[for-next][PATCH 0/9] tracing: Updates for 4.4

[for-next][PATCH 0/9] tracing: Updates for 4.4

[Steven Rostedt]

  git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace.git
for-next

Head SHA1: ddd70280bf0e92ad81a9526971409603fba21679


Dmitry Safonov (5):
      ftrace: Remove redundant strsep in mod_callback
      ftrace: Clarify code for mod command
      ftrace: Introduce ftrace_glob structure
      ftrace: add module globbing
      Documentation: ftrace: Module globbing usage

Rasmus Villemoes (2):
      tracing: Use kstrdup_const instead of private implementation
      ftrace: Remove redundant swap function

Tal Shorer (2):
      tracing: Allow disabling compilation of specific trace systems
      tracing: gpio: Add Kconfig option for enabling/disabling trace events

----
 Documentation/trace/ftrace.txt |  17 ++++
 include/linux/tracepoint.h     |  17 +++-
 include/trace/define_trace.h   |   2 +-
 include/trace/events/gpio.h    |   4 +
 kernel/trace/Kconfig           |   7 ++
 kernel/trace/ftrace.c          | 178 ++++++++++++++++++++---------------------
 kernel/trace/trace_events.c    |  24 ++----
 7 files changed, 138 insertions(+), 111 deletions(-)

[for-next][PATCH 1/9] tracing: Use kstrdup_const instead of private implementation

[Steven Rostedt]

[-- Attachment #1: 0001-tracing-Use-kstrdup_const-instead-of-private-impleme.patch --]
[-- Type: text/plain, Size: 2842 bytes --]

From: Rasmus Villemoes <linux@rasmusvillemoes.dk>

The kernel now has kstrdup_const/kfree_const for reusing .rodata
(typically string literals) when possible; there's no reason to
duplicate that logic in the tracing system. Moreover, as the comment
above core_kernel_data states, it may not always return true for
.rodata - that is for example the case on x86_64, where we thus end up
kstrdup'ing all the passed-in strings.

Arguably, testing for .rodata explicitly (as kstrdup_const does) is
also more correct: I don't think one is supposed to be able to change
the name after creating the event_subsystem by passing the address of
a static char (but non-const) array.

Link: http://lkml.kernel.org/r/1441833841-12955-1-git-send-email-linux@rasmusvillemoes.dk

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
---
 kernel/trace/trace_events.c | 24 ++++++++----------------
 1 file changed, 8 insertions(+), 16 deletions(-)

diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
index 57c9e709772c..d120cfe3cca7 100644
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -38,21 +38,19 @@ static LIST_HEAD(ftrace_common_fields);
 static struct kmem_cache *field_cachep;
 static struct kmem_cache *file_cachep;
 
-#define SYSTEM_FL_FREE_NAME		(1 << 31)
-
 static inline int system_refcount(struct event_subsystem *system)
 {
-	return system->ref_count & ~SYSTEM_FL_FREE_NAME;
+	return system->ref_count;
 }
 
 static int system_refcount_inc(struct event_subsystem *system)
 {
-	return (system->ref_count++) & ~SYSTEM_FL_FREE_NAME;
+	return system->ref_count++;
 }
 
 static int system_refcount_dec(struct event_subsystem *system)
 {
-	return (--system->ref_count) & ~SYSTEM_FL_FREE_NAME;
+	return --system->ref_count;
 }
 
 /* Double loops, do not use break, only goto's work */
@@ -461,8 +459,7 @@ static void __put_system(struct event_subsystem *system)
 		kfree(filter->filter_string);
 		kfree(filter);
 	}
-	if (system->ref_count & SYSTEM_FL_FREE_NAME)
-		kfree(system->name);
+	kfree_const(system->name);
 	kfree(system);
 }
 
@@ -1493,13 +1490,9 @@ create_new_subsystem(const char *name)
 	system->ref_count = 1;
 
 	/* Only allocate if dynamic (kprobes and modules) */
-	if (!core_kernel_data((unsigned long)name)) {
-		system->ref_count |= SYSTEM_FL_FREE_NAME;
-		system->name = kstrdup(name, GFP_KERNEL);
-		if (!system->name)
-			goto out_free;
-	} else
-		system->name = name;
+	system->name = kstrdup_const(name, GFP_KERNEL);
+	if (!system->name)
+		goto out_free;
 
 	system->filter = NULL;
 
