#include <linux/stop_machine.h>
#include <linux/clocksource.h>
#include <linux/kallsyms.h>
-#include <linux/kthread.h>
+#include <linux/seq_file.h>
+#include <linux/debugfs.h>
#include <linux/hardirq.h>
+#include <linux/kthread.h>
+#include <linux/uaccess.h>
+#include <linux/kprobes.h>
#include <linux/ftrace.h>
-#include <linux/module.h>
#include <linux/sysctl.h>
-#include <linux/hash.h>
+#include <linux/ctype.h>
#include <linux/list.h>
+#include <asm/ftrace.h>
+
#include "trace.h"
-#ifdef CONFIG_DYNAMIC_FTRACE
-# define FTRACE_ENABLED_INIT 1
-#else
-# define FTRACE_ENABLED_INIT 0
-#endif
+#define FTRACE_WARN_ON(cond) \
+ do { \
+ if (WARN_ON(cond)) \
+ ftrace_kill(); \
+ } while (0)
+
+#define FTRACE_WARN_ON_ONCE(cond) \
+ do { \
+ if (WARN_ON_ONCE(cond)) \
+ ftrace_kill(); \
+ } while (0)
+
+/* ftrace_enabled is a method to turn ftrace on or off */
+int ftrace_enabled __read_mostly;
+static int last_ftrace_enabled;
-int ftrace_enabled = FTRACE_ENABLED_INIT;
-static int last_ftrace_enabled = FTRACE_ENABLED_INIT;
+/* set when tracing only a pid */
+struct pid *ftrace_pid_trace;
+static struct pid * const ftrace_swapper_pid = &init_struct_pid;
+
+/* Quick disabling of function tracer. */
+int function_trace_stop;
+
+/*
+ * 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_SPINLOCK(ftrace_lock);
static DEFINE_MUTEX(ftrace_sysctl_lock);
+static DEFINE_MUTEX(ftrace_start_lock);
static struct ftrace_ops ftrace_list_end __read_mostly =
{
static struct ftrace_ops *ftrace_list __read_mostly = &ftrace_list_end;
ftrace_func_t ftrace_trace_function __read_mostly = ftrace_stub;
+ftrace_func_t __ftrace_trace_function __read_mostly = ftrace_stub;
+ftrace_func_t ftrace_pid_function __read_mostly = ftrace_stub;
-/* mcount is defined per arch in assembly */
-EXPORT_SYMBOL(mcount);
-
-notrace void ftrace_list_func(unsigned long ip, unsigned long parent_ip)
+static void ftrace_list_func(unsigned long ip, unsigned long parent_ip)
{
struct ftrace_ops *op = ftrace_list;
};
}
+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
*
void clear_ftrace_function(void)
{
ftrace_trace_function = ftrace_stub;
+ __ftrace_trace_function = 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 int notrace __register_ftrace_function(struct ftrace_ops *ops)
+static int __register_ftrace_function(struct ftrace_ops *ops)
{
- /* Should never be called by interrupts */
+ /* should not be called from interrupt context */
spin_lock(&ftrace_lock);
ops->next = ftrace_list;
ftrace_list = ops;
if (ftrace_enabled) {
+ ftrace_func_t func;
+
+ if (ops->next == &ftrace_list_end)
+ func = ops->func;
+ else
+ func = ftrace_list_func;
+
+ if (ftrace_pid_trace) {
+ set_ftrace_pid_function(func);
+ func = ftrace_pid_func;
+ }
+
/*
* For one func, simply call it directly.
* For more than one func, call the chain.
*/
- if (ops->next == &ftrace_list_end)
- ftrace_trace_function = ops->func;
- else
- ftrace_trace_function = ftrace_list_func;
+#ifdef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST
+ ftrace_trace_function = func;
+#else
+ __ftrace_trace_function = func;
+ ftrace_trace_function = ftrace_test_stop_func;
+#endif
}
spin_unlock(&ftrace_lock);
return 0;
}
-static int notrace __unregister_ftrace_function(struct ftrace_ops *ops)
+static int __unregister_ftrace_function(struct ftrace_ops *ops)
{
struct ftrace_ops **p;
int ret = 0;
+ /* should not be called from interrupt context */
spin_lock(&ftrace_lock);
/*
if (ftrace_enabled) {
/* If we only have one func left, then call that directly */
- if (ftrace_list == &ftrace_list_end ||
- ftrace_list->next == &ftrace_list_end)
- ftrace_trace_function = ftrace_list->func;
+ if (ftrace_list->next == &ftrace_list_end) {
+ ftrace_func_t func = ftrace_list->func;
+
+ if (ftrace_pid_trace) {
+ set_ftrace_pid_function(func);
+ func = ftrace_pid_func;
+ }
+#ifdef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST
+ ftrace_trace_function = func;
+#else
+ __ftrace_trace_function = func;
+#endif
+ }
}
out:
return ret;
}
+static void ftrace_update_pid_func(void)
+{
+ ftrace_func_t func;
+
+ /* should not be called from interrupt context */
+ spin_lock(&ftrace_lock);
+
+ if (ftrace_trace_function == ftrace_stub)
+ goto out;
+
+ func = ftrace_trace_function;
+
+ if (ftrace_pid_trace) {
+ set_ftrace_pid_function(func);
+ func = ftrace_pid_func;
+ } else {
+ if (func == ftrace_pid_func)
+ func = ftrace_pid_function;
+ }
+
+#ifdef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST
+ ftrace_trace_function = func;
+#else
+ __ftrace_trace_function = func;
+#endif
+
+ out:
+ spin_unlock(&ftrace_lock);
+}
+
#ifdef CONFIG_DYNAMIC_FTRACE
+#ifndef CONFIG_FTRACE_MCOUNT_RECORD
+# error Dynamic ftrace depends on MCOUNT_RECORD
+#endif
+
+/*
+ * Since MCOUNT_ADDR may point to mcount itself, we do not want
+ * to get it confused by reading a reference in the code as we
+ * are parsing on objcopy output of text. Use a variable for
+ * it instead.
