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| author | Daniel Axtens <dja@axtens.net> | 2022-04-21 15:24:14 +1000 |
|---|---|---|
| committer | Daniel Kiper <daniel.kiper@oracle.com> | 2022-06-29 12:41:29 +0200 |
| commit | 1df8fe66c57087eb33bd6dc69f786ed124615aa7 (patch) | |
| tree | 5bf8ba10b8e4a6e8cd3ee29b409d6dc756985dcc | |
| parent | 188d2ff1c3a5d72220bb599e0d95e0f752bae7e9 (diff) | |
| download | grub-1df8fe66c57087eb33bd6dc69f786ed124615aa7.tar.gz | |
mm: Assert that we preserve header vs region alignment
grub_mm_region_init() does:
h = (grub_mm_header_t) (r + 1);
where h is a grub_mm_header_t and r is a grub_mm_region_t.
Cells are supposed to be GRUB_MM_ALIGN aligned, but while grub_mm_dump
ensures this vs the region header, grub_mm_region_init() does not.
It's better to be explicit than implicit here: rather than changing
grub_mm_region_init() to ALIGN_UP(), require that the struct is
explicitly a multiple of the header size.
Signed-off-by: Daniel Axtens <dja@axtens.net>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
Tested-by: Patrick Steinhardt <ps@pks.im>
| -rw-r--r-- | include/grub/mm_private.h | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/include/grub/mm_private.h b/include/grub/mm_private.h index 203533cc3..a688b92a8 100644 --- a/include/grub/mm_private.h +++ b/include/grub/mm_private.h @@ -20,6 +20,7 @@ #define GRUB_MM_PRIVATE_H 1 #include <grub/mm.h> +#include <grub/misc.h> /* For context, see kern/mm.c */ @@ -89,4 +90,17 @@ typedef struct grub_mm_region extern grub_mm_region_t EXPORT_VAR (grub_mm_base); #endif +static inline void +grub_mm_size_sanity_check (void) { + /* Ensure we preserve alignment when doing h = (grub_mm_header_t) (r + 1). */ + COMPILE_TIME_ASSERT ((sizeof (struct grub_mm_region) % + sizeof (struct grub_mm_header)) == 0); + + /* + * GRUB_MM_ALIGN is supposed to represent cell size, and a mm_header is + * supposed to be 1 cell. + */ + COMPILE_TIME_ASSERT (sizeof (struct grub_mm_header) == GRUB_MM_ALIGN); +} + #endif |