@@ -1512,8 +1505,7 @@ create_new_subsystem(const char *name)
 	return system;
 
  out_free:
-	if (system->ref_count & SYSTEM_FL_FREE_NAME)
-		kfree(system->name);
+	kfree_const(system->name);
 	kfree(system);
 	return NULL;
 }
-- 
2.6.1

[for-next][PATCH 2/9] ftrace: Remove redundant swap function

[Steven Rostedt]

[-- Attachment #1: 0002-ftrace-Remove-redundant-swap-function.patch --]
[-- Type: text/plain, Size: 1516 bytes --]

From: Rasmus Villemoes <linux@rasmusvillemoes.dk>

To cover the common case of sorting an array of pointers, Daniel
Wagner recently modified the library sort() to use a specific swap
function for size==8, in addition to the size==4 case which was
already handled. Since sizeof(long) is either 4 or 8,
ftrace_swap_ips() is redundant and we can just let sort() pick an
appropriate and fast swap callback.

Link: http://lkml.kernel.org/r/1441834023-13130-1-git-send-email-linux@rasmusvillemoes.dk

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
---
 kernel/trace/ftrace.c | 13 +------------
 1 file changed, 1 insertion(+), 12 deletions(-)

diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index e76384894147..f7b78d75c605 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -4788,17 +4788,6 @@ static int ftrace_cmp_ips(const void *a, const void *b)
 	return 0;
 }
 
-static void ftrace_swap_ips(void *a, void *b, int size)
-{
-	unsigned long *ipa = a;
-	unsigned long *ipb = b;
-	unsigned long t;
-
-	t = *ipa;
-	*ipa = *ipb;
-	*ipb = t;
-}
-
 static int ftrace_process_locs(struct module *mod,
 			       unsigned long *start,
 			       unsigned long *end)
@@ -4818,7 +4807,7 @@ static int ftrace_process_locs(struct module *mod,
 		return 0;
 
 	sort(start, count, sizeof(*start),
-	     ftrace_cmp_ips, ftrace_swap_ips);
+	     ftrace_cmp_ips, NULL);
 
 	start_pg = ftrace_allocate_pages(count);
 	if (!start_pg)
-- 
2.6.1

[for-next][PATCH 3/9] ftrace: Remove redundant strsep in mod_callback

[Steven Rostedt]

[-- Attachment #1: 0003-ftrace-Remove-redundant-strsep-in-mod_callback.patch --]
[-- Type: text/plain, Size: 1580 bytes --]

From: Dmitry Safonov <0x7f454c46@gmail.com>

By now there isn't any subcommand for mod.

Before:
	sh$ echo '*:mod:ipv6:a' > set_ftrace_filter
	sh$ echo '*:mod:ipv6' > set_ftrace_filter
had the same results, but now first will result in:
	sh$ echo '*:mod:ipv6:a' > set_ftrace_filter
	-bash: echo: write error: Invalid argument

Also, I clarified ftrace_mod_callback code a little.

Link: http://lkml.kernel.org/r/1443545176-3215-1-git-send-email-0x7f454c46@gmail.com

Signed-off-by: Dmitry Safonov <0x7f454c46@gmail.com>
[ converted 'if (ret == 0)' to 'if (!ret)' ]
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
---
 kernel/trace/ftrace.c | 15 +++++----------
 1 file changed, 5 insertions(+), 10 deletions(-)

diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index f7b78d75c605..8892b45b4368 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -3569,8 +3569,7 @@ static int
 ftrace_mod_callback(struct ftrace_hash *hash,
 		    char *func, char *cmd, char *param, int enable)
 {
-	char *mod;
-	int ret = -EINVAL;
+	int ret;
 
 	/*
 	 * cmd == 'mod' because we only registered this func
@@ -3581,16 +3580,12 @@ ftrace_mod_callback(struct ftrace_hash *hash,
 	 */
 
 	/* we must have a module name */
-	if (!param)
-		return ret;
-
-	mod = strsep(&param, ":");
-	if (!strlen(mod))
-		return ret;
+	if (!param || !strlen(param))
+		return -EINVAL;
 
