[PATCH] [perf] Remove the node from rblist in strlist__remove

[Suzuki K. Poulose]

The following commit:

author	David Ahern <dsahern@xxxxxxxxx>
	Tue, 31 Jul 2012 04:31:33 +0000 (22:31 -0600)
committer	Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
	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@xxxxxxxxxx>
Signed-off-by: Suzuki K. Poulose <suzuki@xxxxxxxxxx>
Cc: David Ahern <dsahern@xxxxxxxxx>
Cc: Arnaldo Carvalho de Melo <acme@xxxxxxxxxxxxx>
---

 tools/perf/util/strlist.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/tools/perf/util/strlist.c b/tools/perf/util/strlist.c
index 95856ff..155d8b7 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)

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