[RFC PATCH 11/16] arm64: kpkeys: Support KPKEYS_LVL_PGTABLES

Kevin Brodsky
2024-12-06T10:13:48Z

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 | 2 ++
1 file changed, 2 insertions(+)

diff --git a/arch/arm64/include/asm/kpkeys.h b/arch/arm64/include/asm/kpkeys.h
index e17f6df41873..4854e1f3babd 100644
--- a/arch/arm64/include/asm/kpkeys.h
+++ b/arch/arm64/include/asm/kpkeys.h
@@ -18,6 +18,8 @@ static inline bool arch_kpkeys_enabled(void)
static inline u64 por_set_kpkeys_level(u64 por, int level)
{
por = por_set_pkey_perms(por, KPKEYS_PKEY_DEFAULT, POE_RXW);
+ por = por_set_pkey_perms(por, KPKEYS_PKEY_PGTABLES,
+ level == KPKEYS_LVL_PGTABLES ? POE_RW : POE_R);

return por;
}
--
2.47.0