-	ret = ftrace_match_module_records(hash, func, mod);
+	ret = ftrace_match_module_records(hash, func, param);
 	if (!ret)
-		ret = -EINVAL;
+		return -EINVAL;
 	if (ret < 0)
 		return ret;
 
-- 
2.6.1

[for-next][PATCH 4/9] ftrace: Clarify code for mod command

[Steven Rostedt]

[-- Attachment #1: 0004-ftrace-Clarify-code-for-mod-command.patch --]
[-- Type: text/plain, Size: 3614 bytes --]

From: Dmitry Safonov <0x7f454c46@gmail.com>

"Not" is too abstract variable name - changed to clear_filter.
Removed ftrace_match_module_records function: comparison with !* or *
not does the general code in filter_parse_regex() as it works without
mod command for
  sh# echo '!*' > /sys/kernel/debug/tracing/set_ftrace_filter

Link: http://lkml.kernel.org/r/1443545176-3215-2-git-send-email-0x7f454c46@gmail.com

Signed-off-by: Dmitry Safonov <0x7f454c46@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
---
 kernel/trace/ftrace.c | 37 ++++++++++---------------------------
 1 file changed, 10 insertions(+), 27 deletions(-)

diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 8892b45b4368..fc755a49704f 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -3454,13 +3454,13 @@ static int ftrace_match(char *str, char *regex, int len, int type)
 }
 
 static int
-enter_record(struct ftrace_hash *hash, struct dyn_ftrace *rec, int not)
+enter_record(struct ftrace_hash *hash, struct dyn_ftrace *rec, int clear_filter)
 {
 	struct ftrace_func_entry *entry;
 	int ret = 0;
 
 	entry = ftrace_lookup_ip(hash, rec->ip);
-	if (not) {
+	if (clear_filter) {
 		/* Do nothing if it doesn't exist */
 		if (!entry)
 			return 0;
@@ -3499,8 +3499,7 @@ ftrace_match_record(struct dyn_ftrace *rec, char *mod,
 }
 
 static int
-match_records(struct ftrace_hash *hash, char *buff,
-	      int len, char *mod, int not)
+match_records(struct ftrace_hash *hash, char *buff, int len, char *mod)
 {
 	unsigned search_len = 0;
 	struct ftrace_page *pg;
@@ -3509,9 +3508,10 @@ match_records(struct ftrace_hash *hash, char *buff,
 	char *search = buff;
 	int found = 0;
 	int ret;
+	int clear_filter;
 
 	if (len) {
-		type = filter_parse_regex(buff, len, &search, &not);
+		type = filter_parse_regex(buff, len, &search, &clear_filter);
 		search_len = strlen(search);
 	}
 
@@ -3522,7 +3522,7 @@ match_records(struct ftrace_hash *hash, char *buff,
 
 	do_for_each_ftrace_rec(pg, rec) {
 		if (ftrace_match_record(rec, mod, search, search_len, type)) {
-			ret = enter_record(hash, rec, not);
+			ret = enter_record(hash, rec, clear_filter);
 			if (ret < 0) {
 				found = ret;
 				goto out_unlock;
@@ -3539,26 +3539,9 @@ match_records(struct ftrace_hash *hash, char *buff,
 static int
 ftrace_match_records(struct ftrace_hash *hash, char *buff, int len)
 {
-	return match_records(hash, buff, len, NULL, 0);
+	return match_records(hash, buff, len, NULL);
 }
 
-static int
-ftrace_match_module_records(struct ftrace_hash *hash, char *buff, char *mod)
-{
-	int not = 0;
-
-	/* blank or '*' mean the same */
-	if (strcmp(buff, "*") == 0)
-		buff[0] = 0;
-
-	/* handle the case of 'dont filter this module' */
-	if (strcmp(buff, "!") == 0 || strcmp(buff, "!*") == 0) {
-		buff[0] = 0;
-		not = 1;
-	}
-
-	return match_records(hash, buff, strlen(buff), mod, not);
-}
 
 /*
  * We register the module command as a template to show others how
@@ -3567,7 +3550,7 @@ ftrace_match_module_records(struct ftrace_hash *hash, char *buff, char *mod)
 
 static int
 ftrace_mod_callback(struct ftrace_hash *hash,
-		    char *func, char *cmd, char *param, int enable)
+		    char *func, char *cmd, char *module, int enable)
 {
 	int ret;
 