+ */
+static unsigned long mcount_addr = MCOUNT_ADDR;
+
+enum {
+ FTRACE_ENABLE_CALLS = (1 << 0),
+ FTRACE_DISABLE_CALLS = (1 << 1),
+ FTRACE_UPDATE_TRACE_FUNC = (1 << 2),
+ FTRACE_ENABLE_MCOUNT = (1 << 3),
+ FTRACE_DISABLE_MCOUNT = (1 << 4),
+ FTRACE_START_FUNC_RET = (1 << 5),
+ FTRACE_STOP_FUNC_RET = (1 << 6),
+};
-static struct hlist_head ftrace_hash[FTRACE_HASHSIZE];
+static int ftrace_filtered;
-static DEFINE_PER_CPU(int, ftrace_shutdown_disable_cpu);
+static LIST_HEAD(ftrace_new_addrs);
-static DEFINE_SPINLOCK(ftrace_shutdown_lock);
-static DEFINE_MUTEX(ftraced_lock);
+static DEFINE_MUTEX(ftrace_regex_lock);
struct ftrace_page {
struct ftrace_page *next;
- int index;
+ unsigned long index;
struct dyn_ftrace records[];
-} __attribute__((packed));
+};
#define ENTRIES_PER_PAGE \
((PAGE_SIZE - sizeof(struct ftrace_page)) / sizeof(struct dyn_ftrace))
static struct ftrace_page *ftrace_pages_start;
static struct ftrace_page *ftrace_pages;
-static int ftraced_trigger;
-static int ftraced_suspend;
+static struct dyn_ftrace *ftrace_free_records;
+
-static int ftrace_record_suspend;
+#ifdef CONFIG_KPROBES
-static inline int
-notrace ftrace_ip_in_hash(unsigned long ip, unsigned long key)
+static int frozen_record_count;
+
+static inline void freeze_record(struct dyn_ftrace *rec)
{
- struct dyn_ftrace *p;
- struct hlist_node *t;
- int found = 0;
+ if (!(rec->flags & FTRACE_FL_FROZEN)) {
+ rec->flags |= FTRACE_FL_FROZEN;
+ frozen_record_count++;
+ }
+}
- hlist_for_each_entry(p, t, &ftrace_hash[key], node) {
- if (p->ip == ip) {
- found = 1;
- break;
- }
+static inline void unfreeze_record(struct dyn_ftrace *rec)
+{
+ if (rec->flags & FTRACE_FL_FROZEN) {
+ rec->flags &= ~FTRACE_FL_FROZEN;
+ frozen_record_count--;
}
+}
- return found;
+static inline int record_frozen(struct dyn_ftrace *rec)
+{
+ return rec->flags & FTRACE_FL_FROZEN;
}
+#else
+# define freeze_record(rec) ({ 0; })
+# define unfreeze_record(rec) ({ 0; })
+# define record_frozen(rec) ({ 0; })
+#endif /* CONFIG_KPROBES */
-static inline void notrace
-ftrace_add_hash(struct dyn_ftrace *node, unsigned long key)
+static void ftrace_free_rec(struct dyn_ftrace *rec)
{
- hlist_add_head(&node->node, &ftrace_hash[key]);
+ rec->ip = (unsigned long)ftrace_free_records;
+ ftrace_free_records = rec;
+ rec->flags |= FTRACE_FL_FREE;
}
-static notrace struct dyn_ftrace *ftrace_alloc_shutdown_node(unsigned long ip)
+void ftrace_release(void *start, unsigned long size)
{
- /* If this was already converted, skip it */
- if (ftrace_ip_converted(ip))
- return NULL;
+ struct dyn_ftrace *rec;
+ struct ftrace_page *pg;
+ unsigned long s = (unsigned long)start;
+ unsigned long e = s + size;
+ int i;
- if (ftrace_pages->index == ENTRIES_PER_PAGE) {
- if (!ftrace_pages->next)
+ if (ftrace_disabled || !start)
+ return;
+
+ /* should not be called from interrupt context */
+ spin_lock(&ftrace_lock);
+
+ for (pg = ftrace_pages_start; pg; pg = pg->next) {
+ for (i = 0; i < pg->index; i++) {
+ rec = &pg->records[i];
+
+ if ((rec->ip >= s) && (rec->ip < e))
+ ftrace_free_rec(rec);
+ }
+ }
+ spin_unlock(&ftrace_lock);
+}
+
+static struct dyn_ftrace *ftrace_alloc_dyn_node(unsigned long ip)
+{
+ struct dyn_ftrace *rec;
+
+ /* First check for freed records */
+ if (ftrace_free_records) {
+ rec = ftrace_free_records;
+
+ if (unlikely(!(rec->flags & FTRACE_FL_FREE))) {
+ FTRACE_WARN_ON_ONCE(1);
+ ftrace_free_records = NULL;
return NULL;
+ }
+
+ ftrace_free_records = (void *)rec->ip;
+ memset(rec, 0, sizeof(*rec));
+ return rec;
+ }
+
+ if (ftrace_pages->index == ENTRIES_PER_PAGE) {
+ if (!ftrace_pages->next) {
+ /* allocate another page */
+ ftrace_pages->next =
+ (void *)get_zeroed_page(GFP_KERNEL);
+ if (!ftrace_pages->next)
+ return NULL;
+ }
ftrace_pages = ftrace_pages->next;
}
return &ftrace_pages->records[ftrace_pages->index++];
}
-static void notrace
-ftrace_record_ip(unsigned long ip, unsigned long parent_ip)
+static struct dyn_ftrace *
+ftrace_record_ip(unsigned long ip)
{
- struct dyn_ftrace *node;
- unsigned long flags;
- unsigned long key;
- int resched;
- int atomic;
+ struct dyn_ftrace *rec;
- resched = need_resched();
- preempt_disable_notrace();
+ if (ftrace_disabled)
+ return NULL;
- /* We simply need to protect against recursion */
- __get_cpu_var(ftrace_shutdown_disable_cpu)++;
- if (__get_cpu_var(ftrace_shutdown_disable_cpu) != 1)
- goto out;
+ rec = ftrace_alloc_dyn_node(ip);
+ if (!rec)
+ return NULL;
- if (unlikely(ftrace_record_suspend))
- goto out;
+ rec->ip = ip;
- key = hash_long(ip, FTRACE_HASHBITS);
+ list_add(&rec->list, &ftrace_new_addrs);
- WARN_ON_ONCE(key >= FTRACE_HASHSIZE);
+ 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]);
+}
+
+static 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);
+ }
+}
- if (ftrace_ip_in_hash(ip, key))
- goto out;
- atomic = irqs_disabled();
+static int
+__ftrace_replace_code(struct dyn_ftrace *rec, int enable)
+{
+ unsigned long ip, fl;
+ unsigned long ftrace_addr;
- spin_lock_irqsave(&ftrace_shutdown_lock, flags);
+ ftrace_addr = (unsigned long)ftrace_caller;
- /* This ip may have hit the hash before the lock */
- if (ftrace_ip_in_hash(ip, key))
- goto out_unlock;
+ ip = rec->ip;
/*
- * There's a slight race that the ftraced will update the
- * hash and reset here. The arch alloc is responsible
- * for seeing if the IP has already changed, and if
- * it has, the alloc will fail.
+ * If this record is not to be traced and
+ * it is not enabled then do nothing.
+ *
+ * If this record is not to be traced and
+ * it is enabled then disabled it.
