = strict_strtoul(buf, 10, &val);
-	if (ret < 0)
+	ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
+	if (ret)
 		return ret;
 
 	if (val)

kernel/trace/ring_buffer_benchmark.c

@@ -106,7 +106,7 @@ static enum event_status read_page(int cpu)
 	int inc;
 	int i;
 
-	bpage = ring_buffer_alloc_read_page(buffer);
+	bpage = ring_buffer_alloc_read_page(buffer, cpu);
 	if (!bpage)
 		return EVENT_DROPPED;
 

kernel/trace/trace.c

@@ -343,26 +343,27 @@ unsigned long trace_flags = TRACE_ITER_PRINT_PARENT | TRACE_ITER_PRINTK |
 static int trace_stop_count;
 static DEFINE_SPINLOCK(tracing_start_lock);
 
+static void wakeup_work_handler(struct work_struct *work)
+{
+	wake_up(&trace_wait);
+}
+
+static DECLARE_DELAYED_WORK(wakeup_work, wakeup_work_handler);
+
 /**
  * trace_wake_up - wake up tasks waiting for trace input
  *
- * Simply wakes up any task that is blocked on the trace_wait
- * queue. These is used with trace_poll for tasks polling the trace.
+ * Schedules a delayed work to wake up any task that is blocked on the
+ * trace_wait queue. These is used with trace_poll for tasks polling the
+ * trace.
  */
 void trace_wake_up(void)
 {
-	int cpu;
+	const unsigned long delay = msecs_to_jiffies(2);
 
 	if (trace_flags & TRACE_ITER_BLOCK)
 		return;
-	/*
-	 * The runqueue_is_locked() can fail, but this is the best we
-	 * have for now:
-	 */
-	cpu = get_cpu();
-	if (!runqueue_is_locked(cpu))
-		wake_up(&trace_wait);
-	put_cpu();
+	schedule_delayed_work(&wakeup_work, delay);
 }
 
 static int __init set_buf_size(char *str)
@@ -424,6 +425,7 @@ static const char *trace_options[] = {
 	"graph-time",
 	"record-cmd",
 	"overwrite",
+	"disable_on_free",
 	NULL
 };
 
@@ -1191,6 +1193,18 @@ void trace_nowake_buffer_unlock_commit(struct ring_buffer *buffer,
 }
 EXPORT_SYMBOL_GPL(trace_nowake_buffer_unlock_commit);
 
+void trace_nowake_buffer_unlock_commit_regs(struct ring_buffer *buffer,
+					    struct ring_buffer_event *event,
+					    unsigned long flags, int pc,
+					    struct pt_regs *regs)
+{
+	ring_buffer_unlock_commit(buffer, event);
+
+	ftrace_trace_stack_regs(buffer, flags, 0, pc, regs);
+	ftrace_trace_userstack(buffer, flags, pc);
+}
+EXPORT_SYMBOL_GPL(trace_nowake_buffer_unlock_commit_regs);
+
 void trace_current_buffer_discard_commit(struct ring_buffer *buffer,
 					 struct ring_buffer_event *event)
 {
@@ -1234,30 +1248,103 @@ ftrace(struct trace_array *tr, struct trace_array_cpu *data,
 }
 
 #ifdef CONFIG_STACKTRACE
+
+#define FTRACE_STACK_MAX_ENTRIES (PAGE_SIZE / sizeof(unsigned long))
+struct ftrace_stack {
+	unsigned long		calls[FTRACE_STACK_MAX_ENTRIES];
+};
+
+static DEFINE_PER_CPU(struct ftrace_stack, ftrace_stack);
+static DEFINE_PER_CPU(int, ftrace_stack_reserve);
+
 static void __ftrace_trace_stack(struct ring_buffer *buffer,
 				 unsigned long flags,
-				 int skip, int pc)
+				 int skip, int pc, struct pt_regs *regs)
 {
 	struct ftrace_event_call *call = &event_kernel_stack;
 	struct ring_buffer_event *event;
 	struct stack_entry *entry;
 	struct stack_trace trace;
-
-	event = trace_buffer_lock_reserve(buffer, TRACE_STACK,
-					  sizeof(*entry), flags, pc);
-	if (!event)
-		return;
-	entry	= ring_buffer_event_data(event);
-	memset(&entry->caller, 0, sizeof(entry->caller));
+	int use_stack;
+	int size = FTRACE_STACK_ENTRIES;
 
 	trace.nr_entries	= 0;
-	trace.max_entries	= FTRACE_STACK_ENTRIES;
 	trace.skip		= skip;
-	trace.entries		= entry->caller;
 
-	save_stack_trace(&trace);
+	/*
+	 * Since events can happen in NMIs there's no safe way to
+	 * use the per cpu ftrace_stacks. We reserve it and if an interrupt
+	 * or NMI comes in, it will just have to use the default
+	 * FTRACE_STACK_SIZE.
+	 */
+	preempt_disable_notrace();
+
+	use_stack = ++__get_cpu_var(ftrace_stack_reserve);
+	/*
+	 * We don't need any atomic variables, just a barrier.
+	 * If an interrupt comes in, we don't care, because it would
+	 * have exited and put the counter back to what we want.
+	 * We just need a barrier to keep gcc from moving things
+	 * around.
+	 */
+	barrier();
+	if (use_stack == 1) {
+		trace.entries		= &__get_cpu_var(ftrace_stack).calls[0];
+		trace.max_entries	= FTRACE_STACK_MAX_ENTRIES;
+
+		if (regs)
+			save_stack_trace_regs(regs, &trace);
+		else
+			save_stack_trace(&trace);
+
+		if (trace.nr_entries > size)
+			size = trace.nr_entries;
+	} else
+		/* From now on, use_stack is a boolean */
+		use_stack = 0;
+
+	size *= sizeof(unsigned long);
+
+	event = trace_buffer_lock_reserve(buffer, TRACE_STACK,
+					  sizeof(*entry) + size, flags, pc);
+	if (!event)
+		goto out;
+	entry = ring_buffer_event_data(event);
+
+	memset(&entry->caller, 0, size);
+
+	if (use_stack)
+		memcpy(&entry->caller, trace.entries,
+		       trace.nr_entries * sizeof(unsigned long));
+	else {
+		trace.max_entries	= FTRACE_STACK_ENTRIES;
+		trace.entries		= entry->caller;
+		if (regs)
+			save_stack_trace_regs(regs, &trace);
+		else
+			save_stack_trace(&trace);
+	}
+
+	entry->size = trace.nr_entries;
+
 	if (!filter_check_discard(call, entry, buffer, event))
 		ring_buffer_unlock_commit(buffer, event);
+
+ out:
+	/* Again, don't let gcc optimize things here */
+	barrier();
+	__get_cpu_var(ftrace_stack_reserve)--;
+	preempt_enable_notrace();
+
+}
+
+void ftrace_trace_stack_regs(struct ring_buffer *buffer, unsigned long flags,
+			     int skip, int pc, struct pt_regs *regs)
+{
+	if (!(trace_flags & TRACE_ITER_STACKTRACE))
+		return;
+
+	__ftrace_trace_stack(buffer, flags, skip, pc, regs);
 }
 
 void ftrace_trace_stack(struct ring_buffer *buffer, unsigned long flags,
@@ -1266,13 +1353,13 @@ void ftrace_trace_stack(struct ring_buffer *buffer, unsigned long flags,
 	if (!(trace_flags & TRACE_ITER_STACKTRACE))
 		return;
 
-	__ftrace_trace_stack(buffer, flags, skip, pc);
+	__ftrace_trace_stack(buffer, flags, skip, pc, NULL);
 }
 
 void __trace_stack(struct trace_array *tr, unsigned long flags, int skip,
 		   int pc)
 {
-	__ftrace_trace_stack(tr->buffer, flags, skip, pc);
+	__ftrace_trace_stack(tr->buffer, flags, skip, pc, NULL);
 }
 
 /**
@@ -1288,7 +1375,7 @@ void trace_dump_stack(void)
 	local_save_flags(flags);
 
 	/* skipping 3 traces, seems to get us at the caller of this function */
-	__ftrace_trace_stack(global_trace.buffer, flags, 3, preempt_count());
+	__ftrace_trace_stack(global_trace.buffer, flags, 3, preempt_count(), NULL);
 }
 
 static DEFINE_PER_CPU(int, user_stack_count);
@@ -1536,7 +1623,12 @@ peek_next_entry(struct trace_iterator *iter, int cpu, u64 *ts,
 
 	ftrace_enable_cpu();
 
-	return event ? ring_buffer_event_data(event) : NULL;
+	if (event) {
+		iter->ent_size = ring_buffer_event_length(event);
+		return ring_buffer_event_data(event);
+	}
+	iter->ent_size = 0;
+	return NULL;
 }
 
 static struct trace_entry *
@@ -2051,6 +2143,9 @@ void trace_default_header(struct seq_file *m)
 {
 	struct trace_iterator *iter = m->private;
 
+	if (!(trace_flags & TRACE_ITER_CONTEXT_INFO))
+		return;
+
 	if (iter->iter_flags & TRACE_FILE_LAT_FMT) {
 		/* print nothing if the buffers are empty */
 		if (trace_empty(iter))
@@ -2701,20 +2796,11 @@ tracing_ctrl_write(struct file *filp, const char __user *ubuf,
 		   size_t cnt, loff_t *ppos)
 {
 	struct trace_array *tr = filp->private_data;
-	char buf[64];
 	unsigned long val;
 	int ret;
 
