zte's code,first commit
Change-Id: I9a04da59e459a9bc0d67f101f700d9d7dc8d681b
diff --git a/ap/os/linux/linux-3.4.x/kernel/trace/ftrace.c b/ap/os/linux/linux-3.4.x/kernel/trace/ftrace.c
new file mode 100644
index 0000000..ffea326
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/kernel/trace/ftrace.c
@@ -0,0 +1,4800 @@
+/*
+ * Infrastructure for profiling code inserted by 'gcc -pg'.
+ *
+ * Copyright (C) 2007-2008 Steven Rostedt <srostedt@redhat.com>
+ * Copyright (C) 2004-2008 Ingo Molnar <mingo@redhat.com>
+ *
+ * Originally ported from the -rt patch by:
+ * Copyright (C) 2007 Arnaldo Carvalho de Melo <acme@redhat.com>
+ *
+ * Based on code in the latency_tracer, that is:
+ *
+ * Copyright (C) 2004-2006 Ingo Molnar
+ * Copyright (C) 2004 William Lee Irwin III
+ */
+
+#include <linux/stop_machine.h>
+#include <linux/clocksource.h>
+#include <linux/kallsyms.h>
+#include <linux/seq_file.h>
+#include <linux/suspend.h>
+#include <linux/debugfs.h>
+#include <linux/hardirq.h>
+#include <linux/kthread.h>
+#include <linux/uaccess.h>
+#include <linux/bsearch.h>
+#include <linux/module.h>
+#include <linux/ftrace.h>
+#include <linux/sysctl.h>
+#include <linux/slab.h>
+#include <linux/ctype.h>
+#include <linux/sort.h>
+#include <linux/list.h>
+#include <linux/hash.h>
+#include <linux/rcupdate.h>
+
+#include <trace/events/sched.h>
+
+#include <asm/setup.h>
+
+#include "trace_output.h"
+#include "trace_stat.h"
+
+#define FTRACE_WARN_ON(cond) \
+ ({ \
+ int ___r = cond; \
+ if (WARN_ON(___r)) \
+ ftrace_kill(); \
+ ___r; \
+ })
+
+#define FTRACE_WARN_ON_ONCE(cond) \
+ ({ \
+ int ___r = cond; \
+ if (WARN_ON_ONCE(___r)) \
+ ftrace_kill(); \
+ ___r; \
+ })
+
+/* hash bits for specific function selection */
+#define FTRACE_HASH_BITS 7
+#define FTRACE_FUNC_HASHSIZE (1 << FTRACE_HASH_BITS)
+#define FTRACE_HASH_DEFAULT_BITS 10
+#define FTRACE_HASH_MAX_BITS 12
+
+#define FL_GLOBAL_CONTROL_MASK (FTRACE_OPS_FL_GLOBAL | FTRACE_OPS_FL_CONTROL)
+
+/* ftrace_enabled is a method to turn ftrace on or off */
+int ftrace_enabled __read_mostly;
+static int last_ftrace_enabled;
+
+/* Quick disabling of function tracer. */
+int function_trace_stop;
+
+/* List for set_ftrace_pid's pids. */
+LIST_HEAD(ftrace_pids);
+struct ftrace_pid {
+ struct list_head list;
+ struct pid *pid;
+};
+
+/*
+ * ftrace_disabled is set when an anomaly is discovered.
+ * ftrace_disabled is much stronger than ftrace_enabled.
+ */
+static int ftrace_disabled __read_mostly;
+
+static DEFINE_MUTEX(ftrace_lock);
+
+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_control_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;
+static struct ftrace_ops control_ops;
+
+static void
+ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip);
+
+/*
+ * Traverse the ftrace_global_list, invoking all entries. The reason that we
+ * can use rcu_dereference_raw() is that elements removed from this list
+ * are simply leaked, so there is no need to interact with a grace-period
+ * mechanism. The rcu_dereference_raw() calls are needed to handle
+ * concurrent insertions into the ftrace_global_list.
+ *
+ * Silly Alpha and silly pointer-speculation compiler optimizations!
+ */
+static void ftrace_global_list_func(unsigned long ip,
+ unsigned long parent_ip)
+{
+ struct ftrace_ops *op;
+
+ if (unlikely(trace_recursion_test(TRACE_GLOBAL_BIT)))
+ return;
+
+ trace_recursion_set(TRACE_GLOBAL_BIT);
+ op = rcu_dereference_raw(ftrace_global_list); /*see above*/
+ while (op != &ftrace_list_end) {
+ op->func(ip, parent_ip);
+ op = rcu_dereference_raw(op->next); /*see above*/
+ };
+ trace_recursion_clear(TRACE_GLOBAL_BIT);
+}
+
+static void ftrace_pid_func(unsigned long ip, unsigned long parent_ip)
+{
+ if (!test_tsk_trace_trace(current))
+ return;
+
+ ftrace_pid_function(ip, parent_ip);
+}
+
+static void set_ftrace_pid_function(ftrace_func_t func)
+{
+ /* do not set ftrace_pid_function to itself! */
+ if (func != ftrace_pid_func)
+ ftrace_pid_function = func;
+}
+
+/**
+ * clear_ftrace_function - reset the ftrace function
+ *
+ * This NULLs the ftrace function and in essence stops
+ * tracing. There may be lag
+ */
+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;
+}
+
+#ifndef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST
+/*
+ * For those archs that do not test ftrace_trace_stop in their
+ * mcount call site, we need to do it from C.
+ */
+static void ftrace_test_stop_func(unsigned long ip, unsigned long parent_ip)
+{
+ if (function_trace_stop)
+ return;
+
+ __ftrace_trace_function(ip, parent_ip);
+}
+#endif
+
+static void control_ops_disable_all(struct ftrace_ops *ops)
+{
+ int cpu;
+
+ for_each_possible_cpu(cpu)
+ *per_cpu_ptr(ops->disabled, cpu) = 1;
+}
+
+static int control_ops_alloc(struct ftrace_ops *ops)
+{
+ int __percpu *disabled;
+
+ disabled = alloc_percpu(int);
+ if (!disabled)
+ return -ENOMEM;
+
+ ops->disabled = disabled;
+ control_ops_disable_all(ops);
+ return 0;
+}
+
+static void control_ops_free(struct ftrace_ops *ops)
+{
+ free_percpu(ops->disabled);
+}
+
+static void update_global_ops(void)
+{
+ ftrace_func_t func;
+
+ /*
+ * If there's only one function registered, then call that
+ * function directly. Otherwise, we need to iterate over the
+ * registered callers.
+ */
+ if (ftrace_global_list == &ftrace_list_end ||
+ ftrace_global_list->next == &ftrace_list_end)
+ func = ftrace_global_list->func;
+ else
+ func = ftrace_global_list_func;
+
+ /* If we filter on pids, update to use the pid function */
+ if (!list_empty(&ftrace_pids)) {
+ set_ftrace_pid_function(func);
+ func = ftrace_pid_func;
+ }
+
+ global_ops.func = func;
+}
+
+static void ftrace_sync(struct work_struct *work)
+{
+ /*
+ * This function is just a stub to implement a hard force
+ * of synchronize_sched(). This requires synchronizing
+ * tasks even in userspace and idle.
+ *
+ * Yes, function tracing is rude.
+ */
+}
+
+static void ftrace_sync_ipi(void *data)
+{
+ /* Probably not needed, but do it anyway */
+ smp_rmb();
+}
+
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+static void update_function_graph_func(void);
+#else
+static inline void update_function_graph_func(void) { }
+#endif
+
+static void update_ftrace_function(void)
+{
+ ftrace_func_t func;
+
+ update_global_ops();
+
+ /*
+ * If we are at the end of the list and this ops is
+ * not dynamic, then have the mcount trampoline call
+ * the function directly
+ */
+ if (ftrace_ops_list == &ftrace_list_end ||
+ (ftrace_ops_list->next == &ftrace_list_end &&
+ !(ftrace_ops_list->flags & FTRACE_OPS_FL_DYNAMIC)))
+ func = ftrace_ops_list->func;
+ else
+ func = ftrace_ops_list_func;
+
+ update_function_graph_func();
+
+#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 =
+ (func == ftrace_stub) ? func : ftrace_test_stop_func;
+#endif
+}
+
+static void add_ftrace_ops(struct ftrace_ops **list, struct ftrace_ops *ops)
+{
+ ops->next = *list;
+ /*
+ * We are entering ops into the list but another
+ * CPU might be walking that list. We need to make sure
+ * the ops->next pointer is valid before another CPU sees
+ * the ops pointer included into the list.
+ */
+ rcu_assign_pointer(*list, ops);
+}
+
+static int remove_ftrace_ops(struct ftrace_ops **list, struct ftrace_ops *ops)
+{
+ struct ftrace_ops **p;
+
+ /*
+ * If we are removing the last function, then simply point
+ * to the ftrace_stub.
+ */
+ if (*list == ops && ops->next == &ftrace_list_end) {
+ *list = &ftrace_list_end;
+ return 0;
+ }
+
+ for (p = list; *p != &ftrace_list_end; p = &(*p)->next)
+ if (*p == ops)
+ break;
+
+ if (*p != ops)
+ return -1;
+
+ *p = (*p)->next;
+ return 0;
+}
+
+static void add_ftrace_list_ops(struct ftrace_ops **list,
+ struct ftrace_ops *main_ops,
+ struct ftrace_ops *ops)
+{
+ int first = *list == &ftrace_list_end;
+ add_ftrace_ops(list, ops);
+ if (first)
+ add_ftrace_ops(&ftrace_ops_list, main_ops);
+}
+
+static int remove_ftrace_list_ops(struct ftrace_ops **list,
+ struct ftrace_ops *main_ops,
+ struct ftrace_ops *ops)
+{
+ int ret = remove_ftrace_ops(list, ops);
+ if (!ret && *list == &ftrace_list_end)
+ ret = remove_ftrace_ops(&ftrace_ops_list, main_ops);
+ return ret;
+}
+
+static int __register_ftrace_function(struct ftrace_ops *ops)
+{
+ if (FTRACE_WARN_ON(ops == &global_ops))
+ return -EINVAL;
+
+ if (WARN_ON(ops->flags & FTRACE_OPS_FL_ENABLED))
+ return -EBUSY;
+
+ /* We don't support both control and global flags set. */
+ if ((ops->flags & FL_GLOBAL_CONTROL_MASK) == FL_GLOBAL_CONTROL_MASK)
+ return -EINVAL;
+
+ if (!core_kernel_data((unsigned long)ops))
+ ops->flags |= FTRACE_OPS_FL_DYNAMIC;
+
+ if (ops->flags & FTRACE_OPS_FL_GLOBAL) {
+ add_ftrace_list_ops(&ftrace_global_list, &global_ops, ops);
+ ops->flags |= FTRACE_OPS_FL_ENABLED;
+ } else if (ops->flags & FTRACE_OPS_FL_CONTROL) {
+ if (control_ops_alloc(ops))
+ return -ENOMEM;
+ add_ftrace_list_ops(&ftrace_control_list, &control_ops, ops);
+ } else
+ add_ftrace_ops(&ftrace_ops_list, ops);
+
+ if (ftrace_enabled)
+ update_ftrace_function();
+
+ return 0;
+}
+
+static int __unregister_ftrace_function(struct ftrace_ops *ops)
+{
+ int ret;
+
+ if (WARN_ON(!(ops->flags & FTRACE_OPS_FL_ENABLED)))
+ return -EBUSY;
+
+ if (FTRACE_WARN_ON(ops == &global_ops))
+ return -EINVAL;
+
+ if (ops->flags & FTRACE_OPS_FL_GLOBAL) {
+ ret = remove_ftrace_list_ops(&ftrace_global_list,
+ &global_ops, ops);
+ if (!ret)
+ ops->flags &= ~FTRACE_OPS_FL_ENABLED;
+ } else if (ops->flags & FTRACE_OPS_FL_CONTROL) {
+ ret = remove_ftrace_list_ops(&ftrace_control_list,
+ &control_ops, ops);
+ } else
+ ret = remove_ftrace_ops(&ftrace_ops_list, ops);
+
+ if (ret < 0)
+ return ret;
+
+ if (ftrace_enabled)
+ update_ftrace_function();
+
+ return 0;
+}
+
+static void ftrace_update_pid_func(void)
+{
+ /* Only do something if we are tracing something */
+ if (ftrace_trace_function == ftrace_stub)
+ return;
+
+ update_ftrace_function();
+}
+
+#ifdef CONFIG_FUNCTION_PROFILER
+struct ftrace_profile {
+ struct hlist_node node;
+ unsigned long ip;
+ unsigned long counter;
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+ unsigned long long time;
+ unsigned long long time_squared;
+#endif
+};
+
+struct ftrace_profile_page {
+ struct ftrace_profile_page *next;
+ unsigned long index;
+ struct ftrace_profile records[];
+};
+
+struct ftrace_profile_stat {
+ atomic_t disabled;
+ struct hlist_head *hash;
+ struct ftrace_profile_page *pages;
+ struct ftrace_profile_page *start;
+ struct tracer_stat stat;
+};
+
+#define PROFILE_RECORDS_SIZE \
+ (PAGE_SIZE - offsetof(struct ftrace_profile_page, records))
+
+#define PROFILES_PER_PAGE \
+ (PROFILE_RECORDS_SIZE / sizeof(struct ftrace_profile))
+
+static int ftrace_profile_bits __read_mostly;
+static int ftrace_profile_enabled __read_mostly;
+
+/* ftrace_profile_lock - synchronize the enable and disable of the profiler */
+static DEFINE_MUTEX(ftrace_profile_lock);
+
+static DEFINE_PER_CPU(struct ftrace_profile_stat, ftrace_profile_stats);
+
+#define FTRACE_PROFILE_HASH_SIZE 1024 /* must be power of 2 */
+
+static void *
+function_stat_next(void *v, int idx)
+{
+ struct ftrace_profile *rec = v;
+ struct ftrace_profile_page *pg;
+
+ pg = (struct ftrace_profile_page *)((unsigned long)rec & PAGE_MASK);
+
+ again:
+ if (idx != 0)
+ rec++;
+
+ if ((void *)rec >= (void *)&pg->records[pg->index]) {
+ pg = pg->next;
+ if (!pg)
+ return NULL;
+ rec = &pg->records[0];
+ if (!rec->counter)
+ goto again;
+ }
+
+ return rec;
+}
+
+static void *function_stat_start(struct tracer_stat *trace)
+{
+ struct ftrace_profile_stat *stat =
+ container_of(trace, struct ftrace_profile_stat, stat);
+
+ if (!stat || !stat->start)
+ return NULL;
+
+ return function_stat_next(&stat->start->records[0], 0);
+}
+
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+/* function graph compares on total time */
+static int function_stat_cmp(void *p1, void *p2)
+{
+ struct ftrace_profile *a = p1;
+ struct ftrace_profile *b = p2;
+
+ if (a->time < b->time)
+ return -1;
+ if (a->time > b->time)
+ return 1;
+ else
+ return 0;
+}
+#else
+/* not function graph compares against hits */
+static int function_stat_cmp(void *p1, void *p2)
+{
+ struct ftrace_profile *a = p1;
+ struct ftrace_profile *b = p2;
+
+ if (a->counter < b->counter)
+ return -1;
+ if (a->counter > b->counter)
+ return 1;
+ else
+ return 0;
+}
+#endif
+
+static int function_stat_headers(struct seq_file *m)
+{
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+ seq_printf(m, " Function "
+ "Hit Time Avg s^2\n"
+ " -------- "
+ "--- ---- --- ---\n");
+#else
+ seq_printf(m, " Function Hit\n"
+ " -------- ---\n");
+#endif
+ return 0;
+}
+
+static int function_stat_show(struct seq_file *m, void *v)
+{
+ struct ftrace_profile *rec = v;
+ char str[KSYM_SYMBOL_LEN];
+ int ret = 0;
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+ static struct trace_seq s;
+ unsigned long long avg;
+ unsigned long long stddev;
+#endif
+ mutex_lock(&ftrace_profile_lock);
+
+ /* we raced with function_profile_reset() */
+ if (unlikely(rec->counter == 0)) {
+ ret = -EBUSY;
+ goto out;
+ }
+
+ kallsyms_lookup(rec->ip, NULL, NULL, NULL, str);
+ seq_printf(m, " %-30.30s %10lu", str, rec->counter);
+
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+ seq_printf(m, " ");
+ avg = rec->time;
+ do_div(avg, rec->counter);
+
+ /* Sample standard deviation (s^2) */
+ if (rec->counter <= 1)
+ stddev = 0;
+ else {
+ stddev = rec->time_squared - rec->counter * avg * avg;
+ /*
+ * Divide only 1000 for ns^2 -> us^2 conversion.
+ * trace_print_graph_duration will divide 1000 again.
