From 1018e91dce8bd5c60c073c16209b979b033460a7 Mon Sep 17 00:00:00 2001 From: Andrei Borzenkov Date: Fri, 6 Nov 2015 21:33:28 +0300 Subject: [PATCH] mkimage: zero fill alignment space This did not cause real problem but is good for reproducible builds. I hit it with recent bootinfoscript that displays embedded config; I was puzzled by random garbage at the end. Prezero memory buffer used to assemble core.img. This makes individual memset redundant. Also ensure buffer is filled with zeroes in several other places. Also remove redundant zeroing code where we fill in the whole memory block anyway. --- util/grub-mkimagexx.c | 3 ++- util/mkimage.c | 30 +++++++++--------------------- 2 files changed, 11 insertions(+), 22 deletions(-) diff --git a/util/grub-mkimagexx.c b/util/grub-mkimagexx.c index 3c76d0708..a1ddc6269 100644 --- a/util/grub-mkimagexx.c +++ b/util/grub-mkimagexx.c @@ -101,7 +101,7 @@ SUFFIX (generate_elf) (const struct grub_install_image_target_desc *image_target program_size = ALIGN_ADDR (*core_size); elf_img = xmalloc (program_size + header_size + footer_size); - memset (elf_img, 0, program_size + header_size); + memset (elf_img, 0, program_size + header_size + footer_size); memcpy (elf_img + header_size, *core_img, *core_size); ehdr = (void *) elf_img; phdr = (void *) (elf_img + sizeof (*ehdr)); @@ -1587,6 +1587,7 @@ SUFFIX (load_image) (const char *kernel_path, size_t *exec_size, } out_img = xmalloc (*kernel_sz + total_module_size); + memset (out_img, 0, *kernel_sz + total_module_size); if (image_target->id == IMAGE_EFI) { diff --git a/util/mkimage.c b/util/mkimage.c index 35df99871..dc4046185 100644 --- a/util/mkimage.c +++ b/util/mkimage.c @@ -992,7 +992,7 @@ grub_install_generate_image (const char *dir, const char *prefix, { char *kernel_img, *core_img; size_t kernel_size, total_module_size, core_size, exec_size; - size_t memdisk_size = 0, config_size = 0, config_size_pure = 0; + size_t memdisk_size = 0, config_size = 0; size_t prefix_size = 0; char *kernel_path; size_t offset; @@ -1043,8 +1043,7 @@ grub_install_generate_image (const char *dir, const char *prefix, if (config_path) { - config_size_pure = grub_util_get_image_size (config_path) + 1; - config_size = ALIGN_ADDR (config_size_pure); + config_size = ALIGN_ADDR (grub_util_get_image_size (config_path) + 1); grub_util_info ("the size of config file is 0x%" GRUB_HOST_PRIxLONG_LONG, (unsigned long long) config_size); total_module_size += config_size + sizeof (struct grub_module_header); @@ -1080,7 +1079,10 @@ grub_install_generate_image (const char *dir, const char *prefix, = grub_host_to_target32 (total_module_size); if (image_target->flags & PLATFORM_FLAGS_MODULES_BEFORE_KERNEL) - memmove (kernel_img + total_module_size, kernel_img, kernel_size); + { + memmove (kernel_img + total_module_size, kernel_img, kernel_size); + memset (kernel_img, 0, total_module_size); + } if (image_target->voidp_sizeof == 8) { @@ -1090,7 +1092,6 @@ grub_install_generate_image (const char *dir, const char *prefix, modinfo = (struct grub_module_info64 *) kernel_img; else modinfo = (struct grub_module_info64 *) (kernel_img + kernel_size); - memset (modinfo, 0, sizeof (struct grub_module_info64)); modinfo->magic = grub_host_to_target32 (GRUB_MODULE_MAGIC); modinfo->offset = grub_host_to_target_addr (sizeof (struct grub_module_info64)); modinfo->size = grub_host_to_target_addr (total_module_size); @@ -1107,7 +1108,6 @@ grub_install_generate_image (const char *dir, const char *prefix, modinfo = (struct grub_module_info32 *) kernel_img; else modinfo = (struct grub_module_info32 *) (kernel_img + kernel_size); - memset (modinfo, 0, sizeof (struct grub_module_info32)); modinfo->magic = grub_host_to_target32 (GRUB_MODULE_MAGIC); modinfo->offset = grub_host_to_target_addr (sizeof (struct grub_module_info32)); modinfo->size = grub_host_to_target_addr (total_module_size); @@ -1120,17 +1120,14 @@ grub_install_generate_image (const char *dir, const char *prefix, for (p = path_list; p; p = p->next) { struct grub_module_header *header; - size_t mod_size, orig_size; + size_t mod_size; - orig_size = grub_util_get_image_size (p->name); - mod_size = ALIGN_ADDR (orig_size); + mod_size = ALIGN_ADDR (grub_util_get_image_size (p->name)); header = (struct grub_module_header *) (kernel_img + offset); - memset (header, 0, sizeof (struct grub_module_header)); header->type = grub_host_to_target32 (OBJ_TYPE_ELF); header->size = grub_host_to_target32 (mod_size + sizeof (*header)); offset += sizeof (*header); - memset (kernel_img + offset + orig_size, 0, mod_size - orig_size); grub_util_load_image (p->name, kernel_img + offset); offset += mod_size; @@ -1146,7 +1143,6 @@ grub_install_generate_image (const char *dir, const char *prefix, curs = grub_util_get_image_size (pubkey_paths[i]); header = (struct grub_module_header *) (kernel_img + offset); - memset (header, 0, sizeof (struct grub_module_header)); header->type = grub_host_to_target32 (OBJ_TYPE_PUBKEY); header->size = grub_host_to_target32 (curs + sizeof (*header)); offset += sizeof (*header); @@ -1161,7 +1157,6 @@ grub_install_generate_image (const char *dir, const char *prefix, struct grub_module_header *header; header = (struct grub_module_header *) (kernel_img + offset); - memset (header, 0, sizeof (struct grub_module_header)); header->type = grub_host_to_target32 (OBJ_TYPE_MEMDISK); header->size = grub_host_to_target32 (memdisk_size + sizeof (*header)); offset += sizeof (*header); @@ -1175,13 +1170,11 @@ grub_install_generate_image (const char *dir, const char *prefix, struct grub_module_header *header; header = (struct grub_module_header *) (kernel_img + offset); - memset (header, 0, sizeof (struct grub_module_header)); header->type = grub_host_to_target32 (OBJ_TYPE_CONFIG); header->size = grub_host_to_target32 (config_size + sizeof (*header)); offset += sizeof (*header); grub_util_load_image (config_path, kernel_img + offset); - *(kernel_img + offset + config_size_pure - 1) = 0; offset += config_size; } @@ -1190,12 +1183,10 @@ grub_install_generate_image (const char *dir, const char *prefix, struct grub_module_header *header; header = (struct grub_module_header *) (kernel_img + offset); - memset (header, 0, sizeof (struct grub_module_header)); header->type = grub_host_to_target32 (OBJ_TYPE_PREFIX); header->size = grub_host_to_target32 (prefix_size + sizeof (*header)); offset += sizeof (*header); - grub_memset (kernel_img + offset, 0, prefix_size); grub_strcpy (kernel_img + offset, prefix); offset += prefix_size; } @@ -1269,15 +1260,11 @@ grub_install_generate_image (const char *dir, const char *prefix, full_size = core_size + decompress_size; full_img = xmalloc (full_size); - memset (full_img, 0, full_size); memcpy (full_img, decompress_img, decompress_size); memcpy (full_img + decompress_size, core_img, core_size); - memset (full_img + decompress_size + core_size, 0, - full_size - (decompress_size + core_size)); - free (core_img); core_img = full_img; core_size = full_size; @@ -1428,6 +1415,7 @@ grub_install_generate_image (const char *dir, const char *prefix, pe_img = xmalloc (reloc_addr + reloc_size); memset (pe_img, 0, header_size); memcpy ((char *) pe_img + header_size, core_img, core_size); + memset ((char *) pe_img + header_size + core_size, 0, reloc_addr - (header_size + core_size)); memcpy ((char *) pe_img + reloc_addr, rel_section, reloc_size); header = pe_img;