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

[Suzuki K. Poulose]

On 08/29/2012 11:59 AM, David Ahern wrote:
> On 8/29/12 12:00 AM, Suzuki K. Poulose wrote:
> > 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>
>
> Acked-by: David Ahern <dsahern@xxxxxxxxx>
>
> Same type of change is needed for util/intlist.c if you want to submit
> one, otherwise I will take care of it.

I can send it.

Thanks
Suzuki

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