linux/arch/arc
Vineet Gupta 8aa9e85ada ARC: !PREEMPT: Ensure Return to kernel mode is IRQ safe
There was a very small race window where resume to kernel mode from a
Exception Path (or pure kernel mode which is true for most of ARC
exceptions anyways), was not disabling interrupts in restore_regs,
clobbering the exception regs

Anton found the culprit call flow (after many sleepless nights)

| 1. we got a Trap from user land
| 2. started to service it.
| 3. While doing some stuff on user-land memory (I think it is padzero()),
|     we got a DataTlbMiss
| 4. On return from it we are taking "resume_kernel_mode" path
| 5. NEED_RESHED is not set, so we go to "return from exception" path in
|     restore regs.
| 6. there seems to be IRQ happening

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Cc: <stable@vger.kernel.org>   #3.10, 3.12, 3.13, 3.14
Cc: Anton Kolesov <Anton.Kolesov@synopsys.com>
Cc: Francois Bedard <Francois.Bedard@synopsys.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-30 08:21:43 -07:00
..
boot ARC: [nsimosci] Unbork console 2014-04-05 18:36:51 +05:30
configs ARC: [nsimosci] Unbork console 2014-04-05 18:36:51 +05:30
include ARC: Delete stale barrier.h 2014-04-18 13:49:15 -07:00
kernel ARC: !PREEMPT: Ensure Return to kernel mode is IRQ safe 2014-04-30 08:21:43 -07:00
lib ARC: switch to generic ENTRY/END assembler annotations 2014-03-26 14:31:28 +05:30
mm ARC: [SMP] General Fixes 2014-04-05 14:46:42 +05:30
oprofile ARC: OProfile support 2013-02-15 23:16:00 +05:30
plat-arcfpga ARC: Remove ARC_HAS_COH_RTSC 2014-03-26 14:31:28 +05:30
plat-tb10x ARC: [TB10x] Updates for GPIO and pinctrl 2013-11-11 09:57:44 +05:30
Kbuild
Kconfig Kconfig: rename HAS_IOPORT to HAS_IOPORT_MAP 2014-04-07 16:36:11 -07:00
Kconfig.debug consolidate per-arch stack overflow debugging options 2013-07-04 11:25:39 -07:00
Makefile ARC: Adjustments for gcc 4.8 2013-06-27 14:35:32 +05:30