[PATCH v4 12/41] powerpc/book3s64/pkeys: Mark all the pkeys above max pkey as reserved
From: Aneesh Kumar K.V <hidden>
Date: 2020-06-15 06:37:05
Subsystem:
linux for powerpc (32-bit and 64-bit), the rest · Maintainers:
Madhavan Srinivasan, Linus Torvalds
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 <redacted> --- 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 73b5ef1490c8..0ff59acdbb84 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)); }
--
2.26.2