-	if (cnt >= sizeof(buf))
-		return -EINVAL;
-
-	if (copy_from_user(&buf, ubuf, cnt))
-		return -EFAULT;
-
-	buf[cnt] = 0;
-
-	ret = strict_strtoul(buf, 10, &val);
-	if (ret < 0)
+	ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
+	if (ret)
 		return ret;
 
 	val = !!val;
@@ -2767,7 +2853,7 @@ int tracer_init(struct tracer *t, struct trace_array *tr)
 	return t->init(tr);
 }
 
-static int tracing_resize_ring_buffer(unsigned long size)
+static int __tracing_resize_ring_buffer(unsigned long size)
 {
 	int ret;
 
@@ -2819,6 +2905,41 @@ static int tracing_resize_ring_buffer(unsigned long size)
 	return ret;
 }
 
+static ssize_t tracing_resize_ring_buffer(unsigned long size)
+{
+	int cpu, ret = size;
+
+	mutex_lock(&trace_types_lock);
+
+	tracing_stop();
+
+	/* disable all cpu buffers */
+	for_each_tracing_cpu(cpu) {
+		if (global_trace.data[cpu])
+			atomic_inc(&global_trace.data[cpu]->disabled);
+		if (max_tr.data[cpu])
+			atomic_inc(&max_tr.data[cpu]->disabled);
+	}
+
+	if (size != global_trace.entries)
+		ret = __tracing_resize_ring_buffer(size);
+
+	if (ret < 0)
+		ret = -ENOMEM;
+
+	for_each_tracing_cpu(cpu) {
+		if (global_trace.data[cpu])
+			atomic_dec(&global_trace.data[cpu]->disabled);
+		if (max_tr.data[cpu])
+			atomic_dec(&max_tr.data[cpu]->disabled);
+	}
+
+	tracing_start();
+	mutex_unlock(&trace_types_lock);
+
+	return ret;
+}
+
 
 /**
  * tracing_update_buffers - used by tracing facility to expand ring buffers
@@ -2836,7 +2957,7 @@ int tracing_update_buffers(void)
 
 	mutex_lock(&trace_types_lock);
 	if (!ring_buffer_expanded)
-		ret = tracing_resize_ring_buffer(trace_buf_size);
+		ret = __tracing_resize_ring_buffer(trace_buf_size);
 	mutex_unlock(&trace_types_lock);
 
 	return ret;
@@ -2860,7 +2981,7 @@ static int tracing_set_tracer(const char *buf)
 	mutex_lock(&trace_types_lock);
 
 	if (!ring_buffer_expanded) {
-		ret = tracing_resize_ring_buffer(trace_buf_size);
+		ret = __tracing_resize_ring_buffer(trace_buf_size);
 		if (ret < 0)
 			goto out;
 		ret = 0;
@@ -2966,20 +3087,11 @@ tracing_max_lat_write(struct file *filp, const char __user *ubuf,
 		      size_t cnt, loff_t *ppos)
 {
 	unsigned long *ptr = filp->private_data;
-	char buf[64];
 	unsigned long val;
 	int ret;
 
-	if (cnt >= sizeof(buf))
-		return -EINVAL;
-
-	if (copy_from_user(&buf, ubuf, cnt))
-		return -EFAULT;
-
-	buf[cnt] = 0;
-
-	ret = strict_strtoul(buf, 10, &val);
-	if (ret < 0)
+	ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
+	if (ret)
 		return ret;
 
 	*ptr = val * 1000;
@@ -3434,67 +3546,54 @@ tracing_entries_write(struct file *filp, const char __user *ubuf,
 		      size_t cnt, loff_t *ppos)
 {
 	unsigned long val;
-	char buf[64];
-	int ret, cpu;
+	int ret;
 
-	if (cnt >= sizeof(buf))
-		return -EINVAL;
-
-	if (copy_from_user(&buf, ubuf, cnt))
-		return -EFAULT;
-
-	buf[cnt] = 0;
-
-	ret = strict_strtoul(buf, 10, &val);
-	if (ret < 0)
+	ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
+	if (ret)
 		return ret;
 
 	/* must have at least 1 entry */
 	if (!val)
 		return -EINVAL;
 
-	mutex_lock(&trace_types_lock);
-
-	tracing_stop();
-
-	/* disable all cpu buffers */
-	for_each_tracing_cpu(cpu) {
-		if (global_trace.data[cpu])
-			atomic_inc(&global_trace.data[cpu]->disabled);
-		if (max_tr.data[cpu])
-			atomic_inc(&max_tr.data[cpu]->disabled);
-	}
-
 	/* value is in KB */
 	val <<= 10;
 
-	if (val != global_trace.entries) {
-		ret = tracing_resize_ring_buffer(val);
-		if (ret < 0) {
-			cnt = ret;
-			goto out;
-		}
-	}
+	ret = tracing_resize_ring_buffer(val);
+	if (ret < 0)
+		return ret;
 
 	*ppos += cnt;
 
-	/* If check pages failed, return ENOMEM */
-	if (tracing_disabled)
-		cnt = -ENOMEM;
- out:
-	for_each_tracing_cpu(cpu) {
-		if (global_trace.data[cpu])
-			atomic_dec(&global_trace.data[cpu]->disabled);
-		if (max_tr.data[cpu])
-			atomic_dec(&max_tr.data[cpu]->disabled);
-	}
+	return cnt;
+}
 
-	tracing_start();
-	mutex_unlock(&trace_types_lock);
+static ssize_t
+tracing_free_buffer_write(struct file *filp, const char __user *ubuf,
+			  size_t cnt, loff_t *ppos)
+{
+	/*
+	 * There is no need to read what the user has written, this function
+	 * is just to make sure that there is no error when "echo" is used
+	 */
+
+	*ppos += cnt;
 
 	return cnt;
 }
 
+static int
+tracing_free_buffer_release(struct inode *inode, struct file *filp)
+{
+	/* disable tracing ? */
+	if (trace_flags & TRACE_ITER_STOP_ON_FREE)
+		tracing_off();
+	/* resize the ring buffer to 0 */
+	tracing_resize_ring_buffer(0);
+
+	return 0;
+}
+
 static int mark_printk(const char *fmt, ...)
 {
 	int ret;
@@ -3640,6 +3739,11 @@ static const struct file_operations tracing_entries_fops = {
 	.llseek		= generic_file_llseek,
 };
 
+static const struct file_operations tracing_free_buffer_fops = {
+	.write		= tracing_free_buffer_write,
+	.release	= tracing_free_buffer_release,
+};
+
 static const struct file_operations tracing_mark_fops = {
 	.open		= tracing_open_generic,
 	.write		= tracing_mark_write,
@@ -3696,7 +3800,7 @@ tracing_buffers_read(struct file *filp, char __user *ubuf,
 		return 0;
 
 	if (!info->spare)
-		info->spare = ring_buffer_alloc_read_page(info->tr->buffer);
+		info->spare = ring_buffer_alloc_read_page(info->tr->buffer, info->cpu);
 	if (!info->spare)
 		return -ENOMEM;
 
@@ -3853,7 +3957,7 @@ tracing_buffers_splice_read(struct file *file, loff_t *ppos,
 
 		ref->ref = 1;
 		ref->buffer = info->tr->buffer;
-		ref->page = ring_buffer_alloc_read_page(ref->buffer);
+		ref->page = ring_buffer_alloc_read_page(ref->buffer, info->cpu);
 		if (!ref->page) {
 			kfree(ref);
 			break;
@@ -3862,8 +3966,7 @@ tracing_buffers_splice_read(struct file *file, loff_t *ppos,
 		r = ring_buffer_read_page(ref->buffer, &ref->page,
 					  len, info->cpu, 1);
 		if (r < 0) {
-			ring_buffer_free_read_page(ref->buffer,
-						   ref->page);
+			ring_buffer_free_read_page(ref->buffer, ref->page);
 			kfree(ref);
 			break;
 		}
@@ -4099,19 +4202,10 @@ trace_options_write(struct file *filp, const char __user *ubuf, size_t cnt,
 {
 	struct trace_option_dentry *topt = filp->private_data;
 	unsigned long val;
-	char buf[64];
 	int ret;
 
-	if (cnt >= sizeof(buf))
-		return -EINVAL;
-
-	if (copy_from_user(&buf, ubuf, cnt))
-		return -EFAULT;
-
-	buf[cnt] = 0;
-
-	ret = strict_strtoul(buf, 10, &val);
-	if (ret < 0)
+	ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
+	if (ret)
 		return ret;
 
 	if (val != 0 && val != 1)
@@ -4159,20 +4253,11 @@ trace_options_core_write(struct file *filp, const char __user *ubuf, size_t cnt,
 			 loff_t *ppos)
 {
 	long index = (long)filp->private_data;
-	char buf[64];
 	unsigned long val;
 	int ret;
 
-	if (cnt >= sizeof(buf))
-		return -EINVAL;
-
-	if (copy_from_user(&buf, ubuf, cnt))
-		return -EFAULT;
-
-	buf[cnt] = 0;
-
-	ret = strict_strtoul(buf, 10, &val);
-	if (ret < 0)
+	ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
+	if (ret)
 		return ret;
 
 	if (val != 0 && val != 1)
@@ -4365,6 +4450,9 @@ static __init int tracer_init_debugfs(void)
 	trace_create_file("buffer_size_kb", 0644, d_tracer,
 			&global_trace, &tracing_entries_fops);
 
