[PATCH] x86/efi: skip memattr table on kexec boot

[Dave Young]

efi_memattr_init() added a sanity check to avoid firmware caused corruption.
The check is based on efi memmap entry numbers, but kexec only takes the
runtime related memmap entries thus this caused many false warnings, see
below thread for details:

https://lore.kernel.org/all/20250108215957.3437660-2-usamaarif642@gmail.com/

Ard suggests to skip the efi memattr table in kexec, this makes sense because
those memattr fixups are not critical.

Reported-by: Breno Leitao <leitao at debian.org>
Reported-and-tested-by: Usama Arif <usamaarif642 at gmail.com>
Suggested-by: Ard Biesheuvel <ardb at kernel.org>
Signed-off-by: Dave Young <dyoung at redhat.com>

diff --git a/arch/x86/platform/efi/quirks.c b/arch/x86/platform/efi/quirks.c
index 846bf49f2508..553f330198f2 100644
--- a/arch/x86/platform/efi/quirks.c
+++ b/arch/x86/platform/efi/quirks.c
@@ -561,6 +561,11 @@ int __init efi_reuse_config(u64 tables, int nr_tables)
 
 		if (!efi_guidcmp(guid, SMBIOS_TABLE_GUID))
 			((efi_config_table_64_t *)p)->table = data->smbios;
+
+		/* Do not bother to play with mem attr table across kexec */
+		if (!efi_guidcmp(guid, EFI_MEMORY_ATTRIBUTES_TABLE_GUID))
+			((efi_config_table_64_t *)p)->table = EFI_INVALID_TABLE_ADDR;
+
 		p += sz;
 	}
 	early_memunmap(tablep, nr_tables * sz);