+ */
+ do_div(stddev, (rec->counter - 1) * 1000);
+ }
+
+ trace_seq_init(&s);
+ trace_print_graph_duration(rec->time, &s);
+ trace_seq_puts(&s, " ");
+ trace_print_graph_duration(avg, &s);
+ trace_seq_puts(&s, " ");
+ trace_print_graph_duration(stddev, &s);
+ trace_print_seq(m, &s);
+#endif
+ seq_putc(m, '\n');
+out:
+ mutex_unlock(&ftrace_profile_lock);
+
+ return ret;
+}
+
+static void ftrace_profile_reset(struct ftrace_profile_stat *stat)
+{
+ struct ftrace_profile_page *pg;
+
+ pg = stat->pages = stat->start;
+
+ while (pg) {
+ memset(pg->records, 0, PROFILE_RECORDS_SIZE);
+ pg->index = 0;
+ pg = pg->next;
+ }
+
+ memset(stat->hash, 0,
+ FTRACE_PROFILE_HASH_SIZE * sizeof(struct hlist_head));
+}
+
+int ftrace_profile_pages_init(struct ftrace_profile_stat *stat)
+{
+ struct ftrace_profile_page *pg;
+ int functions;
+ int pages;
+ int i;
+
+ /* If we already allocated, do nothing */
+ if (stat->pages)
+ return 0;
+
+ stat->pages = (void *)get_zeroed_page(GFP_KERNEL);
+ if (!stat->pages)
+ return -ENOMEM;
+
+#ifdef CONFIG_DYNAMIC_FTRACE
+ functions = ftrace_update_tot_cnt;
+#else
+ /*
+ * We do not know the number of functions that exist because
+ * dynamic tracing is what counts them. With past experience
+ * we have around 20K functions. That should be more than enough.
+ * It is highly unlikely we will execute every function in
+ * the kernel.
+ */
+ functions = 20000;
+#endif
+
+ pg = stat->start = stat->pages;
+
+ pages = DIV_ROUND_UP(functions, PROFILES_PER_PAGE);
+
+ for (i = 1; i < pages; i++) {
+ pg->next = (void *)get_zeroed_page(GFP_KERNEL);
+ if (!pg->next)
+ goto out_free;
+ pg = pg->next;
+ }
+
+ return 0;
+
+ out_free:
+ pg = stat->start;
+ while (pg) {
+ unsigned long tmp = (unsigned long)pg;
+
+ pg = pg->next;
+ free_page(tmp);
+ }
+
+ stat->pages = NULL;
+ stat->start = NULL;
+
+ return -ENOMEM;
+}
+
+static int ftrace_profile_init_cpu(int cpu)
+{
+ struct ftrace_profile_stat *stat;
+ int size;
+
+ stat = &per_cpu(ftrace_profile_stats, cpu);
+
+ if (stat->hash) {
+ /* If the profile is already created, simply reset it */
+ ftrace_profile_reset(stat);
+ return 0;
+ }
+
+ /*
+ * We are profiling all functions, but usually only a few thousand
+ * functions are hit. We'll make a hash of 1024 items.
+ */
+ size = FTRACE_PROFILE_HASH_SIZE;
+
+ stat->hash = kzalloc(sizeof(struct hlist_head) * size, GFP_KERNEL);
+
+ if (!stat->hash)
+ return -ENOMEM;
+
+ if (!ftrace_profile_bits) {
+ size--;
+
+ for (; size; size >>= 1)
+ ftrace_profile_bits++;
+ }
+
+ /* Preallocate the function profiling pages */
+ if (ftrace_profile_pages_init(stat) < 0) {
+ kfree(stat->hash);
+ stat->hash = NULL;
+ return -ENOMEM;
+ }
+
+ return 0;
+}
+
+static int ftrace_profile_init(void)
+{
+ int cpu;
+ int ret = 0;
+
+ for_each_possible_cpu(cpu) {
+ ret = ftrace_profile_init_cpu(cpu);
+ if (ret)
+ break;
+ }
+
+ return ret;
+}
+
+/* interrupts must be disabled */
+static struct ftrace_profile *
+ftrace_find_profiled_func(struct ftrace_profile_stat *stat, unsigned long ip)
+{
+ struct ftrace_profile *rec;
+ struct hlist_head *hhd;
+ struct hlist_node *n;
+ unsigned long key;
+
+ key = hash_long(ip, ftrace_profile_bits);
+ hhd = &stat->hash[key];
+
+ if (hlist_empty(hhd))
+ return NULL;
+
+ hlist_for_each_entry_rcu(rec, n, hhd, node) {
+ if (rec->ip == ip)
+ return rec;
+ }
+
+ return NULL;
+}
+
+static void ftrace_add_profile(struct ftrace_profile_stat *stat,
+ struct ftrace_profile *rec)
+{
+ unsigned long key;
+
+ key = hash_long(rec->ip, ftrace_profile_bits);
+ hlist_add_head_rcu(&rec->node, &stat->hash[key]);
+}
+
+/*
+ * The memory is already allocated, this simply finds a new record to use.
+ */
+static struct ftrace_profile *
+ftrace_profile_alloc(struct ftrace_profile_stat *stat, unsigned long ip)
+{
+ struct ftrace_profile *rec = NULL;
+
+ /* prevent recursion (from NMIs) */
+ if (atomic_inc_return(&stat->disabled) != 1)
+ goto out;
+
+ /*
+ * Try to find the function again since an NMI
+ * could have added it
+ */
+ rec = ftrace_find_profiled_func(stat, ip);
+ if (rec)
+ goto out;
+
+ if (stat->pages->index == PROFILES_PER_PAGE) {
+ if (!stat->pages->next)
+ goto out;
+ stat->pages = stat->pages->next;
+ }
+
+ rec = &stat->pages->records[stat->pages->index++];
+ rec->ip = ip;
+ ftrace_add_profile(stat, rec);
+
+ out:
+ atomic_dec(&stat->disabled);
+
+ return rec;
+}
+
+static void
+function_profile_call(unsigned long ip, unsigned long parent_ip)
+{
+ struct ftrace_profile_stat *stat;
+ struct ftrace_profile *rec;
+ unsigned long flags;
+
+ if (!ftrace_profile_enabled)
+ return;
+
+ local_irq_save(flags);
+
+ stat = &__get_cpu_var(ftrace_profile_stats);
+ if (!stat->hash || !ftrace_profile_enabled)
+ goto out;
+
+ rec = ftrace_find_profiled_func(stat, ip);
+ if (!rec) {
+ rec = ftrace_profile_alloc(stat, ip);
+ if (!rec)
+ goto out;
+ }
+
+ rec->counter++;
+ out:
+ local_irq_restore(flags);
+}
+
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+static int profile_graph_entry(struct ftrace_graph_ent *trace)
+{
+ function_profile_call(trace->func, 0);
+ return 1;
+}
+
+static void profile_graph_return(struct ftrace_graph_ret *trace)
+{
+ struct ftrace_profile_stat *stat;
+ unsigned long long calltime;
+ struct ftrace_profile *rec;
+ unsigned long flags;
+
+ local_irq_save(flags);
+ stat = &__get_cpu_var(ftrace_profile_stats);
+ if (!stat->hash || !ftrace_profile_enabled)
+ goto out;
+
+ /* If the calltime was zero'd ignore it */
+ if (!trace->calltime)
+ goto out;
+
+ calltime = trace->rettime - trace->calltime;
+
+ if (!(trace_flags & TRACE_ITER_GRAPH_TIME)) {
+ int index;
+
+ index = trace->depth;
+
+ /* Append this call time to the parent time to subtract */
+ if (index)
+ current->ret_stack[index - 1].subtime += calltime;
+
+ if (current->ret_stack[index].subtime < calltime)
+ calltime -= current->ret_stack[index].subtime;
+ else
+ calltime = 0;
+ }
+
+ rec = ftrace_find_profiled_func(stat, trace->func);
+ if (rec) {
+ rec->time += calltime;
+ rec->time_squared += calltime * calltime;
+ }
+
+ out:
+ local_irq_restore(flags);
+}
+
+static int register_ftrace_profiler(void)
+{
+ return register_ftrace_graph(&profile_graph_return,
+ &profile_graph_entry);
+}
+
+static void unregister_ftrace_profiler(void)
+{
+ unregister_ftrace_graph();
+}
+#else
+static struct ftrace_ops ftrace_profile_ops __read_mostly = {
+ .func = function_profile_call,
+};
+
+static int register_ftrace_profiler(void)
+{
+ return register_ftrace_function(&ftrace_profile_ops);
+}
+
+static void unregister_ftrace_profiler(void)
+{
+ unregister_ftrace_function(&ftrace_profile_ops);
+}
+#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
+
+static ssize_t
+ftrace_profile_write(struct file *filp, const char __user *ubuf,
+ size_t cnt, loff_t *ppos)
+{
+ unsigned long val;
+ int ret;
+
+ ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
+ if (ret)
+ return ret;
+
+ val = !!val;
+
+ mutex_lock(&ftrace_profile_lock);
+ if (ftrace_profile_enabled ^ val) {
+ if (val) {
+ ret = ftrace_profile_init();
+ if (ret < 0) {
+ cnt = ret;
+ goto out;
+ }
+
+ ret = register_ftrace_profiler();
+ if (ret < 0) {
+ cnt = ret;
+ goto out;
+ }
+ ftrace_profile_enabled = 1;
+ } else {
+ ftrace_profile_enabled = 0;
+ /*
+ * unregister_ftrace_profiler calls stop_machine
+ * so this acts like an synchronize_sched.
+ */
+ unregister_ftrace_profiler();
+ }
+ }
+ out:
+ mutex_unlock(&ftrace_profile_lock);
+
+ *ppos += cnt;
+
+ return cnt;
+}
+
+static ssize_t
+ftrace_profile_read(struct file *filp, char __user *ubuf,
+ size_t cnt, loff_t *ppos)
+{
+ char buf[64]; /* big enough to hold a number */
+ int r;
+
+ r = sprintf(buf, "%u\n", ftrace_profile_enabled);
+ return simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
+}
+
+static const struct file_operations ftrace_profile_fops = {
+ .open = tracing_open_generic,
+ .read = ftrace_profile_read,
+ .write = ftrace_profile_write,
+ .llseek = default_llseek,
+};
+
+/* used to initialize the real stat files */
+static struct tracer_stat function_stats __initdata = {
+ .name = "functions",
+ .stat_start = function_stat_start,
+ .stat_next = function_stat_next,
+ .stat_cmp = function_stat_cmp,
+ .stat_headers = function_stat_headers,
+ .stat_show = function_stat_show
+};
+
+static __init void ftrace_profile_debugfs(struct dentry *d_tracer)
+{
+ struct ftrace_profile_stat *stat;
+ struct dentry *entry;
+ char *name;
+ int ret;
+ int cpu;
+
+ for_each_possible_cpu(cpu) {
+ stat = &per_cpu(ftrace_profile_stats, cpu);
+
+ /* allocate enough for function name + cpu number */
+ name = kmalloc(32, GFP_KERNEL);
+ if (!name) {
+ /*
+ * The files created are permanent, if something happens
+ * we still do not free memory.
+ */
+ WARN(1,
+ "Could not allocate stat file for cpu %d\n",
+ cpu);
+ return;
+ }
+ stat->stat = function_stats;
+ snprintf(name, 32, "function%d", cpu);
+ stat->stat.name = name;
+ ret = register_stat_tracer(&stat->stat);
+ if (ret) {
+ WARN(1,
+ "Could not register function stat for cpu %d\n",
+ cpu);
+ kfree(name);
+ return;
+ }
+ }
+
+ entry = debugfs_create_file("function_profile_enabled", 0644,
+ d_tracer, NULL, &ftrace_profile_fops);
+ if (!entry)
+ pr_warning("Could not create debugfs "
+ "'function_profile_enabled' entry\n");
+}
+
+#else /* CONFIG_FUNCTION_PROFILER */
+static __init void ftrace_profile_debugfs(struct dentry *d_tracer)
+{
+}
+#endif /* CONFIG_FUNCTION_PROFILER */
+
+static struct pid * const ftrace_swapper_pid = &init_struct_pid;
+
+loff_t
+ftrace_filter_lseek(struct file *file, loff_t offset, int whence)
+{
+ loff_t ret;
+
+ if (file->f_mode & FMODE_READ)
+ ret = seq_lseek(file, offset, whence);
+ else
+ file->f_pos = ret = 1;
+
+ return ret;
+}
+
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+static int ftrace_graph_active;
+#else
+# define ftrace_graph_active 0
+#endif
+
+#ifdef CONFIG_DYNAMIC_FTRACE
+
+#ifndef CONFIG_FTRACE_MCOUNT_RECORD
+# error Dynamic ftrace depends on MCOUNT_RECORD
+#endif
+
+static struct hlist_head ftrace_func_hash[FTRACE_FUNC_HASHSIZE] __read_mostly;
+
+struct ftrace_func_probe {
+ struct hlist_node node;
+ struct ftrace_probe_ops *ops;
+ unsigned long flags;
+ unsigned long ip;
+ void *data;
+ struct rcu_head rcu;
+};
+
+struct ftrace_func_entry {
+ struct hlist_node hlist;
+ unsigned long ip;
+};
+
+struct ftrace_hash {
+ unsigned long size_bits;
+ struct hlist_head *buckets;
+ unsigned long count;
+ struct rcu_head rcu;
+};
+
+/*
+ * We make these constant because no one should touch them,
+ * but they are used as the default "empty hash", to avoid allocating
+ * it all the time. These are in a read only section such that if
+ * anyone does try to modify it, it will cause an exception.
+ */
+static const struct hlist_head empty_buckets[1];
+static const struct ftrace_hash empty_hash = {
+ .buckets = (struct hlist_head *)empty_buckets,
+};
+#define EMPTY_HASH ((struct ftrace_hash *)&empty_hash)
+
+static struct ftrace_ops global_ops = {
+ .func = ftrace_stub,
+ .notrace_hash = EMPTY_HASH,
+ .filter_hash = EMPTY_HASH,
+};
+
+static DEFINE_MUTEX(ftrace_regex_lock);
+
+struct ftrace_page {
+ struct ftrace_page *next;
+ struct dyn_ftrace *records;
+ int index;
+ int size;
+};
+
+static struct ftrace_page *ftrace_new_pgs;
+
+#define ENTRY_SIZE sizeof(struct dyn_ftrace)
+#define ENTRIES_PER_PAGE (PAGE_SIZE / ENTRY_SIZE)
+
+/* estimate from running different kernels */
+#define NR_TO_INIT 10000
+
+static struct ftrace_page *ftrace_pages_start;
+static struct ftrace_page *ftrace_pages;
+
+static bool ftrace_hash_empty(struct ftrace_hash *hash)
+{
+ return !hash || !hash->count;
+}
+
+static struct ftrace_func_entry *
+ftrace_lookup_ip(struct ftrace_hash *hash, unsigned long ip)
+{
+ unsigned long key;
+ struct ftrace_func_entry *entry;
+ struct hlist_head *hhd;
+ struct hlist_node *n;
+
+ if (ftrace_hash_empty(hash))
+ return NULL;
+
+ if (hash->size_bits > 0)
+ key = hash_long(ip, hash->size_bits);
+ else
+ key = 0;
+
+ hhd = &hash->buckets[key];
+
+ hlist_for_each_entry_rcu(entry, n, hhd, hlist) {
+ if (entry->ip == ip)
+ return entry;
+ }
+ return NULL;
+}
+
+static void __add_hash_entry(struct ftrace_hash *hash,
+ struct ftrace_func_entry *entry)
+{
+ struct hlist_head *hhd;
+ unsigned long key;
+
+ if (hash->size_bits)
+ key = hash_long(entry->ip, hash->size_bits);
+ else
+ key = 0;
+
+ hhd = &hash->buckets[key];
+ hlist_add_head(&entry->hlist, hhd);
+ hash->count++;
+}
+
+static int add_hash_entry(struct ftrace_hash *hash, unsigned long ip)
+{
+ struct ftrace_func_entry *entry;
+
+ entry = kmalloc(sizeof(*entry), GFP_KERNEL);
+ if (!entry)
+ return -ENOMEM;
+
+ entry->ip = ip;
+ __add_hash_entry(hash, entry);
+
+ return 0;
+}
+
+static void
+free_hash_entry(struct ftrace_hash *hash,
+ struct ftrace_func_entry *entry)
+{
+ hlist_del(&entry->hlist);
+ kfree(entry);
+ hash->count--;
+}
+
+static void
+remove_hash_entry(struct ftrace_hash *hash,
+ struct ftrace_func_entry *entry)
+{
+ hlist_del(&entry->hlist);
+ hash->count--;
+}
+
+static void ftrace_hash_clear(struct ftrace_hash *hash)
+{
+ struct hlist_head *hhd;
+ struct hlist_node *tp, *tn;
+ struct ftrace_func_entry *entry;
+ int size = 1 << hash->size_bits;
+ int i;
+
+ if (!hash->count)
+ return;
+
+ for (i = 0; i < size; i++) {
+ hhd = &hash->buckets[i];
+ hlist_for_each_entry_safe(entry, tp, tn, hhd, hlist)
+ free_hash_entry(hash, entry);
+ }
+ FTRACE_WARN_ON(hash->count);
+}
+
+static void free_ftrace_hash(struct ftrace_hash *hash)
+{
+ if (!hash || hash == EMPTY_HASH)
+ return;
+ ftrace_hash_clear(hash);
+ kfree(hash->buckets);
+ kfree(hash);
+}
+
+static void __free_ftrace_hash_rcu(struct rcu_head *rcu)
+{
+ struct ftrace_hash *hash;
+
+ hash = container_of(rcu, struct ftrace_hash, rcu);
+ free_ftrace_hash(hash);
+}
+
+static void free_ftrace_hash_rcu(struct ftrace_hash *hash)
+{
+ if (!hash || hash == EMPTY_HASH)
+ return;
+ call_rcu_sched(&hash->rcu, __free_ftrace_hash_rcu);
+}
+
+void ftrace_free_filter(struct ftrace_ops *ops)
+{
+ free_ftrace_hash(ops->filter_hash);
+ free_ftrace_hash(ops->notrace_hash);
+}
+
+static struct ftrace_hash *alloc_ftrace_hash(int size_bits)
+{
+ struct ftrace_hash *hash;
+ int size;
+
+ hash = kzalloc(sizeof(*hash), GFP_KERNEL);
+ if (!hash)
+ return NULL;
+
+ size = 1 << size_bits;
+ hash->buckets = kcalloc(size, sizeof(*hash->buckets), GFP_KERNEL);
+
+ if (!hash->buckets) {
+ kfree(hash);
+ return NULL;
+ }
+
+ hash->size_bits = size_bits;
+
+ return hash;
+}
+
+static struct ftrace_hash *
+alloc_and_copy_ftrace_hash(int size_bits, struct ftrace_hash *hash)
+{
+ struct ftrace_func_entry *entry;
+ struct ftrace_hash *new_hash;
+ struct hlist_node *tp;
+ int size;
+ int ret;
+ int i;
+
+ new_hash = alloc_ftrace_hash(size_bits);
+ if (!new_hash)
+ return NULL;
+
+ /* Empty hash? */
+ if (ftrace_hash_empty(hash))
+ return new_hash;
+
+ size = 1 << hash->size_bits;
+ for (i = 0; i < size; i++) {
+ hlist_for_each_entry(entry, tp, &hash->buckets[i], hlist) {
+ ret = add_hash_entry(new_hash, entry->ip);
+ if (ret < 0)
+ goto free_hash;
+ }
+ }
+
+ FTRACE_WARN_ON(new_hash->count != hash->count);
+
+ return new_hash;
+
+ free_hash:
+ free_ftrace_hash(new_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_ops *ops, int enable,
+ struct ftrace_hash **dst, struct ftrace_hash *src)
+{
+ struct ftrace_func_entry *entry;
+ struct hlist_node *tp, *tn;
+ struct hlist_head *hhd;
+ struct ftrace_hash *old_hash;
+ struct ftrace_hash *new_hash;
+ 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.
