diff options
| -rw-r--r-- | arch/x86/boot/tools/build.c | 16 | ||||
| -rw-r--r-- | drivers/firmware/efi/libstub/x86-stub.c | 33 |
2 files changed, 36 insertions, 13 deletions
diff --git a/arch/x86/boot/tools/build.c b/arch/x86/boot/tools/build.c index 8cac5b6103db..8f8c8e386cea 100644 --- a/arch/x86/boot/tools/build.c +++ b/arch/x86/boot/tools/build.c @@ -238,21 +238,17 @@ static void update_pecoff_text(unsigned int text_start, unsigned int file_sz, pe_header = get_unaligned_le32(&buf[0x3c]); -#ifdef CONFIG_EFI_MIXED /* - * In mixed mode, we will execute startup_32() at whichever offset in - * memory it happened to land when the PE/COFF loader loaded the image, - * which may be misaligned with respect to the kernel_alignment field - * in the setup header. + * The PE/COFF loader may load the image at an address which is + * misaligned with respect to the kernel_alignment field in the setup + * header. * - * In order for startup_32 to safely execute in place at this offset, - * we need to ensure that the CONFIG_PHYSICAL_ALIGN aligned allocation - * it creates for the page tables does not extend beyond the declared - * size of the image in the PE/COFF header. So add the required slack. + * In order to avoid relocating the kernel to correct the misalignment, + * add slack to allow the buffer to be aligned within the declared size + * of the image. */ bss_sz += CONFIG_PHYSICAL_ALIGN; init_sz += CONFIG_PHYSICAL_ALIGN; -#endif /* * Size of code: Subtract the size of the first sector (512 bytes) diff --git a/drivers/firmware/efi/libstub/x86-stub.c b/drivers/firmware/efi/libstub/x86-stub.c index 3e1bc8a370be..4615d29dd665 100644 --- a/drivers/firmware/efi/libstub/x86-stub.c +++ b/drivers/firmware/efi/libstub/x86-stub.c @@ -17,6 +17,9 @@ #include "efistub.h" +/* Maximum physical address for 64-bit kernel with 4-level paging */ +#define MAXMEM_X86_64_4LEVEL (1ull << 46) + static efi_system_table_t *sys_table; extern const bool efi_is64; extern u32 image_offset; @@ -718,6 +721,7 @@ unsigned long efi_main(efi_handle_t handle, struct boot_params *boot_params) { unsigned long bzimage_addr = (unsigned long)startup_32; + unsigned long buffer_start, buffer_end; struct setup_header *hdr = &boot_params->hdr; efi_status_t status; unsigned long cmdline_paddr; @@ -729,10 +733,33 @@ unsigned long efi_main(efi_handle_t handle, efi_exit(handle, EFI_INVALID_PARAMETER); /* - * If the kernel isn't already loaded at the preferred load - * address, relocate it. + * If the kernel isn't already loaded at a suitable address, + * relocate it. + * + * It must be loaded above LOAD_PHYSICAL_ADDR. + * + * The maximum address for 64-bit is 1 << 46 for 4-level paging. This + * is defined as the macro MAXMEM, but unfortunately that is not a + * compile-time constant if 5-level paging is configured, so we instead + * define our own macro for use here. + * + * For 32-bit, the maximum address is complicated to figure out, for + * now use KERNEL_IMAGE_SIZE, which will be 512MiB, the same as what + * KASLR uses. + * + * Also relocate it if image_offset is zero, i.e. we weren't loaded by + * LoadImage, but we are not aligned correctly. */ - if (bzimage_addr - image_offset != hdr->pref_address) { + + buffer_start = ALIGN(bzimage_addr - image_offset, + hdr->kernel_alignment); + buffer_end = buffer_start + hdr->init_size; + + if ((buffer_start < LOAD_PHYSICAL_ADDR) || + (IS_ENABLED(CONFIG_X86_32) && buffer_end > KERNEL_IMAGE_SIZE) || + (IS_ENABLED(CONFIG_X86_64) && buffer_end > MAXMEM_X86_64_4LEVEL) || + (image_offset == 0 && !IS_ALIGNED(bzimage_addr, + hdr->kernel_alignment))) { status = efi_relocate_kernel(&bzimage_addr, hdr->init_size, hdr->init_size, hdr->pref_address, |