lkml.org 
[lkml]   [2022]   [Jan]   [18]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 5.16 21/28] perf annotate: Avoid TUI crash when navigating in the annotation of recursive functions
Date
From: Dario Petrillo <dario.pk1@gmail.com>

commit d5962fb7d69073bf68fb647531cfd4f0adf84be3 upstream.

In 'perf report', entering a recursive function from inside of itself
(either directly of indirectly through some other function) results in
calling symbol__annotate2 multiple() times, and freeing the whole
disassembly when exiting from the innermost instance.

The first issue causes the function's disassembly to be duplicated, and
the latter a heap use-after-free (and crash) when trying to access the
disassembly again.

I reproduced the bug on perf 5.11.22 (Ubuntu 20.04.3 LTS) and 5.16.rc8
with the following testcase (compile with gcc recursive.c -o recursive).
To reproduce:

- perf record ./recursive
- perf report
- enter fibonacci and annotate it
- move the cursor on one of the "callq fibonacci" instructions and press enter
- at this point there will be two copies of the function in the disassembly
- go back by pressing q, and perf will crash

#include <stdio.h>

int fibonacci(int n)
{
if(n <= 2) return 1;
return fibonacci(n-1) + fibonacci(n-2);
}

int main()
{
printf("%d\n", fibonacci(40));
}

This patch addresses the issue by annotating a function and freeing the
associated memory on exit only if no annotation is already present, so
that a recursive function is only annotated on entry.

Signed-off-by: Dario Petrillo <dario.pk1@gmail.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: stable@kernel.org
Link: http://lore.kernel.org/lkml/20220109234441.325106-1-dario.pk1@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
tools/perf/ui/browsers/annotate.c | 23 ++++++++++++++---------
1 file changed, 14 insertions(+), 9 deletions(-)

--- a/tools/perf/ui/browsers/annotate.c
+++ b/tools/perf/ui/browsers/annotate.c
@@ -966,6 +966,7 @@ int symbol__tui_annotate(struct map_symb
.opts = opts,
};
int ret = -1, err;
+ int not_annotated = list_empty(&notes->src->source);

if (sym == NULL)
return -1;
@@ -973,13 +974,15 @@ int symbol__tui_annotate(struct map_symb
if (ms->map->dso->annotate_warned)
return -1;

- err = symbol__annotate2(ms, evsel, opts, &browser.arch);
- if (err) {
- char msg[BUFSIZ];
- ms->map->dso->annotate_warned = true;
- symbol__strerror_disassemble(ms, err, msg, sizeof(msg));
- ui__error("Couldn't annotate %s:\n%s", sym->name, msg);
- goto out_free_offsets;
+ if (not_annotated) {
+ err = symbol__annotate2(ms, evsel, opts, &browser.arch);
+ if (err) {
+ char msg[BUFSIZ];
+ ms->map->dso->annotate_warned = true;
+ symbol__strerror_disassemble(ms, err, msg, sizeof(msg));
+ ui__error("Couldn't annotate %s:\n%s", sym->name, msg);
+ goto out_free_offsets;
+ }
}

ui_helpline__push("Press ESC to exit");
@@ -994,9 +997,11 @@ int symbol__tui_annotate(struct map_symb

ret = annotate_browser__run(&browser, evsel, hbt);

- annotated_source__purge(notes->src);
+ if(not_annotated)
+ annotated_source__purge(notes->src);

out_free_offsets:
- zfree(&notes->offsets);
+ if(not_annotated)
+ zfree(&notes->offsets);
return ret;
}

\
 
 \ /
  Last update: 2022-01-18 17:14    [W:0.195 / U:0.252 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site