+ *
*/
- node = ftrace_alloc_shutdown_node(ip);
- if (!node)
- goto out_unlock;
+ if (rec->flags & FTRACE_FL_NOTRACE) {
+ if (rec->flags & FTRACE_FL_ENABLED)
+ rec->flags &= ~FTRACE_FL_ENABLED;
+ else
+ return 0;
- node->ip = ip;
+ } else if (ftrace_filtered && enable) {
+ /*
+ * Filtering is on:
+ */
- ftrace_add_hash(node, key);
+ fl = rec->flags & (FTRACE_FL_FILTER | FTRACE_FL_ENABLED);
- ftraced_trigger = 1;
+ /* Record is filtered and enabled, do nothing */
+ if (fl == (FTRACE_FL_FILTER | FTRACE_FL_ENABLED))
+ return 0;
- out_unlock:
- spin_unlock_irqrestore(&ftrace_shutdown_lock, flags);
- out:
- __get_cpu_var(ftrace_shutdown_disable_cpu)--;
+ /* Record is not filtered and is not enabled do nothing */
+ if (!fl)
+ return 0;
- /* prevent recursion with scheduler */
- if (resched)
- preempt_enable_no_resched_notrace();
- else
- preempt_enable_notrace();
-}
+ /* Record is not filtered but enabled, disable it */
+ if (fl == FTRACE_FL_ENABLED)
+ rec->flags &= ~FTRACE_FL_ENABLED;
+ else
+ /* Otherwise record is filtered but not enabled, enable it */
+ rec->flags |= FTRACE_FL_ENABLED;
+ } else {
+ /* Disable or not filtered */
-static struct ftrace_ops ftrace_shutdown_ops __read_mostly =
-{
- .func = ftrace_record_ip,
-};
+ if (enable) {
+ /* if record is enabled, do nothing */
+ if (rec->flags & FTRACE_FL_ENABLED)
+ return 0;
+
+ rec->flags |= FTRACE_FL_ENABLED;
+
+ } else {
+
+ /* if record is not enabled do nothing */
+ if (!(rec->flags & FTRACE_FL_ENABLED))
+ return 0;
+
+ rec->flags &= ~FTRACE_FL_ENABLED;
+ }
+ }
-#define MCOUNT_ADDR ((long)(&mcount))
+ if (rec->flags & FTRACE_FL_ENABLED)
+ return ftrace_make_call(rec, ftrace_addr);
+ else
+ return ftrace_make_nop(NULL, rec, ftrace_addr);
+}
-static void notrace ftrace_replace_code(int saved)
+static void ftrace_replace_code(int enable)
{
- unsigned char *new = NULL, *old = NULL;
+ int i, failed;
struct dyn_ftrace *rec;
struct ftrace_page *pg;
- unsigned long ip;
- int failed;
- int i;
-
- if (saved)
- old = ftrace_nop_replace();
- else
- new = ftrace_nop_replace();
for (pg = ftrace_pages_start; pg; pg = pg->next) {
for (i = 0; i < pg->index; i++) {
rec = &pg->records[i];
- /* don't modify code that has already faulted */
- if (rec->flags & FTRACE_FL_FAILED)
+ /*
+ * Skip over free records and records that have
+ * failed.
+ */
+ if (rec->flags & FTRACE_FL_FREE ||
+ rec->flags & FTRACE_FL_FAILED)
continue;
- ip = rec->ip;
-
- if (saved)
- new = ftrace_call_replace(ip, MCOUNT_ADDR);
- else
- old = ftrace_call_replace(ip, MCOUNT_ADDR);
+ /* ignore updates to this record's mcount site */
+ if (get_kprobe((void *)rec->ip)) {
+ freeze_record(rec);
+ continue;
+ } else {
+ unfreeze_record(rec);
+ }
- failed = ftrace_modify_code(ip, old, new);
- if (failed)
+ failed = __ftrace_replace_code(rec, enable);
+ if (failed && (rec->flags & FTRACE_FL_CONVERTED)) {
rec->flags |= FTRACE_FL_FAILED;
+ if ((system_state == SYSTEM_BOOTING) ||
+ !core_kernel_text(rec->ip)) {
+ ftrace_free_rec(rec);
+ } else
+ ftrace_bug(failed, rec->ip);
+ }
}
}
}
-static notrace void ftrace_startup_code(void)
+static int
+ftrace_code_disable(struct module *mod, struct dyn_ftrace *rec)
{
- ftrace_replace_code(1);
-}
+ unsigned long ip;
+ int ret;
-static notrace void ftrace_shutdown_code(void)
-{
- ftrace_replace_code(0);
+ ip = rec->ip;
+
+ ret = ftrace_make_nop(mod, rec, mcount_addr);
+ if (ret) {
+ ftrace_bug(ret, ip);
+ rec->flags |= FTRACE_FL_FAILED;
+ return 0;
+ }
+ return 1;
}
-static notrace void ftrace_shutdown_replenish(void)
+static int __ftrace_modify_code(void *data)
{
- if (ftrace_pages->next)
- return;
+ int *command = data;
- /* allocate another page */
- ftrace_pages->next = (void *)get_zeroed_page(GFP_KERNEL);
-}
+ if (*command & FTRACE_ENABLE_CALLS)
+ ftrace_replace_code(1);
+ else if (*command & FTRACE_DISABLE_CALLS)
+ ftrace_replace_code(0);
-static int notrace __ftrace_modify_code(void *data)
-{
- void (*func)(void) = data;
+ 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();
- func();
return 0;
}
-static notrace void
-ftrace_code_disable(struct dyn_ftrace *rec, unsigned long addr)
+static void ftrace_run_update_code(int command)
{
- unsigned long ip;
- unsigned char *nop, *call;
- int failed;
+ stop_machine(__ftrace_modify_code, &command, NULL);
+}
- ip = rec->ip;
+static ftrace_func_t saved_ftrace_func;
+static int ftrace_start_up;
- nop = ftrace_nop_replace();
- call = ftrace_call_replace(ip, addr);
+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;
+ }
- failed = ftrace_modify_code(ip, call, nop);
- if (failed)
- rec->flags |= FTRACE_FL_FAILED;
-}
+ if (!command || !ftrace_enabled)
+ return;
-static void notrace ftrace_run_startup_code(void)
-{
- stop_machine_run(__ftrace_modify_code, ftrace_startup_code, NR_CPUS);
+ ftrace_run_update_code(command);
}
-static void notrace ftrace_run_shutdown_code(void)
+static void ftrace_startup(int command)
{
- stop_machine_run(__ftrace_modify_code, ftrace_shutdown_code, NR_CPUS);
+ if (unlikely(ftrace_disabled))
+ return;
+
+ mutex_lock(&ftrace_start_lock);
+ ftrace_start_up++;
+ command |= FTRACE_ENABLE_CALLS;
+
+ ftrace_startup_enable(command);
+
+ mutex_unlock(&ftrace_start_lock);
}
-static void notrace ftrace_startup(void)
+static void ftrace_shutdown(int command)
{
- mutex_lock(&ftraced_lock);
- ftraced_suspend++;
- if (ftraced_suspend != 1)
+ if (unlikely(ftrace_disabled))
+ return;
+
+ mutex_lock(&ftrace_start_lock);
+ ftrace_start_up--;
+ if (!ftrace_start_up)
+ command |= FTRACE_DISABLE_CALLS;
+
+ if (saved_ftrace_func != ftrace_trace_function) {
