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| author | Ard Biesheuvel <ardb@kernel.org> | 2020-07-31 16:07:46 -0700 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2020-08-14 12:52:34 +0200 |
| commit | e544ea57ac0734bca752eb2d8635fecbe932c356 (patch) | |
| tree | f94e41e776f29945c427689e5e2bf003cd6bf5bc /drivers/firmware/efi | |
| parent | 262b5cae67a672404da0dcbd009efc1227ad51e4 (diff) | |
| download | linux-e544ea57ac0734bca752eb2d8635fecbe932c356.tar.gz linux-e544ea57ac0734bca752eb2d8635fecbe932c356.tar.bz2 linux-e544ea57ac0734bca752eb2d8635fecbe932c356.zip | |
x86/boot/compressed: Force hidden visibility for all symbol references
Eliminate all GOT entries in the decompressor binary, by forcing hidden
visibility for all symbol references, which informs the compiler that
such references will be resolved at link time without the need for
allocating GOT entries.
To ensure that no GOT entries will creep back in, add an assertion to
the decompressor linker script that will fire if the .got section has
a non-zero size.
[Arvind: move hidden.h to include/linux instead of making a copy]
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Tested-by: Nick Desaulniers <ndesaulniers@google.com>
Tested-by: Sedat Dilek <sedat.dilek@gmail.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Acked-by: Arvind Sankar <nivedita@alum.mit.edu>
Link: https://lore.kernel.org/r/20200731230820.1742553-3-keescook@chromium.org
Diffstat (limited to 'drivers/firmware/efi')
| -rw-r--r-- | drivers/firmware/efi/libstub/Makefile | 2 | ||||
| -rw-r--r-- | drivers/firmware/efi/libstub/hidden.h | 6 |
2 files changed, 1 insertions, 7 deletions
diff --git a/drivers/firmware/efi/libstub/Makefile b/drivers/firmware/efi/libstub/Makefile index 296b18fbd7a2..5eefd60917df 100644 --- a/drivers/firmware/efi/libstub/Makefile +++ b/drivers/firmware/efi/libstub/Makefile @@ -26,7 +26,7 @@ cflags-$(CONFIG_ARM) := $(subst $(CC_FLAGS_FTRACE),,$(KBUILD_CFLAGS)) \ cflags-$(CONFIG_EFI_GENERIC_STUB) += -I$(srctree)/scripts/dtc/libfdt KBUILD_CFLAGS := $(cflags-y) -Os -DDISABLE_BRANCH_PROFILING \ - -include $(srctree)/drivers/firmware/efi/libstub/hidden.h \ + -include $(srctree)/include/linux/hidden.h \ -D__NO_FORTIFY \ -ffreestanding \ -fno-stack-protector \ diff --git a/drivers/firmware/efi/libstub/hidden.h b/drivers/firmware/efi/libstub/hidden.h deleted file mode 100644 index 3493b041f419..000000000000 --- a/drivers/firmware/efi/libstub/hidden.h +++ /dev/null @@ -1,6 +0,0 @@ -/* SPDX-License-Identifier: GPL-2.0 */ -/* - * To prevent the compiler from emitting GOT-indirected (and thus absolute) - * references to any global symbols, override their visibility as 'hidden' - */ -#pragma GCC visibility push(hidden) |