diff options
| author | Catalin Marinas <catalin.marinas@arm.com> | 2026-02-27 18:53:06 +0000 |
|---|---|---|
| committer | Will Deacon <will@kernel.org> | 2026-03-04 14:33:08 +0000 |
| commit | c25c4aa3f79a488cc270507935a29c07dc6bddfc (patch) | |
| tree | 4172214d05f372f4cc1a4be18d790ff123ea0f9c | |
| parent | 212dd8477653fe72c2a6a99143cd662f6430cf4f (diff) | |
arm64: mm: Add PTE_DIRTY back to PAGE_KERNEL* to fix kexec/hibernation
Commit 143937ca51cc ("arm64, mm: avoid always making PTE dirty in
pte_mkwrite()") changed pte_mkwrite_novma() to only clear PTE_RDONLY
when PTE_DIRTY is set. This was to allow writable-clean PTEs for swap
pages that haven't actually been written.
However, this broke kexec and hibernation for some platforms. Both go
through trans_pgd_create_copy() -> _copy_pte(), which calls
pte_mkwrite_novma() to make the temporary linear-map copy fully
writable. With the updated pte_mkwrite_novma(), read-only kernel pages
(without PTE_DIRTY) remain read-only in the temporary mapping.
While such behaviour is fine for user pages where hardware DBM or
trapping will make them writeable, subsequent in-kernel writes by the
kexec relocation code will fault.
Add PTE_DIRTY back to all _PAGE_KERNEL* protection definitions. This was
the case prior to 5.4, commit aa57157be69f ("arm64: Ensure
VM_WRITE|VM_SHARED ptes are clean by default"). With the kernel
linear-map PTEs always having PTE_DIRTY set, pte_mkwrite_novma()
correctly clears PTE_RDONLY.
Fixes: 143937ca51cc ("arm64, mm: avoid always making PTE dirty in pte_mkwrite()")
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: stable@vger.kernel.org
Reported-by: Jianpeng Chang <jianpeng.chang.cn@windriver.com>
Link: https://lore.kernel.org/r/20251204062722.3367201-1-jianpeng.chang.cn@windriver.com
Cc: Will Deacon <will@kernel.org>
Cc: Huang, Ying <ying.huang@linux.alibaba.com>
Cc: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Huang Ying <ying.huang@linux.alibaba.com>
Signed-off-by: Will Deacon <will@kernel.org>
| -rw-r--r-- | arch/arm64/include/asm/pgtable-prot.h | 10 |
1 files changed, 5 insertions, 5 deletions
diff --git a/arch/arm64/include/asm/pgtable-prot.h b/arch/arm64/include/asm/pgtable-prot.h index 2b32639160de..f560e6420267 100644 --- a/arch/arm64/include/asm/pgtable-prot.h +++ b/arch/arm64/include/asm/pgtable-prot.h @@ -50,11 +50,11 @@ #define _PAGE_DEFAULT (_PROT_DEFAULT | PTE_ATTRINDX(MT_NORMAL)) -#define _PAGE_KERNEL (PROT_NORMAL) -#define _PAGE_KERNEL_RO ((PROT_NORMAL & ~PTE_WRITE) | PTE_RDONLY) -#define _PAGE_KERNEL_ROX ((PROT_NORMAL & ~(PTE_WRITE | PTE_PXN)) | PTE_RDONLY) -#define _PAGE_KERNEL_EXEC (PROT_NORMAL & ~PTE_PXN) -#define _PAGE_KERNEL_EXEC_CONT ((PROT_NORMAL & ~PTE_PXN) | PTE_CONT) +#define _PAGE_KERNEL (PROT_NORMAL | PTE_DIRTY) +#define _PAGE_KERNEL_RO ((PROT_NORMAL & ~PTE_WRITE) | PTE_RDONLY | PTE_DIRTY) +#define _PAGE_KERNEL_ROX ((PROT_NORMAL & ~(PTE_WRITE | PTE_PXN)) | PTE_RDONLY | PTE_DIRTY) +#define _PAGE_KERNEL_EXEC ((PROT_NORMAL & ~PTE_PXN) | PTE_DIRTY) +#define _PAGE_KERNEL_EXEC_CONT ((PROT_NORMAL & ~PTE_PXN) | PTE_CONT | PTE_DIRTY) #define _PAGE_SHARED (_PAGE_DEFAULT | PTE_USER | PTE_RDONLY | PTE_NG | PTE_PXN | PTE_UXN | PTE_WRITE) #define _PAGE_SHARED_EXEC (_PAGE_DEFAULT | PTE_USER | PTE_RDONLY | PTE_NG | PTE_PXN | PTE_WRITE) |