+	trace_create_file("free_buffer", 0644, d_tracer,
+			&global_trace, &tracing_free_buffer_fops);
+
 	trace_create_file("trace_marker", 0220, d_tracer,
 			NULL, &tracing_mark_fops);
 

kernel/trace/trace.h

@@ -278,6 +278,29 @@ struct tracer {
 };
 
 
+/* Only current can touch trace_recursion */
+#define trace_recursion_inc() do { (current)->trace_recursion++; } while (0)
+#define trace_recursion_dec() do { (current)->trace_recursion--; } while (0)
+
+/* Ring buffer has the 10 LSB bits to count */
+#define trace_recursion_buffer() ((current)->trace_recursion & 0x3ff)
+
+/* for function tracing recursion */
+#define TRACE_INTERNAL_BIT		(1<<11)
+#define TRACE_GLOBAL_BIT		(1<<12)
+/*
+ * Abuse of the trace_recursion.
+ * As we need a way to maintain state if we are tracing the function
+ * graph in irq because we want to trace a particular function that
+ * was called in irq context but we have irq tracing off. Since this
+ * can only be modified by current, we can reuse trace_recursion.
+ */
+#define TRACE_IRQ_BIT			(1<<13)
+
+#define trace_recursion_set(bit)	do { (current)->trace_recursion |= (bit); } while (0)
+#define trace_recursion_clear(bit)	do { (current)->trace_recursion &= ~(bit); } while (0)
+#define trace_recursion_test(bit)	((current)->trace_recursion & (bit))
+
 #define TRACE_PIPE_ALL_CPU	-1
 
 int tracer_init(struct tracer *t, struct trace_array *tr);
@@ -389,6 +412,9 @@ void update_max_tr_single(struct trace_array *tr,
 void ftrace_trace_stack(struct ring_buffer *buffer, unsigned long flags,
 			int skip, int pc);
 
+void ftrace_trace_stack_regs(struct ring_buffer *buffer, unsigned long flags,
+			     int skip, int pc, struct pt_regs *regs);
+
 void ftrace_trace_userstack(struct ring_buffer *buffer, unsigned long flags,
 			    int pc);
 
@@ -400,6 +426,12 @@ static inline void ftrace_trace_stack(struct ring_buffer *buffer,
 {
 }
 
+static inline void ftrace_trace_stack_regs(struct ring_buffer *buffer,
+					   unsigned long flags, int skip,
+					   int pc, struct pt_regs *regs)
+{
+}
+
 static inline void ftrace_trace_userstack(struct ring_buffer *buffer,
 					  unsigned long flags, int pc)
 {
@@ -507,8 +539,18 @@ static inline int ftrace_graph_addr(unsigned long addr)
 		return 1;
 
 	for (i = 0; i < ftrace_graph_count; i++) {
-		if (addr == ftrace_graph_funcs[i])
+		if (addr == ftrace_graph_funcs[i]) {
+			/*
+			 * If no irqs are to be traced, but a set_graph_function
+			 * is set, and called by an interrupt handler, we still
+			 * want to trace it.
+			 */
+			if (in_irq())
+				trace_recursion_set(TRACE_IRQ_BIT);
+			else
+				trace_recursion_clear(TRACE_IRQ_BIT);
 			return 1;
+		}
 	}
 
 	return 0;
@@ -609,6 +651,7 @@ enum trace_iterator_flags {
 	TRACE_ITER_GRAPH_TIME		= 0x80000,
 	TRACE_ITER_RECORD_CMD		= 0x100000,
 	TRACE_ITER_OVERWRITE		= 0x200000,
+	TRACE_ITER_STOP_ON_FREE		= 0x400000,
 };
 
 /*
@@ -677,6 +720,7 @@ struct event_subsystem {
 	struct dentry		*entry;
 	struct event_filter	*filter;
 	int			nr_events;
+	int			ref_count;
 };
 
 #define FILTER_PRED_INVALID	((unsigned short)-1)
@@ -784,19 +828,4 @@ extern const char *__stop___trace_bprintk_fmt[];
 	FTRACE_ENTRY(call, struct_name, id, PARAMS(tstruct), PARAMS(print))
 #include "trace_entries.h"
 
-/* Only current can touch trace_recursion */
-#define trace_recursion_inc() do { (current)->trace_recursion++; } while (0)
-#define trace_recursion_dec() do { (current)->trace_recursion--; } while (0)
-
-/* Ring buffer has the 10 LSB bits to count */
-#define trace_recursion_buffer() ((current)->trace_recursion & 0x3ff)
-
-/* for function tracing recursion */
-#define TRACE_INTERNAL_BIT		(1<<11)
-#define TRACE_GLOBAL_BIT		(1<<12)
-
-#define trace_recursion_set(bit)	do { (current)->trace_recursion |= (bit); } while (0)
-#define trace_recursion_clear(bit)	do { (current)->trace_recursion &= ~(bit); } while (0)
-#define trace_recursion_test(bit)	((current)->trace_recursion & (bit))
-
 #endif /* _LINUX_KERNEL_TRACE_H */

kernel/trace/trace_entries.h

@@ -161,7 +161,8 @@ FTRACE_ENTRY(kernel_stack, stack_entry,
 	TRACE_STACK,
 
 	F_STRUCT(
-		__array(	unsigned long,	caller, FTRACE_STACK_ENTRIES	)
+		__field(	int,		size	)
+		__dynamic_array(unsigned long,	caller	)
 	),
 
 	F_printk("\t=> (%08lx)\n\t=> (%08lx)\n\t=> (%08lx)\n\t=> (%08lx)\n"

kernel/trace/trace_events.c

@@ -244,6 +244,35 @@ static void ftrace_clear_events(void)
 	mutex_unlock(&event_mutex);
 }
 
+static void __put_system(struct event_subsystem *system)
+{
+	struct event_filter *filter = system->filter;
+
+	WARN_ON_ONCE(system->ref_count == 0);
+	if (--system->ref_count)
+		return;
+
+	if (filter) {
+		kfree(filter->filter_string);
+		kfree(filter);
+	}
+	kfree(system->name);
+	kfree(system);
+}
+
+static void __get_system(struct event_subsystem *system)
+{
+	WARN_ON_ONCE(system->ref_count == 0);
+	system->ref_count++;
+}
+
+static void put_system(struct event_subsystem *system)
+{
+	mutex_lock(&event_mutex);
+	__put_system(system);
+	mutex_unlock(&event_mutex);
+}
+
 /*
  * __ftrace_set_clr_event(NULL, NULL, NULL, set) will set/unset all events.
  */
@@ -486,20 +515,11 @@ event_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
 		   loff_t *ppos)
 {
 	struct ftrace_event_call *call = filp->private_data;
-	char buf[64];
 	unsigned long val;
 	int ret;
 
-	if (cnt >= sizeof(buf))
-		return -EINVAL;
-
-	if (copy_from_user(&buf, ubuf, cnt))
-		return -EFAULT;
-
-	buf[cnt] = 0;
-
-	ret = strict_strtoul(buf, 10, &val);
-	if (ret < 0)
+	ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
+	if (ret)
 		return ret;
 
 	ret = tracing_update_buffers();
@@ -528,7 +548,7 @@ system_enable_read(struct file *filp, char __user *ubuf, size_t cnt,
 		   loff_t *ppos)
 {
 	const char set_to_char[4] = { '?', '0', '1', 'X' };
-	const char *system = filp->private_data;
+	struct event_subsystem *system = filp->private_data;
 	struct ftrace_event_call *call;
 	char buf[2];
 	int set = 0;
@@ -539,7 +559,7 @@ system_enable_read(struct file *filp, char __user *ubuf, size_t cnt,
 		if (!call->name || !call->class || !call->class->reg)
 			continue;
 
-		if (system && strcmp(call->class->system, system) != 0)
+		if (system && strcmp(call->class->system, system->name) != 0)
 			continue;
 
 		/*
@@ -569,21 +589,13 @@ static ssize_t
 system_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
 		    loff_t *ppos)
 {
-	const char *system = filp->private_data;
+	struct event_subsystem *system = filp->private_data;
+	const char *name = NULL;
 	unsigned long val;
-	char buf[64];
 	ssize_t ret;
 
-	if (cnt >= sizeof(buf))
-		return -EINVAL;
-
-	if (copy_from_user(&buf, ubuf, cnt))
-		return -EFAULT;
-
-	buf[cnt] = 0;
-
-	ret = strict_strtoul(buf, 10, &val);
-	if (ret < 0)
+	ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
+	if (ret)
 		return ret;
 
 	ret = tracing_update_buffers();
@@ -593,7 +605,14 @@ system_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
 	if (val != 0 && val != 1)
 		return -EINVAL;
 
-	ret = __ftrace_set_clr_event(NULL, system, NULL, val);
+	/*
+	 * Opening of "enable" adds a ref count to system,
+	 * so the name is safe to use.
+	 */
+	if (system)
+		name = system->name;
+
+	ret = __ftrace_set_clr_event(NULL, name, NULL, val);
 	if (ret)
 		goto out;
 
@@ -826,6 +845,52 @@ event_filter_write(struct file *filp, const char __user *ubuf, size_t cnt,
 	return cnt;
 }
 
