Re: [PATCH -tip 2/8] [BUGFIX] perf-tools: Load map before using map->map_ip

[Arnaldo Carvalho de Melo <acme@ghostprotocols.net>]

Em Thu, Jan 23, 2014 at 02:29:50AM +0000, Masami Hiramatsu escreveu:
> In map_groups__find_symbol() map->map_ip is used without
> ensuring the map is loaded. Then the address passed
> to map->map_ip isn't mapped at the first time.
> 
> E.g. below code always fails to get a symbol at the first call;
> 
> 	addr = /* Somewhere in the kernel text */
> 	symbol_conf.try_vmlinux_path = true;
> 	symbol__init();
> 	host_machine = machine__new_host();
> 	sym = machine__find_kernel_function(host_machine,
> 					 addr, NULL, NULL);
> 	/* Note that machine__find_kernel_function calls
> 	   map_groups__find_symbol */
> 
> This ensures it by calling map__load before using it in
> map_groups__find_symbol().

Good catch! map__find_symbol() will load it if necessary, but that is
after map->map_ip() is called.

Applying.

- Arnaldo
 
> Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
> ---
>  tools/perf/util/map.c |    3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/tools/perf/util/map.c b/tools/perf/util/map.c
> index 9b9bd71..6a805e7 100644
> --- a/tools/perf/util/map.c
> +++ b/tools/perf/util/map.c
> @@ -386,7 +386,8 @@ struct symbol *map_groups__find_symbol(struct map_groups *mg,
>  {
>  	struct map *map = map_groups__find(mg, type, addr);
>  
> -	if (map != NULL) {
> +	/* Ensure map is loaded before using map->map_ip */
> +	if (map != NULL && map__load(map, filter) >= 0) {
>  		if (mapp != NULL)
>  			*mapp = map;
>  		return map__find_symbol(map, map->map_ip(map, addr), filter);
>