From 3e4352aeb8b17eb1040ba288f586620e8294389d Mon Sep 17 00:00:00 2001
From: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com>
Date: Thu, 9 Jul 2020 08:59:35 +0530
Subject: [PATCH] powerpc/book3s64/pkeys: Mark all the pkeys above max pkey as
reserved
References: jsc#SLE-16556 bsc#1078248 FATE#322447
Patch-mainline: v5.9-rc1
Git-commit: 3e4352aeb8b17eb1040ba288f586620e8294389d
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>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200709032946.881753-13-aneesh.kumar@linux.ibm.com
Acked-by: Michal Suchanek <msuchanek@suse.de>
---
arch/powerpc/mm/book3s64/pkeys.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/arch/powerpc/mm/book3s64/pkeys.c b/arch/powerpc/mm/book3s64/pkeys.c
index e9fd0db7fb3c..d84bf55369a3 100644
--- a/arch/powerpc/mm/book3s64/pkeys.c
+++ b/arch/powerpc/mm/book3s64/pkeys.c
@@ -189,9 +189,10 @@ 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 = num_pkey; i < pkeys_total; i++) {
+ for (i = num_pkey; i < 32 ; i++) {
reserved_allocation_mask |= (0x1 << i);
default_uamor &= ~(0x3ul << pkeyshift(i));
}
--
2.26.2