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56 lines
1.8 KiB
56 lines
1.8 KiB
From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001 |
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From: Daniel Axtens <dja@axtens.net> |
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Date: Thu, 21 Apr 2022 15:24:14 +1000 |
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Subject: [PATCH] mm: Assert that we preserve header vs region alignment |
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grub_mm_region_init() does: |
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h = (grub_mm_header_t) (r + 1); |
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where h is a grub_mm_header_t and r is a grub_mm_region_t. |
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Cells are supposed to be GRUB_MM_ALIGN aligned, but while grub_mm_dump |
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ensures this vs the region header, grub_mm_region_init() does not. |
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It's better to be explicit than implicit here: rather than changing |
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grub_mm_region_init() to ALIGN_UP(), require that the struct is |
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explicitly a multiple of the header size. |
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Signed-off-by: Daniel Axtens <dja@axtens.net> |
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Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com> |
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Tested-by: Patrick Steinhardt <ps@pks.im> |
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(cherry picked from commit 1df8fe66c57087eb33bd6dc69f786ed124615aa7) |
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--- |
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include/grub/mm_private.h | 14 ++++++++++++++ |
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1 file changed, 14 insertions(+) |
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diff --git a/include/grub/mm_private.h b/include/grub/mm_private.h |
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index 203533cc3d..a688b92a83 100644 |
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--- a/include/grub/mm_private.h |
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+++ b/include/grub/mm_private.h |
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@@ -20,6 +20,7 @@ |
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#define GRUB_MM_PRIVATE_H 1 |
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#include <grub/mm.h> |
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+#include <grub/misc.h> |
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/* For context, see kern/mm.c */ |
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@@ -89,4 +90,17 @@ typedef struct grub_mm_region |
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extern grub_mm_region_t EXPORT_VAR (grub_mm_base); |
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#endif |
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+static inline void |
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+grub_mm_size_sanity_check (void) { |
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+ /* Ensure we preserve alignment when doing h = (grub_mm_header_t) (r + 1). */ |
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+ COMPILE_TIME_ASSERT ((sizeof (struct grub_mm_region) % |
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+ sizeof (struct grub_mm_header)) == 0); |
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+ |
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+ /* |
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+ * GRUB_MM_ALIGN is supposed to represent cell size, and a mm_header is |
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+ * supposed to be 1 cell. |
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+ */ |
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+ COMPILE_TIME_ASSERT (sizeof (struct grub_mm_header) == GRUB_MM_ALIGN); |
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+} |
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+ |
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#endif
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