Re: [patch] perf: tui: Fix segfault when drawing out-of-bounds jumps

[Arnaldo Carvalho de Melo <acme@redhat.com>]

Em Fri, Jan 11, 2013 at 07:00:43PM -0500, Frederik Deweerdt escreveu:
> Hi,
> 
> When perf.data contains out-of-symbol jumps,
> annotate_browser__mark_jump_targets() correctly avoids marking
> out-of-symbol jump targets. However, when moving the cursor on one of
> said jumps, annotate_browser__draw_current_jump() will end up with a
> bogus 'target' pointer, causing a bogus memory access when dereferencing
> 'bcursor' or 'btarget'
> 
> The following patch performs the same check as mark_jump_targets()
> in order to avoid drawing the bogus jump.

Thanks, I'll apply this one later today and introduce a
disasm_line__is_valid_jump(cursor) routine to be used in both mark and
draw routines, if you don't do it first :-)

- Arnaldo
 
> Regards,
> Frederik
> 
> Signed-off-by: Frederik Deweerdt <frederik.deweerdt@xprog.eu>
> 
> diff --git a/tools/perf/ui/browsers/annotate.c b/tools/perf/ui/browsers/annotate.c
> index 5dab3ca..8b84246 100644
> --- a/tools/perf/ui/browsers/annotate.c
> +++ b/tools/perf/ui/browsers/annotate.c
> @@ -195,8 +195,9 @@ static void annotate_browser__draw_current_jump(struct ui_browser *browser)
>  	if (strstr(sym->name, "@plt"))
>  		return;
>  
> -	if (!cursor || !cursor->ins || !ins__is_jump(cursor->ins) ||
> -	    !disasm_line__has_offset(cursor))
> +	if (!cursor || !cursor->ins || !ins__is_jump(cursor->ins)
> +	    || !disasm_line__has_offset(cursor)
> +	    || cursor->ops.target.offset >= symbol__size(sym))
>  		return;
>  
>  	target = ab->offsets[cursor->ops.target.offset];