In order to store the SBAT data, we create a new ELF note. The string
"Secure-Boot-Advanced-Targeting",
zero-padded to 4 byte alignment, shall be entered in the name field. The string
"sbat"'s ASCII values,
0x41536967, should be entered in the type field.
Signed-off-by: Sudhakar Kuppusamy <sudha...@linux.ibm.com>
Co-authored-by: Daniel Axtens <d...@axtens.net>
---
include/grub/util/mkimage.h | 4 +--
util/grub-mkimagexx.c | 51 +++++++++++++++++++++++++++++++++++--
util/mkimage.c | 5 ++--
3 files changed, 54 insertions(+), 6 deletions(-)
diff --git a/include/grub/util/mkimage.h b/include/grub/util/mkimage.h
index 3819a6744..9d74f82c5 100644
--- a/include/grub/util/mkimage.h
+++ b/include/grub/util/mkimage.h
@@ -51,12 +51,12 @@ grub_mkimage_load_image64 (const char *kernel_path,
const struct grub_install_image_target_desc
*image_target);
void
grub_mkimage_generate_elf32 (const struct grub_install_image_target_desc
*image_target,
- int note, char **core_img, size_t *core_size,
+ int note, char *sbat, char **core_img, size_t
*core_size,
Elf32_Addr target_addr,
struct grub_mkimage_layout *layout);
void
grub_mkimage_generate_elf64 (const struct grub_install_image_target_desc
*image_target,
- int note, char **core_img, size_t *core_size,
+ int note, char *sbat, char **core_img, size_t
*core_size,
Elf64_Addr target_addr,
struct grub_mkimage_layout *layout);
diff --git a/util/grub-mkimagexx.c b/util/grub-mkimagexx.c
index e50b29533..99f6ab05e 100644
--- a/util/grub-mkimagexx.c
+++ b/util/grub-mkimagexx.c
@@ -107,6 +107,14 @@ struct section_metadata
const char *strtab;
};
+#define GRUB_SBAT_NOTE_NAME "Secure-Boot-Advanced-Targeting"
+#define GRUB_SBAT_NOTE_TYPE 0x73626174 /* "sbat" */
+
+struct grub_sbat_note {
+ Elf32_Nhdr header;
+ char name[ALIGN_UP(sizeof(GRUB_SBAT_NOTE_NAME), 4)];
+};
+
static int
is_relocatable (const struct grub_install_image_target_desc *image_target)
{
@@ -208,7 +216,7 @@ grub_arm_reloc_jump24 (grub_uint32_t *target, Elf32_Addr
sym_addr)
void
SUFFIX (grub_mkimage_generate_elf) (const struct
grub_install_image_target_desc *image_target,
- int note, char **core_img, size_t
*core_size,
+ int note, char *sbat, char **core_img,
size_t *core_size,
Elf_Addr target_addr,
struct grub_mkimage_layout *layout)
{
@@ -217,10 +225,17 @@ SUFFIX (grub_mkimage_generate_elf) (const struct
grub_install_image_target_desc
Elf_Ehdr *ehdr;
Elf_Phdr *phdr;
Elf_Shdr *shdr;
- int header_size, footer_size = 0;
+ int header_size, footer_size = 0, footer_offset = 0;
int phnum = 1;
int shnum = 4;
int string_size = sizeof (".text") + sizeof ("mods") + 1;
+ char *footer;
+
+ if (sbat)
+ {
+ phnum++;
+ footer_size += ALIGN_UP (sizeof (struct grub_sbat_note) +
layout->sbat_size, 4);
+ }
if (image_target->id != IMAGE_LOONGSON_ELF)
phnum += 2;
@@ -248,6 +263,7 @@ SUFFIX (grub_mkimage_generate_elf) (const struct
grub_install_image_target_desc
ehdr = (void *) elf_img;
phdr = (void *) (elf_img + sizeof (*ehdr));
shdr = (void *) (elf_img + sizeof (*ehdr) + phnum * sizeof (*phdr));
+ footer = elf_img + program_size + header_size;
