Re: [PATCH] perf tools: Fix segfault in cpu_cache_level__read

[Jiri Olsa]

On Fri, Sep 20, 2019 at 03:20:26PM -0300, Arnaldo Carvalho de Melo wrote:
> Em Thu, Sep 12, 2019 at 12:52:35PM +0200, Jiri Olsa escreveu:
> > We release wrong pointer on error path in
> > cpu_cache_level__read function, leading to
> > segfault:
> > 
> >   (gdb) r record ls
> >   Starting program: /root/perf/tools/perf/perf record ls
> >   ...
> >   [ perf record: Woken up 1 times to write data ]
> >   double free or corruption (out)
> > 
> >   Thread 1 "perf" received signal SIGABRT, Aborted.
> >   0x00007ffff7463798 in raise () from /lib64/power9/libc.so.6
> >   (gdb) bt
> >   #0  0x00007ffff7463798 in raise () from /lib64/power9/libc.so.6
> >   #1  0x00007ffff7443bac in abort () from /lib64/power9/libc.so.6
> >   #2  0x00007ffff74af8bc in __libc_message () from /lib64/power9/libc.so.6
> >   #3  0x00007ffff74b92b8 in malloc_printerr () from /lib64/power9/libc.so.6
> >   #4  0x00007ffff74bb874 in _int_free () from /lib64/power9/libc.so.6
> >   #5  0x0000000010271260 in __zfree (ptr=0x7fffffffa0b0) at ../../lib/zalloc..
> >   #6  0x0000000010139340 in cpu_cache_level__read (cache=0x7fffffffa090, cac..
> >   #7  0x0000000010143c90 in build_caches (cntp=0x7fffffffa118, size=<optimiz..
> >   ...
> > 
> > Releasing the proper pointer.
> 
> You forgot to add:
> 
> Fixes: 720e98b5faf1 ("perf tools: Add perf data cache feature")
> Cc: stable@xxxxxxxxxxxxxxx: # v4.6+
> 
> I did it, please consider doing it next time,

will do, sry

jirka