On Thu, Apr 11, 2024 at 8:39 AM Nathan Chancellor <nat...@kernel.org> wrote: > On Wed, Apr 10, 2024 at 04:26:29PM -0700, John Stultz wrote: > > Building with clang, I see the following warning: > > > > In file included from posix_timers.c:17: > > ./../kselftest.h:398:6: warning: variable 'major' is used uninitialized > > whenever '||' condition is true [-Wsometimes-uninitialized] > > if (uname(&info) || sscanf(info.release, "%u.%u.", &major, &minor) > > != 2) > > ^~~~~~~~~~~~ > > ./../kselftest.h:401:9: note: uninitialized use occurs here > > return major > min_major || (major == min_major && minor >= > > min_minor); > > ^~~~~ > > > > This is a bit of a red-herring as if the uname() call did fail, > > we would hit ksft_exit_fail_msg() which should exit. > > Correct, although we have not really conveyed that to the compiler, > right? exit() is noreturn, which means all functions that call exit() > unconditionally are also noreturn, such as ksft_exit_fail_msg(). LLVM > will figure this out once it performs inlining and such but that happens > after clang's static analysis phase that this warning occurs in. I think > a better solution would be to add __noreturn to the functions in > tools/testing/selftests/kselftest.h that call exit(), so that the > compiler is aware of this through all pipeline phases, maybe something > like this? It resolves the wawrning for me.
No objection from me if this is the better approach. Would you send that patch out? thanks -john
