Commit 3648027d authored by Ard Biesheuvel's avatar Ard Biesheuvel Committed by Will Deacon
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arm64: Fix 5-level paging support in kexec/hibernate trampoline 



Add the missing code to allocate P4D level page tables when cloning the
the kernel page tables. This fixes a crash that may be observed when
attempting to resume from hibernation on an LPA2 capable system with 4k
pages, which therefore uses 5 levels of paging.

Presumably, kexec is equally affected.

Signed-off-by: default avatarArd Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20250110175145.785702-2-ardb+git@google.com


Signed-off-by: default avatarWill Deacon <will@kernel.org>
parent 2014c95a

arch/arm64/mm/trans_pgd.c

+7 −0
Original line number Diff line number Diff line
@@ -162,6 +162,13 @@ static int copy_p4d(struct trans_pgd_info *info, pgd_t *dst_pgdp, 
	unsigned long next;

	unsigned long addr = start;



	if (pgd_none(READ_ONCE(*dst_pgdp))) {

		dst_p4dp = trans_alloc(info);

		if (!dst_p4dp)

			return -ENOMEM;

		pgd_populate(NULL, dst_pgdp, dst_p4dp);

	}



	dst_p4dp = p4d_offset(dst_pgdp, start);

	src_p4dp = p4d_offset(src_pgdp, start);

	do {