Instruct the compiler to realign the stack to 16 bytes, as required by
the UEFI specification for x86_64. This will allow us to drop the asm
helper that converts between MS and SysV calling conventions in a future
patch.
Signed-off-by: Ard Biesheuvel <ardb@xxxxxxxxxx>
---
arch/x86/Makefile | 3 +++
arch/x86/include/asm/efi.h | 2 ++
arch/x86/platform/efi/Makefile | 2 ++
arch/x86/platform/efi/efi_64.c | 2 +-
arch/x86/platform/uv/Makefile | 1 +
arch/x86/platform/uv/bios_uv.c | 4 ++--
drivers/firmware/efi/Makefile | 1 +
drivers/firmware/efi/runtime-wrappers.c | 17 ++++++++++-------
8 files changed, 22 insertions(+), 10 deletions(-)
diff --git a/arch/x86/Makefile b/arch/x86/Makefile
index fdc2e3abd6152f53..debc43fb9a2e6d36 100644
--- a/arch/x86/Makefile
+++ b/arch/x86/Makefile
@@ -36,10 +36,13 @@ export RETPOLINE_VDSO_CFLAGS
ifneq ($(call cc-option, -mpreferred-stack-boundary=4),)
cc_stack_align4 := -mpreferred-stack-boundary=2
cc_stack_align8 := -mpreferred-stack-boundary=3
+ EFI_STACK_ALIGN := -mpreferred-stack-boundary=4
else ifneq ($(call cc-option, -mstack-alignment=16),)
cc_stack_align4 := -mstack-alignment=4
cc_stack_align8 := -mstack-alignment=8
+ EFI_STACK_ALIGN := -mstack-alignment=16
endif
+export EFI_STACK_ALIGN
# How to compile the 16-bit code. Note we always compile for -march=i386;
# that way we can complain to the user if the CPU is insufficient.
diff --git a/arch/x86/include/asm/efi.h b/arch/x86/include/asm/efi.h
index c4555b269a1b2474..c47f2d49e6bc6a09 100644
--- a/arch/x86/include/asm/efi.h
+++ b/arch/x86/include/asm/efi.h
@@ -111,6 +111,8 @@ extern bool efi_disable_ibt_for_runtime;
ret; \
})
+#define __efi_realign_stack __attribute__((force_align_arg_pointer))
+
#ifdef CONFIG_KASAN
/*
* CONFIG_KASAN may redefine memset to __memset. __memset function is present
diff --git a/arch/x86/platform/efi/Makefile b/arch/x86/platform/efi/Makefile
index 543df9a1379d121c..684ac27cdf7cabfe 100644
--- a/arch/x86/platform/efi/Makefile
+++ b/arch/x86/platform/efi/Makefile
@@ -7,3 +7,5 @@ obj-$(CONFIG_EFI) += memmap.o quirks.o efi.o efi_$(BITS).o \
obj-$(CONFIG_EFI_MIXED) += efi_thunk_$(BITS).o
obj-$(CONFIG_EFI_FAKE_MEMMAP) += fake_mem.o
obj-$(CONFIG_EFI_RUNTIME_MAP) += runtime-map.o
+
+CFLAGS_efi_64.o := $(EFI_STACK_ALIGN)
diff --git a/arch/x86/platform/efi/efi_64.c b/arch/x86/platform/efi/efi_64.c
index 91d31ac422d6cde7..8033b4a338c4b431 100644
--- a/arch/x86/platform/efi/efi_64.c
+++ b/arch/x86/platform/efi/efi_64.c
@@ -846,7 +846,7 @@ void __init efi_thunk_runtime_setup(void)
efi.query_capsule_caps = efi_thunk_query_capsule_caps;
}
-efi_status_t __init __no_sanitize_address
+efi_status_t __init __no_sanitize_address __efi_realign_stack
efi_set_virtual_address_map(unsigned long memory_map_size,
unsigned long descriptor_size,
u32 descriptor_version,
diff --git a/arch/x86/platform/uv/Makefile b/arch/x86/platform/uv/Makefile
index 1441dda8edf76879..cb4807ba4ef50f02 100644
--- a/arch/x86/platform/uv/Makefile
+++ b/arch/x86/platform/uv/Makefile
@@ -1,2 +1,3 @@
