[PATCH] os: don't ignore failure from dladdr

[Jeremy Huddleston]

Reviewed-by: Jeremy Huddleston <jeremyhu at apple.com>

On Dec 30, 2011, at 2:41 PM, Julien Cristau wrote:

> If dladdr returns 0, don't go and use the returned Dl_info, it may
> contain garbage.
> 
> X.Org bug#44315 <https://bugs.freedesktop.org/show_bug.cgi?id=44315>
> 
> Reported-and-tested-by: Cyril Brulebois <kibi at debian.org>
> Signed-off-by: Julien Cristau <jcristau at debian.org>
> ---
> os/backtrace.c |    6 +++++-
> 1 files changed, 5 insertions(+), 1 deletions(-)
> 
> diff --git a/os/backtrace.c b/os/backtrace.c
> index 58b4b1f..298bf18 100644
> --- a/os/backtrace.c
> +++ b/os/backtrace.c
> @@ -46,7 +46,11 @@ void xorg_backtrace(void)
>     ErrorF("\nBacktrace:\n");
>     size = backtrace(array, 64);
>     for (i = 0; i < size; i++) {
> -	dladdr(array[i], &info);
> +	int rc = dladdr(array[i], &info);
> +	if (rc == 0) {
> +	    ErrorF("%d: ?? [%p]\n", i, array[i]);
> +	    continue;
> +	}
> 	mod = (info.dli_fname && *info.dli_fname) ? info.dli_fname : "(vdso)";
> 	if (info.dli_saddr)
> 	    ErrorF("%d: %s (%s+0x%lx) [%p]\n", i, mod,
> -- 
> 1.7.7.3
>