int ftrace_enabled __read_mostly;
static int last_ftrace_enabled;
+/* 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;
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;
static void ftrace_list_func(unsigned long ip, unsigned long parent_ip)
{
};
}
+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
*
{
ftrace_trace_function = ftrace_stub;
__ftrace_trace_function = ftrace_stub;
+ ftrace_pid_function = ftrace_stub;
}
#ifndef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST
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.
*/
#ifdef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST
- if (ops->next == &ftrace_list_end)
- ftrace_trace_function = ops->func;
- else
- ftrace_trace_function = ftrace_list_func;
+ ftrace_trace_function = func;
#else
- if (ops->next == &ftrace_list_end)
- __ftrace_trace_function = ops->func;
- else
- __ftrace_trace_function = ftrace_list_func;
+ __ftrace_trace_function = func;
ftrace_trace_function = ftrace_test_stop_func;
#endif
}
if (ftrace_enabled) {
/* If we only have one func left, then call that directly */
- if (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
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 int ftrace_filtered;
printk(KERN_CONT "%s%02x", i ? ":" : "", p[i]);
}
-static void ftrace_bug(int failed, unsigned long ip,
- unsigned char *expected,
- unsigned char *replace)
+static void ftrace_bug(int failed, unsigned long ip)
{
switch (failed) {
case -EFAULT:
FTRACE_WARN_ON_ONCE(1);
pr_info("ftrace failed to modify ");
print_ip_sym(ip);
- print_ip_ins(" expected: ", expected);
print_ip_ins(" actual: ", (unsigned char *)ip);
- print_ip_ins(" replace: ", replace);
printk(KERN_CONT "\n");
break;
case -EPERM:
}
}
-#define FTRACE_ADDR ((long)(ftrace_caller))
static int
-__ftrace_replace_code(struct dyn_ftrace *rec,
- unsigned char *old, unsigned char *new, int enable)
+__ftrace_replace_code(struct dyn_ftrace *rec, int enable)
{
unsigned long ip, fl;
+ unsigned long ftrace_addr;
+
+ ftrace_addr = (unsigned long)ftrace_caller;
ip = rec->ip;
- if (ftrace_filtered && enable) {
+ /*
+ * 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.
+ *
+ */
+ if (rec->flags & FTRACE_FL_NOTRACE) {
+ if (rec->flags & FTRACE_FL_ENABLED)
+ rec->flags &= ~FTRACE_FL_ENABLED;
+ else
+ return 0;
+
+ } else if (ftrace_filtered && enable) {
/*
- * If filtering is on:
- *
- * If this record is set to be filtered and
- * is enabled then do nothing.
- *
- * If this record is set to be filtered and
- * it is not enabled, enable it.
- *
- * If this record is not set to be filtered
- * and it is not enabled do nothing.
- *
- * If this record is set not to trace then
- * do nothing.
- *
- * If this record is set not to trace and
- * it is enabled then disable it.
- *
- * If this record is not set to be filtered and
- * it is enabled, disable it.
+ * Filtering is on:
*/
- fl = rec->flags & (FTRACE_FL_FILTER | FTRACE_FL_NOTRACE |
- FTRACE_FL_ENABLED);
+ fl = rec->flags & (FTRACE_FL_FILTER | FTRACE_FL_ENABLED);
- if ((fl == (FTRACE_FL_FILTER | FTRACE_FL_ENABLED)) ||
- (fl == (FTRACE_FL_FILTER | FTRACE_FL_NOTRACE)) ||
- !fl || (fl == FTRACE_FL_NOTRACE))
+ /* Record is filtered and enabled, do nothing */
+ if (fl == (FTRACE_FL_FILTER | FTRACE_FL_ENABLED))
return 0;
- /*
- * If it is enabled disable it,
- * otherwise enable it!
- */
- if (fl & FTRACE_FL_ENABLED) {
- /* swap new and old */
- new = old;
- old = ftrace_call_replace(ip, FTRACE_ADDR);
+ /* Record is not filtered and is not enabled do nothing */
+ if (!fl)
+ return 0;
+
+ /* Record is not filtered but enabled, disable it */
+ if (fl == FTRACE_FL_ENABLED)
rec->flags &= ~FTRACE_FL_ENABLED;
- } else {
- new = ftrace_call_replace(ip, FTRACE_ADDR);
+ else
+ /* Otherwise record is filtered but not enabled, enable it */
rec->flags |= FTRACE_FL_ENABLED;
- }
} else {
+ /* Disable or not filtered */
if (enable) {
- /*
- * If this record is set not to trace and is
- * not enabled, do nothing.
