From: Hans de Goede hdegoede@redhat.com
[ Upstream commit e2ac07c06058ae2d58b45bbf2a2a352771d76fcb ]
Since the purgatory is a special stand-alone binary, various profiling and sanitizing options must be disabled. Having these options enabled typically will cause dependencies on various special symbols exported by special libs / stubs used by these frameworks. Since the purgatory is special, it is not linked against these stubs causing missing symbols in the purgatory if these options are not disabled.
Sync the set of disabled profiling and sanitizing options with that from drivers/firmware/efi/libstub/Makefile, adding -DDISABLE_BRANCH_PROFILING to the CFLAGS and setting:
GCOV_PROFILE := n UBSAN_SANITIZE := n
This fixes broken references to ftrace_likely_update() when CONFIG_TRACE_BRANCH_PROFILING is enabled and to __gcov_init() and __gcov_exit() when CONFIG_GCOV_KERNEL is enabled.
Signed-off-by: Hans de Goede hdegoede@redhat.com Signed-off-by: Borislav Petkov bp@suse.de Link: https://lkml.kernel.org/r/20200317130841.290418-1-hdegoede@redhat.com Signed-off-by: Sasha Levin sashal@kernel.org --- arch/x86/purgatory/Makefile | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/arch/x86/purgatory/Makefile b/arch/x86/purgatory/Makefile index b81b5172cf994..2cfa0caef1336 100644 --- a/arch/x86/purgatory/Makefile +++ b/arch/x86/purgatory/Makefile @@ -15,7 +15,10 @@ $(obj)/sha256.o: $(srctree)/lib/sha256.c FORCE LDFLAGS_purgatory.ro := -e purgatory_start -r --no-undefined -nostdlib -z nodefaultlib targets += purgatory.ro
+# Sanitizer, etc. runtimes are unavailable and cannot be linked here. +GCOV_PROFILE := n KASAN_SANITIZE := n +UBSAN_SANITIZE := n KCOV_INSTRUMENT := n
# These are adjustments to the compiler flags used for objects that @@ -23,7 +26,7 @@ KCOV_INSTRUMENT := n
PURGATORY_CFLAGS_REMOVE := -mcmodel=kernel PURGATORY_CFLAGS := -mcmodel=large -ffreestanding -fno-zero-initialized-in-bss -PURGATORY_CFLAGS += $(DISABLE_STACKLEAK_PLUGIN) +PURGATORY_CFLAGS += $(DISABLE_STACKLEAK_PLUGIN) -DDISABLE_BRANCH_PROFILING
# 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