+ saved_ftrace_func = ftrace_trace_function;
+ command |= FTRACE_UPDATE_TRACE_FUNC;
+ }
+
+ if (!command || !ftrace_enabled)
goto out;
- __unregister_ftrace_function(&ftrace_shutdown_ops);
- if (ftrace_enabled)
- ftrace_run_startup_code();
+ ftrace_run_update_code(command);
out:
- mutex_unlock(&ftraced_lock);
+ mutex_unlock(&ftrace_start_lock);
}
-static void notrace ftrace_shutdown(void)
+static void ftrace_startup_sysctl(void)
{
- mutex_lock(&ftraced_lock);
- ftraced_suspend--;
- if (ftraced_suspend)
- goto out;
+ int command = FTRACE_ENABLE_MCOUNT;
+
+ if (unlikely(ftrace_disabled))
+ return;
- if (ftrace_enabled)
- ftrace_run_shutdown_code();
+ mutex_lock(&ftrace_start_lock);
+ /* Force update next time */
+ saved_ftrace_func = NULL;
+ /* ftrace_start_up is true if we want ftrace running */
+ if (ftrace_start_up)
+ command |= FTRACE_ENABLE_CALLS;
- __register_ftrace_function(&ftrace_shutdown_ops);
- out:
- mutex_unlock(&ftraced_lock);
+ ftrace_run_update_code(command);
+ mutex_unlock(&ftrace_start_lock);
}
-static void notrace ftrace_startup_sysctl(void)
+static void ftrace_shutdown_sysctl(void)
{
- mutex_lock(&ftraced_lock);
- /* ftraced_suspend is true if we want ftrace running */
- if (ftraced_suspend)
- ftrace_run_startup_code();
- mutex_unlock(&ftraced_lock);
-}
+ int command = FTRACE_DISABLE_MCOUNT;
-static void notrace ftrace_shutdown_sysctl(void)
-{
- mutex_lock(&ftraced_lock);
- /* ftraced_suspend is true if ftrace is running */
- if (ftraced_suspend)
- ftrace_run_shutdown_code();
- mutex_unlock(&ftraced_lock);
+ if (unlikely(ftrace_disabled))
+ return;
+
+ mutex_lock(&ftrace_start_lock);
+ /* ftrace_start_up is true if ftrace is running */
+ if (ftrace_start_up)
+ command |= FTRACE_DISABLE_CALLS;
+
+ ftrace_run_update_code(command);
+ mutex_unlock(&ftrace_start_lock);
}
static cycle_t ftrace_update_time;
static unsigned long ftrace_update_cnt;
unsigned long ftrace_update_tot_cnt;
-static int notrace __ftrace_update_code(void *ignore)
+static int ftrace_update_code(struct module *mod)
{
- struct dyn_ftrace *p;
- struct hlist_head head;
- struct hlist_node *t;
+ struct dyn_ftrace *p, *t;
cycle_t start, stop;
- int i;
- /* Don't be calling ftrace ops now */
- __unregister_ftrace_function(&ftrace_shutdown_ops);
-
- start = now(raw_smp_processor_id());
+ start = ftrace_now(raw_smp_processor_id());
ftrace_update_cnt = 0;
- /* No locks needed, the machine is stopped! */
- for (i = 0; i < FTRACE_HASHSIZE; i++) {
- if (hlist_empty(&ftrace_hash[i]))
- continue;
+ list_for_each_entry_safe(p, t, &ftrace_new_addrs, list) {
- head = ftrace_hash[i];
- INIT_HLIST_HEAD(&ftrace_hash[i]);
+ /* If something went wrong, bail without enabling anything */
+ if (unlikely(ftrace_disabled))
+ return -1;
- /* all CPUS are stopped, we are safe to modify code */
- hlist_for_each_entry(p, t, &head, node) {
- ftrace_code_disable(p, MCOUNT_ADDR);
- ftrace_update_cnt++;
- }
+ list_del_init(&p->list);
+ /* convert record (i.e, patch mcount-call with NOP) */
+ if (ftrace_code_disable(mod, p)) {
+ p->flags |= FTRACE_FL_CONVERTED;
+ ftrace_update_cnt++;
+ } else
+ ftrace_free_rec(p);
}
- stop = now(raw_smp_processor_id());
+ stop = ftrace_now(raw_smp_processor_id());
ftrace_update_time = stop - start;
ftrace_update_tot_cnt += ftrace_update_cnt;
- __register_ftrace_function(&ftrace_shutdown_ops);
-
- return 0;
-}
-
-static void notrace ftrace_update_code(void)
-{
- stop_machine_run(__ftrace_update_code, NULL, NR_CPUS);
-}
-
-static int notrace ftraced(void *ignore)
-{
- unsigned long usecs;
-
- set_current_state(TASK_INTERRUPTIBLE);
-
- while (!kthread_should_stop()) {
-
- /* check once a second */
- schedule_timeout(HZ);
-
- mutex_lock(&ftrace_sysctl_lock);
- mutex_lock(&ftraced_lock);
- if (ftrace_enabled && ftraced_trigger && !ftraced_suspend) {
- ftrace_record_suspend++;
- ftrace_update_code();
- usecs = nsecs_to_usecs(ftrace_update_time);
- if (ftrace_update_tot_cnt > 100000) {
- ftrace_update_tot_cnt = 0;
- pr_info("hm, dftrace overflow: %lu change%s"
- " (%lu total) in %lu usec%s\n",
- ftrace_update_cnt,
- ftrace_update_cnt != 1 ? "s" : "",
- ftrace_update_tot_cnt,
- usecs, usecs != 1 ? "s" : "");
- WARN_ON_ONCE(1);
- }
- ftraced_trigger = 0;
- ftrace_record_suspend--;
- }
- mutex_unlock(&ftraced_lock);
- mutex_unlock(&ftrace_sysctl_lock);
-
- ftrace_shutdown_replenish();
-
- set_current_state(TASK_INTERRUPTIBLE);
- }
- __set_current_state(TASK_RUNNING);
return 0;
}
-static int __init ftrace_dyn_table_alloc(void)
+static int __init ftrace_dyn_table_alloc(unsigned long num_to_init)
{
struct ftrace_page *pg;
int cnt;
int i;
- int ret;
-
- ret = ftrace_dyn_arch_init();
- if (ret)
- return ret;
/* allocate a few pages */
ftrace_pages_start = (void *)get_zeroed_page(GFP_KERNEL);
pg = ftrace_pages = ftrace_pages_start;
- cnt = NR_TO_INIT / ENTRIES_PER_PAGE;
+ cnt = num_to_init / ENTRIES_PER_PAGE;
+ pr_info("ftrace: allocating %ld entries in %d pages\n",
+ num_to_init, cnt + 1);
for (i = 0; i < cnt; i++) {
pg->next = (void *)get_zeroed_page(GFP_KERNEL);
return 0;
}
-static int __init notrace ftrace_shutdown_init(void)
-{
- struct task_struct *p;
- int ret;
+enum {
+ FTRACE_ITER_FILTER = (1 << 0),
+ FTRACE_ITER_CONT = (1 << 1),
+ FTRACE_ITER_NOTRACE = (1 << 2),
+ FTRACE_ITER_FAILURES = (1 << 3),
+};
- ret = ftrace_dyn_table_alloc();
- if (ret)
- return ret;
+#define FTRACE_BUFF_MAX (KSYM_SYMBOL_LEN+4) /* room for wildcards */
- p = kthread_run(ftraced, NULL, "ftraced");
- if (IS_ERR(p))
- return -1;
+struct ftrace_iterator {
+ struct ftrace_page *pg;
+ unsigned idx;
+ unsigned flags;
+ unsigned char buffer[FTRACE_BUFF_MAX+1];
