1 files changed, 0 insertions, 591 deletions
diff --git a/drivers/oprofile/buffer_sync.c b/drivers/oprofile/buffer_sync.c
deleted file mode 100644
index cc917865f13a..000000000000
--- a/drivers/oprofile/buffer_sync.c
+++ /dev/null
@@ -1,591 +0,0 @@
-/**
- * @file buffer_sync.c
- *
- * @remark Copyright 2002-2009 OProfile authors
- * @remark Read the file COPYING
- *
- * @author John Levon <levon@movementarian.org>
- * @author Barry Kasindorf
- * @author Robert Richter <robert.richter@amd.com>
- *
- * This is the core of the buffer management. Each
- * CPU buffer is processed and entered into the
- * global event buffer. Such processing is necessary
- * in several circumstances, mentioned below.
- *
- * The processing does the job of converting the
- * transitory EIP value into a persistent dentry/offset
- * value that the profiler can record at its leisure.
- *
- * See fs/dcookies.c for a description of the dentry/offset
- * objects.
- */
-
-#include <linux/file.h>
-#include <linux/mm.h>
-#include <linux/workqueue.h>
-#include <linux/notifier.h>
-#include <linux/dcookies.h>
-#include <linux/profile.h>
-#include <linux/module.h>
-#include <linux/fs.h>
-#include <linux/oprofile.h>
-#include <linux/sched.h>
-#include <linux/sched/mm.h>
-#include <linux/sched/task.h>
-#include <linux/gfp.h>
-
-#include "oprofile_stats.h"
-#include "event_buffer.h"
-#include "cpu_buffer.h"
-#include "buffer_sync.h"
-
-static LIST_HEAD(dying_tasks);
-static LIST_HEAD(dead_tasks);
-static cpumask_var_t marked_cpus;
-static DEFINE_SPINLOCK(task_mortuary);
-static void process_task_mortuary(void);
-
-/* Take ownership of the task struct and place it on the
- * list for processing. Only after two full buffer syncs
- * does the task eventually get freed, because by then
- * we are sure we will not reference it again.
- * Can be invoked from softirq via RCU callback due to
- * call_rcu() of the task struct, hence the _irqsave.
- */
-static int
-task_free_notify(struct notifier_block *self, unsigned long val, void *data)
-{
-	unsigned long flags;
-	struct task_struct *task = data;
-	spin_lock_irqsave(&task_mortuary, flags);
-	list_add(&task->tasks, &dying_tasks);
-	spin_unlock_irqrestore(&task_mortuary, flags);
-	return NOTIFY_OK;
-}
-
-
-/* The task is on its way out. A sync of the buffer means we can catch
- * any remaining samples for this task.
- */
-static int
-task_exit_notify(struct notifier_block *self, unsigned long val, void *data)
-{
-	/* To avoid latency problems, we only process the current CPU,
-	 * hoping that most samples for the task are on this CPU
-	 */
-	sync_buffer(raw_smp_processor_id());
-	return 0;
-}
-
-
-/* The task is about to try a do_munmap(). We peek at what it's going to
- * do, and if it's an executable region, process the samples first, so
- * we don't lose any. This does not have to be exact, it's a QoI issue
- * only.
- */
-static int
-munmap_notify(struct notifier_block *self, unsigned long val, void *data)
-{
-	unsigned long addr = (unsigned long)data;
-	struct mm_struct *mm = current->mm;
-	struct vm_area_struct *mpnt;
-
-	mmap_read_lock(mm);
-
-	mpnt = find_vma(mm, addr);
-	if (mpnt && mpnt->vm_file && (mpnt->vm_flags & VM_EXEC)) {
-		mmap_read_unlock(mm);
-		/* To avoid latency problems, we only process the current CPU,
-		 * hoping that most samples for the task are on this CPU
-		 */
-		sync_buffer(raw_smp_processor_id());
-		return 0;
-	}
-
-	mmap_read_unlock(mm);
-	return 0;
-}
-
-
-/* We need to be told about new modules so we don't attribute to a previously
- * loaded module, or drop the samples on the floor.