- */
- fl = rec->flags & (FTRACE_FL_NOTRACE | FTRACE_FL_ENABLED);
- if (fl == FTRACE_FL_NOTRACE)
- return 0;
-
- new = ftrace_call_replace(ip, FTRACE_ADDR);
- } else
- old = ftrace_call_replace(ip, FTRACE_ADDR);
-
- 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;
}
}
- return ftrace_modify_code(ip, old, new);
+ if (rec->flags & FTRACE_FL_ENABLED)
+ return ftrace_make_call(rec, ftrace_addr);
+ else
+ return ftrace_make_nop(NULL, rec, ftrace_addr);
}
static void ftrace_replace_code(int enable)
{
int i, failed;
- unsigned char *new = NULL, *old = NULL;
struct dyn_ftrace *rec;
struct ftrace_page *pg;
- if (enable)
- 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;
/* ignore updates to this record's mcount site */
unfreeze_record(rec);
}
- failed = __ftrace_replace_code(rec, old, new, enable);
+ 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, old, new);
+ ftrace_bug(failed, rec->ip);
}
}
}
}
static int
-ftrace_code_disable(struct dyn_ftrace *rec)
+ftrace_code_disable(struct module *mod, struct dyn_ftrace *rec)
{
unsigned long ip;
- unsigned char *nop, *call;
int ret;
ip = rec->ip;
- nop = ftrace_nop_replace();
- call = ftrace_call_replace(ip, mcount_addr);
-
- ret = ftrace_modify_code(ip, call, nop);
+ ret = ftrace_make_nop(mod, rec, mcount_addr);
if (ret) {
- ftrace_bug(ret, ip, call, nop);
+ ftrace_bug(ret, ip);
rec->flags |= FTRACE_FL_FAILED;
return 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;
}
static ftrace_func_t saved_ftrace_func;
static int ftrace_start_up;
-static DEFINE_MUTEX(ftrace_start_lock);
-static void ftrace_startup(void)
+static void ftrace_startup_enable(int command)
{
- int command = 0;
-
- if (unlikely(ftrace_disabled))
- return;
-
- mutex_lock(&ftrace_start_lock);
- ftrace_start_up++;
- if (ftrace_start_up == 1)
- command |= FTRACE_ENABLE_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;
+ return;
ftrace_run_update_code(command);
- out:
- mutex_unlock(&ftrace_start_lock);
}
-static void ftrace_shutdown(void)
+static void ftrace_startup(int command)
{
- int command = 0;
+ 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 ftrace_shutdown(int command)
+{
if (unlikely(ftrace_disabled))
return;
static unsigned long ftrace_update_cnt;
unsigned long ftrace_update_tot_cnt;
-static int ftrace_update_code(void)
+static int ftrace_update_code(struct module *mod)
{
struct dyn_ftrace *p, *t;
cycle_t start, stop;
list_del_init(&p->list);
/* convert record (i.e, patch mcount-call with NOP) */
- if (ftrace_code_disable(p)) {
+ if (ftrace_code_disable(mod, p)) {
p->flags |= FTRACE_FL_CONVERTED;
ftrace_update_cnt++;
} else
cnt = num_to_init / ENTRIES_PER_PAGE;
pr_info("ftrace: allocating %ld entries in %d pages\n",
- num_to_init, cnt);
+ num_to_init, cnt + 1);
for (i = 0; i < cnt; i++) {
pg->next = (void *)get_zeroed_page(GFP_KERNEL);
#define FTRACE_BUFF_MAX (KSYM_SYMBOL_LEN+4) /* room for wildcards */
struct ftrace_iterator {
- loff_t pos;
struct ftrace_page *pg;
unsigned idx;
unsigned flags;
iter->pg = iter->pg->next;
iter->idx = 0;
goto retry;
+ } else {
+ iter->idx = -1;
}
} else {
rec = &iter->pg->records[iter->idx++];
}
spin_unlock(&ftrace_lock);
- iter->pos = *pos;
-
return rec;
}
{
struct ftrace_iterator *iter = m->private;
void *p = NULL;
- loff_t l = -1;
- if (*pos != iter->pos) {
- for (p = t_next(m, p, &l); p && l < *pos; p = t_next(m, p, &l))
- ;
- } else {
- l = *pos;
- p = t_next(m, p, &l);