@@ -3580,10 +3563,10 @@ ftrace_mod_callback(struct ftrace_hash *hash,
 	 */
 
 	/* we must have a module name */
-	if (!param || !strlen(param))
+	if (!module || !strlen(module))
 		return -EINVAL;
 
-	ret = ftrace_match_module_records(hash, func, param);
+	ret = match_records(hash, func, strlen(func), module);
 	if (!ret)
 		return -EINVAL;
 	if (ret < 0)
-- 
2.6.1

[for-next][PATCH 5/9] ftrace: Introduce ftrace_glob structure

[Steven Rostedt]

[-- Attachment #1: 0005-ftrace-Introduce-ftrace_glob-structure.patch --]
[-- Type: text/plain, Size: 7258 bytes --]

From: Dmitry Safonov <0x7f454c46@gmail.com>

ftrace_match parameters are very related and I reduce the number of local
variables & parameters with it.
This is also preparation for module globbing as it would introduce more
realated variables & parameters.

Link: http://lkml.kernel.org/r/1443545176-3215-3-git-send-email-0x7f454c46@gmail.com

Signed-off-by: Dmitry Safonov <0x7f454c46@gmail.com>
[ Made some formatting changes ]
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
---
 kernel/trace/ftrace.c | 84 ++++++++++++++++++++++++++++-----------------------
 1 file changed, 46 insertions(+), 38 deletions(-)

diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index fc755a49704f..450a5f5676ae 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -3425,27 +3425,35 @@ ftrace_notrace_open(struct inode *inode, struct file *file)
 				 inode, file);
 }
 
-static int ftrace_match(char *str, char *regex, int len, int type)
+/* Type for quick search ftrace basic regexes (globs) from filter_parse_regex */
+struct ftrace_glob {
+	char *search;
+	unsigned len;
+	int type;
+};
+
+static int ftrace_match(char *str, struct ftrace_glob *g)
 {
 	int matched = 0;
 	int slen;
 
-	switch (type) {
+	switch (g->type) {
 	case MATCH_FULL:
-		if (strcmp(str, regex) == 0)
+		if (strcmp(str, g->search) == 0)
 			matched = 1;
 		break;
 	case MATCH_FRONT_ONLY:
-		if (strncmp(str, regex, len) == 0)
+		if (strncmp(str, g->search, g->len) == 0)
 			matched = 1;
 		break;
 	case MATCH_MIDDLE_ONLY:
-		if (strstr(str, regex))
+		if (strstr(str, g->search))
 			matched = 1;
 		break;
 	case MATCH_END_ONLY:
 		slen = strlen(str);
-		if (slen >= len && memcmp(str + slen - len, regex, len) == 0)
+		if (slen >= g->len &&
+		    memcmp(str + slen - g->len, g->search, g->len) == 0)
 			matched = 1;
 		break;
 	}
@@ -3477,8 +3485,8 @@ enter_record(struct ftrace_hash *hash, struct dyn_ftrace *rec, int clear_filter)
 }
 
 static int
-ftrace_match_record(struct dyn_ftrace *rec, char *mod,
-		    char *regex, int len, int type)
+ftrace_match_record(struct dyn_ftrace *rec,
+		char *mod, struct ftrace_glob *func_g)
 {
 	char str[KSYM_SYMBOL_LEN];
 	char *modname;
@@ -3491,28 +3499,27 @@ ftrace_match_record(struct dyn_ftrace *rec, char *mod,
 			return 0;
 
 		/* blank search means to match all funcs in the mod */
-		if (!len)
+		if (!func_g->len)
 			return 1;
 	}
 
-	return ftrace_match(str, regex, len, type);
+	return ftrace_match(str, func_g);
 }
 
 static int
-match_records(struct ftrace_hash *hash, char *buff, int len, char *mod)
+match_records(struct ftrace_hash *hash, char *func, int len, char *mod)
 {
-	unsigned search_len = 0;
 	struct ftrace_page *pg;
 	struct dyn_ftrace *rec;
-	int type = MATCH_FULL;
-	char *search = buff;
+	struct ftrace_glob func_g = { .type = MATCH_FULL };
 	int found = 0;
 	int ret;
 	int clear_filter;
 