+ */
+ if (!src->count) {
+ free_ftrace_hash_rcu(*dst);
+ rcu_assign_pointer(*dst, EMPTY_HASH);
+ /* still need to update the function records */
+ ret = 0;
+ goto out;
+ }
+
+ /*
+ * Make the hash size about 1/2 the # found
+ */
+ for (size /= 2; size; size >>= 1)
+ bits++;
+
+ /* Don't allocate too much */
+ if (bits > FTRACE_HASH_MAX_BITS)
+ bits = FTRACE_HASH_MAX_BITS;
+
+ ret = -ENOMEM;
+ new_hash = alloc_ftrace_hash(bits);
+ if (!new_hash)
+ goto out;
+
+ size = 1 << src->size_bits;
+ for (i = 0; i < size; i++) {
+ hhd = &src->buckets[i];
+ hlist_for_each_entry_safe(entry, tp, tn, hhd, hlist) {
+ if (bits > 0)
+ key = hash_long(entry->ip, bits);
+ else
+ key = 0;
+ remove_hash_entry(src, entry);
+ __add_hash_entry(new_hash, entry);
+ }
+ }
+
+ old_hash = *dst;
+ rcu_assign_pointer(*dst, new_hash);
+ free_ftrace_hash_rcu(old_hash);
+
+ 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;
+}
+
+/*
+ * Test the hashes for this ops to see if we want to call
+ * the ops->func or not.
+ *
+ * It's a match if the ip is in the ops->filter_hash or
+ * the filter_hash does not exist or is empty,
+ * AND
+ * the ip is not in the ops->notrace_hash.
+ *
+ * This needs to be called with preemption disabled as
+ * the hashes are freed with call_rcu_sched().
+ */
+static int
+ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip)
+{
+ struct ftrace_hash *filter_hash;
+ struct ftrace_hash *notrace_hash;
+ int ret;
+
+ filter_hash = rcu_dereference_raw(ops->filter_hash);
+ notrace_hash = rcu_dereference_raw(ops->notrace_hash);
+
+ if ((ftrace_hash_empty(filter_hash) ||
+ ftrace_lookup_ip(filter_hash, ip)) &&
+ (ftrace_hash_empty(notrace_hash) ||
+ !ftrace_lookup_ip(notrace_hash, ip)))
+ ret = 1;
+ else
+ ret = 0;
+
+ return ret;
+}
+
+/*
+ * This is a double for. Do not use 'break' to break out of the loop,
+ * you must use a goto.
+ */
+#define do_for_each_ftrace_rec(pg, rec) \
+ for (pg = ftrace_pages_start; pg; pg = pg->next) { \
+ int _____i; \
+ for (_____i = 0; _____i < pg->index; _____i++) { \
+ rec = &pg->records[_____i];
+
+#define while_for_each_ftrace_rec() \
+ } \
+ }
+
+
+static int ftrace_cmp_recs(const void *a, const void *b)
+{
+ const struct dyn_ftrace *reca = a;
+ const struct dyn_ftrace *recb = b;
+
+ if (reca->ip > recb->ip)
+ return 1;
+ if (reca->ip < recb->ip)
+ return -1;
+ return 0;
+}
+
+/**
+ * ftrace_location - return true if the ip giving is a traced location
+ * @ip: the instruction pointer to check
+ *
+ * Returns 1 if @ip given is a pointer to a ftrace location.
+ * That is, the instruction that is either a NOP or call to
+ * the function tracer. It checks the ftrace internal tables to
+ * determine if the address belongs or not.
+ */
+int ftrace_location(unsigned long ip)
+{
+ struct ftrace_page *pg;
+ struct dyn_ftrace *rec;
+ struct dyn_ftrace key;
+
+ key.ip = ip;
+
+ for (pg = ftrace_pages_start; pg; pg = pg->next) {
+ rec = bsearch(&key, pg->records, pg->index,
+ sizeof(struct dyn_ftrace),
+ ftrace_cmp_recs);
+ if (rec)
+ return 1;
+ }
+
+ return 0;
+}
+
+static void __ftrace_hash_rec_update(struct ftrace_ops *ops,
+ int filter_hash,
+ bool inc)
+{
+ struct ftrace_hash *hash;
+ struct ftrace_hash *other_hash;
+ struct ftrace_page *pg;
+ struct dyn_ftrace *rec;
+ int count = 0;
+ int all = 0;
+
+ /* Only update if the ops has been registered */
+ if (!(ops->flags & FTRACE_OPS_FL_ENABLED))
+ return;
+
+ /*
+ * In the filter_hash case:
+ * If the count is zero, we update all records.
+ * Otherwise we just update the items in the hash.
+ *
+ * In the notrace_hash case:
+ * We enable the update in the hash.
+ * As disabling notrace means enabling the tracing,
+ * and enabling notrace means disabling, the inc variable
+ * gets inversed.
+ */
+ if (filter_hash) {
+ hash = ops->filter_hash;
+ other_hash = ops->notrace_hash;
+ if (ftrace_hash_empty(hash))
+ all = 1;
+ } else {
+ inc = !inc;
+ hash = ops->notrace_hash;
+ other_hash = ops->filter_hash;
+ /*
+ * If the notrace hash has no items,
+ * then there's nothing to do.
+ */
+ if (ftrace_hash_empty(hash))
+ return;
+ }
+
+ do_for_each_ftrace_rec(pg, rec) {
+ int in_other_hash = 0;
+ int in_hash = 0;
+ int match = 0;
+
+ if (all) {
+ /*
+ * Only the filter_hash affects all records.
+ * Update if the record is not in the notrace hash.
+ */
+ if (!other_hash || !ftrace_lookup_ip(other_hash, rec->ip))
+ match = 1;
+ } else {
+ in_hash = !!ftrace_lookup_ip(hash, rec->ip);
+ in_other_hash = !!ftrace_lookup_ip(other_hash, rec->ip);
+
+ /*
+ *
+ */
+ if (filter_hash && in_hash && !in_other_hash)
+ match = 1;
+ else if (!filter_hash && in_hash &&
+ (in_other_hash || ftrace_hash_empty(other_hash)))
+ match = 1;
+ }
+ if (!match)
+ continue;
+
+ if (inc) {
+ rec->flags++;
+ if (FTRACE_WARN_ON((rec->flags & ~FTRACE_FL_MASK) == FTRACE_REF_MAX))
+ return;
+ } else {
+ if (FTRACE_WARN_ON((rec->flags & ~FTRACE_FL_MASK) == 0))
+ return;
+ rec->flags--;
+ }
+ count++;
+ /* Shortcut, if we handled all records, we are done. */
+ if (!all && count == hash->count)
+ return;
+ } while_for_each_ftrace_rec();
+}
+
+static void ftrace_hash_rec_disable(struct ftrace_ops *ops,
+ int filter_hash)
+{
+ __ftrace_hash_rec_update(ops, filter_hash, 0);
+}
+
+static void ftrace_hash_rec_enable(struct ftrace_ops *ops,
+ int filter_hash)
+{
+ __ftrace_hash_rec_update(ops, filter_hash, 1);
+}
+
+static struct dyn_ftrace *ftrace_alloc_dyn_node(unsigned long ip)
+{
+ if (ftrace_pages->index == ftrace_pages->size) {
+ /* We should have allocated enough */
+ if (WARN_ON(!ftrace_pages->next))
+ return NULL;
+ ftrace_pages = ftrace_pages->next;
+ }
+
+ return &ftrace_pages->records[ftrace_pages->index++];
+}
+
+static struct dyn_ftrace *
+ftrace_record_ip(unsigned long ip)
+{
+ struct dyn_ftrace *rec;
+
+ if (ftrace_disabled)
+ return NULL;
+
+ rec = ftrace_alloc_dyn_node(ip);
+ if (!rec)
+ return NULL;
+
+ rec->ip = ip;
+
+ return rec;
+}
+
+static void print_ip_ins(const char *fmt, unsigned char *p)
+{
+ int i;
+
+ printk(KERN_CONT "%s", fmt);
+
+ for (i = 0; i < MCOUNT_INSN_SIZE; i++)
+ printk(KERN_CONT "%s%02x", i ? ":" : "", p[i]);
+}
+
+/**
+ * ftrace_bug - report and shutdown function tracer
+ * @failed: The failed type (EFAULT, EINVAL, EPERM)
+ * @ip: The address that failed
+ *
+ * The arch code that enables or disables the function tracing
+ * can call ftrace_bug() when it has detected a problem in
+ * modifying the code. @failed should be one of either:
+ * EFAULT - if the problem happens on reading the @ip address
+ * EINVAL - if what is read at @ip is not what was expected
+ * EPERM - if the problem happens on writting to the @ip address
+ */
+void ftrace_bug(int failed, unsigned long ip)
+{
+ switch (failed) {
+ case -EFAULT:
+ FTRACE_WARN_ON_ONCE(1);
+ pr_info("ftrace faulted on modifying ");
+ print_ip_sym(ip);
+ break;
+ case -EINVAL:
+ FTRACE_WARN_ON_ONCE(1);
+ pr_info("ftrace failed to modify ");
+ print_ip_sym(ip);
+ print_ip_ins(" actual: ", (unsigned char *)ip);
+ printk(KERN_CONT "\n");
+ break;
+ case -EPERM:
+ FTRACE_WARN_ON_ONCE(1);
+ pr_info("ftrace faulted on writing ");
+ print_ip_sym(ip);
+ break;
+ default:
+ FTRACE_WARN_ON_ONCE(1);
+ pr_info("ftrace faulted on unknown error ");
+ print_ip_sym(ip);
+ }
+}
+
+
+/* Return 1 if the address range is reserved for ftrace */
+int ftrace_text_reserved(void *start, void *end)
+{
+ struct dyn_ftrace *rec;
+ struct ftrace_page *pg;
+
+ do_for_each_ftrace_rec(pg, rec) {
+ if (rec->ip <= (unsigned long)end &&
+ rec->ip + MCOUNT_INSN_SIZE > (unsigned long)start)
+ return 1;
+ } while_for_each_ftrace_rec();
+ return 0;
+}
+
+static int ftrace_check_record(struct dyn_ftrace *rec, int enable, int update)
+{
+ unsigned long flag = 0UL;
+
+ /*
+ * If we are updating calls:
+ *
+ * If the record has a ref count, then we need to enable it
+ * because someone is using it.
+ *
+ * Otherwise we make sure its disabled.
+ *
+ * If we are disabling calls, then disable all records that
+ * are enabled.
+ */
+ if (enable && (rec->flags & ~FTRACE_FL_MASK))
+ flag = FTRACE_FL_ENABLED;
+
+ /* If the state of this record hasn't changed, then do nothing */
+ if ((rec->flags & FTRACE_FL_ENABLED) == flag)
+ return FTRACE_UPDATE_IGNORE;
+
+ if (flag) {
+ if (update)
+ rec->flags |= FTRACE_FL_ENABLED;
+ return FTRACE_UPDATE_MAKE_CALL;
+ }
+
+ if (update)
+ rec->flags &= ~FTRACE_FL_ENABLED;
+
+ return FTRACE_UPDATE_MAKE_NOP;
+}
+
+/**
+ * ftrace_update_record, set a record that now is tracing or not
+ * @rec: the record to update
+ * @enable: set to 1 if the record is tracing, zero to force disable
+ *
+ * The records that represent all functions that can be traced need
+ * to be updated when tracing has been enabled.
+ */
+int ftrace_update_record(struct dyn_ftrace *rec, int enable)
+{
+ return ftrace_check_record(rec, enable, 1);
+}
+
+/**
+ * ftrace_test_record, check if the record has been enabled or not
+ * @rec: the record to test
+ * @enable: set to 1 to check if enabled, 0 if it is disabled
+ *
+ * The arch code may need to test if a record is already set to
+ * tracing to determine how to modify the function code that it
+ * represents.
+ */
+int ftrace_test_record(struct dyn_ftrace *rec, int enable)
+{
+ return ftrace_check_record(rec, enable, 0);
+}
+
+static int
+__ftrace_replace_code(struct dyn_ftrace *rec, int enable)
+{
+ unsigned long ftrace_addr;
+ int ret;
+
+ ftrace_addr = (unsigned long)FTRACE_ADDR;
+
+ ret = ftrace_update_record(rec, enable);
+
+ switch (ret) {
+ case FTRACE_UPDATE_IGNORE:
+ return 0;
+
+ case FTRACE_UPDATE_MAKE_CALL:
+ return ftrace_make_call(rec, ftrace_addr);
+
+ case FTRACE_UPDATE_MAKE_NOP:
+ return ftrace_make_nop(NULL, rec, ftrace_addr);
+ }
+
+ return -1; /* unknow ftrace bug */
+}
+
+static void ftrace_replace_code(int update)
+{
+ struct dyn_ftrace *rec;
+ struct ftrace_page *pg;
+ int failed;
+
+ if (unlikely(ftrace_disabled))
+ return;
+
+ do_for_each_ftrace_rec(pg, rec) {
+ failed = __ftrace_replace_code(rec, update);
+ if (failed) {
+ ftrace_bug(failed, rec->ip);
+ /* Stop processing */
+ return;
+ }
+ } while_for_each_ftrace_rec();
+}
+
+struct ftrace_rec_iter {
+ struct ftrace_page *pg;
+ int index;
+};
+
+/**
+ * ftrace_rec_iter_start, start up iterating over traced functions
+ *
+ * Returns an iterator handle that is used to iterate over all
+ * the records that represent address locations where functions
+ * are traced.
+ *
+ * May return NULL if no records are available.
+ */
+struct ftrace_rec_iter *ftrace_rec_iter_start(void)
+{
+ /*
+ * We only use a single iterator.
+ * Protected by the ftrace_lock mutex.
+ */
+ static struct ftrace_rec_iter ftrace_rec_iter;
+ struct ftrace_rec_iter *iter = &ftrace_rec_iter;
+
+ iter->pg = ftrace_pages_start;
+ iter->index = 0;
+
+ /* Could have empty pages */
+ while (iter->pg && !iter->pg->index)
+ iter->pg = iter->pg->next;
+
+ if (!iter->pg)
+ return NULL;
+
+ return iter;
+}
+
+/**
+ * ftrace_rec_iter_next, get the next record to process.
+ * @iter: The handle to the iterator.
+ *
+ * Returns the next iterator after the given iterator @iter.
+ */
+struct ftrace_rec_iter *ftrace_rec_iter_next(struct ftrace_rec_iter *iter)
+{
+ iter->index++;
+
+ if (iter->index >= iter->pg->index) {
+ iter->pg = iter->pg->next;
+ iter->index = 0;
+
+ /* Could have empty pages */
+ while (iter->pg && !iter->pg->index)
+ iter->pg = iter->pg->next;
+ }
+
+ if (!iter->pg)
+ return NULL;
+
+ return iter;
+}
+
+/**
+ * ftrace_rec_iter_record, get the record at the iterator location
+ * @iter: The current iterator location
+ *
+ * Returns the record that the current @iter is at.