- */
-static int
-module_load_notify(struct notifier_block *self, unsigned long val, void *data)
-{
-#ifdef CONFIG_MODULES
-	if (val != MODULE_STATE_COMING)
-		return NOTIFY_DONE;
-
-	/* FIXME: should we process all CPU buffers ? */
-	mutex_lock(&buffer_mutex);
-	add_event_entry(ESCAPE_CODE);
-	add_event_entry(MODULE_LOADED_CODE);
-	mutex_unlock(&buffer_mutex);
-#endif
-	return NOTIFY_OK;
-}
-
-
-static struct notifier_block task_free_nb = {
-	.notifier_call	= task_free_notify,
-};
-
-static struct notifier_block task_exit_nb = {
-	.notifier_call	= task_exit_notify,
-};
-
-static struct notifier_block munmap_nb = {
-	.notifier_call	= munmap_notify,
-};
-
-static struct notifier_block module_load_nb = {
-	.notifier_call = module_load_notify,
-};
-
-static void free_all_tasks(void)
-{
-	/* make sure we don't leak task structs */
-	process_task_mortuary();
-	process_task_mortuary();
-}
-
-int sync_start(void)
-{
-	int err;
-
-	if (!zalloc_cpumask_var(&marked_cpus, GFP_KERNEL))
-		return -ENOMEM;
-
-	err = task_handoff_register(&task_free_nb);
-	if (err)
-		goto out1;
-	err = profile_event_register(PROFILE_TASK_EXIT, &task_exit_nb);
-	if (err)
-		goto out2;
-	err = profile_event_register(PROFILE_MUNMAP, &munmap_nb);
-	if (err)
-		goto out3;
-	err = register_module_notifier(&module_load_nb);
-	if (err)
-		goto out4;
-
-	start_cpu_work();
-
-out:
-	return err;
-out4:
-	profile_event_unregister(PROFILE_MUNMAP, &munmap_nb);
-out3:
-	profile_event_unregister(PROFILE_TASK_EXIT, &task_exit_nb);
-out2:
-	task_handoff_unregister(&task_free_nb);
-	free_all_tasks();
-out1:
-	free_cpumask_var(marked_cpus);
-	goto out;
-}
-
-
-void sync_stop(void)
-{
-	end_cpu_work();
-	unregister_module_notifier(&module_load_nb);
-	profile_event_unregister(PROFILE_MUNMAP, &munmap_nb);
-	profile_event_unregister(PROFILE_TASK_EXIT, &task_exit_nb);
-	task_handoff_unregister(&task_free_nb);
-	barrier();			/* do all of the above first */
-
-	flush_cpu_work();
-
-	free_all_tasks();
-	free_cpumask_var(marked_cpus);
-}
-
-
-/* Optimisation. We can manage without taking the dcookie sem
- * because we cannot reach this code without at least one
- * dcookie user still being registered (namely, the reader
- * of the event buffer). */
-static inline unsigned long fast_get_dcookie(const struct path *path)
-{
-	unsigned long cookie;
-
-	if (path->dentry->d_flags & DCACHE_COOKIE)
-		return (unsigned long)path->dentry;
-	get_dcookie(path, &cookie);
-	return cookie;
-}
-
-
-/* Look up the dcookie for the task's mm->exe_file,
- * which corresponds loosely to "application name". This is
- * not strictly necessary but allows oprofile to associate
- * shared-library samples with particular applications
- */
-static unsigned long get_exec_dcookie(struct mm_struct *mm)
-{
-	unsigned long cookie = NO_COOKIE;
-	struct file *exe_file;
-
-	if (!mm)
-		goto done;
-
-	exe_file = get_mm_exe_file(mm);
-	if (!exe_file)
-		goto done;
-
-	cookie = fast_get_dcookie(&exe_file->f_path);
-	fput(exe_file);
-done:
-	return cookie;
-}
-
-
-/* Convert the EIP value of a sample into a persistent dentry/offset
- * pair that can then be added to the global event buffer. We make
- * sure to do this lookup before a mm->mmap modification happens so
- * we don't lose track.
- *
- * The caller must ensure the mm is not nil (ie: not a kernel thread).
