Messages in this thread Patch in this message | | | From | Nathan Chancellor <> | Subject | [PATCH] locking/ww-mutex: Fix uninitialized use of ret in test_aa() | Date | Wed, 22 Sep 2021 07:58:22 -0700 |
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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()") Link: https://github.com/ClangBuiltLinux/linux/issues/1463 Reported-by: "kernelci.org bot" <bot@kernelci.org> Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Nathan Chancellor <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; } base-commit: 12235da8c80a1f9909008e4ca6036d5772b81192 -- 2.33.0.514.g99c99ed825
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