+ unsigned buffer_idx;
+ unsigned filtered;
+};
- __register_ftrace_function(&ftrace_shutdown_ops);
+static void *
+t_next(struct seq_file *m, void *v, loff_t *pos)
+{
+ struct ftrace_iterator *iter = m->private;
+ struct dyn_ftrace *rec = NULL;
- return 0;
-}
+ (*pos)++;
-core_initcall(ftrace_shutdown_init);
-#else
-# define ftrace_startup() do { } while (0)
-# define ftrace_shutdown() do { } while (0)
-# define ftrace_startup_sysctl() do { } while (0)
-# define ftrace_shutdown_sysctl() do { } while (0)
-#endif /* CONFIG_DYNAMIC_FTRACE */
+ /* should not be called from interrupt context */
+ spin_lock(&ftrace_lock);
+ retry:
+ if (iter->idx >= iter->pg->index) {
+ if (iter->pg->next) {
+ iter->pg = iter->pg->next;
+ iter->idx = 0;
+ goto retry;
+ } else {
+ iter->idx = -1;
+ }
+ } else {
+ rec = &iter->pg->records[iter->idx++];
+ if ((rec->flags & FTRACE_FL_FREE) ||
-/**
- * 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;
+ (!(iter->flags & FTRACE_ITER_FAILURES) &&
+ (rec->flags & FTRACE_FL_FAILED)) ||
- mutex_lock(&ftrace_sysctl_lock);
- ftrace_startup();
+ ((iter->flags & FTRACE_ITER_FAILURES) &&
+ !(rec->flags & FTRACE_FL_FAILED)) ||
- ret = __register_ftrace_function(ops);
- mutex_unlock(&ftrace_sysctl_lock);
+ ((iter->flags & FTRACE_ITER_FILTER) &&
+ !(rec->flags & FTRACE_FL_FILTER)) ||
- return ret;
+ ((iter->flags & FTRACE_ITER_NOTRACE) &&
+ !(rec->flags & FTRACE_FL_NOTRACE))) {
+ rec = NULL;
+ goto retry;
+ }
+ }
+ spin_unlock(&ftrace_lock);
+
+ return rec;
+}
+
+static void *t_start(struct seq_file *m, loff_t *pos)
+{
+ struct ftrace_iterator *iter = m->private;
+ void *p = NULL;
+
+ if (*pos > 0) {
+ if (iter->idx < 0)
+ return p;
+ (*pos)--;
+ iter->idx--;
+ }
+
+ p = t_next(m, p, pos);
+
+ return p;
+}
+
+static void t_stop(struct seq_file *m, void *p)
+{
+}
+
+static int t_show(struct seq_file *m, void *v)
+{
+ struct dyn_ftrace *rec = v;
+ char str[KSYM_SYMBOL_LEN];
+
+ if (!rec)
+ return 0;
+
+ kallsyms_lookup(rec->ip, NULL, NULL, NULL, str);
+
+ seq_printf(m, "%s\n", str);
+
+ return 0;
+}
+
+static 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;
+
+ 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;
+}
+
+int ftrace_avail_release(struct inode *inode, struct file *file)
+{
+ struct seq_file *m = (struct seq_file *)file->private_data;
+ struct ftrace_iterator *iter = m->private;
+
+ seq_release(inode, file);
+ kfree(iter);
+
+ return 0;
+}
+
+static int
+ftrace_failures_open(struct inode *inode, struct file *file)
+{
+ int ret;
+ struct seq_file *m;
+ struct ftrace_iterator *iter;
+
+ ret = ftrace_avail_open(inode, file);
+ if (!ret) {
+ m = (struct seq_file *)file->private_data;
+ iter = (struct ftrace_iterator *)m->private;
+ iter->flags = FTRACE_ITER_FAILURES;
+ }
+
+ return ret;
+}
+
+
+static void ftrace_filter_reset(int enable)
+{
+ struct ftrace_page *pg;
+ struct dyn_ftrace *rec;
+ unsigned long type = enable ? FTRACE_FL_FILTER : FTRACE_FL_NOTRACE;
+ unsigned i;
+
+ /* should not be called from interrupt context */
+ spin_lock(&ftrace_lock);
+ if (enable)
+ ftrace_filtered = 0;
+ pg = ftrace_pages_start;
+ while (pg) {
+ for (i = 0; i < pg->index; i++) {
+ rec = &pg->records[i];
+ if (rec->flags & FTRACE_FL_FAILED)
+ continue;
+ rec->flags &= ~type;
+ }
+ pg = pg->next;
+ }
+ spin_unlock(&ftrace_lock);
+}
+
+static int
+ftrace_regex_open(struct inode *inode, struct file *file, int enable)
+{
+ struct ftrace_iterator *iter;
+ int ret = 0;
+
+ if (unlikely(ftrace_disabled))
+ return -ENODEV;
+
+ iter = kzalloc(sizeof(*iter), GFP_KERNEL);
+ if (!iter)
+ return -ENOMEM;
+
+ mutex_lock(&ftrace_regex_lock);
+ if ((file->f_mode & FMODE_WRITE) &&
+ !(file->f_flags & O_APPEND))
+ ftrace_filter_reset(enable);
+
+ if (file->f_mode & FMODE_READ) {
+ iter->pg = ftrace_pages_start;
+ iter->flags = enable ? FTRACE_ITER_FILTER :
+ FTRACE_ITER_NOTRACE;
+
+ ret = seq_open(file, &show_ftrace_seq_ops);
+ if (!ret) {
+ struct seq_file *m = file->private_data;
+ m->private = iter;
+ } else
+ 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(inode, file, 1);
+}
+
+static int
+ftrace_notrace_open(struct inode *inode, struct file *file)
+{
+ return ftrace_regex_open(inode, file, 0);
+}
+
+static ssize_t
+ftrace_regex_read(struct file *file, char __user *ubuf,
+ size_t cnt, loff_t *ppos)
+{
+ if (file->f_mode & FMODE_READ)
+ return seq_read(file, ubuf, cnt, ppos);
+ else
+ return -EPERM;
+}
+
+static loff_t
+ftrace_regex_lseek(struct file *file, loff_t offset, int origin)
+{
+ loff_t ret;
+
+ if (file->f_mode & FMODE_READ)
+ ret = seq_lseek(file, offset, origin);
+ else
+ file->f_pos = ret = 1;
+
+ return ret;
+}
+
+enum {
+ MATCH_FULL,
+ MATCH_FRONT_ONLY,
+ MATCH_MIDDLE_ONLY,
+ MATCH_END_ONLY,
+};
+
+static void
+ftrace_match(unsigned char *buff, int len, int enable)
+{
+ char str[KSYM_SYMBOL_LEN];
+ char *search = NULL;
+ struct ftrace_page *pg;
+ struct dyn_ftrace *rec;
+ int type = MATCH_FULL;
+ unsigned long flag = enable ? FTRACE_FL_FILTER : FTRACE_FL_NOTRACE;
+ unsigned i, match = 0, search_len = 0;
+ int not = 0;
+
+ if (buff[0] == '!') {
+ not = 1;
+ buff++;
+ len--;
+ }
+
+ for (i = 0; i < len; i++) {
+ if (buff[i] == '*') {
+ if (!i) {
+ search = buff + i + 1;
+ type = MATCH_END_ONLY;
+ search_len = len - (i + 1);
+ } else {
+ if (type == MATCH_END_ONLY) {
+ type = MATCH_MIDDLE_ONLY;
+ } else {
+ match = i;
+ type = MATCH_FRONT_ONLY;
+ }
+ buff[i] = 0;
+ break;
+ }
+ }
+ }
+
+ /* should not be called from interrupt context */
+ spin_lock(&ftrace_lock);
+ if (enable)
+ ftrace_filtered = 1;
+ pg = ftrace_pages_start;