+static LIST_HEAD(event_subsystems);
+
+static int subsystem_open(struct inode *inode, struct file *filp)
+{
+	struct event_subsystem *system = NULL;
+	int ret;
+
+	if (!inode->i_private)
+		goto skip_search;
+
+	/* Make sure the system still exists */
+	mutex_lock(&event_mutex);
+	list_for_each_entry(system, &event_subsystems, list) {
+		if (system == inode->i_private) {
+			/* Don't open systems with no events */
+			if (!system->nr_events) {
+				system = NULL;
+				break;
+			}
+			__get_system(system);
+			break;
+		}
+	}
+	mutex_unlock(&event_mutex);
+
+	if (system != inode->i_private)
+		return -ENODEV;
+
+ skip_search:
+	ret = tracing_open_generic(inode, filp);
+	if (ret < 0 && system)
+		put_system(system);
+
+	return ret;
+}
+
+static int subsystem_release(struct inode *inode, struct file *file)
+{
+	struct event_subsystem *system = inode->i_private;
+
+	if (system)
+		put_system(system);
+
+	return 0;
+}
+
 static ssize_t
 subsystem_filter_read(struct file *filp, char __user *ubuf, size_t cnt,
 		      loff_t *ppos)
@@ -963,17 +1028,19 @@ static const struct file_operations ftrace_event_filter_fops = {
 };
 
 static const struct file_operations ftrace_subsystem_filter_fops = {
-	.open = tracing_open_generic,
+	.open = subsystem_open,
 	.read = subsystem_filter_read,
 	.write = subsystem_filter_write,
 	.llseek = default_llseek,
+	.release = subsystem_release,
 };
 
 static const struct file_operations ftrace_system_enable_fops = {
-	.open = tracing_open_generic,
+	.open = subsystem_open,
 	.read = system_enable_read,
 	.write = system_enable_write,
 	.llseek = default_llseek,
+	.release = subsystem_release,
 };
 
 static const struct file_operations ftrace_show_header_fops = {
@@ -1002,8 +1069,6 @@ static struct dentry *event_trace_events_dir(void)
 	return d_events;
 }
 
-static LIST_HEAD(event_subsystems);
-
 static struct dentry *
 event_subsystem_dir(const char *name, struct dentry *d_events)
 {
@@ -1013,6 +1078,7 @@ event_subsystem_dir(const char *name, struct dentry *d_events)
 	/* First see if we did not already create this dir */
 	list_for_each_entry(system, &event_subsystems, list) {
 		if (strcmp(system->name, name) == 0) {
+			__get_system(system);
 			system->nr_events++;
 			return system->entry;
 		}
@@ -1035,6 +1101,7 @@ event_subsystem_dir(const char *name, struct dentry *d_events)
 	}
 
 	system->nr_events = 1;
+	system->ref_count = 1;
 	system->name = kstrdup(name, GFP_KERNEL);
 	if (!system->name) {
 		debugfs_remove(system->entry);
@@ -1062,8 +1129,7 @@ event_subsystem_dir(const char *name, struct dentry *d_events)
 			   "'%s/filter' entry\n", name);
 	}
 
-	trace_create_file("enable", 0644, system->entry,
-			  (void *)system->name,
+	trace_create_file("enable", 0644, system->entry, system,
 			  &ftrace_system_enable_fops);
 
 	return system->entry;
@@ -1184,16 +1250,9 @@ static void remove_subsystem_dir(const char *name)
 	list_for_each_entry(system, &event_subsystems, list) {
 		if (strcmp(system->name, name) == 0) {
 			if (!--system->nr_events) {
-				struct event_filter *filter = system->filter;
-
 				debugfs_remove_recursive(system->entry);
 				list_del(&system->list);
-				if (filter) {
-					kfree(filter->filter_string);
-					kfree(filter);
-				}
-				kfree(system->name);
-				kfree(system);
+				__put_system(system);
 			}
 			break;
 		}

kernel/trace/trace_events_filter.c

@@ -1886,6 +1886,12 @@ int apply_subsystem_event_filter(struct event_subsystem *system,
 
 	mutex_lock(&event_mutex);
 
+	/* Make sure the system still has events */
+	if (!system->nr_events) {
+		err = -ENODEV;
+		goto out_unlock;
+	}
+
 	if (!strcmp(strstrip(filter_string), "0")) {
 		filter_free_subsystem_preds(system);
 		remove_filter_string(system->filter);

kernel/trace/trace_functions.c

@@ -324,7 +324,8 @@ ftrace_trace_onoff_unreg(char *glob, char *cmd, char *param)
 }
 
 static int
-ftrace_trace_onoff_callback(char *glob, char *cmd, char *param, int enable)
+ftrace_trace_onoff_callback(struct ftrace_hash *hash,
+			    char *glob, char *cmd, char *param, int enable)
 {
 	struct ftrace_probe_ops *ops;
 	void *count = (void *)-1;

kernel/trace/trace_functions_graph.c

@@ -74,6 +74,20 @@ static struct tracer_flags tracer_flags = {
 
 static struct trace_array *graph_array;
 
+/*
+ * DURATION column is being also used to display IRQ signs,
+ * following values are used by print_graph_irq and others
+ * to fill in space into DURATION column.
+ */
+enum {
+	DURATION_FILL_FULL  = -1,
+	DURATION_FILL_START = -2,
+	DURATION_FILL_END   = -3,
+};
+
+static enum print_line_t
+print_graph_duration(unsigned long long duration, struct trace_seq *s,
+		     u32 flags);
 
 /* Add a function return address to the trace stack on thread info.*/
 int
@@ -213,7 +227,7 @@ int __trace_graph_entry(struct trace_array *tr,
 
 static inline int ftrace_graph_ignore_irqs(void)
 {
-	if (!ftrace_graph_skip_irqs)
+	if (!ftrace_graph_skip_irqs || trace_recursion_test(TRACE_IRQ_BIT))
 		return 0;
 
 	return in_irq();
@@ -577,32 +591,6 @@ get_return_for_leaf(struct trace_iterator *iter,
 	return next;
 }
 
-/* Signal a overhead of time execution to the output */
-static int
-print_graph_overhead(unsigned long long duration, struct trace_seq *s,
-		     u32 flags)
-{
-	/* If duration disappear, we don't need anything */
-	if (!(flags & TRACE_GRAPH_PRINT_DURATION))
-		return 1;
-
-	/* Non nested entry or return */
-	if (duration == -1)
-		return trace_seq_printf(s, "  ");
-
-	if (flags & TRACE_GRAPH_PRINT_OVERHEAD) {
-		/* Duration exceeded 100 msecs */
-		if (duration > 100000ULL)
-			return trace_seq_printf(s, "! ");
-
-		/* Duration exceeded 10 msecs */
-		if (duration > 10000ULL)
-			return trace_seq_printf(s, "+ ");
-	}
-
-	return trace_seq_printf(s, "  ");
-}
-
 static int print_graph_abs_time(u64 t, struct trace_seq *s)
 {
 	unsigned long usecs_rem;
@@ -625,34 +613,36 @@ print_graph_irq(struct trace_iterator *iter, unsigned long addr,
 		addr >= (unsigned long)__irqentry_text_end)
 		return TRACE_TYPE_UNHANDLED;
 
-	/* Absolute time */
-	if (flags & TRACE_GRAPH_PRINT_ABS_TIME) {
-		ret = print_graph_abs_time(iter->ts, s);
-		if (!ret)
-			return TRACE_TYPE_PARTIAL_LINE;
-	}
+	if (trace_flags & TRACE_ITER_CONTEXT_INFO) {
+		/* Absolute time */
+		if (flags & TRACE_GRAPH_PRINT_ABS_TIME) {
+			ret = print_graph_abs_time(iter->ts, s);
+			if (!ret)
+				return TRACE_TYPE_PARTIAL_LINE;
+		}
 
-	/* Cpu */
-	if (flags & TRACE_GRAPH_PRINT_CPU) {
-		ret = print_graph_cpu(s, cpu);
-		if (ret == TRACE_TYPE_PARTIAL_LINE)
-			return TRACE_TYPE_PARTIAL_LINE;
-	}
+		/* Cpu */
+		if (flags & TRACE_GRAPH_PRINT_CPU) {
+			ret = print_graph_cpu(s, cpu);
+			if (ret == TRACE_TYPE_PARTIAL_LINE)
+				return TRACE_TYPE_PARTIAL_LINE;
+		}
 
-	/* Proc */
-	if (flags & TRACE_GRAPH_PRINT_PROC) {
-		ret = print_graph_proc(s, pid);
-		if (ret == TRACE_TYPE_PARTIAL_LINE)
-			return TRACE_TYPE_PARTIAL_LINE;
-		ret = trace_seq_printf(s, " | ");
-		if (!ret)
-			return TRACE_TYPE_PARTIAL_LINE;
+		/* Proc */
+		if (flags & TRACE_GRAPH_PRINT_PROC) {
+			ret = print_graph_proc(s, pid);
+			if (ret == TRACE_TYPE_PARTIAL_LINE)
+				return TRACE_TYPE_PARTIAL_LINE;
+			ret = trace_seq_printf(s, " | ");
+			if (!ret)
+				return TRACE_TYPE_PARTIAL_LINE;
+		}
 	}
 