 	if (len) {
-		type = filter_parse_regex(buff, len, &search, &clear_filter);
-		search_len = strlen(search);
+		func_g.type = filter_parse_regex(func, len, &func_g.search,
+						 &clear_filter);
+		func_g.len = strlen(func_g.search);
 	}
 
 	mutex_lock(&ftrace_lock);
@@ -3521,7 +3528,7 @@ match_records(struct ftrace_hash *hash, char *buff, int len, char *mod)
 		goto out_unlock;
 
 	do_for_each_ftrace_rec(pg, rec) {
-		if (ftrace_match_record(rec, mod, search, search_len, type)) {
+		if (ftrace_match_record(rec, mod, &func_g)) {
 			ret = enter_record(hash, rec, clear_filter);
 			if (ret < 0) {
 				found = ret;
@@ -3682,19 +3689,20 @@ register_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,
 {
 	struct ftrace_ops_hash old_hash_ops;
 	struct ftrace_func_probe *entry;
+	struct ftrace_glob func_g;
 	struct ftrace_hash **orig_hash = &trace_probe_ops.func_hash->filter_hash;
 	struct ftrace_hash *old_hash = *orig_hash;
 	struct ftrace_hash *hash;
 	struct ftrace_page *pg;
 	struct dyn_ftrace *rec;
-	int type, len, not;
+	int not;
 	unsigned long key;
 	int count = 0;
-	char *search;
 	int ret;
 
-	type = filter_parse_regex(glob, strlen(glob), &search, &not);
-	len = strlen(search);
+	func_g.type = filter_parse_regex(glob, strlen(glob),
+			&func_g.search, &not);
+	func_g.len = strlen(func_g.search);
 
 	/* we do not support '!' for function probes */
 	if (WARN_ON(not))
@@ -3721,7 +3729,7 @@ register_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,
 
 	do_for_each_ftrace_rec(pg, rec) {
 
-		if (!ftrace_match_record(rec, NULL, search, len, type))
+		if (!ftrace_match_record(rec, NULL, &func_g))
 			continue;
 
 		entry = kmalloc(sizeof(*entry), GFP_KERNEL);
@@ -3794,24 +3802,24 @@ __unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,
 	struct ftrace_func_entry *rec_entry;
 	struct ftrace_func_probe *entry;
 	struct ftrace_func_probe *p;
+	struct ftrace_glob func_g;
 	struct ftrace_hash **orig_hash = &trace_probe_ops.func_hash->filter_hash;
 	struct ftrace_hash *old_hash = *orig_hash;
 	struct list_head free_list;
 	struct ftrace_hash *hash;
 	struct hlist_node *tmp;
 	char str[KSYM_SYMBOL_LEN];
-	int type = MATCH_FULL;
-	int i, len = 0;
-	char *search;
-	int ret;
+	int i, ret;
 
 	if (glob && (strcmp(glob, "*") == 0 || !strlen(glob)))
-		glob = NULL;
+		func_g.search = NULL;
 	else if (glob) {
 		int not;
 
-		type = filter_parse_regex(glob, strlen(glob), &search, &not);
-		len = strlen(search);
+		func_g.type = filter_parse_regex(glob, strlen(glob),
+						 &func_g.search, &not);
+		func_g.len = strlen(func_g.search);
+		func_g.search = glob;
 
 		/* we do not support '!' for function probes */
 		if (WARN_ON(not))
@@ -3840,10 +3848,10 @@ __unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,
 				continue;
 
 			/* do this last, since it is the most expensive */
-			if (glob) {
+			if (func_g.search) {
 				kallsyms_lookup(entry->ip, NULL, NULL,
 						NULL, str);
-				if (!ftrace_match(str, glob, len, type))
+				if (!ftrace_match(str, &func_g))
 					continue;
 			}
 
@@ -3872,7 +3880,7 @@ __unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,
 		ftrace_free_entry(entry);
 	}
 	mutex_unlock(&ftrace_lock);
-		
+
  out_unlock:
 	mutex_unlock(&trace_probe_ops.func_hash->regex_lock);
 	free_ftrace_hash(hash);
@@ -4588,21 +4596,21 @@ ftrace_graph_release(struct inode *inode, struct file *file)
 static int
 ftrace_set_func(unsigned long *array, int *idx, int size, char *buffer)
 {
+	struct ftrace_glob func_g;
 	struct dyn_ftrace *rec;
 	struct ftrace_page *pg;
-	int search_len;
 	int fail = 1;
-	int type, not;
-	char *search;
+	int not;
 	bool exists;
 	int i;
 