+ */
+struct dyn_ftrace *ftrace_rec_iter_record(struct ftrace_rec_iter *iter)
+{
+ return &iter->pg->records[iter->index];
+}
+
+static int
+ftrace_code_disable(struct module *mod, struct dyn_ftrace *rec)
+{
+ unsigned long ip;
+ int ret;
+
+ ip = rec->ip;
+
+ if (unlikely(ftrace_disabled))
+ return 0;
+
+ ret = ftrace_make_nop(mod, rec, MCOUNT_ADDR);
+ if (ret) {
+ ftrace_bug(ret, ip);
+ return 0;
+ }
+ return 1;
+}
+
+/*
+ * archs can override this function if they must do something
+ * before the modifying code is performed.
+ */
+int __weak ftrace_arch_code_modify_prepare(void)
+{
+ return 0;
+}
+
+/*
+ * archs can override this function if they must do something
+ * after the modifying code is performed.
+ */
+int __weak ftrace_arch_code_modify_post_process(void)
+{
+ return 0;
+}
+
+static int __ftrace_modify_code(void *data)
+{
+ int *command = data;
+
+ if (*command & FTRACE_UPDATE_CALLS)
+ ftrace_replace_code(1);
+ else if (*command & FTRACE_DISABLE_CALLS)
+ ftrace_replace_code(0);
+
+ if (*command & FTRACE_UPDATE_TRACE_FUNC)
+ ftrace_update_ftrace_func(ftrace_trace_function);
+
+ if (*command & FTRACE_START_FUNC_RET)
+ ftrace_enable_ftrace_graph_caller();
+ else if (*command & FTRACE_STOP_FUNC_RET)
+ ftrace_disable_ftrace_graph_caller();
+
+ return 0;
+}
+
+/**
+ * ftrace_run_stop_machine, go back to the stop machine method
+ * @command: The command to tell ftrace what to do
+ *
+ * If an arch needs to fall back to the stop machine method, the
+ * it can call this function.
+ */
+void ftrace_run_stop_machine(int command)
+{
+ stop_machine(__ftrace_modify_code, &command, NULL);
+}
+
+/**
+ * arch_ftrace_update_code, modify the code to trace or not trace
+ * @command: The command that needs to be done
+ *
+ * Archs can override this function if it does not need to
+ * run stop_machine() to modify code.
+ */
+void __weak arch_ftrace_update_code(int command)
+{
+ ftrace_run_stop_machine(command);
+}
+
+static void ftrace_run_update_code(int command)
+{
+ int ret;
+
+ ret = ftrace_arch_code_modify_prepare();
+ FTRACE_WARN_ON(ret);
+ if (ret)
+ return;
+ /*
+ * Do not call function tracer while we update the code.
+ * We are in stop machine.
+ */
+ function_trace_stop++;
+
+ /*
+ * By default we use stop_machine() to modify the code.
+ * But archs can do what ever they want as long as it
+ * is safe. The stop_machine() is the safest, but also
+ * produces the most overhead.
+ */
+ arch_ftrace_update_code(command);
+
+#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--;
+
+ ret = ftrace_arch_code_modify_post_process();
+ FTRACE_WARN_ON(ret);
+}
+
+static ftrace_func_t saved_ftrace_func;
+static int ftrace_start_up;
+static int global_start_up;
+
+static void ftrace_startup_enable(int command)
+{
+ if (saved_ftrace_func != ftrace_trace_function) {
+ saved_ftrace_func = ftrace_trace_function;
+ command |= FTRACE_UPDATE_TRACE_FUNC;
+ }
+
+ if (!command || !ftrace_enabled)
+ return;
+
+ ftrace_run_update_code(command);
+}
+
+static int ftrace_startup(struct ftrace_ops *ops, int command)
+{
+ bool hash_enable = true;
+ int ret;
+
+ if (unlikely(ftrace_disabled))
+ return -ENODEV;
+
+ ret = __register_ftrace_function(ops);
+ if (ret)
+ return ret;
+
+ ftrace_start_up++;
+ command |= FTRACE_UPDATE_CALLS;
+
+ /* ops marked global share the filter hashes */
+ if (ops->flags & FTRACE_OPS_FL_GLOBAL) {
+ ops = &global_ops;
+ /* Don't update hash if global is already set */
+ if (global_start_up)
+ hash_enable = false;
+ global_start_up++;
+ }
+
+ ops->flags |= FTRACE_OPS_FL_ENABLED;
+ if (hash_enable)
+ ftrace_hash_rec_enable(ops, 1);
+
+ ftrace_startup_enable(command);
+
+ return 0;
+}
+
+static int ftrace_shutdown(struct ftrace_ops *ops, int command)
+{
+ bool hash_disable = true;
+ int ret;
+
+ if (unlikely(ftrace_disabled))
+ return -ENODEV;
+
+ ret = __unregister_ftrace_function(ops);
+ if (ret)
+ return ret;
+
+ ftrace_start_up--;
+ /*
+ * Just warn in case of unbalance, no need to kill ftrace, it's not
+ * critical but the ftrace_call callers may be never nopped again after
+ * further ftrace uses.
+ */
+ WARN_ON_ONCE(ftrace_start_up < 0);
+
+ if (ops->flags & FTRACE_OPS_FL_GLOBAL) {
+ ops = &global_ops;
+ global_start_up--;
+ WARN_ON_ONCE(global_start_up < 0);
+ /* Don't update hash if global still has users */
+ if (global_start_up) {
+ WARN_ON_ONCE(!ftrace_start_up);
+ hash_disable = false;
+ }
+ }
+
+ if (hash_disable)
+ ftrace_hash_rec_disable(ops, 1);
+
+ if (ops != &global_ops || !global_start_up)
+ ops->flags &= ~FTRACE_OPS_FL_ENABLED;
+
+ command |= FTRACE_UPDATE_CALLS;
+
+ if (saved_ftrace_func != ftrace_trace_function) {
+ saved_ftrace_func = ftrace_trace_function;
+ command |= FTRACE_UPDATE_TRACE_FUNC;
+ }
+
+ if (!command || !ftrace_enabled) {
+ /*
+ * If these are control ops, they still need their
+ * per_cpu field freed. Since, function tracing is
+ * not currently active, we can just free them
+ * without synchronizing all CPUs.
+ */
+ if (ops->flags & FTRACE_OPS_FL_CONTROL)
+ control_ops_free(ops);
+ return 0;
+ }
+
+ ftrace_run_update_code(command);
+
+ /*
+ * Dynamic ops may be freed, we must make sure that all
+ * callers are done before leaving this function.
+ * The same goes for freeing the per_cpu data of the control
+ * ops.
+ *
+ * Again, normal synchronize_sched() is not good enough.
+ * We need to do a hard force of sched synchronization.
+ * This is because we use preempt_disable() to do RCU, but
+ * the function tracers can be called where RCU is not watching
+ * (like before user_exit()). We can not rely on the RCU
+ * infrastructure to do the synchronization, thus we must do it
+ * ourselves.
+ */
+ if (ops->flags & (FTRACE_OPS_FL_DYNAMIC | FTRACE_OPS_FL_CONTROL)) {
+ schedule_on_each_cpu(ftrace_sync);
+
+ if (ops->flags & FTRACE_OPS_FL_CONTROL)
+ control_ops_free(ops);
+ }
+
+ return 0;
+}
+
+static void ftrace_startup_sysctl(void)
+{
+ int command;
+
+ if (unlikely(ftrace_disabled))
+ return;
+
+ /* Force update next time */
+ saved_ftrace_func = NULL;
+ /* ftrace_start_up is true if we want ftrace running */
+ if (ftrace_start_up) {
+ command = FTRACE_UPDATE_CALLS;
+ if (ftrace_graph_active)
+ command |= FTRACE_START_FUNC_RET;
+ ftrace_startup_enable(command);
+ }
+}
+
+static void ftrace_shutdown_sysctl(void)
+{
+ int command;
+
+ if (unlikely(ftrace_disabled))
+ return;
+
+ /* ftrace_start_up is true if ftrace is running */
+ if (ftrace_start_up) {
+ command = FTRACE_DISABLE_CALLS;
+ if (ftrace_graph_active)
+ command |= FTRACE_STOP_FUNC_RET;
+ ftrace_run_update_code(command);
+ }
+}
+
+static cycle_t ftrace_update_time;
+static unsigned long ftrace_update_cnt;
+unsigned long ftrace_update_tot_cnt;
+
+static inline int ops_traces_mod(struct ftrace_ops *ops)
+{
+ /*
+ * Filter_hash being empty will default to trace module.
+ * But notrace hash requires a test of individual module functions.
+ */
+ return ftrace_hash_empty(ops->filter_hash) &&
+ ftrace_hash_empty(ops->notrace_hash);
+}
+
+/*
+ * Check if the current ops references the record.
+ *
+ * If the ops traces all functions, then it was already accounted for.
+ * If the ops does not trace the current record function, skip it.
+ * If the ops ignores the function via notrace filter, skip it.
+ */
+static inline bool
+ops_references_rec(struct ftrace_ops *ops, struct dyn_ftrace *rec)
+{
+ /* If ops isn't enabled, ignore it */
+ if (!(ops->flags & FTRACE_OPS_FL_ENABLED))
+ return 0;
+
+ /* If ops traces all mods, we already accounted for it */
+ if (ops_traces_mod(ops))
+ return 0;
+
+ /* The function must be in the filter */
+ if (!ftrace_hash_empty(ops->filter_hash) &&
+ !ftrace_lookup_ip(ops->filter_hash, rec->ip))
+ return 0;
+
+ /* If in notrace hash, we ignore it too */
+ if (ftrace_lookup_ip(ops->notrace_hash, rec->ip))
+ return 0;
+
+ return 1;
+}
+
+static int referenced_filters(struct dyn_ftrace *rec)
+{
+ struct ftrace_ops *ops;
+ int cnt = 0;
+
+ for (ops = ftrace_ops_list; ops != &ftrace_list_end; ops = ops->next) {
+ if (ops_references_rec(ops, rec))
+ cnt++;
+ }
+
+ return cnt;
+}
+
+static int ftrace_update_code(struct module *mod)
+{
+ struct ftrace_page *pg;
+ struct dyn_ftrace *p;
+ cycle_t start, stop;
+ unsigned long ref = 0;
+ bool test = false;
+ int i;
+
+ /*
+ * 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) {
+ if (ops_traces_mod(ops))
+ ref++;
+ else
+ test = true;
+ }
+ }
+ }
+
+ start = ftrace_now(raw_smp_processor_id());
+ ftrace_update_cnt = 0;
+
+ for (pg = ftrace_new_pgs; pg; pg = pg->next) {
+
+ for (i = 0; i < pg->index; i++) {
+ int cnt = ref;
+
+ /* If something went wrong, bail without enabling anything */
+ if (unlikely(ftrace_disabled))
+ return -1;
+
+ p = &pg->records[i];
+ if (test)
+ cnt += referenced_filters(p);
+ p->flags = cnt;
+
+ /*
+ * Do the initial record conversion from mcount jump
+ * to the NOP instructions.
+ */
+ if (!ftrace_code_disable(mod, p))
+ break;
+
+ ftrace_update_cnt++;
+
+ /*
+ * If the tracing is enabled, go ahead and enable the record.
+ *
+ * The reason not to enable the record immediatelly is the
+ * inherent check of ftrace_make_nop/ftrace_make_call for
+ * correct previous instructions. Making first the NOP
+ * conversion puts the module to the correct state, thus
+ * passing the ftrace_make_call check.
+ */
+ if (ftrace_start_up && cnt) {
+ int failed = __ftrace_replace_code(p, 1);
+ if (failed)
+ ftrace_bug(failed, p->ip);
+ }
+ }
+ }
+
+ ftrace_new_pgs = NULL;
+
+ stop = ftrace_now(raw_smp_processor_id());
+ ftrace_update_time = stop - start;
+ ftrace_update_tot_cnt += ftrace_update_cnt;
+
+ return 0;
+}
+
+static int ftrace_allocate_records(struct ftrace_page *pg, int count)
+{
+ int order;
+ int cnt;
+
+ if (WARN_ON(!count))
+ return -EINVAL;
+
+ order = get_count_order(DIV_ROUND_UP(count, ENTRIES_PER_PAGE));
+
+ /*
+ * We want to fill as much as possible. No more than a page
+ * may be empty.
+ */
+ while ((PAGE_SIZE << order) / ENTRY_SIZE >= count + ENTRIES_PER_PAGE)
+ order--;
+
+ again:
+ pg->records = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, order);
+
+ if (!pg->records) {
+ /* if we can't allocate this size, try something smaller */
+ if (!order)
+ return -ENOMEM;
+ order >>= 1;
+ goto again;
+ }
+
+ cnt = (PAGE_SIZE << order) / ENTRY_SIZE;
+ pg->size = cnt;
+
+ if (cnt > count)
+ cnt = count;
+
+ return cnt;
+}
+
+static struct ftrace_page *
+ftrace_allocate_pages(unsigned long num_to_init)
+{
+ struct ftrace_page *start_pg;
+ struct ftrace_page *pg;
+ int order;
+ int cnt;
+
+ if (!num_to_init)
+ return 0;
+
+ start_pg = pg = kzalloc(sizeof(*pg), GFP_KERNEL);
+ if (!pg)
+ return NULL;
+
+ /*
+ * Try to allocate as much as possible in one continues
+ * location that fills in all of the space. We want to
+ * waste as little space as possible.
+ */
+ for (;;) {
+ cnt = ftrace_allocate_records(pg, num_to_init);
+ if (cnt < 0)
+ goto free_pages;
+
+ num_to_init -= cnt;
+ if (!num_to_init)
+ break;
+
+ pg->next = kzalloc(sizeof(*pg), GFP_KERNEL);
+ if (!pg->next)
+ goto free_pages;
+
+ pg = pg->next;
+ }
+
+ return start_pg;
+
+ free_pages:
+ while (start_pg) {
+ order = get_count_order(pg->size / ENTRIES_PER_PAGE);
+ free_pages((unsigned long)pg->records, order);
+ start_pg = pg->next;
+ kfree(pg);
+ pg = start_pg;
+ }
+ pr_info("ftrace: FAILED to allocate memory for functions\n");
+ return NULL;
+}
+
+static int __init ftrace_dyn_table_alloc(unsigned long num_to_init)
+{
+ int cnt;
+
+ if (!num_to_init) {
+ pr_info("ftrace: No functions to be traced?\n");
+ return -1;
+ }
+
+ cnt = num_to_init / ENTRIES_PER_PAGE;
+ pr_info("ftrace: allocating %ld entries in %d pages\n",
+ num_to_init, cnt + 1);
+
+ return 0;
+}
+
+#define FTRACE_BUFF_MAX (KSYM_SYMBOL_LEN+4) /* room for wildcards */
+
+struct ftrace_iterator {
+ loff_t pos;
+ loff_t func_pos;
+ struct ftrace_page *pg;
+ struct dyn_ftrace *func;
+ struct ftrace_func_probe *probe;
+ struct trace_parser parser;
+ struct ftrace_hash *hash;
+ struct ftrace_ops *ops;
+ int hidx;
+ int idx;
+ unsigned flags;
+};
+
+static void *
+t_hash_next(struct seq_file *m, loff_t *pos)
+{
+ struct ftrace_iterator *iter = m->private;
+ struct hlist_node *hnd = NULL;
+ struct hlist_head *hhd;
+
+ (*pos)++;
+ iter->pos = *pos;
+
+ if (iter->probe)
+ hnd = &iter->probe->node;
+ retry:
+ if (iter->hidx >= FTRACE_FUNC_HASHSIZE)
+ return NULL;
+
+ hhd = &ftrace_func_hash[iter->hidx];
+
+ if (hlist_empty(hhd)) {
+ iter->hidx++;
+ hnd = NULL;
+ goto retry;
+ }
+
+ if (!hnd)
+ hnd = hhd->first;
+ else {
+ hnd = hnd->next;
+ if (!hnd) {
+ iter->hidx++;
+ goto retry;
+ }
+ }
+
+ if (WARN_ON_ONCE(!hnd))
+ return NULL;
+
+ iter->probe = hlist_entry(hnd, struct ftrace_func_probe, node);
+
+ return iter;
+}
+
+static void *t_hash_start(struct seq_file *m, loff_t *pos)
+{
+ struct ftrace_iterator *iter = m->private;
+ void *p = NULL;
+ loff_t l;
+
+ if (!(iter->flags & FTRACE_ITER_DO_HASH))
+ return NULL;
+
+ if (iter->func_pos > *pos)
+ return NULL;
+
+ iter->hidx = 0;
+ for (l = 0; l <= (*pos - iter->func_pos); ) {
+ p = t_hash_next(m, &l);
+ if (!p)
+ break;
+ }
+ if (!p)
+ return NULL;
+
+ /* Only set this if we have an item */
+ iter->flags |= FTRACE_ITER_HASH;
+
+ return iter;
+}
+
+static int
+t_hash_show(struct seq_file *m, struct ftrace_iterator *iter)
+{
+ struct ftrace_func_probe *rec;
+
+ rec = iter->probe;
+ if (WARN_ON_ONCE(!rec))
+ return -EIO;
+
+ if (rec->ops->print)
+ return rec->ops->print(m, rec->ip, rec->ops, rec->data);
+
+ seq_printf(m, "%ps:%ps", (void *)rec->ip, (void *)rec->ops->func);
+
+ if (rec->data)
+ seq_printf(m, ":%p", rec->data);
+ seq_putc(m, '\n');
+
+ return 0;
+}
+
+static void *
+t_next(struct seq_file *m, void *v, loff_t *pos)
+{
+ struct ftrace_iterator *iter = m->private;
+ struct ftrace_ops *ops = iter->ops;
+ struct dyn_ftrace *rec = NULL;
+
+ if (unlikely(ftrace_disabled))
+ return NULL;
+
+ if (iter->flags & FTRACE_ITER_HASH)
+ return t_hash_next(m, pos);
+
+ (*pos)++;
+ iter->pos = iter->func_pos = *pos;
+
+ if (iter->flags & FTRACE_ITER_PRINTALL)
+ return t_hash_start(m, pos);
+
+ retry:
+ if (iter->idx >= iter->pg->index) {
+ if (iter->pg->next) {
+ iter->pg = iter->pg->next;
+ iter->idx = 0;
+ goto retry;
+ }
+ } else {
+ rec = &iter->pg->records[iter->idx++];
+ if (((iter->flags & FTRACE_ITER_FILTER) &&
+ !(ftrace_lookup_ip(ops->filter_hash, rec->ip))) ||
+
+ ((iter->flags & FTRACE_ITER_NOTRACE) &&
+ !ftrace_lookup_ip(ops->notrace_hash, rec->ip)) ||
+
+ ((iter->flags & FTRACE_ITER_ENABLED) &&
+ !(rec->flags & ~FTRACE_FL_MASK))) {
+
+ rec = NULL;
+ goto retry;
+ }
+ }
+
+ if (!rec)
+ return t_hash_start(m, pos);
+
+ iter->func = rec;
+
+ return iter;
+}
+
+static void reset_iter_read(struct ftrace_iterator *iter)
+{
+ iter->pos = 0;
+ iter->func_pos = 0;
+ iter->flags &= ~(FTRACE_ITER_PRINTALL | FTRACE_ITER_HASH);
+}
+
+static void *t_start(struct seq_file *m, loff_t *pos)
+{
+ struct ftrace_iterator *iter = m->private;
+ struct ftrace_ops *ops = iter->ops;
+ void *p = NULL;
+ loff_t l;
+
+ mutex_lock(&ftrace_lock);
+
+ if (unlikely(ftrace_disabled))
+ return NULL;
+
+ /*
+ * If an lseek was done, then reset and start from beginning.
+ */
+ if (*pos < iter->pos)
+ reset_iter_read(iter);
+
+ /*
+ * For set_ftrace_filter reading, if we have the filter
+ * off, we can short cut and just print out that all
+ * functions are enabled.
+ */
+ if (iter->flags & FTRACE_ITER_FILTER &&
+ ftrace_hash_empty(ops->filter_hash)) {
+ if (*pos > 0)
+ return t_hash_start(m, pos);
+ iter->flags |= FTRACE_ITER_PRINTALL;
+ /* reset in case of seek/pread */
+ iter->flags &= ~FTRACE_ITER_HASH;
+ return iter;
+ }
+
+ if (iter->flags & FTRACE_ITER_HASH)
+ return t_hash_start(m, pos);
+
+ /*
+ * Unfortunately, we need to restart at ftrace_pages_start
+ * every time we let go of the ftrace_mutex. This is because
+ * those pointers can change without the lock.
+ */
+ iter->pg = ftrace_pages_start;
+ iter->idx = 0;
+ for (l = 0; l <= *pos; ) {
+ p = t_next(m, p, &l);
+ if (!p)
+ break;
+ }
+
+ if (!p)
+ return t_hash_start(m, pos);
+
+ return iter;
+}
+
+static void t_stop(struct seq_file *m, void *p)
+{
+ mutex_unlock(&ftrace_lock);
+}
+
+static int t_show(struct seq_file *m, void *v)
+{
+ struct ftrace_iterator *iter = m->private;
+ struct dyn_ftrace *rec;
+
+ if (iter->flags & FTRACE_ITER_HASH)
+ return t_hash_show(m, iter);
+
+ if (iter->flags & FTRACE_ITER_PRINTALL) {
+ seq_printf(m, "#### all functions enabled ####\n");
+ return 0;
+ }
+
+ rec = iter->func;
+
+ if (!rec)
+ return 0;
+
+ seq_printf(m, "%ps", (void *)rec->ip);
+ if (iter->flags & FTRACE_ITER_ENABLED)
+ seq_printf(m, " (%ld)",
+ rec->flags & ~FTRACE_FL_MASK);
+ seq_printf(m, "\n");
+
+ return 0;
+}
+
+static const struct seq_operations show_ftrace_seq_ops = {
+ .start = t_start,
+ .next = t_next,
+ .stop = t_stop,
+ .show = t_show,
+};
+
+static int
+ftrace_avail_open(struct inode *inode, struct file *file)
+{
+ struct ftrace_iterator *iter;
+ int ret;
+
+ if (unlikely(ftrace_disabled))
+ return -ENODEV;
+
+ iter = kzalloc(sizeof(*iter), GFP_KERNEL);
+ if (!iter)
+ return -ENOMEM;
+
+ iter->pg = ftrace_pages_start;
+ iter->ops = &global_ops;
+
+ ret = seq_open(file, &show_ftrace_seq_ops);
+ if (!ret) {
+ struct seq_file *m = file->private_data;
+
+ m->private = iter;
+ } else {
+ kfree(iter);
+ }
+
+ return ret;
+}
+
+static int
+ftrace_enabled_open(struct inode *inode, struct file *file)
+{
+ struct ftrace_iterator *iter;
+ int ret;
+
+ if (unlikely(ftrace_disabled))
+ return -ENODEV;
+
+ iter = kzalloc(sizeof(*iter), GFP_KERNEL);
+ if (!iter)
+ return -ENOMEM;
+
+ iter->pg = ftrace_pages_start;
+ iter->flags = FTRACE_ITER_ENABLED;
+ iter->ops = &global_ops;
+
+ ret = seq_open(file, &show_ftrace_seq_ops);
+ if (!ret) {
+ struct seq_file *m = file->private_data;
+
+ m->private = iter;
+ } else {
+ kfree(iter);
+ }
+
+ return ret;
+}
+
+static void ftrace_filter_reset(struct ftrace_hash *hash)
+{
+ mutex_lock(&ftrace_lock);
+ ftrace_hash_clear(hash);
+ mutex_unlock(&ftrace_lock);
+}
+
+/**
+ * ftrace_regex_open - initialize function tracer filter files
+ * @ops: The ftrace_ops that hold the hash filters
+ * @flag: The type of filter to process
+ * @inode: The inode, usually passed in to your open routine
+ * @file: The file, usually passed in to your open routine
+ *
+ * ftrace_regex_open() initializes the filter files for the
+ * @ops. Depending on @flag it may process the filter hash or
+ * the notrace hash of @ops. With this called from the open
+ * routine, you can use ftrace_filter_write() for the write
+ * routine if @flag has FTRACE_ITER_FILTER set, or
+ * ftrace_notrace_write() if @flag has FTRACE_ITER_NOTRACE set.
+ * ftrace_filter_lseek() should be used as the lseek routine, and
+ * release must call ftrace_regex_release().
+ */
+int
+ftrace_regex_open(struct ftrace_ops *ops, int flag,
+ struct inode *inode, struct file *file)
+{
+ struct ftrace_iterator *iter;
+ struct ftrace_hash *hash;
+ int ret = 0;
+
+ if (unlikely(ftrace_disabled))
+ return -ENODEV;
+
+ iter = kzalloc(sizeof(*iter), GFP_KERNEL);
+ if (!iter)
+ return -ENOMEM;
+
+ if (trace_parser_get_init(&iter->parser, FTRACE_BUFF_MAX)) {
+ kfree(iter);
+ return -ENOMEM;
+ }
+
+ if (flag & FTRACE_ITER_NOTRACE)
+ hash = ops->notrace_hash;
+ else
+ hash = ops->filter_hash;
+
+ iter->ops = ops;
+ iter->flags = flag;
+
+ if (file->f_mode & FMODE_WRITE) {
+ mutex_lock(&ftrace_lock);
+ iter->hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, hash);
+ mutex_unlock(&ftrace_lock);
+
+ if (!iter->hash) {
+ trace_parser_put(&iter->parser);
+ kfree(iter);
+ return -ENOMEM;
+ }
+ }
+
+ mutex_lock(&ftrace_regex_lock);
+
+ if ((file->f_mode & FMODE_WRITE) &&
+ (file->f_flags & O_TRUNC))
+ ftrace_filter_reset(iter->hash);
+
+ if (file->f_mode & FMODE_READ) {
+ iter->pg = ftrace_pages_start;
+
+ ret = seq_open(file, &show_ftrace_seq_ops);
+ if (!ret) {
+ struct seq_file *m = file->private_data;
+ m->private = iter;
+ } else {
+ /* Failed */
+ free_ftrace_hash(iter->hash);
+ trace_parser_put(&iter->parser);
+ kfree(iter);
+ }
+ } else
+ file->private_data = iter;
+ mutex_unlock(&ftrace_regex_lock);
+
+ return ret;
+}
+
+static int
+ftrace_filter_open(struct inode *inode, struct file *file)
+{
+ return ftrace_regex_open(&global_ops,
+ FTRACE_ITER_FILTER | FTRACE_ITER_DO_HASH,
+ inode, file);
+}
+
+static int
+ftrace_notrace_open(struct inode *inode, struct file *file)
+{
+ return ftrace_regex_open(&global_ops, FTRACE_ITER_NOTRACE,
+ inode, file);
+}
+
+static int ftrace_match(char *str, char *regex, int len, int type)
+{
+ int matched = 0;
+ int slen;
+
+ switch (type) {
+ case MATCH_FULL:
+ if (strcmp(str, regex) == 0)
+ matched = 1;
+ break;
+ case MATCH_FRONT_ONLY:
+ if (strncmp(str, regex, len) == 0)
+ matched = 1;
+ break;
+ case MATCH_MIDDLE_ONLY:
+ if (strstr(str, regex))
+ matched = 1;
+ break;
+ case MATCH_END_ONLY:
+ slen = strlen(str);
+ if (slen >= len && memcmp(str + slen - len, regex, len) == 0)
+ matched = 1;
+ break;
+ }
+
+ return matched;
+}
+
+static int
+enter_record(struct ftrace_hash *hash, struct dyn_ftrace *rec, int not)
+{
+ struct ftrace_func_entry *entry;
+ int ret = 0;
+
+ entry = ftrace_lookup_ip(hash, rec->ip);
+ if (not) {
+ /* Do nothing if it doesn't exist */
+ if (!entry)
+ return 0;
+
+ free_hash_entry(hash, entry);
+ } else {
+ /* Do nothing if it exists */
+ if (entry)
+ return 0;
+
+ ret = add_hash_entry(hash, rec->ip);
+ }
+ return ret;
+}
+
+static int
+ftrace_match_record(struct dyn_ftrace *rec, char *mod,
+ char *regex, int len, int type)
+{
+ char str[KSYM_SYMBOL_LEN];
+ char *modname;
+
+ kallsyms_lookup(rec->ip, NULL, NULL, &modname, str);
+
+ if (mod) {
+ /* module lookup requires matching the module */
+ if (!modname || strcmp(modname, mod))
+ return 0;
+
+ /* blank search means to match all funcs in the mod */
+ if (!len)
+ return 1;
+ }
+
+ return ftrace_match(str, regex, len, type);
+}
+
+static int
+match_records(struct ftrace_hash *hash, char *buff,
+ int len, char *mod, int not)
+{
+ unsigned search_len = 0;
+ struct ftrace_page *pg;
+ struct dyn_ftrace *rec;
+ int type = MATCH_FULL;
+ char *search = buff;
+ int found = 0;
+ int ret;
+
+ if (len) {
+ type = filter_parse_regex(buff, len, &search, ¬);
+ search_len = strlen(search);
+ }
+
+ mutex_lock(&ftrace_lock);
+
+ if (unlikely(ftrace_disabled))
+ goto out_unlock;
+
+ do_for_each_ftrace_rec(pg, rec) {
+ if (ftrace_match_record(rec, mod, search, search_len, type)) {
+ ret = enter_record(hash, rec, not);
+ if (ret < 0) {
+ found = ret;
+ goto out_unlock;
+ }
+ found = 1;
+ }
+ } while_for_each_ftrace_rec();
+ out_unlock:
+ mutex_unlock(&ftrace_lock);
+
+ return found;
+}
+
+static int
+ftrace_match_records(struct ftrace_hash *hash, char *buff, int len)
+{
+ return match_records(hash, buff, len, NULL, 0);
+}
+
+static int
+ftrace_match_module_records(struct ftrace_hash *hash, char *buff, char *mod)
+{
+ int not = 0;
+
+ /* blank or '*' mean the same */
+ if (strcmp(buff, "*") == 0)
+ buff[0] = 0;
+
+ /* handle the case of 'dont filter this module' */
+ if (strcmp(buff, "!") == 0 || strcmp(buff, "!*") == 0) {
+ buff[0] = 0;
+ not = 1;
+ }
+
+ return match_records(hash, buff, strlen(buff), mod, not);
+}
+
+/*
+ * We register the module command as a template to show others how
+ * to register the a command as well.
+ */
+
+static int
+ftrace_mod_callback(struct ftrace_hash *hash,
+ char *func, char *cmd, char *param, int enable)
+{
+ char *mod;
+ int ret = -EINVAL;
+
+ /*
+ * cmd == 'mod' because we only registered this func
+ * for the 'mod' ftrace_func_command.
+ * But if you register one func with multiple commands,
+ * you can tell which command was used by the cmd
+ * parameter.
+ */
+
+ /* we must have a module name */
+ if (!param)
+ return ret;
+
+ mod = strsep(¶m, ":");
+ if (!strlen(mod))
+ return ret;
+
+ ret = ftrace_match_module_records(hash, func, mod);
+ if (!ret)
+ ret = -EINVAL;
+ if (ret < 0)
+ return ret;
+
+ return 0;
+}
+
+static struct ftrace_func_command ftrace_mod_cmd = {
+ .name = "mod",
+ .func = ftrace_mod_callback,
+};
+
+static int __init ftrace_mod_cmd_init(void)
+{
+ return register_ftrace_command(&ftrace_mod_cmd);
+}
+device_initcall(ftrace_mod_cmd_init);
+
+static void
+function_trace_probe_call(unsigned long ip, unsigned long parent_ip)
+{
+ struct ftrace_func_probe *entry;
+ struct hlist_head *hhd;
+ struct hlist_node *n;
+ unsigned long key;
+
+ key = hash_long(ip, FTRACE_HASH_BITS);
+
+ hhd = &ftrace_func_hash[key];
+
+ if (hlist_empty(hhd))
+ return;
+
+ /*
+ * Disable preemption for these calls to prevent a RCU grace
+ * period. This syncs the hash iteration and freeing of items
+ * on the hash. rcu_read_lock is too dangerous here.
+ */
+ preempt_disable_notrace();
+ hlist_for_each_entry_rcu(entry, n, hhd, node) {
+ if (entry->ip == ip)
+ entry->ops->func(ip, parent_ip, &entry->data);
+ }
+ preempt_enable_notrace();
+}
+
+static struct ftrace_ops trace_probe_ops __read_mostly =
+{
+ .func = function_trace_probe_call,
+};
+
+static int ftrace_probe_registered;
+
+static void __enable_ftrace_function_probe(void)
+{
+ int ret;
+ int i;
+
+ if (ftrace_probe_registered)
+ return;
+
+ for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) {
+ struct hlist_head *hhd = &ftrace_func_hash[i];
+ if (hhd->first)
+ break;
+ }
+ /* Nothing registered? */
+ if (i == FTRACE_FUNC_HASHSIZE)
+ return;
+
+ ret = ftrace_startup(&trace_probe_ops, 0);
+
+ ftrace_probe_registered = 1;
+}
+
+static void __disable_ftrace_function_probe(void)
+{
+ int i;
+
+ if (!ftrace_probe_registered)
+ return;
+
+ for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) {
+ struct hlist_head *hhd = &ftrace_func_hash[i];
+ if (hhd->first)
+ return;
+ }
+
+ /* no more funcs left */
+ ftrace_shutdown(&trace_probe_ops, 0);
+
+ ftrace_probe_registered = 0;
+}
+
+
+static void ftrace_free_entry_rcu(struct rcu_head *rhp)
+{
+ struct ftrace_func_probe *entry =
+ container_of(rhp, struct ftrace_func_probe, rcu);
+
+ if (entry->ops->free)
+ entry->ops->free(&entry->data);
+ kfree(entry);
+}
+
+
+int
+register_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,
+ void *data)
+{
+ struct ftrace_func_probe *entry;
+ struct ftrace_page *pg;
+ struct dyn_ftrace *rec;
+ int type, len, not;
+ unsigned long key;
+ int count = 0;
+ char *search;
+
+ type = filter_parse_regex(glob, strlen(glob), &search, ¬);
+ len = strlen(search);
+
+ /* we do not support '!' for function probes */
+ if (WARN_ON(not))
+ return -EINVAL;
+
+ mutex_lock(&ftrace_lock);
+
+ if (unlikely(ftrace_disabled))
+ goto out_unlock;
+
+ do_for_each_ftrace_rec(pg, rec) {
+
+ if (!ftrace_match_record(rec, NULL, search, len, type))
+ continue;
+
+ entry = kmalloc(sizeof(*entry), GFP_KERNEL);
+ if (!entry) {
+ /* If we did not process any, then return error */
+ if (!count)
+ count = -ENOMEM;
+ goto out_unlock;
+ }
+
+ count++;
+
+ entry->data = data;
+
+ /*
+ * The caller might want to do something special
+ * for each function we find. We call the callback
+ * to give the caller an opportunity to do so.
