From: Suzuki K. Poulose <suzuki@in.ibm.com>
Date: Wed, 29 Aug 2012 06:00:07 +0000 (+0530)
Subject: perf tools: Remove the node from rblist in strlist__remove
X-Git-Tag: v3.7-rc1~195^2~13^2~14
X-Git-Url: http://git.cascardo.info/?a=commitdiff_plain;h=4592281403e74dc4401d5803ec9948d43bbee7ae;p=cascardo%2Flinux.git

perf tools: Remove the node from rblist in strlist__remove

The following commit:

author	David Ahern <dsahern@gmail.com>
	Tue, 31 Jul 2012 04:31:33 +0000 (22:31 -0600)
committer	Arnaldo Carvalho de Melo <acme@redhat.com>
	Fri, 3 Aug 2012 13:39:51 +0000 (10:39 -0300)
commit	ee8dd3ca43f151d9fbe1edeef68fb8a77eb9f047

causes a double free during a probe deletion as the node is never
removed from the list via strlist__remove(), even though it gets
'deleted' (read free()'d). This causes a double free when we do
strlist__delete() as the node is already deleted but present in the
rblist.

[suzukikp@suzukikp perf]$ sudo ./perf probe -a do_fork
Added new event:
  probe:do_fork        (on do_fork)

You can now use it in all perf tools, such as:

	perf record -e probe:do_fork -aR sleep 1

[suzukikp@suzukikp perf]$ sudo ./perf probe -d do_fork
Removed event: probe:do_fork
*** glibc detected *** ./perf: double free or corruption (fasttop): 0x000000000133d600 ***
======= Backtrace: =========
/lib64/libc.so.6[0x38eec7dda6]
./perf(rblist__delete+0x5c)[0x47d3dc]
./perf(del_perf_probe_events+0xb6)[0x47b826]
./perf(cmd_probe+0x471)[0x42c8d1]
./perf[0x4150b3]
./perf(main+0x501)[0x4148e1]
/lib64/libc.so.6(__libc_start_main+0xed)[0x38eec2169d]
./perf[0x414a61]

Make sure we remove the node from the rblist before we delete the node.
The rblist__remove_node() will invoke rblist->node_delete, which  will
take care of deleting the node with the suitable function provided by
the user.

Reported-by: Ananth N. Mavinakayanahalli <ananth@in.ibm.com>
Signed-off-by: Suzuki K. Poulose <suzuki@in.ibm.com>
Acked-by: David Ahern <dsahern@gmail.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20120829055840.7802.1459.stgit@suzukikp.in.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---

diff --git a/tools/perf/util/strlist.c b/tools/perf/util/strlist.c
index 95856ff3dda4..155d8b7078a7 100644
--- a/tools/perf/util/strlist.c
+++ b/tools/perf/util/strlist.c
@@ -93,7 +93,7 @@ out:
 
 void strlist__remove(struct strlist *slist, struct str_node *snode)
 {
-	str_node__delete(snode, slist->dupstr);
+	rblist__remove_node(&slist->rblist, &snode->rb_node);
 }
 
 struct str_node *strlist__find(struct strlist *slist, const char *entry)