 	/* decode regex */
-	type = filter_parse_regex(buffer, strlen(buffer), &search, &not);
+	func_g.type = filter_parse_regex(buffer, strlen(buffer),
+					 &func_g.search, &not);
 	if (!not && *idx >= size)
 		return -EBUSY;
 
-	search_len = strlen(search);
+	func_g.len = strlen(func_g.search);
 
 	mutex_lock(&ftrace_lock);
 
@@ -4613,7 +4621,7 @@ 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, search, search_len, type)) {
+		if (ftrace_match_record(rec, NULL, &func_g)) {
 			/* if it is in the array */
 			exists = false;
 			for (i = 0; i < *idx; i++) {
-- 
2.6.1

[for-next][PATCH 6/9] ftrace: add module globbing

[Steven Rostedt]

[-- Attachment #1: 0006-ftrace-add-module-globbing.patch --]
[-- Type: text/plain, Size: 4870 bytes --]

From: Dmitry Safonov <0x7f454c46@gmail.com>

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: Dmitry Safonov <0x7f454c46@gmail.com>
[ Made format changes ]
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
---
 kernel/trace/ftrace.c | 51 ++++++++++++++++++++++++++++++++++++---------------
 1 file changed, 36 insertions(+), 15 deletions(-)

diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 450a5f5676ae..ea2725053771 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -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++) {
-- 
2.6.1

[for-next][PATCH 7/9] Documentation: ftrace: Module globbing usage

[Steven Rostedt]

[-- Attachment #1: 0007-Documentation-ftrace-Module-globbing-usage.patch --]
[-- Type: text/plain, Size: 1233 bytes --]

From: Dmitry Safonov <0x7f454c46@gmail.com>

Link: http://lkml.kernel.org/r/1443545176-3215-5-git-send-email-0x7f454c46@gmail.com

Signed-off-by: Dmitry Safonov <0x7f454c46@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
---
 Documentation/trace/ftrace.txt | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/Documentation/trace/ftrace.txt b/Documentation/trace/ftrace.txt
index ef621d34ba5b..db18362c14f3 100644
--- a/Documentation/trace/ftrace.txt
+++ b/Documentation/trace/ftrace.txt
@@ -2437,6 +2437,23 @@ The following commands are supported:
 
    echo '!writeback*:mod:ext3' >> set_ftrace_filter
 
+  Mod command supports module globbing. Disable tracing for all
+  functions except a specific module:
+
+   echo '!*:mod:!ext3' >> set_ftrace_filter
+
+  Disable tracing for all modules, but still trace kernel:
+
+   echo '!*:mod:*' >> set_ftrace_filter
+
+  Enable filter only for kernel:
+
+   echo '*write*:mod:!*' >> set_ftrace_filter
+
+  Enable filter for module globbing:
+
+   echo '*write*:mod:*snd*' >> set_ftrace_filter
+
 - traceon/traceoff
   These commands turn tracing on and off when the specified
   functions are hit. The parameter determines how many times the
-- 
2.6.1

[for-next][PATCH 8/9] tracing: Allow disabling compilation of specific trace systems

[Steven Rostedt]

[-- Attachment #1: 0008-tracing-Allow-disabling-compilation-of-specific-trac.patch --]
[-- Type: text/plain, Size: 2421 bytes --]

From: Tal Shorer <tal.shorer@gmail.com>

Allow a trace events header file to disable compilation of its
trace events by defining the preprocessor macro NOTRACE.

This could be done, for example, according to a Kconfig option.

Link: http://lkml.kernel.org/r/1438432079-11704-3-git-send-email-tal.shorer@gmail.com

Signed-off-by: Tal Shorer <tal.shorer@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
---
 include/linux/tracepoint.h   | 17 ++++++++++++++---
 include/trace/define_trace.h |  2 +-
 2 files changed, 15 insertions(+), 4 deletions(-)

diff --git a/include/linux/tracepoint.h b/include/linux/tracepoint.h
index a5f7f3ecafa3..afada369c5b7 100644
--- a/include/linux/tracepoint.h
+++ b/include/linux/tracepoint.h
@@ -111,7 +111,18 @@ extern void syscall_unregfunc(void);
 #define TP_ARGS(args...)	args
 #define TP_CONDITION(args...)	args
 
