linux/arch/arc/kernel
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
..
.gitignore
Makefile
arc_hostlink.c
arcksyms.c
asm-offsets.c
clk.c
ctx_sw.c
ctx_sw_asm.S
devtree.c
disasm.c
entry.S ARC: !PREEMPT: Ensure Return to kernel mode is IRQ safe 2014-04-30 08:21:43 -07:00
fpu.c
head.S ARC: [SMP] General Fixes 2014-04-05 14:46:42 +05:30
irq.c
kgdb.c
kprobes.c
module.c
perf_event.c
process.c
ptrace.c
reset.c
setup.c
signal.c
smp.c
stacktrace.c
sys.c
time.c ARC: [clockevent] simplify timer ISR 2014-03-26 14:31:30 +05:30
traps.c
troubleshoot.c
unaligned.c
unwind.c
vmlinux.lds.S