+ while (pg) {
+ for (i = 0; i < pg->index; i++) {
+ int matched = 0;
+ char *ptr;
+
+ rec = &pg->records[i];
+ if (rec->flags & FTRACE_FL_FAILED)
+ continue;
+ kallsyms_lookup(rec->ip, NULL, NULL, NULL, str);
+ switch (type) {
+ case MATCH_FULL:
+ if (strcmp(str, buff) == 0)
+ matched = 1;
+ break;
+ case MATCH_FRONT_ONLY:
+ if (memcmp(str, buff, match) == 0)
+ matched = 1;
+ break;
+ case MATCH_MIDDLE_ONLY:
+ if (strstr(str, search))
+ matched = 1;
+ break;
+ case MATCH_END_ONLY:
+ ptr = strstr(str, search);
+ if (ptr && (ptr[search_len] == 0))
+ matched = 1;
+ break;
+ }
+ if (matched) {
+ if (not)
+ rec->flags &= ~flag;
+ else
+ rec->flags |= flag;
+ }
+ }
+ pg = pg->next;
+ }
+ spin_unlock(&ftrace_lock);
+}
+
+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;
+ char ch;
+ size_t read = 0;
+ ssize_t ret;
+
+ if (!cnt || cnt < 0)
+ return 0;
+
+ mutex_lock(&ftrace_regex_lock);
+
+ if (file->f_mode & FMODE_READ) {
+ struct seq_file *m = file->private_data;
+ iter = m->private;
+ } else
+ iter = file->private_data;
+
+ if (!*ppos) {
+ iter->flags &= ~FTRACE_ITER_CONT;
+ iter->buffer_idx = 0;
+ }
+
+ ret = get_user(ch, ubuf++);
+ if (ret)
+ goto out;
+ read++;
+ cnt--;
+
+ if (!(iter->flags & ~FTRACE_ITER_CONT)) {
+ /* skip white space */
+ while (cnt && isspace(ch)) {
+ ret = get_user(ch, ubuf++);
+ if (ret)
+ goto out;
+ read++;
+ cnt--;
+ }
+
+ if (isspace(ch)) {
+ file->f_pos += read;
+ ret = read;
+ goto out;
+ }
+
+ iter->buffer_idx = 0;
+ }
+
+ while (cnt && !isspace(ch)) {
+ if (iter->buffer_idx < FTRACE_BUFF_MAX)
+ iter->buffer[iter->buffer_idx++] = ch;
+ else {
+ ret = -EINVAL;
+ goto out;
+ }
+ ret = get_user(ch, ubuf++);
+ if (ret)
+ goto out;
+ read++;
+ cnt--;
+ }
+
+ if (isspace(ch)) {
+ iter->filtered++;
+ iter->buffer[iter->buffer_idx] = 0;
+ ftrace_match(iter->buffer, iter->buffer_idx, enable);
+ iter->buffer_idx = 0;
+ } else
+ iter->flags |= FTRACE_ITER_CONT;
+
+
+ file->f_pos += read;
+
+ ret = read;
+ out:
+ mutex_unlock(&ftrace_regex_lock);
+
+ return ret;
+}
+
+static 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);
+}
+
+static 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 void
+ftrace_set_regex(unsigned char *buf, int len, int reset, int enable)
+{
+ if (unlikely(ftrace_disabled))
+ return;
+
+ mutex_lock(&ftrace_regex_lock);
+ if (reset)
+ ftrace_filter_reset(enable);
+ if (buf)
+ ftrace_match(buf, len, enable);
+ mutex_unlock(&ftrace_regex_lock);
+}
+
+/**
+ * ftrace_set_filter - set a function to filter on in ftrace
+ * @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_filter(unsigned char *buf, int len, int reset)
+{
+ ftrace_set_regex(buf, len, reset, 1);
+}
+
+/**
+ * ftrace_set_notrace - set a function to not trace in ftrace
+ * @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_notrace(unsigned char *buf, int len, int reset)
+{
+ ftrace_set_regex(buf, len, reset, 0);
+}
+
+static int
+ftrace_regex_release(struct inode *inode, struct file *file, int enable)
+{
+ struct seq_file *m = (struct seq_file *)file->private_data;
+ struct ftrace_iterator *iter;
+
+ mutex_lock(&ftrace_regex_lock);
+ if (file->f_mode & FMODE_READ) {
+ iter = m->private;
+
+ seq_release(inode, file);
+ } else
+ iter = file->private_data;
+
+ if (iter->buffer_idx) {
+ iter->filtered++;
+ iter->buffer[iter->buffer_idx] = 0;
+ ftrace_match(iter->buffer, iter->buffer_idx, enable);
+ }
+
+ mutex_lock(&ftrace_sysctl_lock);
+ mutex_lock(&ftrace_start_lock);
+ if (ftrace_start_up && ftrace_enabled)
+ ftrace_run_update_code(FTRACE_ENABLE_CALLS);
+ mutex_unlock(&ftrace_start_lock);
+ mutex_unlock(&ftrace_sysctl_lock);
+
+ kfree(iter);
+ mutex_unlock(&ftrace_regex_lock);
+ return 0;
+}
+
+static int
+ftrace_filter_release(struct inode *inode, struct file *file)
+{
+ return ftrace_regex_release(inode, file, 1);
+}
+
+static int
+ftrace_notrace_release(struct inode *inode, struct file *file)
+{
+ return ftrace_regex_release(inode, file, 0);
+}
+
+static struct file_operations ftrace_avail_fops = {
+ .open = ftrace_avail_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = ftrace_avail_release,
+};
+
+static struct file_operations ftrace_failures_fops = {
+ .open = ftrace_failures_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = ftrace_avail_release,
+};
+
+static struct file_operations ftrace_filter_fops = {
+ .open = ftrace_filter_open,
+ .read = ftrace_regex_read,
+ .write = ftrace_filter_write,
+ .llseek = ftrace_regex_lseek,
+ .release = ftrace_filter_release,
+};
+
+static struct file_operations ftrace_notrace_fops = {
+ .open = ftrace_notrace_open,
+ .read = ftrace_regex_read,
+ .write = ftrace_notrace_write,
+ .llseek = ftrace_regex_lseek,
+ .release = ftrace_notrace_release,
+};
+
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+
+static DEFINE_MUTEX(graph_lock);
+
+int ftrace_graph_count;
+unsigned long ftrace_graph_funcs[FTRACE_GRAPH_MAX_FUNCS] __read_mostly;
+
+static void *
+g_next(struct seq_file *m, void *v, loff_t *pos)
+{
+ unsigned long *array = m->private;
+ int index = *pos;
+
+ (*pos)++;
+
+ if (index >= ftrace_graph_count)
+ return NULL;
+
+ return &array[index];
+}
+
+static void *g_start(struct seq_file *m, loff_t *pos)
+{
+ void *p = NULL;
+
+ mutex_lock(&graph_lock);
+
+ p = g_next(m, p, pos);
+
+ return p;
+}
+
+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;
+ char str[KSYM_SYMBOL_LEN];
+
+ if (!ptr)
+ return 0;
+
+ kallsyms_lookup(*ptr, NULL, NULL, NULL, str);
+
+ seq_printf(m, "%s\n", str);
+
+ return 0;
+}
+
+static 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_APPEND)) {
+ ftrace_graph_count = 0;
