From ff58155ca4fa7e931f34d948fa09fe14c6a66116 Mon Sep 17 00:00:00 2001 From: Arvind Sankar Date: Tue, 16 Jun 2020 18:25:47 -0400 Subject: x86/purgatory: Add -fno-stack-protector The purgatory Makefile removes -fstack-protector options if they were configured in, but does not currently add -fno-stack-protector. If gcc was configured with the --enable-default-ssp configure option, this results in the stack protector still being enabled for the purgatory (absent distro-specific specs files that might disable it again for freestanding compilations), if the main kernel is being compiled with stack protection enabled (if it's disabled for the main kernel, the top-level Makefile will add -fno-stack-protector). This will break the build since commit e4160b2e4b02 ("x86/purgatory: Fail the build if purgatory.ro has missing symbols") and prior to that would have caused runtime failure when trying to use kexec. Explicitly add -fno-stack-protector to avoid this, as done in other Makefiles that need to disable the stack protector. Reported-by: Gabriel C Signed-off-by: Arvind Sankar Signed-off-by: Linus Torvalds --- arch/x86/purgatory/Makefile | 1 + 1 file changed, 1 insertion(+) (limited to 'arch') diff --git a/arch/x86/purgatory/Makefile b/arch/x86/purgatory/Makefile index b04e6e72a592..088bd764e0b7 100644 --- a/arch/x86/purgatory/Makefile +++ b/arch/x86/purgatory/Makefile @@ -34,6 +34,7 @@ KCOV_INSTRUMENT := n PURGATORY_CFLAGS_REMOVE := -mcmodel=kernel PURGATORY_CFLAGS := -mcmodel=large -ffreestanding -fno-zero-initialized-in-bss PURGATORY_CFLAGS += $(DISABLE_STACKLEAK_PLUGIN) -DDISABLE_BRANCH_PROFILING +PURGATORY_CFLAGS += $(call cc-option,-fno-stack-protector) # Default KBUILD_CFLAGS can have -pg option set when FTRACE is enabled. That # in turn leaves some undefined symbols like __fentry__ in purgatory and not -- cgit v1.2.3-59-g8ed1b