memcpy (ehdr->e_ident, ELFMAG, SELFMAG);
ehdr->e_ident[EI_CLASS] = ELFCLASSXX;
if (!image_target->bigendian)
@@ -420,6 +436,8 @@ SUFFIX (grub_mkimage_generate_elf) (const struct
grub_install_image_target_desc
phdr->p_filesz = grub_host_to_target32 (XEN_NOTE_SIZE);
phdr->p_memsz = 0;
phdr->p_offset = grub_host_to_target32 (header_size + program_size);
+ footer = ptr;
+ footer_offset = XEN_NOTE_SIZE;
}
if (image_target->id == IMAGE_XEN_PVH)
@@ -453,6 +471,8 @@ SUFFIX (grub_mkimage_generate_elf) (const struct
grub_install_image_target_desc
phdr->p_filesz = grub_host_to_target32 (XEN_PVH_NOTE_SIZE);
phdr->p_memsz = 0;
phdr->p_offset = grub_host_to_target32 (header_size + program_size);
+ footer = ptr;
+ footer_offset = XEN_PVH_NOTE_SIZE;
}
if (note)
@@ -483,6 +503,33 @@ SUFFIX (grub_mkimage_generate_elf) (const struct
grub_install_image_target_desc
phdr->p_filesz = grub_host_to_target32 (note_size);
phdr->p_memsz = 0;
phdr->p_offset = grub_host_to_target32 (header_size + program_size);
+ footer = (elf_img + program_size + header_size + note_size);
+ footer_offset += note_size;
+ }
+
+ if (sbat)
+ {
+ int note_size = ALIGN_UP(sizeof (struct grub_sbat_note) +
layout->sbat_size, 4);
+ struct grub_sbat_note *note_ptr = (struct grub_sbat_note *)footer;
+
+ note_ptr->header.n_namesz = grub_host_to_target32 (sizeof
(GRUB_SBAT_NOTE_NAME));
+ note_ptr->header.n_descsz = grub_host_to_target32
(ALIGN_UP(layout->sbat_size, 4));
+ note_ptr->header.n_type = grub_host_to_target32 (GRUB_SBAT_NOTE_TYPE);
+ memcpy (note_ptr->name, GRUB_SBAT_NOTE_NAME, sizeof
(GRUB_SBAT_NOTE_NAME));
+ memcpy ((char *)(note_ptr + 1), sbat, layout->sbat_size);
+
+ phdr++;
+ phdr->p_type = grub_host_to_target32 (PT_NOTE);
+ phdr->p_flags = grub_host_to_target32 (PF_R);
+ phdr->p_align = grub_host_to_target32 (image_target->voidp_sizeof);
+ phdr->p_vaddr = 0;
+ phdr->p_paddr = 0;
+ phdr->p_filesz = grub_host_to_target32 (note_size);
+ phdr->p_memsz = 0;
+ phdr->p_offset = grub_host_to_target32 (header_size + program_size +
footer_offset);
+
+ footer += note_size;
+ footer_offset += note_size;
}
{
diff --git a/util/mkimage.c b/util/mkimage.c
index 8c5660825..e67f7ce73 100644
--- a/util/mkimage.c
+++ b/util/mkimage.c
@@ -1813,6 +1813,7 @@ grub_install_generate_image (const char *dir, const char
*prefix,
case IMAGE_I386_IEEE1275:
{
grub_uint64_t target_addr;
+ char *sbat = NULL;
if (image_target->id == IMAGE_LOONGSON_ELF)
{
if (comp == GRUB_COMPRESSION_NONE)
@@ -1824,10 +1825,10 @@ grub_install_generate_image (const char *dir, const
char *prefix,
else
target_addr = image_target->link_addr;
if (image_target->voidp_sizeof == 4)
- grub_mkimage_generate_elf32 (image_target, note, &core_img,
&core_size,
+ grub_mkimage_generate_elf32 (image_target, note, sbat, &core_img,
&core_size,
target_addr, &layout);
else
- grub_mkimage_generate_elf64 (image_target, note, &core_img,
&core_size,
+ grub_mkimage_generate_elf64 (image_target, note, sbat, &core_img,
&core_size,
target_addr, &layout);
}
break;
--
2.39.3
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