+ memset(ftrace_graph_funcs, 0, sizeof(ftrace_graph_funcs));
+ }
+
+ if (file->f_mode & FMODE_READ) {
+ ret = seq_open(file, &ftrace_graph_seq_ops);
+ if (!ret) {
+ struct seq_file *m = file->private_data;
+ m->private = ftrace_graph_funcs;
+ }
+ } else
+ file->private_data = ftrace_graph_funcs;
+ mutex_unlock(&graph_lock);
+
+ return ret;
+}
+
+static ssize_t
+ftrace_graph_read(struct file *file, char __user *ubuf,
+ size_t cnt, loff_t *ppos)
+{
+ if (file->f_mode & FMODE_READ)
+ return seq_read(file, ubuf, cnt, ppos);
+ else
+ return -EPERM;
+}
+
+static int
+ftrace_set_func(unsigned long *array, int idx, char *buffer)
+{
+ char str[KSYM_SYMBOL_LEN];
+ struct dyn_ftrace *rec;
+ struct ftrace_page *pg;
+ int found = 0;
+ int i, j;
+
+ if (ftrace_disabled)
+ return -ENODEV;
+
+ /* should not be called from interrupt context */
+ spin_lock(&ftrace_lock);
+
+ for (pg = ftrace_pages_start; pg; pg = pg->next) {
+ for (i = 0; i < pg->index; i++) {
+ rec = &pg->records[i];
+
+ if (rec->flags & (FTRACE_FL_FAILED | FTRACE_FL_FREE))
+ continue;
+
+ kallsyms_lookup(rec->ip, NULL, NULL, NULL, str);
+ if (strcmp(str, buffer) == 0) {
+ found = 1;
+ for (j = 0; j < idx; j++)
+ if (array[j] == rec->ip) {
+ found = 0;
+ break;
+ }
+ if (found)
+ array[idx] = rec->ip;
+ break;
+ }
+ }
+ }
+ spin_unlock(&ftrace_lock);
+
+ return found ? 0 : -EINVAL;
+}
+
+static ssize_t
+ftrace_graph_write(struct file *file, const char __user *ubuf,
+ size_t cnt, loff_t *ppos)
+{
+ unsigned char buffer[FTRACE_BUFF_MAX+1];
+ unsigned long *array;
+ size_t read = 0;
+ ssize_t ret;
+ int index = 0;
+ char ch;
+
+ if (!cnt || cnt < 0)
+ return 0;
+
+ mutex_lock(&graph_lock);
+
+ if (ftrace_graph_count >= FTRACE_GRAPH_MAX_FUNCS) {
+ ret = -EBUSY;
+ goto out;
+ }
+
+ if (file->f_mode & FMODE_READ) {
+ struct seq_file *m = file->private_data;
+ array = m->private;
+ } else
+ array = file->private_data;
+
+ ret = get_user(ch, ubuf++);
+ if (ret)
+ goto out;
+ read++;
+ cnt--;
+
+ /* skip white space */
+ while (cnt && isspace(ch)) {
+ ret = get_user(ch, ubuf++);
+ if (ret)
+ goto out;
+ read++;
+ cnt--;
+ }
+
+ if (isspace(ch)) {
+ *ppos += read;
+ ret = read;
+ goto out;
+ }
+
+ while (cnt && !isspace(ch)) {
+ if (index < FTRACE_BUFF_MAX)
+ buffer[index++] = ch;
+ else {
+ ret = -EINVAL;
+ goto out;
+ }
+ ret = get_user(ch, ubuf++);
+ if (ret)
+ goto out;
+ read++;
+ cnt--;
+ }
+ buffer[index] = 0;
+
+ /* we allow only one at a time */
+ ret = ftrace_set_func(array, ftrace_graph_count, buffer);
+ if (ret)
+ goto out;
+
+ ftrace_graph_count++;
+
+ file->f_pos += read;
+
+ ret = read;
+ out:
+ mutex_unlock(&graph_lock);
+
+ return ret;
+}
+
+static const struct file_operations ftrace_graph_fops = {
+ .open = ftrace_graph_open,
+ .read = ftrace_graph_read,
+ .write = ftrace_graph_write,
+};
+#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
+
+static __init int ftrace_init_dyn_debugfs(struct dentry *d_tracer)
+{
+ struct dentry *entry;
+
+ entry = debugfs_create_file("available_filter_functions", 0444,
+ d_tracer, NULL, &ftrace_avail_fops);
+ if (!entry)
+ pr_warning("Could not create debugfs "
+ "'available_filter_functions' entry\n");
+
+ entry = debugfs_create_file("failures", 0444,
+ d_tracer, NULL, &ftrace_failures_fops);
+ if (!entry)
+ pr_warning("Could not create debugfs 'failures' entry\n");
+
+ entry = debugfs_create_file("set_ftrace_filter", 0644, d_tracer,
+ NULL, &ftrace_filter_fops);
+ if (!entry)
+ pr_warning("Could not create debugfs "
+ "'set_ftrace_filter' entry\n");
+
+ entry = debugfs_create_file("set_ftrace_notrace", 0644, d_tracer,
+ NULL, &ftrace_notrace_fops);
+ if (!entry)
+ pr_warning("Could not create debugfs "
+ "'set_ftrace_notrace' entry\n");
+
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+ entry = debugfs_create_file("set_graph_function", 0444, d_tracer,
+ NULL,
+ &ftrace_graph_fops);
+ if (!entry)
+ pr_warning("Could not create debugfs "
+ "'set_graph_function' entry\n");
+#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
+
+ return 0;
+}
+
+static int ftrace_convert_nops(struct module *mod,
+ unsigned long *start,
+ unsigned long *end)
+{
+ unsigned long *p;
+ unsigned long addr;
+ unsigned long flags;
+
+ mutex_lock(&ftrace_start_lock);
+ 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;
+ ftrace_record_ip(addr);
+ }
+
+ /* disable interrupts to prevent kstop machine */
+ local_irq_save(flags);
+ ftrace_update_code(mod);
+ local_irq_restore(flags);
+ mutex_unlock(&ftrace_start_lock);
+
+ return 0;
+}
+
+void ftrace_init_module(struct module *mod,
+ unsigned long *start, unsigned long *end)
+{
+ if (ftrace_disabled || start == end)
+ return;
+ ftrace_convert_nops(mod, start, end);
+}
+
+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_convert_nops(NULL,
+ __start_mcount_loc,
+ __stop_mcount_loc);
+
+ return;
+ failed:
+ ftrace_disabled = 1;
+}
+
+#else
+
+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(command) do { } while (0)
+# define ftrace_shutdown(command) do { } while (0)
+# define ftrace_startup_sysctl() do { } while (0)
+# define ftrace_shutdown_sysctl() do { } while (0)
+#endif /* CONFIG_DYNAMIC_FTRACE */
+
+static ssize_t
+ftrace_pid_read(struct file *file, char __user *ubuf,
+ size_t cnt, loff_t *ppos)
+{
+ char buf[64];
+ int r;
+
+ if (ftrace_pid_trace == ftrace_swapper_pid)
+ r = sprintf(buf, "swapper tasks\n");
+ else if (ftrace_pid_trace)
+ r = sprintf(buf, "%u\n", pid_nr(ftrace_pid_trace));
+ else
+ r = sprintf(buf, "no pid\n");
+
+ return simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
+}
+