 	/* No overhead */
-	ret = print_graph_overhead(-1, s, flags);
-	if (!ret)
-		return TRACE_TYPE_PARTIAL_LINE;
+	ret = print_graph_duration(DURATION_FILL_START, s, flags);
+	if (ret != TRACE_TYPE_HANDLED)
+		return ret;
 
 	if (type == TRACE_GRAPH_ENT)
 		ret = trace_seq_printf(s, "==========>");
@@ -662,9 +652,10 @@ print_graph_irq(struct trace_iterator *iter, unsigned long addr,
 	if (!ret)
 		return TRACE_TYPE_PARTIAL_LINE;
 
-	/* Don't close the duration column if haven't one */
-	if (flags & TRACE_GRAPH_PRINT_DURATION)
-		trace_seq_printf(s, " |");
+	ret = print_graph_duration(DURATION_FILL_END, s, flags);
+	if (ret != TRACE_TYPE_HANDLED)
+		return ret;
+
 	ret = trace_seq_printf(s, "\n");
 
 	if (!ret)
@@ -716,9 +707,49 @@ trace_print_graph_duration(unsigned long long duration, struct trace_seq *s)
 }
 
 static enum print_line_t
-print_graph_duration(unsigned long long duration, struct trace_seq *s)
+print_graph_duration(unsigned long long duration, struct trace_seq *s,
+		     u32 flags)
 {
-	int ret;
+	int ret = -1;
+
+	if (!(flags & TRACE_GRAPH_PRINT_DURATION) ||
+	    !(trace_flags & TRACE_ITER_CONTEXT_INFO))
+			return TRACE_TYPE_HANDLED;
+
+	/* No real adata, just filling the column with spaces */
+	switch (duration) {
+	case DURATION_FILL_FULL:
+		ret = trace_seq_printf(s, "              |  ");
+		return ret ? TRACE_TYPE_HANDLED : TRACE_TYPE_PARTIAL_LINE;
+	case DURATION_FILL_START:
+		ret = trace_seq_printf(s, "  ");
+		return ret ? TRACE_TYPE_HANDLED : TRACE_TYPE_PARTIAL_LINE;
+	case DURATION_FILL_END:
+		ret = trace_seq_printf(s, " |");
+		return ret ? TRACE_TYPE_HANDLED : TRACE_TYPE_PARTIAL_LINE;
+	}
+
+	/* Signal a overhead of time execution to the output */
+	if (flags & TRACE_GRAPH_PRINT_OVERHEAD) {
+		/* Duration exceeded 100 msecs */
+		if (duration > 100000ULL)
+			ret = trace_seq_printf(s, "! ");
+		/* Duration exceeded 10 msecs */
+		else if (duration > 10000ULL)
+			ret = trace_seq_printf(s, "+ ");
+	}
+
+	/*
+	 * The -1 means we either did not exceed the duration tresholds
+	 * or we dont want to print out the overhead. Either way we need
+	 * to fill out the space.
+	 */
+	if (ret == -1)
+		ret = trace_seq_printf(s, "  ");
+
+	/* Catching here any failure happenned above */
+	if (!ret)
+		return TRACE_TYPE_PARTIAL_LINE;
 
 	ret = trace_print_graph_duration(duration, s);
 	if (ret != TRACE_TYPE_HANDLED)
@@ -767,18 +798,11 @@ print_graph_entry_leaf(struct trace_iterator *iter,
 			cpu_data->enter_funcs[call->depth] = 0;
 	}
 
-	/* Overhead */
-	ret = print_graph_overhead(duration, s, flags);
-	if (!ret)
+	/* Overhead and duration */
+	ret = print_graph_duration(duration, s, flags);
+	if (ret == TRACE_TYPE_PARTIAL_LINE)
 		return TRACE_TYPE_PARTIAL_LINE;
 
-	/* Duration */
-	if (flags & TRACE_GRAPH_PRINT_DURATION) {
-		ret = print_graph_duration(duration, s);
-		if (ret == TRACE_TYPE_PARTIAL_LINE)
-			return TRACE_TYPE_PARTIAL_LINE;
-	}
-
 	/* Function */
 	for (i = 0; i < call->depth * TRACE_GRAPH_INDENT; i++) {
 		ret = trace_seq_printf(s, " ");
@@ -815,17 +839,10 @@ print_graph_entry_nested(struct trace_iterator *iter,
 			cpu_data->enter_funcs[call->depth] = call->func;
 	}
 
-	/* No overhead */
-	ret = print_graph_overhead(-1, s, flags);
-	if (!ret)
-		return TRACE_TYPE_PARTIAL_LINE;
-
 	/* No time */
-	if (flags & TRACE_GRAPH_PRINT_DURATION) {
-		ret = trace_seq_printf(s, "            |  ");
-		if (!ret)
-			return TRACE_TYPE_PARTIAL_LINE;
-	}
+	ret = print_graph_duration(DURATION_FILL_FULL, s, flags);
+	if (ret != TRACE_TYPE_HANDLED)
+		return ret;
 
 	/* Function */
 	for (i = 0; i < call->depth * TRACE_GRAPH_INDENT; i++) {
@@ -865,6 +882,9 @@ print_graph_prologue(struct trace_iterator *iter, struct trace_seq *s,
 			return TRACE_TYPE_PARTIAL_LINE;
 	}
 
+	if (!(trace_flags & TRACE_ITER_CONTEXT_INFO))
+		return 0;
+
 	/* Absolute time */
 	if (flags & TRACE_GRAPH_PRINT_ABS_TIME) {
 		ret = print_graph_abs_time(iter->ts, s);
@@ -1078,18 +1098,11 @@ print_graph_return(struct ftrace_graph_ret *trace, struct trace_seq *s,
 	if (print_graph_prologue(iter, s, 0, 0, flags))
 		return TRACE_TYPE_PARTIAL_LINE;
 
-	/* Overhead */
-	ret = print_graph_overhead(duration, s, flags);
-	if (!ret)
+	/* Overhead and duration */
+	ret = print_graph_duration(duration, s, flags);
+	if (ret == TRACE_TYPE_PARTIAL_LINE)
 		return TRACE_TYPE_PARTIAL_LINE;
 
-	/* Duration */
-	if (flags & TRACE_GRAPH_PRINT_DURATION) {
-		ret = print_graph_duration(duration, s);
-		if (ret == TRACE_TYPE_PARTIAL_LINE)
-			return TRACE_TYPE_PARTIAL_LINE;
-	}
-
 	/* Closing brace */
 	for (i = 0; i < trace->depth * TRACE_GRAPH_INDENT; i++) {
 		ret = trace_seq_printf(s, " ");
@@ -1146,17 +1159,10 @@ print_graph_comment(struct trace_seq *s, struct trace_entry *ent,
 	if (print_graph_prologue(iter, s, 0, 0, flags))
 		return TRACE_TYPE_PARTIAL_LINE;
 
-	/* No overhead */
-	ret = print_graph_overhead(-1, s, flags);
-	if (!ret)
-		return TRACE_TYPE_PARTIAL_LINE;
-
 	/* No time */
-	if (flags & TRACE_GRAPH_PRINT_DURATION) {
-		ret = trace_seq_printf(s, "            |  ");
-		if (!ret)
-			return TRACE_TYPE_PARTIAL_LINE;
-	}
+	ret = print_graph_duration(DURATION_FILL_FULL, s, flags);
+	if (ret != TRACE_TYPE_HANDLED)
+		return ret;
 
 	/* Indentation */
 	if (depth > 0)
@@ -1207,7 +1213,7 @@ print_graph_comment(struct trace_seq *s, struct trace_entry *ent,
 
 
 enum print_line_t
-__print_graph_function_flags(struct trace_iterator *iter, u32 flags)
+print_graph_function_flags(struct trace_iterator *iter, u32 flags)
 {
 	struct ftrace_graph_ent_entry *field;
 	struct fgraph_data *data = iter->private;
@@ -1270,18 +1276,7 @@ __print_graph_function_flags(struct trace_iterator *iter, u32 flags)
 static enum print_line_t
 print_graph_function(struct trace_iterator *iter)
 {
-	return __print_graph_function_flags(iter, tracer_flags.val);
-}
-
-enum print_line_t print_graph_function_flags(struct trace_iterator *iter,
-					     u32 flags)
-{
-	if (trace_flags & TRACE_ITER_LATENCY_FMT)
-		flags |= TRACE_GRAPH_PRINT_DURATION;
-	else
-		flags |= TRACE_GRAPH_PRINT_ABS_TIME;
-
-	return __print_graph_function_flags(iter, flags);
+	return print_graph_function_flags(iter, tracer_flags.val);
 }
 
 static enum print_line_t
@@ -1309,8 +1304,7 @@ static void print_lat_header(struct seq_file *s, u32 flags)
 	seq_printf(s, "#%.*s / _----=> need-resched    \n", size, spaces);
 	seq_printf(s, "#%.*s| / _---=> hardirq/softirq \n", size, spaces);
 	seq_printf(s, "#%.*s|| / _--=> preempt-depth   \n", size, spaces);
-	seq_printf(s, "#%.*s||| / _-=> lock-depth      \n", size, spaces);
-	seq_printf(s, "#%.*s|||| /                     \n", size, spaces);
+	seq_printf(s, "#%.*s||| /                      \n", size, spaces);
 }
 
 static void __print_graph_headers_flags(struct seq_file *s, u32 flags)
@@ -1329,7 +1323,7 @@ static void __print_graph_headers_flags(struct seq_file *s, u32 flags)
 	if (flags & TRACE_GRAPH_PRINT_PROC)
 		seq_printf(s, "  TASK/PID       ");
 	if (lat)
-		seq_printf(s, "|||||");
+		seq_printf(s, "||||");
 	if (flags & TRACE_GRAPH_PRINT_DURATION)
 		seq_printf(s, "  DURATION   ");
 	seq_printf(s, "               FUNCTION CALLS\n");
@@ -1343,7 +1337,7 @@ static void __print_graph_headers_flags(struct seq_file *s, u32 flags)
 	if (flags & TRACE_GRAPH_PRINT_PROC)
 		seq_printf(s, "   |    |        ");
 	if (lat)
-		seq_printf(s, "|||||");
+		seq_printf(s, "||||");
 	if (flags & TRACE_GRAPH_PRINT_DURATION)
 		seq_printf(s, "   |   |      ");
 	seq_printf(s, "               |   |   |   |\n");
@@ -1358,15 +1352,16 @@ void print_graph_headers_flags(struct seq_file *s, u32 flags)
 {
 	struct trace_iterator *iter = s->private;
 