+ if (*pos > 0) {
+ if (iter->idx < 0)
+ return p;
+ (*pos)--;
+ iter->idx--;
}
+ p = t_next(m, p, pos);
+
return p;
}
return -ENOMEM;
iter->pg = ftrace_pages_start;
- iter->pos = -1;
ret = seq_open(file, &show_ftrace_seq_ops);
if (!ret) {
if (file->f_mode & FMODE_READ) {
iter->pg = ftrace_pages_start;
- iter->pos = -1;
iter->flags = enable ? FTRACE_ITER_FILTER :
FTRACE_ITER_NOTRACE;
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] == '*') {
matched = 1;
break;
}
- if (matched)
- rec->flags |= flag;
+ if (matched) {
+ if (not)
+ rec->flags &= ~flag;
+ else
+ rec->flags |= flag;
+ }
}
pg = pg->next;
}
mutex_lock(&ftrace_sysctl_lock);
mutex_lock(&ftrace_start_lock);
- if (iter->filtered && ftrace_start_up && ftrace_enabled)
+ if (ftrace_start_up && ftrace_enabled)
ftrace_run_update_code(FTRACE_ENABLE_CALLS);
mutex_unlock(&ftrace_start_lock);
mutex_unlock(&ftrace_sysctl_lock);
.release = ftrace_notrace_release,
};
-static __init int ftrace_init_debugfs(void)
+#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)
{
- struct dentry *d_tracer;
- struct dentry *entry;
+ unsigned long *array = m->private;
+ int index = *pos;
- d_tracer = tracing_init_dentry();
+ (*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);
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;
}
-fs_initcall(ftrace_init_debugfs);
-
-static int ftrace_convert_nops(unsigned long *start,
+static int ftrace_convert_nops(struct module *mod,
+ unsigned long *start,
unsigned long *end)
{
unsigned long *p;
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();
+ ftrace_update_code(mod);
local_irq_restore(flags);
mutex_unlock(&ftrace_start_lock);
return 0;
}
-void ftrace_init_module(unsigned long *start, unsigned long *end)
+void ftrace_init_module(struct module *mod,
+ unsigned long *start, unsigned long *end)
{
if (ftrace_disabled || start == end)
return;
- ftrace_convert_nops(start, end);
+ ftrace_convert_nops(mod, start, end);
}
extern unsigned long __start_mcount_loc[];
last_ftrace_enabled = ftrace_enabled = 1;
- ret = ftrace_convert_nops(__start_mcount_loc,
+ ret = ftrace_convert_nops(NULL,
+ __start_mcount_loc,
__stop_mcount_loc);
return;
}
device_initcall(ftrace_nodyn_init);
-# define ftrace_startup() do { } while (0)
-# define ftrace_shutdown() do { } while (0)
+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
*
return -1;
mutex_lock(&ftrace_sysctl_lock);
+
ret = __register_ftrace_function(ops);
- ftrace_startup();
- mutex_unlock(&ftrace_sysctl_lock);
+ ftrace_startup(0);
+ mutex_unlock(&ftrace_sysctl_lock);
return ret;
}
mutex_lock(&ftrace_sysctl_lock);
ret = __unregister_ftrace_function(ops);
- ftrace_shutdown();
+ ftrace_shutdown(0);
mutex_unlock(&ftrace_sysctl_lock);
return ret;
return ret;
}
-#ifdef CONFIG_FUNCTION_RET_TRACER
-trace_function_return_t ftrace_function_return =
- (trace_function_return_t)ftrace_stub;
-void register_ftrace_return(trace_function_return_t func)
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+
+static atomic_t ftrace_graph_active;
+
+int ftrace_graph_entry_stub(struct ftrace_graph_ent *trace)
{
- ftrace_function_return = func;
+ return 0;
}
-void unregister_ftrace_return(void)
+/* 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)
{
- ftrace_function_return = (trace_function_return_t)ftrace_stub;
+ 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);
}
-#endif
+/* 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