+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;
+
+ do_each_pid_task(pid, PIDTYPE_PID, p) {
+ clear_tsk_trace_trace(p);
+ } while_each_pid_task(pid, PIDTYPE_PID, p);
+ put_pid(pid);
+}
+
+static void set_ftrace_pid(struct pid *pid)
+{
+ struct task_struct *p;
+
+ do_each_pid_task(pid, PIDTYPE_PID, p) {
+ set_tsk_trace_trace(p);
+ } while_each_pid_task(pid, PIDTYPE_PID, p);
+}
+
+static void clear_ftrace_pid_task(struct pid **pid)
+{
+ if (*pid == ftrace_swapper_pid)
+ clear_ftrace_swapper();
+ else
+ clear_ftrace_pid(*pid);
+
+ *pid = NULL;
+}
+
+static void set_ftrace_pid_task(struct pid *pid)
+{
+ if (pid == ftrace_swapper_pid)
+ set_ftrace_swapper();
+ else
+ set_ftrace_pid(pid);
+}
+
+static ssize_t
+ftrace_pid_write(struct file *filp, const char __user *ubuf,
+ size_t cnt, loff_t *ppos)
+{
+ struct pid *pid;
+ char buf[64];
+ long val;
+ int ret;
+
+ if (cnt >= sizeof(buf))
+ return -EINVAL;
+
+ if (copy_from_user(&buf, ubuf, cnt))
+ return -EFAULT;
+
+ buf[cnt] = 0;
+
+ ret = strict_strtol(buf, 10, &val);
+ if (ret < 0)
+ return ret;
+
+ mutex_lock(&ftrace_start_lock);
+ if (val < 0) {
+ /* disable pid tracing */
+ if (!ftrace_pid_trace)
+ goto out;
+
+ clear_ftrace_pid_task(&ftrace_pid_trace);
+
+ } else {
+ /* swapper task is special */
+ if (!val) {
+ pid = ftrace_swapper_pid;
+ if (pid == ftrace_pid_trace)
+ goto out;
+ } else {
+ pid = find_get_pid(val);
+
+ if (pid == ftrace_pid_trace) {
+ put_pid(pid);
+ goto out;
+ }
+ }
+
+ if (ftrace_pid_trace)
+ clear_ftrace_pid_task(&ftrace_pid_trace);
+
+ if (!pid)
+ goto out;
+
+ ftrace_pid_trace = pid;
+
+ set_ftrace_pid_task(ftrace_pid_trace);
+ }
+
+ /* update the function call */
+ ftrace_update_pid_func();
+ ftrace_startup_enable(0);
+
+ out:
+ mutex_unlock(&ftrace_start_lock);
+
+ return cnt;
+}
+
+static struct file_operations ftrace_pid_fops = {
+ .read = ftrace_pid_read,
+ .write = ftrace_pid_write,
+};
+
+static __init int ftrace_init_debugfs(void)
+{
+ struct dentry *d_tracer;
+ struct dentry *entry;
+
+ d_tracer = tracing_init_dentry();
+ if (!d_tracer)
+ return 0;
+
+ ftrace_init_dyn_debugfs(d_tracer);
+
+ entry = debugfs_create_file("set_ftrace_pid", 0644, d_tracer,
+ NULL, &ftrace_pid_fops);
+ if (!entry)
+ pr_warning("Could not create debugfs "
+ "'set_ftrace_pid' entry\n");
+ 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();
+}
+
+/**
+ * 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;
+
+ if (unlikely(ftrace_disabled))
+ return -1;
+
+ mutex_lock(&ftrace_sysctl_lock);
+
+ ret = __register_ftrace_function(ops);
+ ftrace_startup(0);
+
+ mutex_unlock(&ftrace_sysctl_lock);
+ return ret;
}
/**
mutex_lock(&ftrace_sysctl_lock);
ret = __unregister_ftrace_function(ops);
-
- if (ftrace_list == &ftrace_list_end)
- ftrace_shutdown();
-
+ ftrace_shutdown(0);
mutex_unlock(&ftrace_sysctl_lock);
return ret;
}
-notrace int
+int
ftrace_enable_sysctl(struct ctl_table *table, int write,
- struct file *filp, void __user *buffer, size_t *lenp,
+ struct file *file, void __user *buffer, size_t *lenp,
loff_t *ppos)
{
int ret;
+ if (unlikely(ftrace_disabled))
+ return -ENODEV;
+
mutex_lock(&ftrace_sysctl_lock);
- ret = proc_dointvec(table, write, filp, buffer, lenp, ppos);
+ ret = proc_dointvec(table, write, file, buffer, lenp, ppos);
if (ret || !write || (last_ftrace_enabled == ftrace_enabled))
goto out;
mutex_unlock(&ftrace_sysctl_lock);
return ret;
}
+
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+
+static atomic_t ftrace_graph_active;
+
+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;
+
+/* 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) {
+ t->curr_ret_stack = -1;
+ /* Make sure IRQs see the -1 first: */
+ barrier();
+ t->ret_stack = ret_stack_list[start++];
+ atomic_set(&t->tracing_graph_pause, 0);
+ atomic_set(&t->trace_overrun, 0);
+ }
+ } 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;
+}
+
+/* Allocate a return stack for each task */
+static int start_graph_tracing(void)
+{
+ struct ftrace_ret_stack **ret_stack_list;
+ int ret;
+
+ ret_stack_list = kmalloc(FTRACE_RETSTACK_ALLOC_SIZE *
+ sizeof(struct ftrace_ret_stack *),
+ GFP_KERNEL);
+
+ if (!ret_stack_list)
+ return -ENOMEM;
+
+ do {
+ ret = alloc_retstack_tasklist(ret_stack_list);
+ } while (ret == -EAGAIN);
+
+ kfree(ret_stack_list);
+ return ret;
+}
+
+int register_ftrace_graph(trace_func_graph_ret_t retfunc,
+ trace_func_graph_ent_t entryfunc)
+{
+ int ret = 0;
+
+ mutex_lock(&ftrace_sysctl_lock);
+
+ atomic_inc(&ftrace_graph_active);
+ ret = start_graph_tracing();
+ if (ret) {
+ atomic_dec(&ftrace_graph_active);
+ goto out;
+ }
+
+ ftrace_graph_return = retfunc;
+ ftrace_graph_entry = entryfunc;
+
+ ftrace_startup(FTRACE_START_FUNC_RET);
+
+out:
+ mutex_unlock(&ftrace_sysctl_lock);
+ return ret;
+}
+
+void unregister_ftrace_graph(void)
+{
+ mutex_lock(&ftrace_sysctl_lock);
+
+ atomic_dec(&ftrace_graph_active);
+ ftrace_graph_return = (trace_func_graph_ret_t)ftrace_stub;
+ ftrace_graph_entry = ftrace_graph_entry_stub;
+ ftrace_shutdown(FTRACE_STOP_FUNC_RET);
+
+ mutex_unlock(&ftrace_sysctl_lock);
+}
+
+/* Allocate a return stack for newly created task */
+void ftrace_graph_init_task(struct task_struct *t)
+{
+ if (atomic_read(&ftrace_graph_active)) {
+ t->ret_stack = kmalloc(FTRACE_RETFUNC_DEPTH
+ * sizeof(struct ftrace_ret_stack),
+ GFP_KERNEL);
+ if (!t->ret_stack)
+ return;
+ t->curr_ret_stack = -1;
+ atomic_set(&t->tracing_graph_pause, 0);
+ atomic_set(&t->trace_overrun, 0);
+ } else
+ t->ret_stack = NULL;
+}
+
+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
+
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff