[PATCH resend 4/9] linux/arm: unify ARM/arm64 vs Xen PE/COFF header handling

Ard Biesheuvel
2022-08-18T08:56:02Z

Xen has its own version of the image header, to account for the
additional PE/COFF header fields. Since we are adding references to
those in the shared EFI loader code, update the common definitions
and drop the Xen specific one which no longer has a purpose.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
---
grub-core/loader/arm64/linux.c | 12 +++++-----
grub-core/loader/arm64/xen_boot.c | 23 ++++----------------
include/grub/arm/linux.h | 6 +++++
include/grub/arm64/linux.h | 4 ++++
include/grub/efi/efi.h | 4 +++-
5 files changed, 24 insertions(+), 25 deletions(-)

diff --git a/grub-core/loader/arm64/linux.c b/grub-core/loader/arm64/linux.c
index b5b559c236e0..7c0f17cf933d 100644
--- a/grub-core/loader/arm64/linux.c
+++ b/grub-core/loader/arm64/linux.c
@@ -49,8 +49,13 @@ static grub_addr_t initrd_start;
static grub_addr_t initrd_end;

grub_err_t
-grub_arch_efi_linux_check_image (struct linux_arch_kernel_header * lh)
+grub_arch_efi_linux_load_image_header (grub_file_t file,
+ struct linux_arch_kernel_header * lh)
{
+ grub_file_seek (file, 0);
+ if (grub_file_read (file, lh, sizeof (*lh)) < (long) sizeof (*lh))
+ return grub_error(GRUB_ERR_FILE_READ_ERROR, "failed to read Linux image header");
+
if ((lh->code0 & 0xffff) != GRUB_PE32_MAGIC)
return grub_error (GRUB_ERR_NOT_IMPLEMENTED_YET,
N_("plain image kernel not supported - rebuild with CONFIG_(U)EFI_STUB enabled"));
@@ -301,10 +306,7 @@ grub_cmd_linux (grub_command_t cmd __attribute__ ((unused)),

kernel_size = grub_file_size (file);

- if (grub_file_read (file, &lh, sizeof (lh)) < (long) sizeof (lh))
- return grub_errno;
-
- if (grub_arch_efi_linux_check_image (&lh) != GRUB_ERR_NONE)
+ if (grub_arch_efi_linux_load_image_header (file, &lh) != GRUB_ERR_NONE)
goto fail;

grub_loader_unset();
diff --git a/grub-core/loader/arm64/xen_boot.c b/grub-core/loader/arm64/xen_boot.c
index 22cc25eccd9d..e5895ee78218 100644
--- a/grub-core/loader/arm64/xen_boot.c
+++ b/grub-core/loader/arm64/xen_boot.c
@@ -31,7 +31,6 @@
#include <grub/efi/efi.h>
#include <grub/efi/fdtload.h>
#include <grub/efi/memory.h>
-#include <grub/efi/pe32.h> /* required by struct xen_hypervisor_header */
#include <grub/i18n.h>
#include <grub/lib/cmdline.h>

@@ -65,18 +64,6 @@ enum module_type
};
typedef enum module_type module_type_t;

-struct xen_hypervisor_header
-{
- struct linux_arm64_kernel_header efi_head;
-
- /* This is always PE\0\0. */
- grub_uint8_t signature[GRUB_PE32_SIGNATURE_SIZE];
- /* The COFF file header. */
- struct grub_pe32_coff_header coff_header;
- /* The Optional header. */
- struct grub_pe64_optional_header optional_header;
-};
-
struct xen_boot_binary
{
struct xen_boot_binary *next;
@@ -452,7 +439,7 @@ static grub_err_t
grub_cmd_xen_hypervisor (grub_command_t cmd __attribute__ ((unused)),
int argc, char *argv[])
{
- struct xen_hypervisor_header sh;
+ struct linux_arm64_kernel_header lh;
grub_file_t file = NULL;

grub_dl_ref (my_mod);
@@ -467,10 +454,7 @@ grub_cmd_xen_hypervisor (grub_command_t cmd __attribute__ ((unused)),
if (!file)
goto fail;

- if (grub_file_read (file, &sh, sizeof (sh)) != (long) sizeof (sh))
- goto fail;
- if (grub_arch_efi_linux_check_image
- ((struct linux_arch_kernel_header *) &sh) != GRUB_ERR_NONE)
+ if (grub_arch_efi_linux_load_image_header (file, &lh) != GRUB_ERR_NONE)
goto fail;
grub_file_seek (file, 0);

@@ -484,7 +468,8 @@ grub_cmd_xen_hypervisor (grub_command_t cmd __attribute__ ((unused)),
return grub_errno;

xen_hypervisor->is_hypervisor = 1;
- xen_hypervisor->align = (grub_size_t) sh.optional_header.section_alignment;
+ xen_hypervisor->align
+ = (grub_size_t) lh.coff_image_header.optional_header.section_alignment;

xen_boot_binary_load (xen_hypervisor, file, argc, argv);
if (grub_errno == GRUB_ERR_NONE)
diff --git a/include/grub/arm/linux.h b/include/grub/arm/linux.h
index bfab334dd87f..f2a2c0379795 100644
--- a/include/grub/arm/linux.h
+++ b/include/grub/arm/linux.h
@@ -22,6 +22,8 @@

#include "system.h"

+#include <grub/efi/pe32.h>
+
#define GRUB_LINUX_ARM_MAGIC_SIGNATURE 0x016f2818

struct linux_arm_kernel_header {
@@ -32,6 +34,10 @@ struct linux_arm_kernel_header {
grub_uint32_t end; /* _edata */
grub_uint32_t reserved2[3];
grub_uint32_t hdr_offset;
+
+#if defined GRUB_MACHINE_EFI
+ struct grub_coff_image_header coff_image_header;
+#endif
};

#if defined(__arm__)
diff --git a/include/grub/arm64/linux.h b/include/grub/arm64/linux.h
index 96f1494e05a2..e00bbcfa2ff2 100644
--- a/include/grub/arm64/linux.h
+++ b/include/grub/arm64/linux.h
@@ -21,6 +21,8 @@

#include <grub/types.h>

+#include <grub/efi/pe32.h>
+
#define GRUB_LINUX_ARM64_MAGIC_SIGNATURE 0x644d5241 /* 'ARM\x64' */

/* From linux/Documentation/arm64/booting.txt */
@@ -36,6 +38,8 @@ struct linux_arm64_kernel_header
grub_uint64_t res4; /* reserved */
grub_uint32_t magic; /* Magic number, little endian, "ARM\x64" */
grub_uint32_t hdr_offset; /* Offset of PE/COFF header */
+
+ struct grub_coff_image_header coff_image_header;
};

#if defined(__aarch64__)
diff --git a/include/grub/efi/efi.h b/include/grub/efi/efi.h
index eb2dfdfce9f8..e61272de5330 100644
--- a/include/grub/efi/efi.h
+++ b/include/grub/efi/efi.h
@@ -102,7 +102,9 @@ extern void (*EXPORT_VAR(grub_efi_net_config)) (grub_efi_handle_t hnd,
void *EXPORT_FUNC(grub_efi_get_firmware_fdt)(void);
grub_err_t EXPORT_FUNC(grub_efi_get_ram_base)(grub_addr_t *);
#include <grub/cpu/linux.h>
-grub_err_t grub_arch_efi_linux_check_image(struct linux_arch_kernel_header *lh);
+#include <grub/file.h>
+grub_err_t grub_arch_efi_linux_load_image_header(grub_file_t file,
+ struct linux_arch_kernel_header *lh);
grub_err_t grub_arch_efi_linux_boot_image(grub_addr_t addr, grub_size_t size,
char *args);
#endif
--
2.35.1