linux/arch/powerpc
Anton Blanchard 178f358208 powerpc: Ignore reserved field in DCSR and PVR reads and writes
IBM bit 31 (for the rest of us - bit 0) is a reserved field in the
instruction definition of mtspr and mfspr. Hardware is encouraged to
(and does) ignore it.

As a result, if userspace executes an mtspr DSCR with the reserved bit
set, we get a DSCR facility unavailable exception. The kernel fails to
match against the expected value/mask, and we silently return to
userspace to try and re-execute the same mtspr DSCR instruction. We
loop forever until the process is killed.

We should do something here, and it seems mirroring what hardware does
is the better option vs killing the process. While here, relax the
matching of mfspr PVR too.

Cc: stable@vger.kernel.org
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-01-20 15:21:35 +11:00
..
boot
configs
crypto
include powerpc: Ignore reserved field in DCSR and PVR reads and writes 2017-01-20 15:21:35 +11:00
kernel powerpc/ptrace: Preserve previous TM fprs/vsrs on short regset write 2017-01-20 14:55:19 +11:00
kvm ktime: Cleanup ktime_set() usage 2016-12-25 17:21:22 +01:00
lib Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
math-emu Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
mm powerpc/mm: Fix little-endian 4K hugetlb 2017-01-18 11:58:50 +11:00
net
oprofile ktime: Cleanup ktime_set() usage 2016-12-25 17:21:22 +01:00
perf powerpc/perf: Use MSR to report privilege level on P9 DD1 2017-01-18 16:15:58 +11:00
platforms Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
purgatory
scripts
sysdev powerpc/icp-opal: Fix missing KVM case and harden replay 2017-01-17 11:50:03 +11:00
xmon
Kconfig
Kconfig.debug
Makefile
relocs_check.sh