Commit 0b507e1e authored by Dmitry Safonov's avatar Dmitry Safonov Committed by Steven Rostedt
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ftrace: add module globbing 

Extend module command for function filter selection with globbing.
It uses the same globbing as function filter.

  sh# echo '*alloc*:mod:*' > set_ftrace_filter

Will trace any function with the letters 'alloc' in the name in any
module but not in kernel.

  sh# echo '!*alloc*:mod:ipv6' >> set_ftrace_filter

Will prevent from tracing functions with 'alloc' in the name from module
ipv6 (do not forget to append to set_ftrace_filter file).

  sh# echo '*alloc*:mod:!ipv6' > set_ftrace_filter

Will trace functions with 'alloc' in the name from kernel and any
module except ipv6.

  sh# echo '*alloc*:mod:!*' > set_ftrace_filter

Will trace any function with the letters 'alloc' in the name only from
kernel, but not from any module.

  sh# echo '*:mod:!*' > set_ftrace_filter
or
  sh# echo ':mod:!' > set_ftrace_filter

Will trace every function in the kernel, but will not trace functions
from any module.

  sh# echo '*:mod:*' > set_ftrace_filter
or
  sh# echo ':mod:' > set_ftrace_filter

As the opposite will trace all functions from all modules, but not from
kernel.

  sh# echo '*:mod:*snd*' > set_ftrace_filter

Will trace your sound drivers only (if any).

Link: http://lkml.kernel.org/r/1443545176-3215-4-git-send-email-0x7f454c46@gmail.com



Signed-off-by: default avatarDmitry Safonov <0x7f454c46@gmail.com>
[ Made format changes ]
Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
parent 3ba00929

kernel/trace/ftrace.c

+36 −15
Original line number Diff line number Diff line
@@ -3485,19 +3485,37 @@ enter_record(struct ftrace_hash *hash, struct dyn_ftrace *rec, int clear_filter) 
}



static int

ftrace_match_record(struct dyn_ftrace *rec,

		char *mod, struct ftrace_glob *func_g)

ftrace_match_record(struct dyn_ftrace *rec, struct ftrace_glob *func_g,

		struct ftrace_glob *mod_g, int exclude_mod)

{

	char str[KSYM_SYMBOL_LEN];

	char *modname;



	kallsyms_lookup(rec->ip, NULL, NULL, &modname, str);



	if (mod) {

		/* module lookup requires matching the module */

		if (!modname || strcmp(modname, mod))

	if (mod_g) {

		int mod_matches = (modname) ? ftrace_match(modname, mod_g) : 0;



		/* blank module name to match all modules */

		if (!mod_g->len) {

			/* blank module globbing: modname xor exclude_mod */

			if ((!exclude_mod) != (!modname))

				goto func_match;

			return 0;

		}



		/* not matching the module */

		if (!modname || !mod_matches) {

			if (exclude_mod)

				goto func_match;

			else

				return 0;

		}



		if (mod_matches && exclude_mod)

			return 0;



func_match:

		/* blank search means to match all funcs in the mod */

		if (!func_g->len)

			return 1;
@@ -3512,23 +3530,32 @@ match_records(struct ftrace_hash *hash, char *func, int len, char *mod) 
	struct ftrace_page *pg;

	struct dyn_ftrace *rec;

	struct ftrace_glob func_g = { .type = MATCH_FULL };

	struct ftrace_glob mod_g = { .type = MATCH_FULL };

	struct ftrace_glob *mod_match = (mod) ? &mod_g : NULL;

	int exclude_mod = 0;

	int found = 0;

	int ret;

	int clear_filter;



	if (len) {

	if (func) {

		func_g.type = filter_parse_regex(func, len, &func_g.search,

						 &clear_filter);

		func_g.len = strlen(func_g.search);

	}



	if (mod) {

		mod_g.type = filter_parse_regex(mod, strlen(mod),

				&mod_g.search, &exclude_mod);

		mod_g.len = strlen(mod_g.search);

	}



	mutex_lock(&ftrace_lock);



	if (unlikely(ftrace_disabled))

		goto out_unlock;



	do_for_each_ftrace_rec(pg, rec) {

		if (ftrace_match_record(rec, mod, &func_g)) {

		if (ftrace_match_record(rec, &func_g, mod_match, exclude_mod)) {

			ret = enter_record(hash, rec, clear_filter);

			if (ret < 0) {

				found = ret;
@@ -3568,17 +3595,11 @@ ftrace_mod_callback(struct ftrace_hash *hash, 
	 * you can tell which command was used by the cmd

	 * parameter.

	 */



	/* we must have a module name */

	if (!module || !strlen(module))

		return -EINVAL;



	ret = match_records(hash, func, strlen(func), module);

	if (!ret)

		return -EINVAL;

	if (ret < 0)

		return ret;



	return 0;

}
@@ -3729,7 +3750,7 @@ register_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, 


	do_for_each_ftrace_rec(pg, rec) {



		if (!ftrace_match_record(rec, NULL, &func_g))

		if (!ftrace_match_record(rec, &func_g, NULL, 0))

			continue;



		entry = kmalloc(sizeof(*entry), GFP_KERNEL);
@@ -4621,7 +4642,7 @@ ftrace_set_func(unsigned long *array, int *idx, int size, char *buffer) 


	do_for_each_ftrace_rec(pg, rec) {



		if (ftrace_match_record(rec, NULL, &func_g)) {

		if (ftrace_match_record(rec, &func_g, NULL, 0)) {

			/* if it is in the array */

			exists = false;

			for (i = 0; i < *idx; i++) {

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