+ */
+ if (ops->callback) {
+ if (ops->callback(rec->ip, &entry->data) < 0) {
+ /* caller does not like this func */
+ kfree(entry);
+ continue;
+ }
+ }
+
+ entry->ops = ops;
+ entry->ip = rec->ip;
+
+ key = hash_long(entry->ip, FTRACE_HASH_BITS);
+ hlist_add_head_rcu(&entry->node, &ftrace_func_hash[key]);
+
+ } while_for_each_ftrace_rec();
+ __enable_ftrace_function_probe();
+
+ out_unlock:
+ mutex_unlock(&ftrace_lock);
+
+ return count;
+}
+
+enum {
+ PROBE_TEST_FUNC = 1,
+ PROBE_TEST_DATA = 2
+};
+
+static void
+__unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,
+ void *data, int flags)
+{
+ struct ftrace_func_probe *entry;
+ struct hlist_node *n, *tmp;
+ char str[KSYM_SYMBOL_LEN];
+ int type = MATCH_FULL;
+ int i, len = 0;
+ char *search;
+
+ if (glob && (strcmp(glob, "*") == 0 || !strlen(glob)))
+ glob = NULL;
+ else if (glob) {
+ int not;
+
+ type = filter_parse_regex(glob, strlen(glob), &search, ¬);
+ len = strlen(search);
+
+ /* we do not support '!' for function probes */
+ if (WARN_ON(not))
+ return;
+ }
+
+ mutex_lock(&ftrace_lock);
+ for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) {
+ struct hlist_head *hhd = &ftrace_func_hash[i];
+
+ hlist_for_each_entry_safe(entry, n, tmp, hhd, node) {
+
+ /* break up if statements for readability */
+ if ((flags & PROBE_TEST_FUNC) && entry->ops != ops)
+ continue;
+
+ if ((flags & PROBE_TEST_DATA) && entry->data != data)
+ continue;
+
+ /* do this last, since it is the most expensive */
+ if (glob) {
+ kallsyms_lookup(entry->ip, NULL, NULL,
+ NULL, str);
+ if (!ftrace_match(str, glob, len, type))
+ continue;
+ }
+
+ hlist_del_rcu(&entry->node);
+ call_rcu_sched(&entry->rcu, ftrace_free_entry_rcu);
+ }
+ }
+ __disable_ftrace_function_probe();
+ mutex_unlock(&ftrace_lock);
+}
+
+void
+unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,
+ void *data)
+{
+ __unregister_ftrace_function_probe(glob, ops, data,
+ PROBE_TEST_FUNC | PROBE_TEST_DATA);
+}
+
+void
+unregister_ftrace_function_probe_func(char *glob, struct ftrace_probe_ops *ops)
+{
+ __unregister_ftrace_function_probe(glob, ops, NULL, PROBE_TEST_FUNC);
+}
+
+void unregister_ftrace_function_probe_all(char *glob)
+{
+ __unregister_ftrace_function_probe(glob, NULL, NULL, 0);
+}
+
+static LIST_HEAD(ftrace_commands);
+static DEFINE_MUTEX(ftrace_cmd_mutex);
+
+int register_ftrace_command(struct ftrace_func_command *cmd)
+{
+ struct ftrace_func_command *p;
+ int ret = 0;
+
+ mutex_lock(&ftrace_cmd_mutex);
+ list_for_each_entry(p, &ftrace_commands, list) {
+ if (strcmp(cmd->name, p->name) == 0) {
+ ret = -EBUSY;
+ goto out_unlock;
+ }
+ }
+ list_add(&cmd->list, &ftrace_commands);
+ out_unlock:
+ mutex_unlock(&ftrace_cmd_mutex);
+
+ return ret;
+}
+
+int unregister_ftrace_command(struct ftrace_func_command *cmd)
+{
+ struct ftrace_func_command *p, *n;
+ int ret = -ENODEV;
+
+ mutex_lock(&ftrace_cmd_mutex);
+ list_for_each_entry_safe(p, n, &ftrace_commands, list) {
+ if (strcmp(cmd->name, p->name) == 0) {
+ ret = 0;
+ list_del_init(&p->list);
+ goto out_unlock;
+ }
+ }
+ out_unlock:
+ mutex_unlock(&ftrace_cmd_mutex);
+
+ return ret;
+}
+
+static int ftrace_process_regex(struct ftrace_hash *hash,
+ char *buff, int len, int enable)
+{
+ char *func, *command, *next = buff;
+ struct ftrace_func_command *p;
+ int ret = -EINVAL;
+
+ func = strsep(&next, ":");
+
+ if (!next) {
+ ret = ftrace_match_records(hash, func, len);
+ if (!ret)
+ ret = -EINVAL;
+ if (ret < 0)
+ return ret;
+ return 0;
+ }
+
+ /* command found */
+
+ command = strsep(&next, ":");
+
+ mutex_lock(&ftrace_cmd_mutex);
+ list_for_each_entry(p, &ftrace_commands, list) {
+ if (strcmp(p->name, command) == 0) {
+ ret = p->func(hash, func, command, next, enable);
+ goto out_unlock;
+ }
+ }
+ out_unlock:
+ mutex_unlock(&ftrace_cmd_mutex);
+
+ return ret;
+}
+
+static ssize_t
+ftrace_regex_write(struct file *file, const char __user *ubuf,
+ size_t cnt, loff_t *ppos, int enable)
+{
+ struct ftrace_iterator *iter;
+ struct trace_parser *parser;
+ ssize_t ret, read;
+
+ if (!cnt)
+ return 0;
+
+ mutex_lock(&ftrace_regex_lock);
+
+ ret = -ENODEV;
+ if (unlikely(ftrace_disabled))
+ goto out_unlock;
+
+ if (file->f_mode & FMODE_READ) {
+ struct seq_file *m = file->private_data;
+ iter = m->private;
+ } else
+ iter = file->private_data;
+
+ parser = &iter->parser;
+ read = trace_get_user(parser, ubuf, cnt, ppos);
+
+ if (read >= 0 && trace_parser_loaded(parser) &&
+ !trace_parser_cont(parser)) {
+ ret = ftrace_process_regex(iter->hash, parser->buffer,
+ parser->idx, enable);
+ trace_parser_clear(parser);
+ if (ret)
+ goto out_unlock;
+ }
+
+ ret = read;
+out_unlock:
+ mutex_unlock(&ftrace_regex_lock);
+
+ return ret;
+}
+
+ssize_t
+ftrace_filter_write(struct file *file, const char __user *ubuf,
+ size_t cnt, loff_t *ppos)
+{
+ return ftrace_regex_write(file, ubuf, cnt, ppos, 1);
+}
+
+ssize_t
+ftrace_notrace_write(struct file *file, const char __user *ubuf,
+ size_t cnt, loff_t *ppos)
+{
+ return ftrace_regex_write(file, ubuf, cnt, ppos, 0);
+}
+
+static int
+ftrace_set_regex(struct ftrace_ops *ops, unsigned char *buf, int len,
+ int reset, int enable)
+{
+ struct ftrace_hash **orig_hash;
+ struct ftrace_hash *hash;
+ int ret;
+
+ /* All global ops uses the global ops filters */
+ if (ops->flags & FTRACE_OPS_FL_GLOBAL)
+ ops = &global_ops;
+
+ if (unlikely(ftrace_disabled))
+ return -ENODEV;
+
+ if (enable)
+ orig_hash = &ops->filter_hash;
+ else
+ orig_hash = &ops->notrace_hash;
+
+ hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, *orig_hash);
+ if (!hash)
+ return -ENOMEM;
+
+ mutex_lock(&ftrace_regex_lock);
+ if (reset)
+ ftrace_filter_reset(hash);
+ if (buf && !ftrace_match_records(hash, buf, len)) {
+ ret = -EINVAL;
+ goto out_regex_unlock;
+ }
+
+ mutex_lock(&ftrace_lock);
+ ret = ftrace_hash_move(ops, enable, orig_hash, hash);
+ if (!ret && ops->flags & FTRACE_OPS_FL_ENABLED
+ && ftrace_enabled)
+ ftrace_run_update_code(FTRACE_UPDATE_CALLS);
+
+ mutex_unlock(&ftrace_lock);
+
+ out_regex_unlock:
+ mutex_unlock(&ftrace_regex_lock);
+
+ free_ftrace_hash(hash);
+ return ret;
+}
+
+/**
+ * ftrace_set_filter - set a function to filter on in ftrace
+ * @ops - the ops to set the filter with
+ * @buf - the string that holds the function filter text.
+ * @len - the length of the string.
+ * @reset - non zero to reset all filters before applying this filter.
+ *
+ * Filters denote which functions should be enabled when tracing is enabled.
+ * If @buf is NULL and reset is set, all functions will be enabled for tracing.
+ */
+int ftrace_set_filter(struct ftrace_ops *ops, unsigned char *buf,
+ int len, int reset)
+{
+ return ftrace_set_regex(ops, buf, len, reset, 1);
+}
+EXPORT_SYMBOL_GPL(ftrace_set_filter);
+
+/**
+ * ftrace_set_notrace - set a function to not trace in ftrace
+ * @ops - the ops to set the notrace filter with
+ * @buf - the string that holds the function notrace text.
+ * @len - the length of the string.
+ * @reset - non zero to reset all filters before applying this filter.
+ *
+ * Notrace Filters denote which functions should not be enabled when tracing
+ * is enabled. If @buf is NULL and reset is set, all functions will be enabled
+ * for tracing.
+ */
+int ftrace_set_notrace(struct ftrace_ops *ops, unsigned char *buf,
+ int len, int reset)
+{
+ return ftrace_set_regex(ops, buf, len, reset, 0);
+}
+EXPORT_SYMBOL_GPL(ftrace_set_notrace);
+/**
+ * ftrace_set_filter - set a function to filter on in ftrace
+ * @ops - the ops to set the filter with
+ * @buf - the string that holds the function filter text.
+ * @len - the length of the string.
+ * @reset - non zero to reset all filters before applying this filter.
+ *
+ * Filters denote which functions should be enabled when tracing is enabled.
+ * If @buf is NULL and reset is set, all functions will be enabled for tracing.
+ */
+void ftrace_set_global_filter(unsigned char *buf, int len, int reset)
+{
+ ftrace_set_regex(&global_ops, buf, len, reset, 1);
+}
+EXPORT_SYMBOL_GPL(ftrace_set_global_filter);
+
+/**
+ * ftrace_set_notrace - set a function to not trace in ftrace
+ * @ops - the ops to set the notrace filter with
+ * @buf - the string that holds the function notrace text.
+ * @len - the length of the string.
+ * @reset - non zero to reset all filters before applying this filter.
+ *
+ * Notrace Filters denote which functions should not be enabled when tracing
+ * is enabled. If @buf is NULL and reset is set, all functions will be enabled
+ * for tracing.
+ */
+void ftrace_set_global_notrace(unsigned char *buf, int len, int reset)
+{
+ ftrace_set_regex(&global_ops, buf, len, reset, 0);
+}
+EXPORT_SYMBOL_GPL(ftrace_set_global_notrace);
+
+/*
+ * command line interface to allow users to set filters on boot up.
+ */
+#define FTRACE_FILTER_SIZE COMMAND_LINE_SIZE
+static char ftrace_notrace_buf[FTRACE_FILTER_SIZE] __initdata;
+static char ftrace_filter_buf[FTRACE_FILTER_SIZE] __initdata;
+
+static int __init set_ftrace_notrace(char *str)
+{
+ strncpy(ftrace_notrace_buf, str, FTRACE_FILTER_SIZE);
+ return 1;
+}
+__setup("ftrace_notrace=", set_ftrace_notrace);
+
+static int __init set_ftrace_filter(char *str)
+{
+ strncpy(ftrace_filter_buf, str, FTRACE_FILTER_SIZE);
+ return 1;
+}
+__setup("ftrace_filter=", set_ftrace_filter);
+
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+static char ftrace_graph_buf[FTRACE_FILTER_SIZE] __initdata;
+static int ftrace_set_func(unsigned long *array, int *idx, char *buffer);
+
+static int __init set_graph_function(char *str)
+{
+ strlcpy(ftrace_graph_buf, str, FTRACE_FILTER_SIZE);
+ return 1;
+}
+__setup("ftrace_graph_filter=", set_graph_function);
+
+static void __init set_ftrace_early_graph(char *buf)
+{
+ int ret;
+ char *func;
+
+ while (buf) {
+ func = strsep(&buf, ",");
+ /* we allow only one expression at a time */
+ ret = ftrace_set_func(ftrace_graph_funcs, &ftrace_graph_count,
+ func);
+ if (ret)
+ printk(KERN_DEBUG "ftrace: function %s not "
+ "traceable\n", func);
+ }
+}
+#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
+
+void __init
+ftrace_set_early_filter(struct ftrace_ops *ops, char *buf, int enable)
+{
+ char *func;
+
+ while (buf) {
+ func = strsep(&buf, ",");
+ ftrace_set_regex(ops, func, strlen(func), 0, enable);
+ }
+}
+
+static void __init set_ftrace_early_filters(void)
+{
+ if (ftrace_filter_buf[0])
+ ftrace_set_early_filter(&global_ops, ftrace_filter_buf, 1);
+ if (ftrace_notrace_buf[0])
+ ftrace_set_early_filter(&global_ops, ftrace_notrace_buf, 0);
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+ if (ftrace_graph_buf[0])
+ set_ftrace_early_graph(ftrace_graph_buf);
+#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
+}
+
+int ftrace_regex_release(struct inode *inode, struct file *file)
+{
+ struct seq_file *m = (struct seq_file *)file->private_data;
+ struct ftrace_iterator *iter;
+ struct ftrace_hash **orig_hash;
+ struct trace_parser *parser;
+ int filter_hash;
+ int ret;
+
+ mutex_lock(&ftrace_regex_lock);
+ if (file->f_mode & FMODE_READ) {
+ iter = m->private;
+
+ seq_release(inode, file);
+ } else
+ iter = file->private_data;
+
+ parser = &iter->parser;
+ if (trace_parser_loaded(parser)) {
+ parser->buffer[parser->idx] = 0;
+ ftrace_match_records(iter->hash, parser->buffer, parser->idx);
+ }
+
+ trace_parser_put(parser);
+
+ if (file->f_mode & FMODE_WRITE) {
+ filter_hash = !!(iter->flags & FTRACE_ITER_FILTER);
+
+ if (filter_hash)
+ orig_hash = &iter->ops->filter_hash;
+ else
+ orig_hash = &iter->ops->notrace_hash;
+
+ mutex_lock(&ftrace_lock);
+ 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_UPDATE_CALLS);
+
+ mutex_unlock(&ftrace_lock);
+ }
+ free_ftrace_hash(iter->hash);
+ kfree(iter);
+
+ mutex_unlock(&ftrace_regex_lock);
+ return 0;
+}
+
+static const struct file_operations ftrace_avail_fops = {
+ .open = ftrace_avail_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = seq_release_private,
+};
+
+static const struct file_operations ftrace_enabled_fops = {
+ .open = ftrace_enabled_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = seq_release_private,
+};
+
+static const struct file_operations ftrace_filter_fops = {
+ .open = ftrace_filter_open,
+ .read = seq_read,
+ .write = ftrace_filter_write,
+ .llseek = ftrace_filter_lseek,
+ .release = ftrace_regex_release,
+};
+
+static const struct file_operations ftrace_notrace_fops = {
+ .open = ftrace_notrace_open,
+ .read = seq_read,
+ .write = ftrace_notrace_write,
+ .llseek = ftrace_filter_lseek,
+ .release = ftrace_regex_release,
+};
+
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+
+static DEFINE_MUTEX(graph_lock);
+
+int ftrace_graph_count;
+int ftrace_graph_filter_enabled;
+unsigned long ftrace_graph_funcs[FTRACE_GRAPH_MAX_FUNCS] __read_mostly;
+
+static void *
+__g_next(struct seq_file *m, loff_t *pos)
+{
+ if (*pos >= ftrace_graph_count)
+ return NULL;
+ return &ftrace_graph_funcs[*pos];
+}
+
+static void *
+g_next(struct seq_file *m, void *v, loff_t *pos)
+{
+ (*pos)++;
+ return __g_next(m, pos);
+}
+
+static void *g_start(struct seq_file *m, loff_t *pos)
+{
+ mutex_lock(&graph_lock);
+
+ /* Nothing, tell g_show to print all functions are enabled */
+ if (!ftrace_graph_filter_enabled && !*pos)
+ return (void *)1;
+
+ return __g_next(m, pos);
+}
+
+static void g_stop(struct seq_file *m, void *p)
+{
+ mutex_unlock(&graph_lock);
+}
+
+static int g_show(struct seq_file *m, void *v)
+{
+ unsigned long *ptr = v;
+
+ if (!ptr)
+ return 0;
+
+ if (ptr == (unsigned long *)1) {
+ seq_printf(m, "#### all functions enabled ####\n");
+ return 0;
+ }
+
+ seq_printf(m, "%ps\n", (void *)*ptr);
+
+ return 0;
+}
+
+static const struct seq_operations ftrace_graph_seq_ops = {
+ .start = g_start,
+ .next = g_next,
+ .stop = g_stop,
+ .show = g_show,
+};
+
+static int
+ftrace_graph_open(struct inode *inode, struct file *file)
+{
+ int ret = 0;
+
+ if (unlikely(ftrace_disabled))
+ return -ENODEV;
+
+ mutex_lock(&graph_lock);
+ if ((file->f_mode & FMODE_WRITE) &&
+ (file->f_flags & O_TRUNC)) {
+ ftrace_graph_filter_enabled = 0;
+ ftrace_graph_count = 0;
+ memset(ftrace_graph_funcs, 0, sizeof(ftrace_graph_funcs));
+ }
+ mutex_unlock(&graph_lock);
