linux/arch/powerpc
Michael Neuling cf13435b73 powerpc/tm: Fix userspace r13 corruption
When we treclaim we store the userspace checkpointed r13 to a scratch
SPR and then later save the scratch SPR to the user thread struct.

Unfortunately, this doesn't work as accessing the user thread struct
can take an SLB fault and the SLB fault handler will write the same
scratch SPRG that now contains the userspace r13.

To fix this, we store r13 to the kernel stack (which can't fault)
before we access the user thread struct.

Found by running P8 guest + powervm + disable_1tb_segments + TM. Seen
as a random userspace segfault with r13 looking like a kernel address.

Signed-off-by: Michael Neuling <mikey@neuling.org>
Reviewed-by: Breno Leitao <leitao@debian.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-09-25 22:51:08 +10:00
..
boot powerpc updates for 4.19 2018-08-17 11:32:50 -07:00
configs powerpc updates for 4.19 2018-08-17 11:32:50 -07:00
crypto powerpc updates for 4.19 2018-08-17 11:32:50 -07:00
include powerpc: Avoid code patching freed init sections 2018-09-18 22:42:54 +10:00
kernel powerpc/tm: Fix userspace r13 corruption 2018-09-25 22:51:08 +10:00
kvm PPC KVM fixes for 4.19 2018-09-04 21:12:46 +02:00
lib powerpc: fix csum_ipv6_magic() on little endian platforms 2018-09-20 21:12:28 +10:00
math-emu License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
mm powerpc/pseries: Fix unitialized timer reset on migration 2018-09-24 21:05:38 +10:00
net powerpc updates for 4.19 2018-08-17 11:32:50 -07:00
oprofile treewide: kzalloc() -> kcalloc() 2018-06-12 16:19:22 -07:00
perf powerpc updates for 4.19 2018-08-17 11:32:50 -07:00
platforms powerpc/powernv/ioda2: Reduce upper limit for DMA window size (again) 2018-09-20 14:31:03 +10:00
purgatory powerpc updates for 4.19 2018-08-17 11:32:50 -07:00
sysdev treewide: correct "differenciate" and "instanciate" typos 2018-08-23 18:48:43 -07:00
tools powerpc: Add a checkpatch wrapper with our preferred settings 2018-08-07 21:49:25 +10:00
xmon Merge branch 'fixes' into next 2018-08-13 15:59:06 +10:00
Kconfig powerpc: disable support for relative ksymtab references 2018-08-29 16:12:07 -07:00
Kconfig.debug Kconfig: consolidate the "Kernel hacking" menu 2018-08-02 08:06:48 +09:00
Makefile kbuild: rename LDFLAGS to KBUILD_LDFLAGS 2018-08-24 08:22:08 +09:00
Makefile.postlink License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00