- */
-static unsigned long
-lookup_dcookie(struct mm_struct *mm, unsigned long addr, off_t *offset)
-{
-	unsigned long cookie = NO_COOKIE;
-	struct vm_area_struct *vma;
-
-	mmap_read_lock(mm);
-	for (vma = find_vma(mm, addr); vma; vma = vma->vm_next) {
-
-		if (addr < vma->vm_start || addr >= vma->vm_end)
-			continue;
-
-		if (vma->vm_file) {
-			cookie = fast_get_dcookie(&vma->vm_file->f_path);
-			*offset = (vma->vm_pgoff << PAGE_SHIFT) + addr -
-				vma->vm_start;
-		} else {
-			/* must be an anonymous map */
-			*offset = addr;
-		}
-
-		break;
-	}
-
-	if (!vma)
-		cookie = INVALID_COOKIE;
-	mmap_read_unlock(mm);
-
-	return cookie;
-}
-
-static unsigned long last_cookie = INVALID_COOKIE;
-
-static void add_cpu_switch(int i)
-{
-	add_event_entry(ESCAPE_CODE);
-	add_event_entry(CPU_SWITCH_CODE);
-	add_event_entry(i);
-	last_cookie = INVALID_COOKIE;
-}
-
-static void add_kernel_ctx_switch(unsigned int in_kernel)
-{
-	add_event_entry(ESCAPE_CODE);
-	if (in_kernel)
-		add_event_entry(KERNEL_ENTER_SWITCH_CODE);
-	else
-		add_event_entry(KERNEL_EXIT_SWITCH_CODE);
-}
-
-static void
-add_user_ctx_switch(struct task_struct const *task, unsigned long cookie)
-{
-	add_event_entry(ESCAPE_CODE);
-	add_event_entry(CTX_SWITCH_CODE);
-	add_event_entry(task->pid);
-	add_event_entry(cookie);
-	/* Another code for daemon back-compat */
-	add_event_entry(ESCAPE_CODE);
-	add_event_entry(CTX_TGID_CODE);
-	add_event_entry(task->tgid);
-}
-
-
-static void add_cookie_switch(unsigned long cookie)
-{
-	add_event_entry(ESCAPE_CODE);
-	add_event_entry(COOKIE_SWITCH_CODE);
-	add_event_entry(cookie);
-}
-
-
-static void add_trace_begin(void)
-{
-	add_event_entry(ESCAPE_CODE);
-	add_event_entry(TRACE_BEGIN_CODE);
-}
-
-static void add_data(struct op_entry *entry, struct mm_struct *mm)
-{
-	unsigned long code, pc, val;
-	unsigned long cookie;
-	off_t offset;
-
-	if (!op_cpu_buffer_get_data(entry, &code))
-		return;
-	if (!op_cpu_buffer_get_data(entry, &pc))
-		return;
-	if (!op_cpu_buffer_get_size(entry))
-		return;
-
-	if (mm) {
-		cookie = lookup_dcookie(mm, pc, &offset);
-
-		if (cookie == NO_COOKIE)
-			offset = pc;
-		if (cookie == INVALID_COOKIE) {
-			atomic_inc(&oprofile_stats.sample_lost_no_mapping);
-			offset = pc;
-		}
-		if (cookie != last_cookie) {
-			add_cookie_switch(cookie);
-			last_cookie = cookie;
-		}
-	} else
-		offset = pc;
-
-	add_event_entry(ESCAPE_CODE);
-	add_event_entry(code);
-	add_event_entry(offset);	/* Offset from Dcookie */
-
-	while (op_cpu_buffer_get_data(entry, &val))
-		add_event_entry(val);
-}
-
-static inline void add_sample_entry(unsigned long offset, unsigned long event)
-{
-	add_event_entry(offset);
-	add_event_entry(event);
-}
-
-
-/*
- * Add a sample to the global event buffer. If possible the
- * sample is converted into a persistent dentry/offset pair
- * for later lookup from userspace. Return 0 on failure.
- */
-static int
-add_sample(struct mm_struct *mm, struct op_sample *s, int in_kernel)
-{
-	unsigned long cookie;
-	off_t offset;
-
-	if (in_kernel) {
-		add_sample_entry(s->eip, s->event);
-		return 1;
-	}
-
-	/* add userspace sample */
-
-	if (!mm) {
-		atomic_inc(&oprofile_stats.sample_lost_no_mm);
-		return 0;
-	}
-
-	cookie = lookup_dcookie(mm, s->eip, &offset);
-
-	if (cookie == INVALID_COOKIE) {
-		atomic_inc(&oprofile_stats.sample_lost_no_mapping);
-		return 0;
-	}
-
-	if (cookie != last_cookie) {
-		add_cookie_switch(cookie);
-		last_cookie = cookie;
-	}
-
-	add_sample_entry(offset, s->event);
-
-	return 1;
-}
-
-
-static void release_mm(struct mm_struct *mm)
-{
-	if (!mm)
-		return;
-	mmput(mm);
-}
-
-static inline int is_code(unsigned long val)
-{
-	return val == ESCAPE_CODE;
-}
-
-
-/* Move tasks along towards death. Any tasks on dead_tasks
- * will definitely have no remaining references in any
- * CPU buffers at this point, because we use two lists,
- * and to have reached the list, it must have gone through
- * one full sync already.
