diff options
| author | Ard Biesheuvel <ardb@kernel.org> | 2025-08-28 12:22:23 +0200 |
|---|---|---|
| committer | Borislav Petkov (AMD) <bp@alien8.de> | 2025-09-03 18:05:42 +0200 |
| commit | e7b88bc0051c5062bdd73b58837cf277d0057358 (patch) | |
| tree | 298ec15fd6815e00e0f373f5dd02595c79fa005f | |
| parent | 7b38dec3c5af54665a4b29483aa02bd1c1e71cf1 (diff) | |
efistub/x86: Remap inittext read-execute when needed
Recent EFI x86 systems are more strict when it comes to mapping boot
images, and require that mappings are either read-write or read-execute.
Now that the boot code is being cleaned up and refactored, most of it is
being moved into .init.text [where it arguably belongs] but that implies
that when booting on such strict EFI firmware, we need to take care to
map .init.text (and the .altinstr_aux section that follows it)
read-execute as well.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/20250828102202.1849035-44-ardb+git@google.com
| -rw-r--r-- | arch/x86/boot/compressed/Makefile | 2 | ||||
| -rw-r--r-- | arch/x86/boot/compressed/misc.c | 2 | ||||
| -rw-r--r-- | arch/x86/include/asm/boot.h | 2 | ||||
| -rw-r--r-- | arch/x86/kernel/vmlinux.lds.S | 2 | ||||
| -rw-r--r-- | drivers/firmware/efi/libstub/x86-stub.c | 4 |
5 files changed, 10 insertions, 2 deletions
diff --git a/arch/x86/boot/compressed/Makefile b/arch/x86/boot/compressed/Makefile index 3a38fdcdb9bd..74657589264d 100644 --- a/arch/x86/boot/compressed/Makefile +++ b/arch/x86/boot/compressed/Makefile @@ -73,7 +73,7 @@ LDFLAGS_vmlinux += -T hostprogs := mkpiggy HOST_EXTRACFLAGS += -I$(srctree)/tools/include -sed-voffset := -e 's/^\([0-9a-fA-F]*\) [ABbCDGRSTtVW] \(_text\|__start_rodata\|__bss_start\|_end\)$$/\#define VO_\2 _AC(0x\1,UL)/p' +sed-voffset := -e 's/^\([0-9a-fA-F]*\) [ABbCDGRSTtVW] \(_text\|__start_rodata\|_sinittext\|__inittext_end\|__bss_start\|_end\)$$/\#define VO_\2 _AC(0x\1,UL)/p' quiet_cmd_voffset = VOFFSET $@ cmd_voffset = $(NM) $< | sed -n $(sed-voffset) > $@ diff --git a/arch/x86/boot/compressed/misc.c b/arch/x86/boot/compressed/misc.c index 94b5991da001..0f41ca0e52c0 100644 --- a/arch/x86/boot/compressed/misc.c +++ b/arch/x86/boot/compressed/misc.c @@ -332,6 +332,8 @@ static size_t parse_elf(void *output) } const unsigned long kernel_text_size = VO___start_rodata - VO__text; +const unsigned long kernel_inittext_offset = VO__sinittext - VO__text; +const unsigned long kernel_inittext_size = VO___inittext_end - VO__sinittext; const unsigned long kernel_total_size = VO__end - VO__text; static u8 boot_heap[BOOT_HEAP_SIZE] __aligned(4); diff --git a/arch/x86/include/asm/boot.h b/arch/x86/include/asm/boot.h index 02b23aa78955..f7b67cb73915 100644 --- a/arch/x86/include/asm/boot.h +++ b/arch/x86/include/asm/boot.h @@ -82,6 +82,8 @@ #ifndef __ASSEMBLER__ extern unsigned int output_len; extern const unsigned long kernel_text_size; +extern const unsigned long kernel_inittext_offset; +extern const unsigned long kernel_inittext_size; extern const unsigned long kernel_total_size; unsigned long decompress_kernel(unsigned char *outbuf, unsigned long virt_addr, diff --git a/arch/x86/kernel/vmlinux.lds.S b/arch/x86/kernel/vmlinux.lds.S index 5d5e3a95e1f9..4277efb26358 100644 --- a/arch/x86/kernel/vmlinux.lds.S +++ b/arch/x86/kernel/vmlinux.lds.S @@ -227,6 +227,8 @@ SECTIONS */ .altinstr_aux : AT(ADDR(.altinstr_aux) - LOAD_OFFSET) { *(.altinstr_aux) + . = ALIGN(PAGE_SIZE); + __inittext_end = .; } INIT_DATA_SECTION(16) diff --git a/drivers/firmware/efi/libstub/x86-stub.c b/drivers/firmware/efi/libstub/x86-stub.c index cafc90d4caaf..0d05eac7c72b 100644 --- a/drivers/firmware/efi/libstub/x86-stub.c +++ b/drivers/firmware/efi/libstub/x86-stub.c @@ -788,7 +788,9 @@ static efi_status_t efi_decompress_kernel(unsigned long *kernel_entry, *kernel_entry = addr + entry; - return efi_adjust_memory_range_protection(addr, kernel_text_size); + return efi_adjust_memory_range_protection(addr, kernel_text_size) ?: + efi_adjust_memory_range_protection(addr + kernel_inittext_offset, + kernel_inittext_size); } static void __noreturn enter_kernel(unsigned long kernel_addr, |