From f9349a8f978929a0c71d2c42ae299f7d462c239d Mon Sep 17 00:00:00 2001 From: Frederic Weisbecker Date: Thu, 19 Feb 2009 21:13:12 +0100 Subject: [PATCH] tracing/function-graph-tracer: make set_graph_function file support ftrace regex Impact: trace only functions matching a pattern The set_graph_function file let one to trace only one or several chosen functions and follow all their code flow. Currently, only a constant function name is allowed so this patch allows the ftrace_regex functions: - matches all functions that end with "name": echo *name > set_graph_function - matches all functions that begin with "name": echo name* > set_graph_function - matches all functions that contains "name": echo *name* > set_graph_function Example: echo mutex* > set_graph_function 0) | mutex_lock_nested() { 0) 0.563 us | __might_sleep(); 0) 2.072 us | } 0) | mutex_unlock() { 0) 1.036 us | __mutex_unlock_slowpath(); 0) 2.433 us | } 0) | mutex_unlock() { 0) 0.691 us | __mutex_unlock_slowpath(); 0) 1.787 us | } 0) | mutex_lock_interruptible_nested() { 0) 0.548 us | __might_sleep(); 0) 1.945 us | } Signed-off-by: Frederic Weisbecker Cc: Arnaldo Carvalho de Melo Cc: Steven Rostedt Signed-off-by: Ingo Molnar --- kernel/trace/ftrace.c | 56 +++++++++++++++++++++++++++++-------------- 1 file changed, 38 insertions(+), 18 deletions(-) diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 7dd5a2bef9c..cf59f4c5474 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -1895,6 +1895,10 @@ 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_count && !*pos) + return (void *)1; + p = g_next(m, p, pos); return p; @@ -1913,6 +1917,11 @@ static int g_show(struct seq_file *m, void *v) if (!ptr) return 0; + if (ptr == (unsigned long *)1) { + seq_printf(m, "#### all functions enabled ####\n"); + return 0; + } + kallsyms_lookup(*ptr, NULL, NULL, NULL, str); seq_printf(m, "%s\n", str); @@ -1966,38 +1975,51 @@ ftrace_graph_read(struct file *file, char __user *ubuf, } static int -ftrace_set_func(unsigned long *array, int idx, char *buffer) +ftrace_set_func(unsigned long *array, int *idx, char *buffer) { - char str[KSYM_SYMBOL_LEN]; struct dyn_ftrace *rec; struct ftrace_page *pg; + int search_len; int found = 0; - int j; + int type, not; + char *search; + bool exists; + int i; if (ftrace_disabled) return -ENODEV; + /* decode regex */ + type = ftrace_setup_glob(buffer, strlen(buffer), &search, ¬); + if (not) + return -EINVAL; + + search_len = strlen(search); + mutex_lock(&ftrace_lock); do_for_each_ftrace_rec(pg, rec) { + if (*idx >= FTRACE_GRAPH_MAX_FUNCS) + break; + if (rec->flags & (FTRACE_FL_FAILED | FTRACE_FL_FREE)) continue; - kallsyms_lookup(rec->ip, NULL, NULL, NULL, str); - if (strcmp(str, buffer) == 0) { - /* Return 1 if we add it to the array */ - found = 1; - for (j = 0; j < idx; j++) - if (array[j] == rec->ip) { - found = 0; + if (ftrace_match_record(rec, search, search_len, type)) { + /* ensure it is not already in the array */ + exists = false; + for (i = 0; i < *idx; i++) + if (array[i] == rec->ip) { + exists = true; break; } - if (found) - array[idx] = rec->ip; - goto out; + if (!exists) { + array[(*idx)++] = rec->ip; + found = 1; + } } } while_for_each_ftrace_rec(); - out: + mutex_unlock(&ftrace_lock); return found ? 0 : -EINVAL; @@ -2066,13 +2088,11 @@ ftrace_graph_write(struct file *file, const char __user *ubuf, } buffer[index] = 0; - /* we allow only one at a time */ - ret = ftrace_set_func(array, ftrace_graph_count, buffer); + /* we allow only one expression 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; -- 2.41.1