- */
-static void process_task_mortuary(void)
-{
-	unsigned long flags;
-	LIST_HEAD(local_dead_tasks);
-	struct task_struct *task;
-	struct task_struct *ttask;
-
-	spin_lock_irqsave(&task_mortuary, flags);
-
-	list_splice_init(&dead_tasks, &local_dead_tasks);
-	list_splice_init(&dying_tasks, &dead_tasks);
-
-	spin_unlock_irqrestore(&task_mortuary, flags);
-
-	list_for_each_entry_safe(task, ttask, &local_dead_tasks, tasks) {
-		list_del(&task->tasks);
-		free_task(task);
-	}
-}
-
-
-static void mark_done(int cpu)
-{
-	int i;
-
-	cpumask_set_cpu(cpu, marked_cpus);
-
-	for_each_online_cpu(i) {
-		if (!cpumask_test_cpu(i, marked_cpus))
-			return;
-	}
-
-	/* All CPUs have been processed at least once,
-	 * we can process the mortuary once
-	 */
-	process_task_mortuary();
-
-	cpumask_clear(marked_cpus);
-}
-
-
-/* FIXME: this is not sufficient if we implement syscall barrier backtrace
- * traversal, the code switch to sb_sample_start at first kernel enter/exit
- * switch so we need a fifth state and some special handling in sync_buffer()
- */
-typedef enum {
-	sb_bt_ignore = -2,
-	sb_buffer_start,
-	sb_bt_start,
-	sb_sample_start,
-} sync_buffer_state;
-
-/* Sync one of the CPU's buffers into the global event buffer.
- * Here we need to go through each batch of samples punctuated
- * by context switch notes, taking the task's mmap_lock and doing
- * lookup in task->mm->mmap to convert EIP into dcookie/offset
- * value.
- */
-void sync_buffer(int cpu)
-{
-	struct mm_struct *mm = NULL;
-	struct mm_struct *oldmm;
-	unsigned long val;
-	struct task_struct *new;
-	unsigned long cookie = 0;
-	int in_kernel = 1;
-	sync_buffer_state state = sb_buffer_start;
-	unsigned int i;
-	unsigned long available;
-	unsigned long flags;
-	struct op_entry entry;
-	struct op_sample *sample;
-
-	mutex_lock(&buffer_mutex);
-
-	add_cpu_switch(cpu);
-
-	op_cpu_buffer_reset(cpu);
-	available = op_cpu_buffer_entries(cpu);
-
-	for (i = 0; i < available; ++i) {
-		sample = op_cpu_buffer_read_entry(&entry, cpu);
-		if (!sample)
-			break;
-
-		if (is_code(sample->eip)) {
-			flags = sample->event;
-			if (flags & TRACE_BEGIN) {
-				state = sb_bt_start;
-				add_trace_begin();
-			}
-			if (flags & KERNEL_CTX_SWITCH) {
-				/* kernel/userspace switch */
-				in_kernel = flags & IS_KERNEL;
-				if (state == sb_buffer_start)
-					state = sb_sample_start;
-				add_kernel_ctx_switch(flags & IS_KERNEL);
-			}
-			if (flags & USER_CTX_SWITCH
-			    && op_cpu_buffer_get_data(&entry, &val)) {
-				/* userspace context switch */
-				new = (struct task_struct *)val;
-				oldmm = mm;
-				release_mm(oldmm);
-				mm = get_task_mm(new);
-				if (mm != oldmm)
-					cookie = get_exec_dcookie(mm);
-				add_user_ctx_switch(new, cookie);
-			}
-			if (op_cpu_buffer_get_size(&entry))
-				add_data(&entry, mm);
-			continue;
-		}
-
-		if (state < sb_bt_start)
-			/* ignore sample */
-			continue;
-
-		if (add_sample(mm, sample, in_kernel))
-			continue;
-
-		/* ignore backtraces if failed to add a sample */
-		if (state == sb_bt_start) {
-			state = sb_bt_ignore;
-			atomic_inc(&oprofile_stats.bt_lost_no_mapping);
-		}
-	}
-	release_mm(mm);
-
-	mark_done(cpu);
-
-	mutex_unlock(&buffer_mutex);
-}
-
-/* The function can be used to add a buffer worth of data directly to
- * the kernel buffer. The buffer is assumed to be a circular buffer.
- * Take the entries from index start and end at index end, wrapping
- * at max_entries.
- */
-void oprofile_put_buff(unsigned long *buf, unsigned int start,
-		       unsigned int stop, unsigned int max)
-{
-	int i;
-
-	i = start;
-
-	mutex_lock(&buffer_mutex);
-	while (i != stop) {
-		add_event_entry(buf[i++]);
-
-		if (i >= max)
-			i = 0;
-	}
-
-	mutex_unlock(&buffer_mutex);
-}
-