From d3d9acf646679c1981032b0985b386d12fccc60c Mon Sep 17 00:00:00 2001
From: Tejun Heo <tj@kernel.org>
Date: Wed, 23 Nov 2011 08:49:49 -0800
Subject: trace_events_filter: Use rcu_assign_pointer() when setting
ftrace_event_call->filter
ftrace_event_call->filter is sched RCU protected but didn't use
rcu_assign_pointer(). Use it.
TODO: Add proper __rcu annotation to call->filter and all its users.
-v2: Use RCU_INIT_POINTER() for %NULL clearing as suggested by Eric.
Link: http://lkml.kernel.org/r/20111123164949.GA29639@google.com
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: stable@kernel.org # (2.6.39+)
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
---
kernel/trace/trace_events_filter.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
(limited to 'kernel/trace')
diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events_filter.c
index 816d3d074979..d6e7926dcd26 100644
--- a/kernel/trace/trace_events_filter.c
+++ b/kernel/trace/trace_events_filter.c
@@ -1686,7 +1686,7 @@ static int replace_system_preds(struct event_subsystem *system,
* replace the filter for the call.
*/
filter = call->filter;
- call->filter = filter_item->filter;
+ rcu_assign_pointer(call->filter, filter_item->filter);
filter_item->filter = filter;
fail = false;
@@ -1741,7 +1741,7 @@ int apply_event_filter(struct ftrace_event_call *call, char *filter_string)
filter = call->filter;
if (!filter)
goto out_unlock;
- call->filter = NULL;
+ RCU_INIT_POINTER(call->filter, NULL);
/* Make sure the filter is not being used */
synchronize_sched();
__free_filter(filter);
@@ -1782,7 +1782,7 @@ out:
* string
*/
tmp = call->filter;
- call->filter = filter;
+ rcu_assign_pointer(call->filter, filter);
if (tmp) {
/* Make sure the call is done with the filter */
synchronize_sched();
--
cgit v1.2.2
From cb59974742aea24adf6637eb0c4b8e7b48bca6fb Mon Sep 17 00:00:00 2001
From: Ilya Dryomov <idryomov@gmail.com>
Date: Mon, 31 Oct 2011 11:07:42 +0200
Subject: tracing: fix event_subsystem ref counting
Fix a bug introduced by e9dbfae5, which prevents event_subsystem from
ever being released.
Ref_count was added to keep track of subsystem users, not for counting
events. Subsystem is created with ref_count = 1, so there is no need to
increment it for every event, we have nr_events for that. Fix this by
touching ref_count only when we actually have a new user -
subsystem_open().
Cc: stable@vger.kernel.org
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Link: http://lkml.kernel.org/r/1320052062-7846-1-git-send-email-idryomov@gmail.com
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
---
kernel/trace/trace_events.c | 1 -
1 file changed, 1 deletion(-)
(limited to 'kernel/trace')
diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
index 581876f9f387..c212a7f934ec 100644
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -1078,7 +1078,6 @@ event_subsystem_dir(const char *name, struct dentry *d_events)
/* First see if we did not already create this dir */
list_for_each_entry(system, &event_subsystems, list) {
if (strcmp(system->name, name) == 0) {
- __get_system(system);
system->nr_events++;
return system->entry;
}
--
cgit v1.2.2
From 27b14b56af081ec7edeefb3a38b2c9577cc5ef48 Mon Sep 17 00:00:00 2001
From: Li Zefan <lizf@cn.fujitsu.com>
Date: Tue, 1 Nov 2011 09:09:35 +0800
Subject: tracing: Restore system filter behavior
Though not all events have field 'prev_pid', it was allowed to do this:
# echo 'prev_pid == 100' > events/sched/filter
but commit 75b8e98263fdb0bfbdeba60d4db463259f1fe8a2 (tracing/filter: Swap
entire filter of events) broke it without any reason.
