On 2/26/26 09:14, Mikle Lappo wrote:
Add maintainers into CC
On Wed, Feb 25, 2026 at 2:07 PM <[email protected]
<mailto:[email protected]>> wrote:
From: Mikhail Lappo <[email protected] <mailto:[email protected]>>
libfdt requires the FDT blob to be 8-byte aligned. The alignment is
validated in fdt_check_header(), and misaligned blobs may be rejected
or cause failures on architectures that enforce strict alignment.
Currently the blob is allocated with grub_malloc(), which does not
guarantee 8-byte alignment. Replace it with grub_memalign(8, size)
to ensure the required alignment.
Signed-off-by: Mikhail Lappo <[email protected]
<mailto:[email protected]>>
---
grub-core/loader/efi/fdt.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/grub-core/loader/efi/fdt.c b/grub-core/loader/efi/fdt.c
index e510b3491..f25d362d3 100644
--- a/grub-core/loader/efi/fdt.c
+++ b/grub-core/loader/efi/fdt.c
@@ -38,6 +38,7 @@ static void *fdt;
#define FDT_ADDR_SIZE_EXTRA ((2 * grub_fdt_prop_entry_size
(sizeof(grub_uint32_t))) + \
sizeof (FDT_ADDR_CELLS_STRING) + \
sizeof (FDT_SIZE_CELLS_STRING))
+#define FDT_BLOB_ALIGNMENT 8
static const struct grub_arg_option options_fdtdump[] = {
{"prop", 'p', 0, N_("Get property."), N_("prop"),
ARG_TYPE_STRING},
@@ -145,7 +146,7 @@ grub_cmd_devicetree (grub_command_t cmd
__attribute__ ((unused)),
goto out;
size = grub_file_size (dtb);
- blob = grub_malloc (size);
+ blob = grub_memalign (FDT_BLOB_ALIGNMENT, size);
if (!blob)
goto out;
--
2.44.0
Isn't #define GRUB_MM_ALIGN_LOG2 setting a minimum alignment of 16 bytes
on 32-bit and 32 bytes on 64-bit systems?
Please, have a look at the code starting here:
grub-core/kern/mm.c:478: align = (align >> GRUB_MM_ALIGN_LOG2);
Best regards
Heinrich
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