From 6f05106e20f0ed26a2dbd6a5d44a302ce81642e0 Mon Sep 17 00:00:00 2001 From: Ard Biesheuvel Date: Mon, 10 Feb 2020 17:02:32 +0100 Subject: [PATCH] efi/libstub: Use hidden visibility for all source files Instead of setting the visibility pragma for a small set of symbol declarations that could result in absolute references that we cannot support in the stub, declare hidden visibility for all code in the EFI stub, which is more robust and future proof. To ensure that the #pragma is taken into account before any other includes are processed, put it in a header file of its own and include it via the compiler command line using the -include option. Signed-off-by: Ard Biesheuvel --- arch/arm64/include/asm/efi.h | 3 --- drivers/firmware/efi/libstub/Makefile | 1 + drivers/firmware/efi/libstub/arm64-stub.c | 8 +------- drivers/firmware/efi/libstub/hidden.h | 6 ++++++ 4 files changed, 8 insertions(+), 10 deletions(-) create mode 100644 drivers/firmware/efi/libstub/hidden.h diff --git a/arch/arm64/include/asm/efi.h b/arch/arm64/include/asm/efi.h index 44531a69d32b..56ae87401a26 100644 --- a/arch/arm64/include/asm/efi.h +++ b/arch/arm64/include/asm/efi.h @@ -107,9 +107,6 @@ static inline void free_screen_info(struct screen_info *si) { } -/* redeclare as 'hidden' so the compiler will generate relative references */ -extern struct screen_info screen_info __attribute__((__visibility__("hidden"))); - static inline void efifb_setup_from_dmi(struct screen_info *si, const char *opt) { } diff --git a/drivers/firmware/efi/libstub/Makefile b/drivers/firmware/efi/libstub/Makefile index f14b7636323a..fc9e9e883eb4 100644 --- a/drivers/firmware/efi/libstub/Makefile +++ b/drivers/firmware/efi/libstub/Makefile @@ -25,6 +25,7 @@ cflags-$(CONFIG_ARM) := $(subst $(CC_FLAGS_FTRACE),,$(KBUILD_CFLAGS)) \ cflags-$(CONFIG_EFI_ARMSTUB) += -I$(srctree)/scripts/dtc/libfdt KBUILD_CFLAGS := $(cflags-y) -DDISABLE_BRANCH_PROFILING \ + -include $(srctree)/drivers/firmware/efi/libstub/hidden.h \ -D__NO_FORTIFY \ $(call cc-option,-ffreestanding) \ $(call cc-option,-fno-stack-protector) \ diff --git a/drivers/firmware/efi/libstub/arm64-stub.c b/drivers/firmware/efi/libstub/arm64-stub.c index ad5f24a4489b..9254cd8ab2d3 100644 --- a/drivers/firmware/efi/libstub/arm64-stub.c +++ b/drivers/firmware/efi/libstub/arm64-stub.c @@ -6,17 +6,11 @@ * Adapted from ARM version by Mark Salter */ -/* - * To prevent the compiler from emitting GOT-indirected (and thus absolute) - * references to the section markers, override their visibility as 'hidden' - */ -#pragma GCC visibility push(hidden) -#include -#pragma GCC visibility pop #include #include #include +#include #include #include "efistub.h" diff --git a/drivers/firmware/efi/libstub/hidden.h b/drivers/firmware/efi/libstub/hidden.h new file mode 100644 index 000000000000..3493b041f419 --- /dev/null +++ b/drivers/firmware/efi/libstub/hidden.h @@ -0,0 +1,6 @@ +/* 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)