Link: http://lkml.kernel.org/r/4EAF46CF.8040408@cn.fujitsu.com
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
---
kernel/trace/trace_events_filter.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
(limited to 'kernel/trace')
diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events_filter.c
index d6e7926dcd26..95dc31efd6dd 100644
--- a/kernel/trace/trace_events_filter.c
+++ b/kernel/trace/trace_events_filter.c
@@ -1649,7 +1649,9 @@ static int replace_system_preds(struct event_subsystem *system,
*/
err = replace_preds(call, NULL, ps, filter_string, true);
if (err)
- goto fail;
+ call->flags |= TRACE_EVENT_FL_NO_SET_FILTER;
+ else
+ call->flags &= ~TRACE_EVENT_FL_NO_SET_FILTER;
}
list_for_each_entry(call, &ftrace_events, list) {
@@ -1658,6 +1660,9 @@ static int replace_system_preds(struct event_subsystem *system,
if (strcmp(call->class->system, system->name) != 0)
continue;
+ if (call->flags & TRACE_EVENT_FL_NO_SET_FILTER)
+ continue;
+
filter_item = kzalloc(sizeof(*filter_item), GFP_KERNEL);
if (!filter_item)
goto fail_mem;
--
cgit v1.2.2
From c7c6ec8becaf742b223c7b491f4893014be23a07 Mon Sep 17 00:00:00 2001
From: Steven Rostedt <srostedt@redhat.com>
Date: Fri, 4 Nov 2011 10:45:23 -0400
Subject: ftrace: Remove force undef config value left for testing
A forced undef of a config value was used for testing and was
accidently left in during the final commit. This causes x86 to
run slower than needed while running function tracing as well
as causes the function graph selftest to fail when DYNMAIC_FTRACE
is not set. This is because the code in MCOUNT expects the ftrace
code to be processed with the config value set that happened to
be forced not set.
The forced config option was left in by:
commit 6331c28c962561aee59e5a493b7556a4bb585957
ftrace: Fix dynamic selftest failure on some archs
Link: http://lkml.kernel.org/r/20111102150255.GA6973@debian
Cc: stable@vger.kernel.org
Reported-by: Rabin Vincent <rabin@rab.in>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
---
kernel/trace/ftrace.c | 1 -
1 file changed, 1 deletion(-)
(limited to 'kernel/trace')
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 900b409543db..1276b3ca1598 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -152,7 +152,6 @@ void clear_ftrace_function(void)
ftrace_pid_function = ftrace_stub;
}
-#undef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST
#ifndef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST
/*
* For those archs that do not test ftrace_trace_stop in their
--
cgit v1.2.2
From ddf6e0e50723b62ac76ed18eb53e9417c6eefba7 Mon Sep 17 00:00:00 2001
From: Steven Rostedt <srostedt@redhat.com>
Date: Fri, 4 Nov 2011 20:32:39 -0400
Subject: ftrace: Fix hash record accounting bug
If the set_ftrace_filter is cleared by writing just whitespace to
it, then the filter hash refcounts will be decremented but not
updated. This causes two bugs:
1) No functions will be enabled for tracing when they all should be
2) If the users clears the set_ftrace_filter twice, it will crash ftrace:
------------[ cut here ]------------
WARNING: at /home/rostedt/work/git/linux-trace.git/kernel/trace/ftrace.c:1384 __ftrace_hash_rec_update.part.27+0x157/0x1a7()
Modules linked in:
Pid: 2330, comm: bash Not tainted 3.1.0-test+ #32
Call Trace:
[<ffffffff81051828>] warn_slowpath_common+0x83/0x9b
[<ffffffff8105185a>] warn_slowpath_null+0x1a/0x1c
[<ffffffff810ba362>] __ftrace_hash_rec_update.part.27+0x157/0x1a7
[<ffffffff810ba6e8>] ? ftrace_regex_release+0xa7/0x10f
[<ffffffff8111bdfe>] ? kfree+0xe5/0x115
[<ffffffff810ba51e>] ftrace_hash_move+0x2e/0x151
[<ffffffff810ba6fb>] ftrace_regex_release+0xba/0x10f
[<ffffffff8112e49a>] fput+0xfd/0x1c2
[<ffffffff8112b54c>] filp_close+0x6d/0x78
[<ffffffff8113a92d>] sys_dup3+0x197/0x1c1
[<ffffffff8113a9a6>] sys_dup2+0x4f/0x54
[<ffffffff8150cac2>] system_call_fastpath+0x16/0x1b
---[ end trace 77a3a7ee73794a02 ]---
Link: http://lkml.kernel.org/r/20111101141420.GA4918@debian
Reported-by: Rabin Vincent <rabin@rab.in>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
---
kernel/trace/ftrace.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
(limited to 'kernel/trace')
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 1276b3ca1598..b1e8943fed1d 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -1211,7 +1211,9 @@ ftrace_hash_move(struct ftrace_ops *ops, int enable,
if (!src->count) {
free_ftrace_hash_rcu(*dst);
rcu_assign_pointer(*dst, EMPTY_HASH);
- return 0;
+ /* still need to update the function records */
+ ret = 0;
+ goto out;
}
/*
--
cgit v1.2.2