diff options
| author | Joerg Roedel <jroedel@suse.de> | 2020-09-07 15:15:13 +0200 |
|---|---|---|
| committer | Borislav Petkov <bp@suse.de> | 2020-09-07 19:45:25 +0200 |
| commit | 6ba0efa46047936afa81460489cfd24bc95dd863 (patch) | |
| tree | b3c1d1c3dcbdb1cde3d5dce2511d3a56e9c1c93b /arch/x86/boot | |
| parent | 5901781a11175a5e5ee91746ec8627f18d47eebd (diff) | |
| download | linux-6ba0efa46047936afa81460489cfd24bc95dd863.tar.gz linux-6ba0efa46047936afa81460489cfd24bc95dd863.tar.bz2 linux-6ba0efa46047936afa81460489cfd24bc95dd863.zip | |
x86/boot/compressed/64: Disable red-zone usage
The x86-64 ABI defines a red-zone on the stack:
The 128-byte area beyond the location pointed to by %rsp is considered
to be reserved and shall not be modified by signal or interrupt
handlers. Therefore, functions may use this area for temporary data
that is not needed across function calls. In particular, leaf
functions may use this area for their entire stack frame, rather than
adjusting the stack pointer in the prologue and epilogue. This area is
known as the red zone.
This is not compatible with exception handling, because the IRET frame
written by the hardware at the stack pointer and the functions to handle
the exception will overwrite the temporary variables of the interrupted
function, causing undefined behavior. So disable red-zones for the
pre-decompression boot code.
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Kees Cook <keescook@chromium.org>
Link: https://lkml.kernel.org/r/20200907131613.12703-13-joro@8bytes.org
Diffstat (limited to 'arch/x86/boot')
| -rw-r--r-- | arch/x86/boot/compressed/Makefile | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/x86/boot/compressed/Makefile b/arch/x86/boot/compressed/Makefile index 3962f592633d..5343079af973 100644 --- a/arch/x86/boot/compressed/Makefile +++ b/arch/x86/boot/compressed/Makefile @@ -32,7 +32,7 @@ KBUILD_CFLAGS := -m$(BITS) -O2 KBUILD_CFLAGS += -fno-strict-aliasing $(call cc-option, -fPIE, -fPIC) KBUILD_CFLAGS += -DDISABLE_BRANCH_PROFILING cflags-$(CONFIG_X86_32) := -march=i386 -cflags-$(CONFIG_X86_64) := -mcmodel=small +cflags-$(CONFIG_X86_64) := -mcmodel=small -mno-red-zone KBUILD_CFLAGS += $(cflags-y) KBUILD_CFLAGS += -mno-mmx -mno-sse KBUILD_CFLAGS += -ffreestanding |