From 51ba7a816ccdadf7f943fb30a1933ded72a4c178 Mon Sep 17 00:00:00 2001 From: "Nick Desaulniers (paternity leave)" Date: Mon, 20 May 2024 14:05:49 -0700 Subject: [PATCH] [libc][setjmp] disable -ftrivial-auto-var-init=pattern for now (#92796) This would consistently fail for me locally, to the point where I could not run ninja libc-unit-tests without ninja libc_setjmp_unittests failing. Turns out that since I enabled -ftrivial-auto-var-init=pattern in commit 1d5c16d ("[libc] default enable -ftrivial-auto-var-init=pattern (#78776)") this has been a problem. Our x86_64 setjmp definition disabled -Wuninitialized, so we wound up clobbering these registers and instead backing up 0xAAAAAAAAAAAAAAAA rather than the actual register value. The implemenation should be rewritten entirely. I've proposed three different ways to do so (linked below). Until we decide which way to go, at least disable this hardening feature for this function for now so that the unit tests go back to green. Link: #87837 Link: #88054 Link: #88157 Fixes: #91164 --- libc/src/setjmp/x86_64/CMakeLists.txt | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/libc/src/setjmp/x86_64/CMakeLists.txt b/libc/src/setjmp/x86_64/CMakeLists.txt index 9899c00e7c4a65a..ae84322a654010e 100644 --- a/libc/src/setjmp/x86_64/CMakeLists.txt +++ b/libc/src/setjmp/x86_64/CMakeLists.txt @@ -9,6 +9,11 @@ add_entrypoint_object( COMPILE_OPTIONS -O3 -fno-omit-frame-pointer + # TODO: Remove once one of these lands: + # https://github.com/llvm/llvm-project/pull/87837 + # https://github.com/llvm/llvm-project/pull/88054 + # https://github.com/llvm/llvm-project/pull/88157 + -ftrivial-auto-var-init=uninitialized ) add_entrypoint_object(