diff options
| author | Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> | 2020-11-27 10:14:10 +0530 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2020-12-04 01:01:25 +1100 |
| commit | d94b827e89dc3f92cd871d10f4992a6bd3c861e5 (patch) | |
| tree | cf3fd6317c4c6b93f539381c2bd0d081f272b88c /arch/powerpc/mm/book3s64/pkeys.c | |
| parent | d5b810b5c938e73fd21b2b05ef6a79837eeaa305 (diff) | |
powerpc/book3s64/kuap: Use Key 3 for kernel mapping with hash translation
This patch updates kernel hash page table entries to use storage key 3
for its mapping. This implies all kernel access will now use key 3 to
control READ/WRITE. The patch also prevents the allocation of key 3 from
userspace and UAMOR value is updated such that userspace cannot modify key 3.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Reviewed-by: Sandipan Das <sandipan@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20201127044424.40686-9-aneesh.kumar@linux.ibm.com
Diffstat (limited to 'arch/powerpc/mm/book3s64/pkeys.c')
| -rw-r--r-- | arch/powerpc/mm/book3s64/pkeys.c | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/arch/powerpc/mm/book3s64/pkeys.c b/arch/powerpc/mm/book3s64/pkeys.c index c5c61aa18a04..e434c0a2ee5d 100644 --- a/arch/powerpc/mm/book3s64/pkeys.c +++ b/arch/powerpc/mm/book3s64/pkeys.c @@ -205,6 +205,18 @@ void __init pkey_early_init_devtree(void) reserved_allocation_mask |= (0x1 << 1); default_uamor &= ~(0x3ul << pkeyshift(1)); + /* handle key which is used by kernel for KAUP */ + reserved_allocation_mask |= (0x1 << 3); + /* + * Mark access for KUAP key in default amr so that + * we continue to operate with that AMR in + * copy_to/from_user(). + */ + default_amr &= ~(0x3ul << pkeyshift(3)); + default_iamr &= ~(0x1ul << pkeyshift(3)); + default_uamor &= ~(0x3ul << pkeyshift(3)); + + /* * Prevent the usage of OS reserved keys. Update UAMOR * for those keys. Also mark the rest of the bits in the |