Patch "perf config: Fix caching and memory leak in perf_home_perfconfig()" has been added to the 5.14-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    perf config: Fix caching and memory leak in perf_home_perfconfig()

to the 5.14-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     perf-config-fix-caching-and-memory-leak-in-perf_home.patch
and it can be found in the queue-5.14 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 06afb2bbec60d8cbddeb014526b0e866b09da85a
Author: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Date:   Fri Aug 20 11:13:36 2021 -0300

    perf config: Fix caching and memory leak in perf_home_perfconfig()
    
    [ Upstream commit 261f491133aecb943ccfdc3b3794e2d775607a87 ]
    
    Acaict, perf_home_perfconfig() is supposed to cache the result of
    home_perfconfig, which returns the default location of perfconfig for
    the user, given the HOME environment variable.
    
    However, the current implementation calls home_perfconfig every time
    perf_home_perfconfig() is called (so no caching is actually performed),
    replacing the previous pointer, thus also causing a memory leak.
    
    This patch adds a check of whether either config or failed is set and,
    in that case, directly returns config without calling home_perfconfig at
    each invocation.
    
    Fixes: f5f03e19ce14fc31 ("perf config: Add perf_home_perfconfig function")
    Signed-off-by: Riccardo Mancini <rickyman7@xxxxxxxxx>
    Cc: Alexander Shishkin <alexander.shishkin@xxxxxxxxxxxxxxx>
    Cc: Ian Rogers <irogers@xxxxxxxxxx>
    Cc: Jin Yao <yao.jin@xxxxxxxxxxxxxxx>
    Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
    Cc: Mark Rutland <mark.rutland@xxxxxxx>
    Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
    Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
    Cc: Song Liu <song@xxxxxxxxxx>
    Link: http://lore.kernel.org/lkml/20210820130817.740536-1-rickyman7@xxxxxxxxx
    [ Removed needless double check for the 'failed' variable ]
    Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/tools/perf/util/config.c b/tools/perf/util/config.c
index 63d472b336de..4fb5e90d7a57 100644
--- a/tools/perf/util/config.c
+++ b/tools/perf/util/config.c
@@ -581,7 +581,10 @@ const char *perf_home_perfconfig(void)
 	static const char *config;
 	static bool failed;
 
-	config = failed ? NULL : home_perfconfig();
+	if (failed || config)
+		return config;
+
+	config = home_perfconfig();
 	if (!config)
 		failed = true;