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security/memory_clear: fix wrong size of reserved memory range

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The code used to reserve MEMSET_PAE_PGTL_SIZE (20 KiB) for page used
for clearing the memory above 4 GiB that was assumed to be 2 MiB page.
memset_pae() checks only the alignment and not the size of this region,
so no error was reported by it.

In most cases this reserved memory in 2-4 MiB range, and because this
range isn't usually used by coreboot (architectural stuff is located in
lower 1 MiB, coreboot tables and ramstage are close to TOLUM and payload
isn't yet loaded when the broken code is executed), it never caused any
problems.

Change MEMSET_PAE_PGTL_SIZE to MEMSET_PAE_VMEM_SIZE and fix wrong macro
definition to reserve properly sized region.

Change-Id: I0df15b0d1767196fe70be14d94428ccdf8dbd5d3
Signed-off-by: Krystian Hebel <krystian.hebel@3mdeb.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/82397
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Sergii Dmytruk <sergii.dmytruk@3mdeb.com>
Reviewed-by: Paul Menzel <paulepanter@mailbox.org>
This commit is contained in:
Krystian Hebel 2024-05-13 12:24:37 +02:00 committed by Felix Held
parent ca88b5f0ac
commit 5ba17d5ccb
1 changed files with 2 additions and 2 deletions
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4
src/security/memory/memory_clear.c
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@ -6,8 +6,8 @@
#define memset_pae(a, b, c, d, e) 0
#define MEMSET_PAE_PGTL_ALIGN 0
#define MEMSET_PAE_PGTL_SIZE 0
#define MEMSET_PAE_PGTL_SIZE 0
#define MEMSET_PAE_VMEM_ALIGN 0
#define MEMSET_PAE_VMEM_SIZE 0
#endif
#include <memrange.h>
@ -92,7 +92,7 @@ static void clear_memory(void *unused)
BM_MEM_TABLE);
vmem_addr = get_free_memory_range(&mem, MEMSET_PAE_VMEM_ALIGN,
MEMSET_PAE_PGTL_SIZE);
MEMSET_PAE_VMEM_SIZE);
printk(BIOS_SPEW, "%s: pgtbl at %p, virt memory at %p\n",
__func__, (void *)pgtbl, (void *)vmem_addr);