diff mbox series

[RFC,01/25] powerpc/book3s64/pkeys: Mark all the pkeys above max pkey as reserved

Message ID 20200427080507.1626327-2-aneesh.kumar@linux.ibm.com (mailing list archive)
State Superseded
Headers show
Series Kernel userspace access/execution prevention with hash translation | expand

Checks

Context Check Description
snowpatch_ozlabs/apply_patch warning Failed to apply on branch powerpc/merge (54dc28ff5e0b3585224d49a31b53e030342ca5c3)
snowpatch_ozlabs/apply_patch warning Failed to apply on branch powerpc/next (45591da765885f7320a111d290b3a28a23eed359)
snowpatch_ozlabs/apply_patch warning Failed to apply on branch linus/master (6a8b55ed4056ea5559ebe4f6a4b247f627870d4c)
snowpatch_ozlabs/apply_patch warning Failed to apply on branch powerpc/fixes (5990cdee689c6885b27c6d969a3d58b09002b0bc)
snowpatch_ozlabs/apply_patch warning Failed to apply on branch linux-next (8bdabd09ec86a993419c8c98a4f34c12bc902c6c)
snowpatch_ozlabs/apply_patch fail Failed to apply to any branch

Commit Message

Aneesh Kumar K V April 27, 2020, 8:04 a.m. UTC 
The hypervisor can return less than max allowed pkey (for ex: 31) instead
of 32. We should mark all the pkeys above max allowed as reserved so
that we avoid the allocation of the wrong pkey(for ex: key 31 in the above
case) by userspace.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
---
 arch/powerpc/mm/book3s64/pkeys.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)
diff mbox series

Patch

diff --git a/arch/powerpc/mm/book3s64/pkeys.c b/arch/powerpc/mm/book3s64/pkeys.c
index 78aaa9300ac2..0303df9368e1 100644
--- a/arch/powerpc/mm/book3s64/pkeys.c
+++ b/arch/powerpc/mm/book3s64/pkeys.c
@@ -175,9 +175,10 @@  static int pkey_initialize(void)
 
 	/*
 	 * Prevent the usage of OS reserved keys. Update UAMOR
-	 * for those keys.
+	 * for those keys. Also mark the rest of the bits in the
+	 * 32 bit mask as reserved.
 	 */
-	for (i = max_pkey; i < pkeys_total; i++) {
+	for (i = max_pkey; i < 32 ; i++) {
 		reserved_allocation_mask |= (0x1 << i);
 		default_uamor &= ~(0x3ul << pkeyshift(i));
 	}