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author | Vineet Gupta <Vineet.Gupta1@synopsys.com> | 2014-04-30 15:26:45 +0530 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2014-04-30 08:21:43 -0700 |
commit | 8aa9e85adac609588eeec356e5a85059b3b819ba (patch) | |
tree | 446070ce57b0657a1236ea393c9bc301f9f5b5e8 /MAINTAINERS | |
parent | 71dc96e39d0a81854303dd498b4eafa7d1d90f81 (diff) | |
download | op-kernel-dev-8aa9e85adac609588eeec356e5a85059b3b819ba.zip op-kernel-dev-8aa9e85adac609588eeec356e5a85059b3b819ba.tar.gz |
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>
Diffstat (limited to 'MAINTAINERS')
0 files changed, 0 insertions, 0 deletions