+	if (!(trace_flags & TRACE_ITER_CONTEXT_INFO))
+		return;
+
 	if (trace_flags & TRACE_ITER_LATENCY_FMT) {
 		/* print nothing if the buffers are empty */
 		if (trace_empty(iter))
 			return;
 
 		print_trace_header(s, iter);
-		flags |= TRACE_GRAPH_PRINT_DURATION;
-	} else
-		flags |= TRACE_GRAPH_PRINT_ABS_TIME;
+	}
 
 	__print_graph_headers_flags(s, flags);
 }

kernel/trace/trace_irqsoff.c

@@ -226,7 +226,9 @@ static void irqsoff_trace_close(struct trace_iterator *iter)
 }
 
 #define GRAPH_TRACER_FLAGS (TRACE_GRAPH_PRINT_CPU | \
-			    TRACE_GRAPH_PRINT_PROC)
+			    TRACE_GRAPH_PRINT_PROC | \
+			    TRACE_GRAPH_PRINT_ABS_TIME | \
+			    TRACE_GRAPH_PRINT_DURATION)
 
 static enum print_line_t irqsoff_print_line(struct trace_iterator *iter)
 {

kernel/trace/trace_kprobe.c

@@ -343,6 +343,14 @@ DEFINE_BASIC_FETCH_FUNCS(deref)
 DEFINE_FETCH_deref(string)
 DEFINE_FETCH_deref(string_size)
 
+static __kprobes void update_deref_fetch_param(struct deref_fetch_param *data)
+{
+	if (CHECK_FETCH_FUNCS(deref, data->orig.fn))
+		update_deref_fetch_param(data->orig.data);
+	else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn))
+		update_symbol_cache(data->orig.data);
+}
+
 static __kprobes void free_deref_fetch_param(struct deref_fetch_param *data)
 {
 	if (CHECK_FETCH_FUNCS(deref, data->orig.fn))
@@ -376,6 +384,19 @@ DEFINE_BASIC_FETCH_FUNCS(bitfield)
 #define fetch_bitfield_string NULL
 #define fetch_bitfield_string_size NULL
 
+static __kprobes void
+update_bitfield_fetch_param(struct bitfield_fetch_param *data)
+{
+	/*
+	 * Don't check the bitfield itself, because this must be the
+	 * last fetch function.
+	 */
+	if (CHECK_FETCH_FUNCS(deref, data->orig.fn))
+		update_deref_fetch_param(data->orig.data);
+	else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn))
+		update_symbol_cache(data->orig.data);
+}
+
 static __kprobes void
 free_bitfield_fetch_param(struct bitfield_fetch_param *data)
 {
@@ -389,6 +410,7 @@ free_bitfield_fetch_param(struct bitfield_fetch_param *data)
 		free_symbol_cache(data->orig.data);
 	kfree(data);
 }
+
 /* Default (unsigned long) fetch type */
 #define __DEFAULT_FETCH_TYPE(t) u##t
 #define _DEFAULT_FETCH_TYPE(t) __DEFAULT_FETCH_TYPE(t)
@@ -536,6 +558,7 @@ struct probe_arg {
 /* Flags for trace_probe */
 #define TP_FLAG_TRACE	1
 #define TP_FLAG_PROFILE	2
+#define TP_FLAG_REGISTERED 4
 
 struct trace_probe {
 	struct list_head	list;
@@ -555,16 +578,49 @@ struct trace_probe {
 	(sizeof(struct probe_arg) * (n)))
 
 
-static __kprobes int probe_is_return(struct trace_probe *tp)
+static __kprobes int trace_probe_is_return(struct trace_probe *tp)
 {
 	return tp->rp.handler != NULL;
 }
 
-static __kprobes const char *probe_symbol(struct trace_probe *tp)
+static __kprobes const char *trace_probe_symbol(struct trace_probe *tp)
 {
 	return tp->symbol ? tp->symbol : "unknown";
 }
 
+static __kprobes unsigned long trace_probe_offset(struct trace_probe *tp)
+{
+	return tp->rp.kp.offset;
+}
+
+static __kprobes bool trace_probe_is_enabled(struct trace_probe *tp)
+{
+	return !!(tp->flags & (TP_FLAG_TRACE | TP_FLAG_PROFILE));
+}
+
+static __kprobes bool trace_probe_is_registered(struct trace_probe *tp)
+{
+	return !!(tp->flags & TP_FLAG_REGISTERED);
+}
+
+static __kprobes bool trace_probe_has_gone(struct trace_probe *tp)
+{
+	return !!(kprobe_gone(&tp->rp.kp));
+}
+
+static __kprobes bool trace_probe_within_module(struct trace_probe *tp,
+						struct module *mod)
+{
+	int len = strlen(mod->name);
+	const char *name = trace_probe_symbol(tp);
+	return strncmp(mod->name, name, len) == 0 && name[len] == ':';
+}
+
+static __kprobes bool trace_probe_is_on_module(struct trace_probe *tp)
+{
+	return !!strchr(trace_probe_symbol(tp), ':');
+}
+
 static int register_probe_event(struct trace_probe *tp);
 static void unregister_probe_event(struct trace_probe *tp);
 
@@ -646,6 +702,16 @@ error:
 	return ERR_PTR(ret);
 }
 
+static void update_probe_arg(struct probe_arg *arg)
+{
+	if (CHECK_FETCH_FUNCS(bitfield, arg->fetch.fn))
+		update_bitfield_fetch_param(arg->fetch.data);
+	else if (CHECK_FETCH_FUNCS(deref, arg->fetch.fn))
+		update_deref_fetch_param(arg->fetch.data);
+	else if (CHECK_FETCH_FUNCS(symbol, arg->fetch.fn))
+		update_symbol_cache(arg->fetch.data);
+}
+
 static void free_probe_arg(struct probe_arg *arg)
 {
 	if (CHECK_FETCH_FUNCS(bitfield, arg->fetch.fn))
@@ -671,7 +737,7 @@ static void free_trace_probe(struct trace_probe *tp)
 	kfree(tp);
 }
 
-static struct trace_probe *find_probe_event(const char *event,
+static struct trace_probe *find_trace_probe(const char *event,
 					    const char *group)
 {
 	struct trace_probe *tp;
@@ -683,13 +749,96 @@ static struct trace_probe *find_probe_event(const char *event,
 	return NULL;
 }
 
