diff --git a/drivers/firmware/efi/libstub/arm64-stub.c b/drivers/firmware/efi/libstub/arm64-stub.c index fc9f8ab533a7..cfd535c13242 100644 --- a/drivers/firmware/efi/libstub/arm64-stub.c +++ b/drivers/firmware/efi/libstub/arm64-stub.c @@ -34,6 +34,15 @@ efi_status_t check_platform_features(void) return EFI_SUCCESS; } +/* + * Relocatable kernels can fix up the misalignment with respect to + * MIN_KIMG_ALIGN, so they only require a minimum alignment of EFI_KIMG_ALIGN + * (which accounts for the alignment of statically allocated objects such as + * the swapper stack.) + */ +static const u64 min_kimg_align = IS_ENABLED(CONFIG_RELOCATABLE) ? EFI_KIMG_ALIGN + : MIN_KIMG_ALIGN; + efi_status_t handle_kernel_image(unsigned long *image_addr, unsigned long *image_size, unsigned long *reserve_addr, @@ -43,7 +52,6 @@ efi_status_t handle_kernel_image(unsigned long *image_addr, { efi_status_t status; unsigned long kernel_size, kernel_memsize = 0; - unsigned long preferred_offset; u64 phys_seed = 0; if (IS_ENABLED(CONFIG_RANDOMIZE_BASE)) { @@ -61,14 +69,8 @@ efi_status_t handle_kernel_image(unsigned long *image_addr, } } - /* - * The preferred offset of the kernel Image is TEXT_OFFSET bytes beyond - * a 2 MB aligned base, which itself may be lower than dram_base, as - * long as the resulting offset equals or exceeds it. - */ - preferred_offset = round_down(dram_base, MIN_KIMG_ALIGN) + TEXT_OFFSET; - if (preferred_offset < dram_base) - preferred_offset += MIN_KIMG_ALIGN; + if (image->image_base != _text) + pr_efi_err("FIRMWARE BUG: efi_loaded_image_t::image_base has bogus value\n"); kernel_size = _edata - _text; kernel_memsize = kernel_size + (_end - _edata); @@ -103,46 +105,32 @@ efi_status_t handle_kernel_image(unsigned long *image_addr, *image_addr = *reserve_addr + offset; } else { - /* - * Else, try a straight allocation at the preferred offset. - * This will work around the issue where, if dram_base == 0x0, - * efi_low_alloc() refuses to allocate at 0x0 (to prevent the - * address of the allocation to be mistaken for a FAIL return - * value or a NULL pointer). It will also ensure that, on - * platforms where the [dram_base, dram_base + TEXT_OFFSET) - * interval is partially occupied by the firmware (like on APM - * Mustang), we can still place the kernel at the address - * 'dram_base + TEXT_OFFSET'. - */ - *image_addr = (unsigned long)_text; - if (*image_addr == preferred_offset) - return EFI_SUCCESS; - - *image_addr = *reserve_addr = preferred_offset; - *reserve_size = round_up(kernel_memsize, EFI_ALLOC_ALIGN); - - status = efi_bs_call(allocate_pages, EFI_ALLOCATE_ADDRESS, - EFI_LOADER_DATA, - *reserve_size / EFI_PAGE_SIZE, - (efi_physical_addr_t *)reserve_addr); + status = EFI_OUT_OF_RESOURCES; } if (status != EFI_SUCCESS) { - *reserve_size = kernel_memsize + TEXT_OFFSET; + if (IS_ALIGNED((u64)_text - TEXT_OFFSET, min_kimg_align)) { + /* + * Just execute from wherever we were loaded by the + * UEFI PE/COFF loader if the alignment is suitable. + */ + *image_addr = (u64)_text; + *reserve_size = 0; + return EFI_SUCCESS; + } + + *reserve_size = kernel_memsize + TEXT_OFFSET % min_kimg_align; status = efi_low_alloc(*reserve_size, - MIN_KIMG_ALIGN, reserve_addr); + min_kimg_align, reserve_addr); if (status != EFI_SUCCESS) { pr_efi_err("Failed to relocate kernel\n"); *reserve_size = 0; return status; } - *image_addr = *reserve_addr + TEXT_OFFSET; + *image_addr = *reserve_addr + TEXT_OFFSET % min_kimg_align; } - if (image->image_base != _text) - pr_efi_err("FIRMWARE BUG: efi_loaded_image_t::image_base has bogus value\n"); - memcpy((void *)*image_addr, _text, kernel_size); return EFI_SUCCESS;