linux/arch/powerpc
Valentin Rothberg 39715bf972 powerpc/process: Fix CONFIG_ALIVEC typo in restore_tm_state()
It should be ALTIVEC, not ALIVEC.

Cyril explains: If a thread performs a transaction with altivec and then
gets preempted for whatever reason, this bug may cause the kernel to not
re-enable altivec when that thread runs again. This will result in an
altivec unavailable fault, when that fault happens inside a user
transaction the kernel has no choice but to enable altivec and doom the
transaction.

The result is that transactions using altivec may get aborted more often
than they should.

The difficulty in catching this with a selftest is my deliberate use of
the word may above. Optimisations to avoid FPU/altivec/VSX faults mean
that the kernel will always leave them on for 255 switches. This code
prevents the kernel turning it off if it got to the 256th switch (and
userspace was transactional).

Fixes: dc16b553c9 ("powerpc: Always restore FPU/VEC/VSX if hardware transactional memory in use")
Reviewed-by: Cyril Bur <cyrilbur@gmail.com>
Signed-off-by: Valentin Rothberg <valentinrothberg@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-10-27 21:52:59 +11:00
..
boot powerpc/boot: Fix boot on systems with uncompressed kernel image 2016-10-19 20:35:34 +11:00
configs Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/scottwood/linux into next 2016-10-11 20:07:56 +11:00
crypto Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 2016-10-10 14:04:16 -07:00
include powerpc: Convert cmp to cmpd in idle enter sequence 2016-10-22 08:44:38 +11:00
kernel powerpc/process: Fix CONFIG_ALIVEC typo in restore_tm_state() 2016-10-27 21:52:59 +11:00
kvm KVM: PPC: Book3S HV: Fix build error when SMP=n 2016-10-22 08:44:37 +11:00
lib Merge branch 'kbuild' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild 2016-10-14 14:26:58 -07:00
math-emu
mm powerpc: Fix numa topology console print 2016-10-19 20:35:41 +11:00
net powerpc/bpf: Add support for bpf constant blinding 2016-10-04 20:33:20 +11:00
oprofile powerpc/sparse: Make a bunch of things static 2016-09-13 17:35:47 +10:00
perf powerpc/sparse: Make a bunch of things static 2016-09-13 17:35:47 +10:00
platforms powerpc updates for 4.9 #2 2016-10-14 11:07:42 -07:00
scripts powerpc/ftrace: Add Kconfig & Make glue for mprofile-kernel 2016-03-07 14:53:56 +11:00
sysdev Merge branch 'kbuild' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild 2016-10-14 14:26:58 -07:00
xmon powerpc/xmon: Don't use ld on 32-bit 2016-09-13 17:37:02 +10:00
Kconfig Merge branch 'akpm' (patches from Andrew) 2016-10-07 21:38:00 -07:00
Kconfig.debug powerpc/mm: Catch usage of cpu/mmu_has_feature() before jump label init 2016-08-01 11:15:06 +10:00
Makefile arch/powerpc: Add CONFIG_FSL_DPAA to corenetXX_smp_defconfig 2016-09-25 02:39:01 -05:00
relocs_check.sh powerpc/64: whitelist unresolved modversions CRCs 2016-09-22 14:46:31 +02:00