+/* Enable trace_probe - @flag must be TP_FLAG_TRACE or TP_FLAG_PROFILE */
+static int enable_trace_probe(struct trace_probe *tp, int flag)
+{
+	int ret = 0;
+
+	tp->flags |= flag;
+	if (trace_probe_is_enabled(tp) && trace_probe_is_registered(tp) &&
+	    !trace_probe_has_gone(tp)) {
+		if (trace_probe_is_return(tp))
+			ret = enable_kretprobe(&tp->rp);
+		else
+			ret = enable_kprobe(&tp->rp.kp);
+	}
+
+	return ret;
+}
+
+/* Disable trace_probe - @flag must be TP_FLAG_TRACE or TP_FLAG_PROFILE */
+static void disable_trace_probe(struct trace_probe *tp, int flag)
+{
+	tp->flags &= ~flag;
+	if (!trace_probe_is_enabled(tp) && trace_probe_is_registered(tp)) {
+		if (trace_probe_is_return(tp))
+			disable_kretprobe(&tp->rp);
+		else
+			disable_kprobe(&tp->rp.kp);
+	}
+}
+
+/* Internal register function - just handle k*probes and flags */
+static int __register_trace_probe(struct trace_probe *tp)
+{
+	int i, ret;
+
+	if (trace_probe_is_registered(tp))
+		return -EINVAL;
+
+	for (i = 0; i < tp->nr_args; i++)
+		update_probe_arg(&tp->args[i]);
+
+	/* Set/clear disabled flag according to tp->flag */
+	if (trace_probe_is_enabled(tp))
+		tp->rp.kp.flags &= ~KPROBE_FLAG_DISABLED;
+	else
+		tp->rp.kp.flags |= KPROBE_FLAG_DISABLED;
+
+	if (trace_probe_is_return(tp))
+		ret = register_kretprobe(&tp->rp);
+	else
+		ret = register_kprobe(&tp->rp.kp);
+
+	if (ret == 0)
+		tp->flags |= TP_FLAG_REGISTERED;
+	else {
+		pr_warning("Could not insert probe at %s+%lu: %d\n",
+			   trace_probe_symbol(tp), trace_probe_offset(tp), ret);
+		if (ret == -ENOENT && trace_probe_is_on_module(tp)) {
+			pr_warning("This probe might be able to register after"
+				   "target module is loaded. Continue.\n");
+			ret = 0;
+		} else if (ret == -EILSEQ) {
+			pr_warning("Probing address(0x%p) is not an "
+				   "instruction boundary.\n",
+				   tp->rp.kp.addr);
+			ret = -EINVAL;
+		}
+	}
+
+	return ret;
+}
+
+/* Internal unregister function - just handle k*probes and flags */
+static void __unregister_trace_probe(struct trace_probe *tp)
+{
+	if (trace_probe_is_registered(tp)) {
+		if (trace_probe_is_return(tp))
+			unregister_kretprobe(&tp->rp);
+		else
+			unregister_kprobe(&tp->rp.kp);
+		tp->flags &= ~TP_FLAG_REGISTERED;
+		/* Cleanup kprobe for reuse */
+		if (tp->rp.kp.symbol_name)
+			tp->rp.kp.addr = NULL;
+	}
+}
+
 /* Unregister a trace_probe and probe_event: call with locking probe_lock */
 static void unregister_trace_probe(struct trace_probe *tp)
 {
-	if (probe_is_return(tp))
-		unregister_kretprobe(&tp->rp);
-	else
-		unregister_kprobe(&tp->rp.kp);
+	__unregister_trace_probe(tp);
 	list_del(&tp->list);
 	unregister_probe_event(tp);
 }
@@ -702,41 +851,65 @@ static int register_trace_probe(struct trace_probe *tp)
 
 	mutex_lock(&probe_lock);
 
-	/* register as an event */
-	old_tp = find_probe_event(tp->call.name, tp->call.class->system);
+	/* Delete old (same name) event if exist */
+	old_tp = find_trace_probe(tp->call.name, tp->call.class->system);
 	if (old_tp) {
-		/* delete old event */
 		unregister_trace_probe(old_tp);
 		free_trace_probe(old_tp);
 	}
+
+	/* Register new event */
 	ret = register_probe_event(tp);
 	if (ret) {
 		pr_warning("Failed to register probe event(%d)\n", ret);
 		goto end;
 	}
 
-	tp->rp.kp.flags |= KPROBE_FLAG_DISABLED;
-	if (probe_is_return(tp))
-		ret = register_kretprobe(&tp->rp);
-	else
-		ret = register_kprobe(&tp->rp.kp);
-
-	if (ret) {
-		pr_warning("Could not insert probe(%d)\n", ret);
-		if (ret == -EILSEQ) {
-			pr_warning("Probing address(0x%p) is not an "
-				   "instruction boundary.\n",
-				   tp->rp.kp.addr);
-			ret = -EINVAL;
-		}
+	/* Register k*probe */
+	ret = __register_trace_probe(tp);
+	if (ret < 0)
 		unregister_probe_event(tp);
-	} else
+	else
 		list_add_tail(&tp->list, &probe_list);
+
 end:
 	mutex_unlock(&probe_lock);
 	return ret;
 }
 
+/* Module notifier call back, checking event on the module */
+static int trace_probe_module_callback(struct notifier_block *nb,
+				       unsigned long val, void *data)
+{
+	struct module *mod = data;
+	struct trace_probe *tp;
+	int ret;
+
+	if (val != MODULE_STATE_COMING)
+		return NOTIFY_DONE;
+
+	/* Update probes on coming module */
+	mutex_lock(&probe_lock);
+	list_for_each_entry(tp, &probe_list, list) {
+		if (trace_probe_within_module(tp, mod)) {
+			__unregister_trace_probe(tp);
+			ret = __register_trace_probe(tp);
+			if (ret)
+				pr_warning("Failed to re-register probe %s on"
+					   "%s: %d\n",
+					   tp->call.name, mod->name, ret);
+		}
+	}
+	mutex_unlock(&probe_lock);
+
+	return NOTIFY_DONE;
+}
+
+static struct notifier_block trace_probe_module_nb = {
+	.notifier_call = trace_probe_module_callback,
+	.priority = 1	/* Invoked after kprobe module callback */
+};
+
 /* Split symbol and offset. */
 static int split_symbol_offset(char *symbol, unsigned long *offset)
 {
@@ -962,8 +1135,8 @@ static int create_trace_probe(int argc, char **argv)
 {
 	/*
 	 * Argument syntax:
-	 *  - Add kprobe: p[:[GRP/]EVENT] KSYM[+OFFS]|KADDR [FETCHARGS]
-	 *  - Add kretprobe: r[:[GRP/]EVENT] KSYM[+0] [FETCHARGS]
+	 *  - Add kprobe: p[:[GRP/]EVENT] [MOD:]KSYM[+OFFS]|KADDR [FETCHARGS]
+	 *  - Add kretprobe: r[:[GRP/]EVENT] [MOD:]KSYM[+0] [FETCHARGS]
 	 * Fetch args:
 	 *  $retval	: fetch return value
 	 *  $stack	: fetch stack address
@@ -1025,7 +1198,7 @@ static int create_trace_probe(int argc, char **argv)
 			return -EINVAL;
 		}
 		mutex_lock(&probe_lock);
-		tp = find_probe_event(event, group);
+		tp = find_trace_probe(event, group);
 		if (!tp) {
 			mutex_unlock(&probe_lock);
 			pr_info("Event %s/%s doesn't exist.\n", group, event);
@@ -1144,7 +1317,7 @@ error:
 	return ret;
 }
 
-static void cleanup_all_probes(void)
+static void release_all_trace_probes(void)
 {
 	struct trace_probe *tp;
 
@@ -1158,7 +1331,6 @@ static void cleanup_all_probes(void)
 	mutex_unlock(&probe_lock);
 }
 
-
 /* Probes listing interfaces */
 static void *probes_seq_start(struct seq_file *m, loff_t *pos)
 {
@@ -1181,15 +1353,16 @@ static int probes_seq_show(struct seq_file *m, void *v)
 	struct trace_probe *tp = v;
 	int i;
 
-	seq_printf(m, "%c", probe_is_return(tp) ? 'r' : 'p');
+	seq_printf(m, "%c", trace_probe_is_return(tp) ? 'r' : 'p');
 	seq_printf(m, ":%s/%s", tp->call.class->system, tp->call.name);
 
 	if (!tp->symbol)
 		seq_printf(m, " 0x%p", tp->rp.kp.addr);
 	else if (tp->rp.kp.offset)
-		seq_printf(m, " %s+%u", probe_symbol(tp), tp->rp.kp.offset);
+		seq_printf(m, " %s+%u", trace_probe_symbol(tp),
+			   tp->rp.kp.offset);
 	else
-		seq_printf(m, " %s", probe_symbol(tp));
+		seq_printf(m, " %s", trace_probe_symbol(tp));
 
 	for (i = 0; i < tp->nr_args; i++)
 		seq_printf(m, " %s=%s", tp->args[i].name, tp->args[i].comm);
@@ -1209,7 +1382,7 @@ static int probes_open(struct inode *inode, struct file *file)
 {
 	if ((file->f_mode & FMODE_WRITE) &&
 	    (file->f_flags & O_TRUNC))
-		cleanup_all_probes();
+		release_all_trace_probes();
 
 	return seq_open(file, &probes_seq_op);
 }
@@ -1397,7 +1570,8 @@ static __kprobes void kprobe_trace_func(struct kprobe *kp, struct pt_regs *regs)
 	store_trace_args(sizeof(*entry), tp, regs, (u8 *)&entry[1], dsize);
 
 	if (!filter_current_check_discard(buffer, call, entry, event))
-		trace_nowake_buffer_unlock_commit(buffer, event, irq_flags, pc);
+		trace_nowake_buffer_unlock_commit_regs(buffer, event,
+						       irq_flags, pc, regs);
 }
 
 /* Kretprobe handler */
@@ -1429,7 +1603,8 @@ static __kprobes void kretprobe_trace_func(struct kretprobe_instance *ri,
 	store_trace_args(sizeof(*entry), tp, regs, (u8 *)&entry[1], dsize);
 
 	if (!filter_current_check_discard(buffer, call, entry, event))
-		trace_nowake_buffer_unlock_commit(buffer, event, irq_flags, pc);
+		trace_nowake_buffer_unlock_commit_regs(buffer, event,
+						       irq_flags, pc, regs);
 }
 
 /* Event entry printers */
@@ -1511,30 +1686,6 @@ partial:
 	return TRACE_TYPE_PARTIAL_LINE;
 }
 
