X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;f=kernel%2Ftrace%2Fftrace.c;h=9a236ffe2aa45188cacabfc8fbc15e81c6091f64;hb=0637810f24bad641d3d3f80fd3f63f3baffd9536;hp=6d89ab46c6e3777b3c4f57cc1650cace5ac8daa4;hpb=66eafebc1086014709dc38f52ddcb3d67d9b346c;p=safe%2Fjmp%2Flinux-2.6 diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 6d89ab4..9a236ff 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -17,6 +17,7 @@ #include #include #include +#include #include #include #include @@ -47,8 +48,9 @@ int ftrace_enabled __read_mostly; static int last_ftrace_enabled; -/* ftrace_pid_trace >= 0 will only trace threads with this pid */ -static int ftrace_pid_trace = -1; +/* 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; @@ -90,7 +92,7 @@ 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 (current->pid != ftrace_pid_trace) + if (!test_tsk_trace_trace(current)) return; ftrace_pid_function(ip, parent_ip); @@ -153,7 +155,7 @@ static int __register_ftrace_function(struct ftrace_ops *ops) else func = ftrace_list_func; - if (ftrace_pid_trace >= 0) { + if (ftrace_pid_trace) { set_ftrace_pid_function(func); func = ftrace_pid_func; } @@ -209,7 +211,7 @@ static int __unregister_ftrace_function(struct ftrace_ops *ops) if (ftrace_list->next == &ftrace_list_end) { ftrace_func_t func = ftrace_list->func; - if (ftrace_pid_trace >= 0) { + if (ftrace_pid_trace) { set_ftrace_pid_function(func); func = ftrace_pid_func; } @@ -239,7 +241,7 @@ static void ftrace_update_pid_func(void) func = ftrace_trace_function; - if (ftrace_pid_trace >= 0) { + if (ftrace_pid_trace) { set_ftrace_pid_function(func); func = ftrace_pid_func; } else { @@ -1046,6 +1048,13 @@ ftrace_match(unsigned char *buff, int len, int enable) 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] == '*') { @@ -1099,8 +1108,12 @@ ftrace_match(unsigned char *buff, int len, int enable) matched = 1; break; } - if (matched) - rec->flags |= flag; + if (matched) { + if (not) + rec->flags &= ~flag; + else + rec->flags |= flag; + } } pg = pg->next; } @@ -1320,6 +1333,230 @@ static struct file_operations ftrace_notrace_fops = { .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; @@ -1347,6 +1584,15 @@ static __init int ftrace_init_dyn_debugfs(struct dentry *d_tracer) 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; } @@ -1451,18 +1697,89 @@ ftrace_pid_read(struct file *file, char __user *ubuf, char buf[64]; int r; - if (ftrace_pid_trace >= 0) - r = sprintf(buf, "%u\n", ftrace_pid_trace); + 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; + + 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); + + *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; @@ -1480,18 +1797,37 @@ ftrace_pid_write(struct file *filp, const char __user *ubuf, return ret; mutex_lock(&ftrace_start_lock); - if (ret < 0) { + if (val < 0) { /* disable pid tracing */ - if (ftrace_pid_trace < 0) + if (!ftrace_pid_trace) goto out; - ftrace_pid_trace = -1; + + 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 (ftrace_pid_trace == 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 = val; + ftrace_pid_trace = pid; + + set_ftrace_pid_task(ftrace_pid_trace); } /* update the function call */ @@ -1635,12 +1971,17 @@ ftrace_enable_sysctl(struct ctl_table *table, int write, #ifdef CONFIG_FUNCTION_GRAPH_TRACER static atomic_t ftrace_graph_active; +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 = - (trace_func_graph_ent_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) @@ -1671,8 +2012,11 @@ static int alloc_retstack_tasklist(struct ftrace_ret_stack **ret_stack_list) } if (t->ret_stack == NULL) { - t->ret_stack = ret_stack_list[start++]; 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); @@ -1706,6 +2050,27 @@ static int start_graph_tracing(void) 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; +} + int register_ftrace_graph(trace_func_graph_ret_t retfunc, trace_func_graph_ent_t entryfunc) { @@ -1713,6 +2078,9 @@ int register_ftrace_graph(trace_func_graph_ret_t retfunc, mutex_lock(&ftrace_sysctl_lock); + ftrace_suspend_notifier.notifier_call = ftrace_suspend_notifier_call; + register_pm_notifier(&ftrace_suspend_notifier); + atomic_inc(&ftrace_graph_active); ret = start_graph_tracing(); if (ret) { @@ -1736,8 +2104,9 @@ void unregister_ftrace_graph(void) atomic_dec(&ftrace_graph_active); ftrace_graph_return = (trace_func_graph_ret_t)ftrace_stub; - ftrace_graph_entry = (trace_func_graph_ent_t)ftrace_stub; + ftrace_graph_entry = ftrace_graph_entry_stub; ftrace_shutdown(FTRACE_STOP_FUNC_RET); + unregister_pm_notifier(&ftrace_suspend_notifier); mutex_unlock(&ftrace_sysctl_lock); } @@ -1752,6 +2121,7 @@ void ftrace_graph_init_task(struct task_struct *t) 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; @@ -1767,5 +2137,10 @@ void ftrace_graph_exit_task(struct task_struct *t) kfree(ret_stack); } + +void ftrace_graph_stop(void) +{ + ftrace_stop(); +} #endif