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| author | Nick Desaulniers | 2019-08-08 00:15:33 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman | 2019-08-16 10:12:41 +0200 |
| commit | b674f7914a64efe9709c912911c72a700683424e (patch) | |
| tree | db3b1d30b92fad081f726f2e9ea2225373711dfa | |
| parent | perf record: Fix module size on s390 (diff) | |
| download | kernel-qcow2-linux-b674f7914a64efe9709c912911c72a700683424e.tar.gz kernel-qcow2-linux-b674f7914a64efe9709c912911c72a700683424e.tar.xz kernel-qcow2-linux-b674f7914a64efe9709c912911c72a700683424e.zip | |
x86/purgatory: Use CFLAGS_REMOVE rather than reset KBUILD_CFLAGS
commit b059f801a937d164e03b33c1848bb3dca67c0b04 upstream.
KBUILD_CFLAGS is very carefully built up in the top level Makefile,
particularly when cross compiling or using different build tools.
Resetting KBUILD_CFLAGS via := assignment is an antipattern.
The comment above the reset mentions that -pg is problematic. Other
Makefiles use `CFLAGS_REMOVE_file.o = $(CC_FLAGS_FTRACE)` when
CONFIG_FUNCTION_TRACER is set. Prefer that pattern to wiping out all of
the important KBUILD_CFLAGS then manually having to re-add them. Seems
also that __stack_chk_fail references are generated when using
CONFIG_STACKPROTECTOR or CONFIG_STACKPROTECTOR_STRONG.
Fixes: 8fc5b4d4121c ("purgatory: core purgatory functionality")
Reported-by: Vaibhav Rustagi <vaibhavrustagi@google.com>
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Vaibhav Rustagi <vaibhavrustagi@google.com>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20190807221539.94583-2-ndesaulniers@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | arch/x86/purgatory/Makefile | 33 |
1 files changed, 28 insertions, 5 deletions
diff --git a/arch/x86/purgatory/Makefile b/arch/x86/purgatory/Makefile index 3cf302b26332..3d8144627b12 100644 --- a/arch/x86/purgatory/Makefile +++ b/arch/x86/purgatory/Makefile @@ -17,11 +17,34 @@ KCOV_INSTRUMENT := n # Default KBUILD_CFLAGS can have -pg option set when FTRACE is enabled. That # in turn leaves some undefined symbols like __fentry__ in purgatory and not -# sure how to relocate those. Like kexec-tools, use custom flags. - -KBUILD_CFLAGS := -fno-strict-aliasing -Wall -Wstrict-prototypes -fno-zero-initialized-in-bss -fno-builtin -ffreestanding -c -Os -mcmodel=large -KBUILD_CFLAGS += -m$(BITS) -KBUILD_CFLAGS += $(call cc-option,-fno-PIE) +# sure how to relocate those. +ifdef CONFIG_FUNCTION_TRACER +CFLAGS_REMOVE_sha256.o += $(CC_FLAGS_FTRACE) +CFLAGS_REMOVE_purgatory.o += $(CC_FLAGS_FTRACE) +CFLAGS_REMOVE_string.o += $(CC_FLAGS_FTRACE) +CFLAGS_REMOVE_kexec-purgatory.o += $(CC_FLAGS_FTRACE) +endif + +ifdef CONFIG_STACKPROTECTOR +CFLAGS_REMOVE_sha256.o += -fstack-protector +CFLAGS_REMOVE_purgatory.o += -fstack-protector +CFLAGS_REMOVE_string.o += -fstack-protector +CFLAGS_REMOVE_kexec-purgatory.o += -fstack-protector +endif + +ifdef CONFIG_STACKPROTECTOR_STRONG +CFLAGS_REMOVE_sha256.o += -fstack-protector-strong +CFLAGS_REMOVE_purgatory.o += -fstack-protector-strong +CFLAGS_REMOVE_string.o += -fstack-protector-strong +CFLAGS_REMOVE_kexec-purgatory.o += -fstack-protector-strong +endif + +ifdef CONFIG_RETPOLINE +CFLAGS_REMOVE_sha256.o += $(RETPOLINE_CFLAGS) +CFLAGS_REMOVE_purgatory.o += $(RETPOLINE_CFLAGS) +CFLAGS_REMOVE_string.o += $(RETPOLINE_CFLAGS) +CFLAGS_REMOVE_kexec-purgatory.o += $(RETPOLINE_CFLAGS) +endif $(obj)/purgatory.ro: $(PURGATORY_OBJS) FORCE $(call if_changed,ld) |