From 1415b49bcd321bca7347f43f8b269c91ec46d1dc Mon Sep 17 00:00:00 2001 From: Nathan Chancellor Date: Wed, 22 Sep 2021 07:58:22 -0700 Subject: [PATCH] locking/ww-mutex: Fix uninitialized use of ret in test_aa() Clang warns: kernel/locking/test-ww_mutex.c:138:7: error: variable 'ret' is used uninitialized whenever 'if' condition is true [-Werror,-Wsometimes-uninitialized] if (!ww_mutex_trylock(&mutex, &ctx)) { ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ kernel/locking/test-ww_mutex.c:172:9: note: uninitialized use occurs here return ret; ^~~ kernel/locking/test-ww_mutex.c:138:3: note: remove the 'if' if its condition is always false if (!ww_mutex_trylock(&mutex, &ctx)) { ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ kernel/locking/test-ww_mutex.c:125:9: note: initialize the variable 'ret' to silence this warning int ret; ^ = 0 1 error generated. Assign !ww_mutex_trylock(...) to ret so that it is always initialized. Fixes: 12235da8c80a ("kernel/locking: Add context to ww_mutex_trylock()") Reported-by: "kernelci.org bot" Reported-by: Stephen Rothwell Signed-off-by: Nathan Chancellor Signed-off-by: Peter Zijlstra (Intel) Acked-by: Waiman Long Link: https://lore.kernel.org/r/20210922145822.3935141-1-nathan@kernel.org --- kernel/locking/test-ww_mutex.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/kernel/locking/test-ww_mutex.c b/kernel/locking/test-ww_mutex.c index d63ac411f367..353004155d65 100644 --- a/kernel/locking/test-ww_mutex.c +++ b/kernel/locking/test-ww_mutex.c @@ -135,7 +135,8 @@ static int test_aa(bool trylock) goto out; } } else { - if (!ww_mutex_trylock(&mutex, &ctx)) { + ret = !ww_mutex_trylock(&mutex, &ctx); + if (ret) { pr_err("%s: initial trylock failed!\n", __func__); goto out; }