+
+ if (file->f_mode & FMODE_READ)
+ ret = seq_open(file, &ftrace_graph_seq_ops);
+
+ return ret;
+}
+
+static int
+ftrace_graph_release(struct inode *inode, struct file *file)
+{
+ if (file->f_mode & FMODE_READ)
+ seq_release(inode, file);
+ return 0;
+}
+
+static int
+ftrace_set_func(unsigned long *array, int *idx, char *buffer)
+{
+ struct dyn_ftrace *rec;
+ struct ftrace_page *pg;
+ int search_len;
+ int fail = 1;
+ int type, not;
+ char *search;
+ bool exists;
+ int i;
+
+ /* decode regex */
+ type = filter_parse_regex(buffer, strlen(buffer), &search, ¬);
+ if (!not && *idx >= FTRACE_GRAPH_MAX_FUNCS)
+ return -EBUSY;
+
+ search_len = strlen(search);
+
+ mutex_lock(&ftrace_lock);
+
+ if (unlikely(ftrace_disabled)) {
+ mutex_unlock(&ftrace_lock);
+ return -ENODEV;
+ }
+
+ do_for_each_ftrace_rec(pg, rec) {
+
+ if (ftrace_match_record(rec, NULL, search, search_len, type)) {
+ /* if it is in the array */
+ exists = false;
+ for (i = 0; i < *idx; i++) {
+ if (array[i] == rec->ip) {
+ exists = true;
+ break;
+ }
+ }
+
+ if (!not) {
+ fail = 0;
+ if (!exists) {
+ array[(*idx)++] = rec->ip;
+ if (*idx >= FTRACE_GRAPH_MAX_FUNCS)
+ goto out;
+ }
+ } else {
+ if (exists) {
+ array[i] = array[--(*idx)];
+ array[*idx] = 0;
+ fail = 0;
+ }
+ }
+ }
+ } while_for_each_ftrace_rec();
+out:
+ mutex_unlock(&ftrace_lock);
+
+ if (fail)
+ return -EINVAL;
+
+ ftrace_graph_filter_enabled = !!(*idx);
+
+ return 0;
+}
+
+static ssize_t
+ftrace_graph_write(struct file *file, const char __user *ubuf,
+ size_t cnt, loff_t *ppos)
+{
+ struct trace_parser parser;
+ ssize_t read, ret;
+
+ if (!cnt)
+ return 0;
+
+ mutex_lock(&graph_lock);
+
+ if (trace_parser_get_init(&parser, FTRACE_BUFF_MAX)) {
+ ret = -ENOMEM;
+ goto out_unlock;
+ }
+
+ read = trace_get_user(&parser, ubuf, cnt, ppos);
+
+ if (read >= 0 && trace_parser_loaded((&parser))) {
+ parser.buffer[parser.idx] = 0;
+
+ /* we allow only one expression at a time */
+ ret = ftrace_set_func(ftrace_graph_funcs, &ftrace_graph_count,
+ parser.buffer);
+ if (ret)
+ goto out_free;
+ }
+
+ ret = read;
+
+out_free:
+ trace_parser_put(&parser);
+out_unlock:
+ mutex_unlock(&graph_lock);
+
+ return ret;
+}
+
+static const struct file_operations ftrace_graph_fops = {
+ .open = ftrace_graph_open,
+ .read = seq_read,
+ .write = ftrace_graph_write,
+ .llseek = ftrace_filter_lseek,
+ .release = ftrace_graph_release,
+};
+#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
+
+static __init int ftrace_init_dyn_debugfs(struct dentry *d_tracer)
+{
+
+ trace_create_file("available_filter_functions", 0444,
+ d_tracer, NULL, &ftrace_avail_fops);
+
+ trace_create_file("enabled_functions", 0444,
+ d_tracer, NULL, &ftrace_enabled_fops);
+
+ trace_create_file("set_ftrace_filter", 0644, d_tracer,
+ NULL, &ftrace_filter_fops);
+
+ trace_create_file("set_ftrace_notrace", 0644, d_tracer,
+ NULL, &ftrace_notrace_fops);
+
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+ trace_create_file("set_graph_function", 0444, d_tracer,
+ NULL,
+ &ftrace_graph_fops);
+#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
+
+ return 0;
+}
+
+static void ftrace_swap_recs(void *a, void *b, int size)
+{
+ struct dyn_ftrace *reca = a;
+ struct dyn_ftrace *recb = b;
+ struct dyn_ftrace t;
+
+ t = *reca;
+ *reca = *recb;
+ *recb = t;
+}
+
+static int ftrace_process_locs(struct module *mod,
+ unsigned long *start,
+ unsigned long *end)
+{
+ struct ftrace_page *pg;
+ unsigned long count;
+ unsigned long *p;
+ unsigned long addr;
+ unsigned long flags = 0; /* Shut up gcc */
+ int ret = -ENOMEM;
+
+ count = end - start;
+
+ if (!count)
+ return 0;
+
+ pg = ftrace_allocate_pages(count);
+ if (!pg)
+ return -ENOMEM;
+
+ mutex_lock(&ftrace_lock);
+
+ /*
+ * Core and each module needs their own pages, as
+ * modules will free them when they are removed.
+ * Force a new page to be allocated for modules.
+ */
+ if (!mod) {
+ WARN_ON(ftrace_pages || ftrace_pages_start);
+ /* First initialization */
+ ftrace_pages = ftrace_pages_start = pg;
+ } else {
+ if (!ftrace_pages)
+ goto out;
+
+ if (WARN_ON(ftrace_pages->next)) {
+ /* Hmm, we have free pages? */
+ while (ftrace_pages->next)
+ ftrace_pages = ftrace_pages->next;
+ }
+
+ ftrace_pages->next = pg;
+ ftrace_pages = pg;
+ }
+
+ p = start;
+ while (p < end) {
+ addr = ftrace_call_adjust(*p++);
+ /*
+ * Some architecture linkers will pad between
+ * the different mcount_loc sections of different
+ * object files to satisfy alignments.
+ * Skip any NULL pointers.
+ */
+ if (!addr)
+ continue;
+ if (!ftrace_record_ip(addr))
+ break;
+ }
+
+ /* These new locations need to be initialized */
+ ftrace_new_pgs = pg;
+
+ /* Make each individual set of pages sorted by ips */
+ for (; pg; pg = pg->next)
+ sort(pg->records, pg->index, sizeof(struct dyn_ftrace),
+ ftrace_cmp_recs, ftrace_swap_recs);
+
+ /*
+ * 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.
+ */
+ if (!mod)
+ local_irq_save(flags);
+ ftrace_update_code(mod);
+ if (!mod)
+ local_irq_restore(flags);
+ ret = 0;
+ out:
+ mutex_unlock(&ftrace_lock);
+
+ return ret;
+}
+
+#ifdef CONFIG_MODULES
+
+#define next_to_ftrace_page(p) container_of(p, struct ftrace_page, next)
+
+void ftrace_release_mod(struct module *mod)
+{
+ struct dyn_ftrace *rec;
+ struct ftrace_page **last_pg;
+ struct ftrace_page *pg;
+ int order;
+
+ mutex_lock(&ftrace_lock);
+
+ if (ftrace_disabled)
+ goto out_unlock;
+
+ /*
+ * Each module has its own ftrace_pages, remove
+ * them from the list.
+ */
+ last_pg = &ftrace_pages_start;
+ for (pg = ftrace_pages_start; pg; pg = *last_pg) {
+ rec = &pg->records[0];
+ if (within_module_core(rec->ip, mod)) {
+ /*
+ * As core pages are first, the first
+ * page should never be a module page.
+ */
+ if (WARN_ON(pg == ftrace_pages_start))
+ goto out_unlock;
+
+ /* Check if we are deleting the last page */
+ if (pg == ftrace_pages)
+ ftrace_pages = next_to_ftrace_page(last_pg);
+
+ *last_pg = pg->next;
+ order = get_count_order(pg->size / ENTRIES_PER_PAGE);
+ free_pages((unsigned long)pg->records, order);
+ kfree(pg);
+ } else
+ last_pg = &pg->next;
+ }
+ out_unlock:
+ mutex_unlock(&ftrace_lock);
+}
+
+static void ftrace_init_module(struct module *mod,
+ unsigned long *start, unsigned long *end)
+{
+ if (ftrace_disabled || start == end)
+ return;
+ ftrace_process_locs(mod, start, end);
+}
+
+void ftrace_module_init(struct module *mod)
+{
+ ftrace_init_module(mod, mod->ftrace_callsites,
+ mod->ftrace_callsites +
+ mod->num_ftrace_callsites);
+}
+
+static int ftrace_module_notify_exit(struct notifier_block *self,
+ unsigned long val, void *data)
+{
+ struct module *mod = data;
+
+ if (val == MODULE_STATE_GOING)
+ ftrace_release_mod(mod);
+
+ return 0;
+}
+#else
+static int ftrace_module_notify_exit(struct notifier_block *self,
+ unsigned long val, void *data)
+{
+ return 0;
+}
+#endif /* CONFIG_MODULES */
+
+struct notifier_block ftrace_module_exit_nb = {
+ .notifier_call = ftrace_module_notify_exit,
+ .priority = INT_MIN, /* Run after anything that can remove kprobes */
+};
+
+extern unsigned long __start_mcount_loc[];
+extern unsigned long __stop_mcount_loc[];
+
+void __init ftrace_init(void)
+{
+ unsigned long count, addr, flags;
+ int ret;
+
+ /* Keep the ftrace pointer to the stub */
+ addr = (unsigned long)ftrace_stub;
+
+ local_irq_save(flags);
+ ftrace_dyn_arch_init(&addr);
+ local_irq_restore(flags);
+
+ /* ftrace_dyn_arch_init places the return code in addr */
+ if (addr)
+ goto failed;
+
+ count = __stop_mcount_loc - __start_mcount_loc;
+
+ ret = ftrace_dyn_table_alloc(count);
+ if (ret)
+ goto failed;
+
+ last_ftrace_enabled = ftrace_enabled = 1;
+
+ ret = ftrace_process_locs(NULL,
+ __start_mcount_loc,
+ __stop_mcount_loc);
+
+ ret = register_module_notifier(&ftrace_module_exit_nb);
+ if (ret)
+ pr_warning("Failed to register trace ftrace module exit notifier\n");
+
+ set_ftrace_early_filters();
+
+ return;
+ failed:
+ ftrace_disabled = 1;
+}
+
+#else
+
+static struct ftrace_ops global_ops = {
+ .func = ftrace_stub,
+};
+
+static int __init ftrace_nodyn_init(void)
+{
+ ftrace_enabled = 1;
+ return 0;
+}
+device_initcall(ftrace_nodyn_init);
+
+static inline int ftrace_init_dyn_debugfs(struct dentry *d_tracer) { return 0; }
+static inline void ftrace_startup_enable(int command) { }
+/* Keep as macros so we do not need to define the commands */
+# define ftrace_startup(ops, command) \
+ ({ \
+ int ___ret = __register_ftrace_function(ops); \
+ if (!___ret) \
+ (ops)->flags |= FTRACE_OPS_FL_ENABLED; \
+ ___ret; \
+ })
+# define ftrace_shutdown(ops, command) __unregister_ftrace_function(ops)
+
+# define ftrace_startup_sysctl() do { } while (0)
+# define ftrace_shutdown_sysctl() do { } while (0)
+
+static inline int
+ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip)
+{
+ return 1;
+}
+
+#endif /* CONFIG_DYNAMIC_FTRACE */
+
+static void
+ftrace_ops_control_func(unsigned long ip, unsigned long parent_ip)
+{
+ struct ftrace_ops *op;
+
+ if (unlikely(trace_recursion_test(TRACE_CONTROL_BIT)))
+ return;
+
+ /*
+ * Some of the ops may be dynamically allocated,
+ * they must be freed after a synchronize_sched().
+ */
+ preempt_disable_notrace();
+ trace_recursion_set(TRACE_CONTROL_BIT);
+ op = rcu_dereference_raw(ftrace_control_list);
+ while (op != &ftrace_list_end) {
+ if (!ftrace_function_local_disabled(op) &&
+ ftrace_ops_test(op, ip))
+ op->func(ip, parent_ip);
+
+ op = rcu_dereference_raw(op->next);
+ };
+ trace_recursion_clear(TRACE_CONTROL_BIT);
+ preempt_enable_notrace();
+}
+
+static struct ftrace_ops control_ops = {
+ .func = ftrace_ops_control_func,
+};
+
+static void
+ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip)
+{
+ struct ftrace_ops *op;
+
+ if (unlikely(trace_recursion_test(TRACE_INTERNAL_BIT)))
+ return;
+
+ trace_recursion_set(TRACE_INTERNAL_BIT);
+ /*
+ * Some of the ops may be dynamically allocated,
+ * they must be freed after a synchronize_sched().
+ */
+ preempt_disable_notrace();
+ op = rcu_dereference_raw(ftrace_ops_list);
+ while (op != &ftrace_list_end) {
+ if (ftrace_ops_test(op, ip))
+ op->func(ip, parent_ip);
+ op = rcu_dereference_raw(op->next);
+ };
+ preempt_enable_notrace();
+ trace_recursion_clear(TRACE_INTERNAL_BIT);
+}
+
+static void clear_ftrace_swapper(void)
+{
+ struct task_struct *p;
+ int cpu;
+
+ get_online_cpus();
+ for_each_online_cpu(cpu) {
+ p = idle_task(cpu);
+ clear_tsk_trace_trace(p);
+ }
+ put_online_cpus();
+}
+
+static void set_ftrace_swapper(void)
+{
+ struct task_struct *p;
+ int cpu;
+
+ get_online_cpus();
+ for_each_online_cpu(cpu) {
+ p = idle_task(cpu);
+ set_tsk_trace_trace(p);
+ }
+ put_online_cpus();
+}
+
+static void clear_ftrace_pid(struct pid *pid)
+{
+ struct task_struct *p;
+
+ rcu_read_lock();
+ do_each_pid_task(pid, PIDTYPE_PID, p) {
+ clear_tsk_trace_trace(p);
+ } while_each_pid_task(pid, PIDTYPE_PID, p);
+ rcu_read_unlock();
+
+ put_pid(pid);
+}
+
+static void set_ftrace_pid(struct pid *pid)
+{
+ struct task_struct *p;
+
+ rcu_read_lock();
+ do_each_pid_task(pid, PIDTYPE_PID, p) {
+ set_tsk_trace_trace(p);
+ } while_each_pid_task(pid, PIDTYPE_PID, p);
+ rcu_read_unlock();
+}
+
+static void clear_ftrace_pid_task(struct pid *pid)
+{
+ if (pid == ftrace_swapper_pid)
+ clear_ftrace_swapper();
+ else
+ clear_ftrace_pid(pid);
+}
+
+static void set_ftrace_pid_task(struct pid *pid)
+{
+ if (pid == ftrace_swapper_pid)
+ set_ftrace_swapper();
+ else
+ set_ftrace_pid(pid);
+}
+
+static int ftrace_pid_add(int p)
+{
+ struct pid *pid;
+ struct ftrace_pid *fpid;
+ int ret = -EINVAL;
+
+ mutex_lock(&ftrace_lock);
+
+ if (!p)
+ pid = ftrace_swapper_pid;
+ else
+ pid = find_get_pid(p);
+
+ if (!pid)
+ goto out;
+
+ ret = 0;
+
+ list_for_each_entry(fpid, &ftrace_pids, list)
+ if (fpid->pid == pid)
+ goto out_put;
+
+ ret = -ENOMEM;
+
+ fpid = kmalloc(sizeof(*fpid), GFP_KERNEL);
+ if (!fpid)
+ goto out_put;
+
+ list_add(&fpid->list, &ftrace_pids);
+ fpid->pid = pid;
+
+ set_ftrace_pid_task(pid);
+
+ ftrace_update_pid_func();
+ ftrace_startup_enable(0);
+
+ mutex_unlock(&ftrace_lock);
+ return 0;
+
+out_put:
+ if (pid != ftrace_swapper_pid)
+ put_pid(pid);
+
+out:
+ mutex_unlock(&ftrace_lock);
+ return ret;
+}
+
+static void ftrace_pid_reset(void)
+{
+ struct ftrace_pid *fpid, *safe;
+
+ mutex_lock(&ftrace_lock);
+ list_for_each_entry_safe(fpid, safe, &ftrace_pids, list) {
+ struct pid *pid = fpid->pid;
+
+ clear_ftrace_pid_task(pid);
+
+ list_del(&fpid->list);
+ kfree(fpid);
+ }
+
+ ftrace_update_pid_func();
+ ftrace_startup_enable(0);
+
+ mutex_unlock(&ftrace_lock);
+}
+
+static void *fpid_start(struct seq_file *m, loff_t *pos)
+{
+ mutex_lock(&ftrace_lock);
+
+ if (list_empty(&ftrace_pids) && (!*pos))
+ return (void *) 1;
+
+ return seq_list_start(&ftrace_pids, *pos);
+}
+
+static void *fpid_next(struct seq_file *m, void *v, loff_t *pos)
+{
+ if (v == (void *)1)
+ return NULL;
+
+ return seq_list_next(v, &ftrace_pids, pos);
+}
+
+static void fpid_stop(struct seq_file *m, void *p)
+{
+ mutex_unlock(&ftrace_lock);
+}
+
+static int fpid_show(struct seq_file *m, void *v)
+{
+ const struct ftrace_pid *fpid = list_entry(v, struct ftrace_pid, list);
+
+ if (v == (void *)1) {
+ seq_printf(m, "no pid\n");
+ return 0;
+ }
+
+ if (fpid->pid == ftrace_swapper_pid)
+ seq_printf(m, "swapper tasks\n");
+ else
+ seq_printf(m, "%u\n", pid_vnr(fpid->pid));
+
+ return 0;
+}
+
+static const struct seq_operations ftrace_pid_sops = {
+ .start = fpid_start,
+ .next = fpid_next,
+ .stop = fpid_stop,
+ .show = fpid_show,
+};
+
+static int
+ftrace_pid_open(struct inode *inode, struct file *file)
+{
+ int ret = 0;
+
+ if ((file->f_mode & FMODE_WRITE) &&
+ (file->f_flags & O_TRUNC))
+ ftrace_pid_reset();
+
+ if (file->f_mode & FMODE_READ)
+ ret = seq_open(file, &ftrace_pid_sops);
+
+ return ret;
+}
+
+static ssize_t
+ftrace_pid_write(struct file *filp, const char __user *ubuf,
+ size_t cnt, loff_t *ppos)
+{
+ char buf[64], *tmp;
+ long val;
+ int ret;
+
+ if (cnt >= sizeof(buf))
+ return -EINVAL;
+
+ if (copy_from_user(&buf, ubuf, cnt))
+ return -EFAULT;
+
+ buf[cnt] = 0;
+
+ /*
+ * Allow "echo > set_ftrace_pid" or "echo -n '' > set_ftrace_pid"
+ * to clean the filter quietly.