-#ifdef CONFIG_TRACEPOINTS
+/*
+ * Individual subsystem my have a separate configuration to
+ * enable their tracepoints. By default, this file will create
+ * the tracepoints if CONFIG_TRACEPOINT is defined. If a subsystem
+ * wants to be able to disable its tracepoints from being created
+ * it can define NOTRACE before including the tracepoint headers.
+ */
+#if defined(CONFIG_TRACEPOINTS) && !defined(NOTRACE)
+#define TRACEPOINTS_ENABLED
+#endif
+
+#ifdef TRACEPOINTS_ENABLED
 
 /*
  * it_func[0] is never NULL because there is at least one element in the array
@@ -234,7 +245,7 @@ extern void syscall_unregfunc(void);
 #define EXPORT_TRACEPOINT_SYMBOL(name)					\
 	EXPORT_SYMBOL(__tracepoint_##name)
 
-#else /* !CONFIG_TRACEPOINTS */
+#else /* !TRACEPOINTS_ENABLED */
 #define __DECLARE_TRACE(name, proto, args, cond, data_proto, data_args) \
 	static inline void trace_##name(proto)				\
 	{ }								\
@@ -266,7 +277,7 @@ extern void syscall_unregfunc(void);
 #define EXPORT_TRACEPOINT_SYMBOL_GPL(name)
 #define EXPORT_TRACEPOINT_SYMBOL(name)
 
-#endif /* CONFIG_TRACEPOINTS */
+#endif /* TRACEPOINTS_ENABLED */
 
 #ifdef CONFIG_TRACING
 /**
diff --git a/include/trace/define_trace.h b/include/trace/define_trace.h
index 09b3880105a9..2d8639ea64d5 100644
--- a/include/trace/define_trace.h
+++ b/include/trace/define_trace.h
@@ -86,7 +86,7 @@
 #undef DECLARE_TRACE
 #define DECLARE_TRACE(name, proto, args)
 
-#ifdef CONFIG_EVENT_TRACING
+#ifdef TRACEPOINTS_ENABLED
 #include <trace/trace_events.h>
 #include <trace/perf.h>
 #endif
-- 
2.6.1

[for-next][PATCH 9/9] tracing: gpio: Add Kconfig option for enabling/disabling trace events

[Steven Rostedt]

[-- Attachment #1: 0009-tracing-gpio-Add-Kconfig-option-for-enabling-disabli.patch --]
[-- Type: text/plain, Size: 1361 bytes --]

From: Tal Shorer <tal.shorer@gmail.com>

Add a new options to trace Kconfig, CONFIG_TRACING_EVENTS_GPIO, that is
used for enabling/disabling compilation of gpio function trace events.

Link: http://lkml.kernel.org/r/1438432079-11704-4-git-send-email-tal.shorer@gmail.com

Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Tal Shorer <tal.shorer@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
---
 include/trace/events/gpio.h | 4 ++++
 kernel/trace/Kconfig        | 7 +++++++
 2 files changed, 11 insertions(+)

diff --git a/include/trace/events/gpio.h b/include/trace/events/gpio.h
index 927a8ad9e51b..2da73b92d47e 100644
--- a/include/trace/events/gpio.h
+++ b/include/trace/events/gpio.h
@@ -1,6 +1,10 @@
 #undef TRACE_SYSTEM
 #define TRACE_SYSTEM gpio
 
+#ifndef CONFIG_TRACING_EVENTS_GPIO
+#define NOTRACE
+#endif
+
 #if !defined(_TRACE_GPIO_H) || defined(TRACE_HEADER_MULTI_READ)
 #define _TRACE_GPIO_H
 
diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig
index 1153c43428f3..8d6363f42169 100644
--- a/kernel/trace/Kconfig
+++ b/kernel/trace/Kconfig
@@ -635,6 +635,13 @@ config TRACE_ENUM_MAP_FILE
 
 	If unsure, say N
 
+config TRACING_EVENTS_GPIO
+	bool "Trace gpio events"
+	depends on GPIOLIB
+	default y
+	help
+	  Enable tracing events for gpio subsystem
+
 endif # FTRACE
 
 endif # TRACING_SUPPORT
-- 
2.6.1