[lttng-dev] [PATCH/babeltrace] Fix babeltrace-log crash

[Hui Zhu]

Looks it cannot be init in ctf_init_pos.

So move init to trace_text.

Thanks,
Hui

On Fri, Sep 7, 2012 at 3:40 PM, Hui Zhu <teawater at gmail.com> wrote:
> Hi,
>
> Got a crash with babeltrace-log.
>
> #0  0x00007ffff744504c in free () from /lib/x86_64-linux-gnu/libc.so.6
> #1  0x00007ffff7ba6fc9 in munmap_align (mma=0x7ffff7ffe620) at
> ../../../babeltrace/include/babeltrace/mmap-align.h:78
> #2  0x00007ffff7ba82db in ctf_packet_seek (stream_pos=0x7fffffffde60,
> index=0, whence=0)
>     at ../../../babeltrace/formats/ctf/ctf.c:623
> #3  0x00007ffff7ba8141 in ctf_init_pos (pos=0x7fffffffde60, fd=8, open_flags=2)
>     at ../../../babeltrace/formats/ctf/ctf.c:576
> #4  0x0000000000401146 in trace_text (output=8, input=0x7ffff7779340
> <_IO_2_1_stdin_>)
>     at ../../babeltrace/converter/babeltrace-log.c:233
> #5  main (argc=<optimized out>, argv=<optimized out>) at
> ../../babeltrace/converter/babeltrace-log.c:342
>
> This issue because pos is used before it init.  This patch init it in
> function ctf_init_pos.
>
> Thanks,
> Hui
>
> --- a/formats/ctf/ctf.c
> +++ b/formats/ctf/ctf.c
> @@ -550,6 +550,7 @@ error:
>
>  void ctf_init_pos(struct ctf_stream_pos *pos, int fd, int open_flags)
>  {
> +       memset(pos, 0, sizeof(*pos));
>         pos->fd = fd;
>         if (fd >= 0) {
>                 pos->packet_cycles_index = g_array_new(FALSE, TRUE,


--- a/converter/babeltrace-log.c
+++ b/converter/babeltrace-log.c
@@ -230,6 +230,7 @@ void trace_text(FILE *input, int output)
 	char *line = NULL, *nl;
 	size_t linesize;

+	memset(&pos, 0, sizeof(pos));
 	ctf_init_pos(&pos, output, O_RDWR);

 	write_packet_header(&pos, s_uuid);