+ */
+ tmp = strstrip(buf);
+ if (strlen(tmp) == 0)
+ return 1;
+
+ ret = strict_strtol(tmp, 10, &val);
+ if (ret < 0)
+ return ret;
+
+ ret = ftrace_pid_add(val);
+
+ return ret ? ret : cnt;
+}
+
+static int
+ftrace_pid_release(struct inode *inode, struct file *file)
+{
+ if (file->f_mode & FMODE_READ)
+ seq_release(inode, file);
+
+ return 0;
+}
+
+static const struct file_operations ftrace_pid_fops = {
+ .open = ftrace_pid_open,
+ .write = ftrace_pid_write,
+ .read = seq_read,
+ .llseek = ftrace_filter_lseek,
+ .release = ftrace_pid_release,
+};
+
+static __init int ftrace_init_debugfs(void)
+{
+ struct dentry *d_tracer;
+
+ d_tracer = tracing_init_dentry();
+ if (!d_tracer)
+ return 0;
+
+ ftrace_init_dyn_debugfs(d_tracer);
+
+ trace_create_file("set_ftrace_pid", 0644, d_tracer,
+ NULL, &ftrace_pid_fops);
+
+ ftrace_profile_debugfs(d_tracer);
+
+ return 0;
+}
+fs_initcall(ftrace_init_debugfs);
+
+/**
+ * ftrace_kill - kill ftrace
+ *
+ * This function should be used by panic code. It stops ftrace
+ * but in a not so nice way. If you need to simply kill ftrace
+ * from a non-atomic section, use ftrace_kill.
+ */
+void ftrace_kill(void)
+{
+ ftrace_disabled = 1;
+ ftrace_enabled = 0;
+ clear_ftrace_function();
+}
+
+/**
+ * Test if ftrace is dead or not.
+ */
+int ftrace_is_dead(void)
+{
+ return ftrace_disabled;
+}
+
+/**
+ * register_ftrace_function - register a function for profiling
+ * @ops - ops structure that holds the function for profiling.
+ *
+ * Register a function to be called by all functions in the
+ * kernel.
+ *
+ * Note: @ops->func and all the functions it calls must be labeled
+ * with "notrace", otherwise it will go into a
+ * recursive loop.
+ */
+int register_ftrace_function(struct ftrace_ops *ops)
+{
+ int ret = -1;
+
+ mutex_lock(&ftrace_lock);
+
+ ret = ftrace_startup(ops, 0);
+
+ mutex_unlock(&ftrace_lock);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(register_ftrace_function);
+
+/**
+ * unregister_ftrace_function - unregister a function for profiling.
+ * @ops - ops structure that holds the function to unregister
+ *
+ * Unregister a function that was added to be called by ftrace profiling.
+ */
+int unregister_ftrace_function(struct ftrace_ops *ops)
+{
+ int ret;
+
+ mutex_lock(&ftrace_lock);
+ ret = ftrace_shutdown(ops, 0);
+ mutex_unlock(&ftrace_lock);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(unregister_ftrace_function);
+
+int
+ftrace_enable_sysctl(struct ctl_table *table, int write,
+ void __user *buffer, size_t *lenp,
+ loff_t *ppos)
+{
+ int ret = -ENODEV;
+
+ mutex_lock(&ftrace_lock);
+
+ if (unlikely(ftrace_disabled))
+ goto out;
+
+ ret = proc_dointvec(table, write, buffer, lenp, ppos);
+
+ if (ret || !write || (last_ftrace_enabled == !!ftrace_enabled))
+ goto out;
+
+ last_ftrace_enabled = !!ftrace_enabled;
+
+ if (ftrace_enabled) {
+
+ /* we are starting ftrace again */
+ if (ftrace_ops_list != &ftrace_list_end)
+ update_ftrace_function();
+
+ ftrace_startup_sysctl();
+
+ } else {
+ /* stopping ftrace calls (just send to ftrace_stub) */
+ ftrace_trace_function = ftrace_stub;
+
+ ftrace_shutdown_sysctl();
+ }
+
+ out:
+ mutex_unlock(&ftrace_lock);
+ return ret;
+}
+
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+
+static struct notifier_block ftrace_suspend_notifier;
+
+int ftrace_graph_entry_stub(struct ftrace_graph_ent *trace)
+{
+ return 0;
+}
+
+/* The callbacks that hook a function */
+trace_func_graph_ret_t ftrace_graph_return =
+ (trace_func_graph_ret_t)ftrace_stub;
+trace_func_graph_ent_t ftrace_graph_entry = ftrace_graph_entry_stub;
+static trace_func_graph_ent_t __ftrace_graph_entry = ftrace_graph_entry_stub;
+
+/* Try to assign a return stack array on FTRACE_RETSTACK_ALLOC_SIZE tasks. */
+static int alloc_retstack_tasklist(struct ftrace_ret_stack **ret_stack_list)
+{
+ int i;
+ int ret = 0;
+ unsigned long flags;
+ int start = 0, end = FTRACE_RETSTACK_ALLOC_SIZE;
+ struct task_struct *g, *t;
+
+ for (i = 0; i < FTRACE_RETSTACK_ALLOC_SIZE; i++) {
+ ret_stack_list[i] = kmalloc(FTRACE_RETFUNC_DEPTH
+ * sizeof(struct ftrace_ret_stack),
+ GFP_KERNEL);
+ if (!ret_stack_list[i]) {
+ start = 0;
+ end = i;
+ ret = -ENOMEM;
+ goto free;
+ }
+ }
+
+ read_lock_irqsave(&tasklist_lock, flags);
+ do_each_thread(g, t) {
+ if (start == end) {
+ ret = -EAGAIN;
+ goto unlock;
+ }
+
+ if (t->ret_stack == NULL) {
+ atomic_set(&t->tracing_graph_pause, 0);
+ atomic_set(&t->trace_overrun, 0);
+ t->curr_ret_stack = -1;
+ /* Make sure the tasks see the -1 first: */
+ smp_wmb();
+ t->ret_stack = ret_stack_list[start++];
+ }
+ } while_each_thread(g, t);
+
+unlock:
+ read_unlock_irqrestore(&tasklist_lock, flags);
+free:
+ for (i = start; i < end; i++)
+ kfree(ret_stack_list[i]);
+ return ret;
+}
+
+static void
+ftrace_graph_probe_sched_switch(void *ignore,
+ struct task_struct *prev, struct task_struct *next)
+{
+ unsigned long long timestamp;
+ int index;
+
+ /*
+ * Does the user want to count the time a function was asleep.
+ * If so, do not update the time stamps.
+ */
+ if (trace_flags & TRACE_ITER_SLEEP_TIME)
+ return;
+
+ timestamp = trace_clock_local();
+
+ prev->ftrace_timestamp = timestamp;
+
+ /* only process tasks that we timestamped */
+ if (!next->ftrace_timestamp)
+ return;
+
+ /*
+ * Update all the counters in next to make up for the
+ * time next was sleeping.
+ */
+ timestamp -= next->ftrace_timestamp;
+
+ for (index = next->curr_ret_stack; index >= 0; index--)
+ next->ret_stack[index].calltime += timestamp;
+}
+
+/* Allocate a return stack for each task */
+static int start_graph_tracing(void)
+{
+ struct ftrace_ret_stack **ret_stack_list;
+ int ret, cpu;
+
+ ret_stack_list = kmalloc(FTRACE_RETSTACK_ALLOC_SIZE *
+ sizeof(struct ftrace_ret_stack *),
+ GFP_KERNEL);
+
+ if (!ret_stack_list)
+ return -ENOMEM;
+
+ /* The cpu_boot init_task->ret_stack will never be freed */
+ for_each_online_cpu(cpu) {
+ if (!idle_task(cpu)->ret_stack)
+ ftrace_graph_init_idle_task(idle_task(cpu), cpu);
+ }
+
+ do {
+ ret = alloc_retstack_tasklist(ret_stack_list);
+ } while (ret == -EAGAIN);
+
+ if (!ret) {
+ ret = register_trace_sched_switch(ftrace_graph_probe_sched_switch, NULL);
+ if (ret)
+ pr_info("ftrace_graph: Couldn't activate tracepoint"
+ " probe to kernel_sched_switch\n");
+ }
+
+ kfree(ret_stack_list);
+ return ret;
+}
+
+/*
+ * Hibernation protection.
+ * The state of the current task is too much unstable during
+ * suspend/restore to disk. We want to protect against that.
+ */
+static int
+ftrace_suspend_notifier_call(struct notifier_block *bl, unsigned long state,
+ void *unused)
+{
+ switch (state) {
+ case PM_HIBERNATION_PREPARE:
+ pause_graph_tracing();
+ break;
+
+ case PM_POST_HIBERNATION:
+ unpause_graph_tracing();
+ break;
+ }
+ return NOTIFY_DONE;
+}
+
+/* Just a place holder for function graph */
+static struct ftrace_ops fgraph_ops __read_mostly = {
+ .func = ftrace_stub,
+ .flags = FTRACE_OPS_FL_GLOBAL,
+};
+
+static int ftrace_graph_entry_test(struct ftrace_graph_ent *trace)
+{
+ if (!ftrace_ops_test(&global_ops, trace->func))
+ return 0;
+ return __ftrace_graph_entry(trace);
+}
+
+/*
+ * The function graph tracer should only trace the functions defined
+ * by set_ftrace_filter and set_ftrace_notrace. If another function
+ * tracer ops is registered, the graph tracer requires testing the
+ * function against the global ops, and not just trace any function
+ * that any ftrace_ops registered.
+ */
+static void update_function_graph_func(void)
+{
+ if (ftrace_ops_list == &ftrace_list_end ||
+ (ftrace_ops_list == &global_ops &&
+ global_ops.next == &ftrace_list_end))
+ ftrace_graph_entry = __ftrace_graph_entry;
+ else
+ ftrace_graph_entry = ftrace_graph_entry_test;
+}
+
+int register_ftrace_graph(trace_func_graph_ret_t retfunc,
+ trace_func_graph_ent_t entryfunc)
+{
+ int ret = 0;
+
+ mutex_lock(&ftrace_lock);
+
+ /* we currently allow only one tracer registered at a time */
+ if (ftrace_graph_active) {
+ ret = -EBUSY;
+ goto out;
+ }
+
+ ftrace_suspend_notifier.notifier_call = ftrace_suspend_notifier_call;
+ register_pm_notifier(&ftrace_suspend_notifier);
+
+ ftrace_graph_active++;
+ ret = start_graph_tracing();
+ if (ret) {
+ ftrace_graph_active--;
+ goto out;
+ }
+
+ ftrace_graph_return = retfunc;
+
+ /*
+ * Update the indirect function to the entryfunc, and the
+ * function that gets called to the entry_test first. Then
+ * call the update fgraph entry function to determine if
+ * the entryfunc should be called directly or not.
+ */
+ __ftrace_graph_entry = entryfunc;
+ ftrace_graph_entry = ftrace_graph_entry_test;
+ update_function_graph_func();
+
+ ret = ftrace_startup(&fgraph_ops, FTRACE_START_FUNC_RET);
+
+out:
+ mutex_unlock(&ftrace_lock);
+ return ret;
+}
+
+void unregister_ftrace_graph(void)
+{
+ mutex_lock(&ftrace_lock);
+
+ if (unlikely(!ftrace_graph_active))
+ goto out;
+
+ ftrace_graph_active--;
+ ftrace_graph_return = (trace_func_graph_ret_t)ftrace_stub;
+ ftrace_graph_entry = ftrace_graph_entry_stub;
+ __ftrace_graph_entry = ftrace_graph_entry_stub;
+ ftrace_shutdown(&fgraph_ops, FTRACE_STOP_FUNC_RET);
+ unregister_pm_notifier(&ftrace_suspend_notifier);
+ unregister_trace_sched_switch(ftrace_graph_probe_sched_switch, NULL);
+
+ out:
+ mutex_unlock(&ftrace_lock);
+}
+
+static DEFINE_PER_CPU(struct ftrace_ret_stack *, idle_ret_stack);
+
+static void
+graph_init_task(struct task_struct *t, struct ftrace_ret_stack *ret_stack)
+{
+ atomic_set(&t->tracing_graph_pause, 0);
+ atomic_set(&t->trace_overrun, 0);
+ t->ftrace_timestamp = 0;
+ /* make curr_ret_stack visible before we add the ret_stack */
+ smp_wmb();
+ t->ret_stack = ret_stack;
+}
+
+/*
+ * Allocate a return stack for the idle task. May be the first
+ * time through, or it may be done by CPU hotplug online.
+ */
+void ftrace_graph_init_idle_task(struct task_struct *t, int cpu)
+{
+ t->curr_ret_stack = -1;
+ /*
+ * The idle task has no parent, it either has its own
+ * stack or no stack at all.
+ */
+ if (t->ret_stack)
+ WARN_ON(t->ret_stack != per_cpu(idle_ret_stack, cpu));
+
+ if (ftrace_graph_active) {
+ struct ftrace_ret_stack *ret_stack;
+
+ ret_stack = per_cpu(idle_ret_stack, cpu);
+ if (!ret_stack) {
+ ret_stack = kmalloc(FTRACE_RETFUNC_DEPTH
+ * sizeof(struct ftrace_ret_stack),
+ GFP_KERNEL);
+ if (!ret_stack)
+ return;
+ per_cpu(idle_ret_stack, cpu) = ret_stack;
+ }
+ graph_init_task(t, ret_stack);
+ }
+}
+
+/* Allocate a return stack for newly created task */
+void ftrace_graph_init_task(struct task_struct *t)
+{
+ /* Make sure we do not use the parent ret_stack */
+ t->ret_stack = NULL;
+ t->curr_ret_stack = -1;
+
+ if (ftrace_graph_active) {
+ struct ftrace_ret_stack *ret_stack;
+
+ ret_stack = kmalloc(FTRACE_RETFUNC_DEPTH
+ * sizeof(struct ftrace_ret_stack),
+ GFP_KERNEL);
+ if (!ret_stack)
+ return;
+ graph_init_task(t, ret_stack);
+ }
+}
+
+void ftrace_graph_exit_task(struct task_struct *t)
+{
+ struct ftrace_ret_stack *ret_stack = t->ret_stack;
+
+ t->ret_stack = NULL;
+ /* NULL must become visible to IRQs before we free it: */
+ barrier();
+
+ kfree(ret_stack);
+}
+
+void ftrace_graph_stop(void)
+{
+ ftrace_stop();
+}
+#endif