Re: [PATCH V3 09/10] perf tools: Only treat files as map files when they have the extension .map

[James Clark <james.clark@arm.com>]

On 01/06/2024 13:59, Chaitanya S Prakash wrote:
> From: Chaitanya S Prakash <chaitanyas.prakash@arm.com>
> 
> Strengthen the check to locate symbol map files in the tool's /tmp
> directory. As the existing check allows non map files named in
> "/tmp/perf-" pattern, it leads to possible dwarf library corruption
> when perf is built with NO_DWARF=1. The try_to_find_probe_trace_events()
> function behaves differently when built in that manner. Extending the
> current check condition using the str_has_suffix() function to not only
> validate the pattern but also ensure the file is of ".map" type allows
> test perf probe of function from different CU to pass when built with
> NO_DWARF=1.
> 
> Signed-off-by: Chaitanya S Prakash <chaitanyas.prakash@arm.com>
> ---
>  tools/perf/util/symbol.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c
> index 9e5940b5bc59..fbcc189edd8d 100644
> --- a/tools/perf/util/symbol.c
> +++ b/tools/perf/util/symbol.c
> @@ -1799,7 +1799,8 @@ int dso__load(struct dso *dso, struct map *map)
>  	const char *map_path = dso__long_name(dso);
>  
>  	mutex_lock(dso__lock(dso));
> -	perfmap = strncmp(dso__name(dso), "/tmp/perf-", 10) == 0;
> +	perfmap = strncmp(dso__name(dso), "/tmp/perf-", 10) == 0 &&
> +		  str_has_prefix(dso__name(dso), ".map") != 0;

Does this work? Shouldn't it be str_has_suffix()?

For reference, there's another fix for the same issue here:
https://lore.kernel.org/linux-perf-users/20240617130332.13427-1-atrajeev@linux.vnet.ibm.com/T/#m9b1e62f0cdbcd4caf019f2ad97d69b29df568522

>  	if (perfmap) {
>  		if (dso__nsinfo(dso) &&
>  		    (dso__find_perf_map(newmapname, sizeof(newmapname),