[PATCH v6 22/30] arm64: kpkeys: Support KPKEYS_LVL_PGTABLES

Kevin Brodsky
2026-02-27T17:57:30Z

Enable RW access to KPKEYS_PKEY_PGTABLES (used to map page table
pages) if switching to KPKEYS_LVL_PGTABLES, otherwise only grant RO
access.

Signed-off-by: Kevin Brodsky <kevin.brodsky@arm.com>
---
arch/arm64/include/asm/kpkeys.h | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/include/asm/kpkeys.h b/arch/arm64/include/asm/kpkeys.h
index 79ae33388088..64d6e22740ec 100644
--- a/arch/arm64/include/asm/kpkeys.h
+++ b/arch/arm64/include/asm/kpkeys.h
@@ -12,7 +12,8 @@
* Equivalent to por_set_kpkeys_level(0, KPKEYS_LVL_DEFAULT), but can also be
* used in assembly.
*/
-#define POR_EL1_INIT POR_ELx_PERM_PREP(KPKEYS_PKEY_DEFAULT, POE_RWX)
+#define POR_EL1_INIT (POR_ELx_PERM_PREP(KPKEYS_PKEY_DEFAULT, POE_RWX) | \
+ POR_ELx_PERM_PREP(KPKEYS_PKEY_PGTABLES, POE_R))

#ifndef __ASSEMBLY__

@@ -26,6 +27,8 @@ static inline bool arch_kpkeys_enabled(void)
static inline u64 por_set_kpkeys_level(u64 por, int level)
{
por = por_elx_set_pkey_perms(por, KPKEYS_PKEY_DEFAULT, POE_RWX);
+ por = por_elx_set_pkey_perms(por, KPKEYS_PKEY_PGTABLES,
+ level == KPKEYS_LVL_PGTABLES ? POE_RW : POE_R);

return por;
}
--
2.51.2