[PATCH v2 6/6] powerpc/pkeys: Deny read/write/execute by default
From: Ram Pai <hidden>
Date: 2018-06-14 00:29:31
Subsystem:
linux for powerpc (32-bit and 64-bit), the rest · Maintainers:
Madhavan Srinivasan, Linus Torvalds
Deny all permissions on all keys, with some exceptions. pkey-0 must allow all permissions, or else everything comes to a screaching halt. Execute-only key must allow execute permission. Signed-off-by: Ram Pai <redacted> --- arch/powerpc/mm/pkeys.c | 10 ++++------ 1 files changed, 4 insertions(+), 6 deletions(-)
diff --git a/arch/powerpc/mm/pkeys.c b/arch/powerpc/mm/pkeys.c
index 9098605..cec990c 100644
--- a/arch/powerpc/mm/pkeys.c
+++ b/arch/powerpc/mm/pkeys.c@@ -128,13 +128,11 @@ int pkey_initialize(void) /* register mask is in BE format */ pkey_amr_mask = ~0x0ul; - pkey_iamr_mask = ~0x0ul; + pkey_amr_mask &= ~(0x3ul << pkeyshift(PKEY_0)); - for (i = 0; i < (pkeys_total - os_reserved); i++) { - pkey_amr_mask &= ~(0x3ul << pkeyshift(i)); - pkey_iamr_mask &= ~(0x1ul << pkeyshift(i)); - } - pkey_amr_mask |= (AMR_RD_BIT|AMR_WR_BIT) << pkeyshift(EXECUTE_ONLY_KEY); + pkey_iamr_mask = ~0x0ul; + pkey_iamr_mask &= ~(0x3ul << pkeyshift(PKEY_0)); + pkey_iamr_mask &= ~(0x3ul << pkeyshift(EXECUTE_ONLY_KEY)); pkey_uamor_mask = ~0x0ul; pkey_uamor_mask &= ~(0x3ul << pkeyshift(PKEY_0));
--
1.7.1