# SPDX-License-Identifier: GPL-2.0-only
obj-$(CONFIG_X86_UV) += bios_uv.o uv_irq.o uv_time.o uv_nmi.o
+CFLAGS_bios_uv.o := $(EFI_STACK_ALIGN)
diff --git a/arch/x86/platform/uv/bios_uv.c b/arch/x86/platform/uv/bios_uv.c
index bf31af3d32d69cbc..d6b69f363aa1f2a9 100644
--- a/arch/x86/platform/uv/bios_uv.c
+++ b/arch/x86/platform/uv/bios_uv.c
@@ -20,8 +20,8 @@ unsigned long uv_systab_phys __ro_after_init = EFI_INVALID_TABLE_ADDR;
struct uv_systab *uv_systab;
-static s64 __uv_bios_call(enum uv_bios_cmd which, u64 a1, u64 a2, u64 a3,
- u64 a4, u64 a5)
+static s64 __efi_realign_stack
+__uv_bios_call(enum uv_bios_cmd which, u64 a1, u64 a2, u64 a3, u64 a4, u64 a5)
{
struct uv_systab *tab = uv_systab;
s64 ret;
diff --git a/drivers/firmware/efi/Makefile b/drivers/firmware/efi/Makefile
index e489fefd23dae0bc..db3f8c1fbc1d8a54 100644
--- a/drivers/firmware/efi/Makefile
+++ b/drivers/firmware/efi/Makefile
@@ -9,6 +9,7 @@
# in efi_call_virt() will cause crash if this code instrumented.
#
KASAN_SANITIZE_runtime-wrappers.o := n
+CFLAGS_runtime-wrappers.o := $(EFI_STACK_ALIGN)
obj-$(CONFIG_ACPI_BGRT) += efi-bgrt.o
obj-$(CONFIG_EFI) += efi.o vars.o reboot.o memattr.o tpm.o
diff --git a/drivers/firmware/efi/runtime-wrappers.c b/drivers/firmware/efi/runtime-wrappers.c
index dfec5969dbaba417..2db9e0b3c2842e50 100644
--- a/drivers/firmware/efi/runtime-wrappers.c
+++ b/drivers/firmware/efi/runtime-wrappers.c
@@ -35,6 +35,10 @@
#include <asm/efi.h>
+#ifndef __efi_realign_stack
+#define __efi_realign_stack
+#endif
+
/*
* Wrap around the new efi_call_virt_generic() macros so that the
* code doesn't get too cluttered:
@@ -213,7 +217,7 @@ extern struct semaphore __efi_uv_runtime_lock __alias(efi_runtime_lock);
* Calls the appropriate efi_runtime_service() with the appropriate
* arguments.
*/
-static void efi_call_rts(struct work_struct *work)
+static void __efi_realign_stack efi_call_rts(struct work_struct *work)
{
const union efi_rts_args *args = efi_rts_work.args;
efi_status_t status = EFI_NOT_FOUND;
@@ -436,7 +440,7 @@ static efi_status_t virt_efi_set_variable(efi_char16_t *name,
return status;
}
-static efi_status_t
+static efi_status_t __efi_realign_stack
virt_efi_set_variable_nb(efi_char16_t *name, efi_guid_t *vendor, u32 attr,
unsigned long data_size, void *data)
{
@@ -470,7 +474,7 @@ static efi_status_t virt_efi_query_variable_info(u32 attr,
return status;
}
-static efi_status_t
+static efi_status_t __efi_realign_stack
virt_efi_query_variable_info_nb(u32 attr, u64 *storage_space,
u64 *remaining_space, u64 *max_variable_size)
{
@@ -500,10 +504,9 @@ static efi_status_t virt_efi_get_next_high_mono_count(u32 *count)
return status;
}
-static void virt_efi_reset_system(int reset_type,
- efi_status_t status,
- unsigned long data_size,
- efi_char16_t *data)
+static void __efi_realign_stack
+virt_efi_reset_system(int reset_type, efi_status_t status,
+ unsigned long data_size, efi_char16_t *data)
{
if (down_trylock(&efi_runtime_lock)) {
pr_warn("failed to invoke the reset_system() runtime service:\n"
--
2.39.2