-static int probe_event_enable(struct ftrace_event_call *call)
-{
-	struct trace_probe *tp = (struct trace_probe *)call->data;
-
-	tp->flags |= TP_FLAG_TRACE;
-	if (probe_is_return(tp))
-		return enable_kretprobe(&tp->rp);
-	else
-		return enable_kprobe(&tp->rp.kp);
-}
-
-static void probe_event_disable(struct ftrace_event_call *call)
-{
-	struct trace_probe *tp = (struct trace_probe *)call->data;
-
-	tp->flags &= ~TP_FLAG_TRACE;
-	if (!(tp->flags & (TP_FLAG_TRACE | TP_FLAG_PROFILE))) {
-		if (probe_is_return(tp))
-			disable_kretprobe(&tp->rp);
-		else
-			disable_kprobe(&tp->rp.kp);
-	}
-}
-
 #undef DEFINE_FIELD
 #define DEFINE_FIELD(type, item, name, is_signed)			\
 	do {								\
@@ -1596,7 +1747,7 @@ static int __set_print_fmt(struct trace_probe *tp, char *buf, int len)
 
 	const char *fmt, *arg;
 
-	if (!probe_is_return(tp)) {
+	if (!trace_probe_is_return(tp)) {
 		fmt = "(%lx)";
 		arg = "REC->" FIELD_STRING_IP;
 	} else {
@@ -1713,49 +1864,25 @@ static __kprobes void kretprobe_perf_func(struct kretprobe_instance *ri,
 	head = this_cpu_ptr(call->perf_events);
 	perf_trace_buf_submit(entry, size, rctx, entry->ret_ip, 1, regs, head);
 }
-
-static int probe_perf_enable(struct ftrace_event_call *call)
-{
-	struct trace_probe *tp = (struct trace_probe *)call->data;
-
-	tp->flags |= TP_FLAG_PROFILE;
-
-	if (probe_is_return(tp))
-		return enable_kretprobe(&tp->rp);
-	else
-		return enable_kprobe(&tp->rp.kp);
-}
-
-static void probe_perf_disable(struct ftrace_event_call *call)
-{
-	struct trace_probe *tp = (struct trace_probe *)call->data;
-
-	tp->flags &= ~TP_FLAG_PROFILE;
-
-	if (!(tp->flags & TP_FLAG_TRACE)) {
-		if (probe_is_return(tp))
-			disable_kretprobe(&tp->rp);
-		else
-			disable_kprobe(&tp->rp.kp);
-	}
-}
 #endif	/* CONFIG_PERF_EVENTS */
 
 static __kprobes
 int kprobe_register(struct ftrace_event_call *event, enum trace_reg type)
 {
+	struct trace_probe *tp = (struct trace_probe *)event->data;
+
 	switch (type) {
 	case TRACE_REG_REGISTER:
-		return probe_event_enable(event);
+		return enable_trace_probe(tp, TP_FLAG_TRACE);
 	case TRACE_REG_UNREGISTER:
-		probe_event_disable(event);
+		disable_trace_probe(tp, TP_FLAG_TRACE);
 		return 0;
 
 #ifdef CONFIG_PERF_EVENTS
 	case TRACE_REG_PERF_REGISTER:
-		return probe_perf_enable(event);
+		return enable_trace_probe(tp, TP_FLAG_PROFILE);
 	case TRACE_REG_PERF_UNREGISTER:
-		probe_perf_disable(event);
+		disable_trace_probe(tp, TP_FLAG_PROFILE);
 		return 0;
 #endif
 	}
@@ -1805,7 +1932,7 @@ static int register_probe_event(struct trace_probe *tp)
 
 	/* Initialize ftrace_event_call */
 	INIT_LIST_HEAD(&call->class->fields);
-	if (probe_is_return(tp)) {
+	if (trace_probe_is_return(tp)) {
 		call->event.funcs = &kretprobe_funcs;
 		call->class->define_fields = kretprobe_event_define_fields;
 	} else {
@@ -1844,6 +1971,9 @@ static __init int init_kprobe_trace(void)
 	struct dentry *d_tracer;
 	struct dentry *entry;
 
+	if (register_module_notifier(&trace_probe_module_nb))
+		return -EINVAL;
+
 	d_tracer = tracing_init_dentry();
 	if (!d_tracer)
 		return 0;
@@ -1897,12 +2027,12 @@ static __init int kprobe_trace_self_tests_init(void)
 		warn++;
 	} else {
 		/* Enable trace point */
-		tp = find_probe_event("testprobe", KPROBE_EVENT_SYSTEM);
+		tp = find_trace_probe("testprobe", KPROBE_EVENT_SYSTEM);
 		if (WARN_ON_ONCE(tp == NULL)) {
 			pr_warning("error on getting new probe.\n");
 			warn++;
 		} else
-			probe_event_enable(&tp->call);
+			enable_trace_probe(tp, TP_FLAG_TRACE);
 	}
 
 	ret = command_trace_probe("r:testprobe2 kprobe_trace_selftest_target "
@@ -1912,12 +2042,12 @@ static __init int kprobe_trace_self_tests_init(void)
 		warn++;
 	} else {
 		/* Enable trace point */
-		tp = find_probe_event("testprobe2", KPROBE_EVENT_SYSTEM);
+		tp = find_trace_probe("testprobe2", KPROBE_EVENT_SYSTEM);
 		if (WARN_ON_ONCE(tp == NULL)) {
 			pr_warning("error on getting new probe.\n");
 			warn++;
 		} else
-			probe_event_enable(&tp->call);
+			enable_trace_probe(tp, TP_FLAG_TRACE);
 	}
 
 	if (warn)
@@ -1938,7 +2068,7 @@ static __init int kprobe_trace_self_tests_init(void)
 	}
 
 end:
-	cleanup_all_probes();
+	release_all_trace_probes();
 	if (warn)
 		pr_cont("NG: Some tests are failed. Please check them.\n");
 	else

kernel/trace/trace_output.c

@@ -1107,19 +1107,20 @@ static enum print_line_t trace_stack_print(struct trace_iterator *iter,
 {
 	struct stack_entry *field;
 	struct trace_seq *s = &iter->seq;
-	int i;
+	unsigned long *p;
+	unsigned long *end;
 
 	trace_assign_type(field, iter->ent);
+	end = (unsigned long *)((long)iter->ent + iter->ent_size);
 
 	if (!trace_seq_puts(s, "<stack trace>\n"))
 		goto partial;
-	for (i = 0; i < FTRACE_STACK_ENTRIES; i++) {
-		if (!field->caller[i] || (field->caller[i] == ULONG_MAX))
-			break;
+
+	for (p = field->caller; p && *p != ULONG_MAX && p < end; p++) {
 		if (!trace_seq_puts(s, " => "))
 			goto partial;
 
-		if (!seq_print_ip_sym(s, field->caller[i], flags))
+		if (!seq_print_ip_sym(s, *p, flags))
 			goto partial;
 		if (!trace_seq_puts(s, "\n"))
 			goto partial;

kernel/trace/trace_sched_wakeup.c

@@ -227,7 +227,9 @@ static void wakeup_trace_close(struct trace_iterator *iter)
 		graph_trace_close(iter);
 }
 
-#define GRAPH_TRACER_FLAGS (TRACE_GRAPH_PRINT_PROC)
+#define GRAPH_TRACER_FLAGS (TRACE_GRAPH_PRINT_PROC | \
+			    TRACE_GRAPH_PRINT_ABS_TIME | \
+			    TRACE_GRAPH_PRINT_DURATION)
 
 static enum print_line_t wakeup_print_line(struct trace_iterator *iter)
 {

kernel/trace/trace_stack.c

@@ -156,20 +156,11 @@ stack_max_size_write(struct file *filp, const char __user *ubuf,
 {
 	long *ptr = filp->private_data;
 	unsigned long val, flags;
-	char buf[64];
 	int ret;
 	int cpu;
 
-	if (count >= sizeof(buf))
-		return -EINVAL;
-
-	if (copy_from_user(&buf, ubuf, count))
-		return -EFAULT;
-
-	buf[count] = 0;
-
-	ret = strict_strtoul(buf, 10, &val);
-	if (ret < 0)
+	ret = kstrtoul_from_user(ubuf, count, 10, &val);
+	if (ret)
 		return ret;
 
 	local_irq_save(flags);

kernel/watchdog.c

@@ -200,6 +200,7 @@ static int is_softlockup(unsigned long touch_ts)
 }
 
 #ifdef CONFIG_HARDLOCKUP_DETECTOR
+
 static struct perf_event_attr wd_hw_attr = {
 	.type		= PERF_TYPE_HARDWARE,
 	.config		= PERF_COUNT_HW_CPU_CYCLES,
@@ -209,7 +210,7 @@ static struct perf_event_attr wd_hw_attr = {
 };
 
 /* Callback function for perf event subsystem */
-static void watchdog_overflow_callback(struct perf_event *event, int nmi,
+static void watchdog_overflow_callback(struct perf_event *event,
 		 struct perf_sample_data *data,
 		 struct pt_regs *regs)
 {
@@ -368,10 +369,11 @@ static int watchdog_nmi_enable(int cpu)
 	if (event != NULL)
 		goto out_enable;
 
-	/* Try to register using hardware perf events */
 	wd_attr = &wd_hw_attr;
 	wd_attr->sample_period = hw_nmi_get_sample_period(watchdog_thresh);
-	event = perf_event_create_kernel_counter(wd_attr, cpu, NULL, watchdog_overflow_callback);
+
+	/* Try to register using hardware perf events */
+	event = perf_event_create_kernel_counter(wd_attr, cpu, NULL, watchdog_overflow_callback, NULL);
 	if (!IS_ERR(event)) {
 		printk(KERN_INFO "NMI watchdog enabled, takes one hw-pmu counter.\n");
 		goto out_save;