[PATCH 0/5] arm: Early IRQ enabling in the Undef user handler

[Arun KS]

On Thu, Mar 13, 2014 at 11:45 PM, Catalin Marinas
<catalin.marinas at arm.com> wrote:
> Hi Russell,
>
> I've had this series in my repo for a long time with some follow-ups on
> the list but without any conclusive ACK or NAK. If there are no
> objections, I plan to send it to the patch system.
>
> The only change is rebasing to 3.14-rc6 and adding some Cc for the
> crunch bits.
>
> The __und_usr handler accesses the user space to read the opcode of the
> faulting instruction. This is currently done with interrupts disabled
> but it could potentially cause a data abort of the page table was
> modified from another CPU. The data abort with interrupts disabled
> triggers a might_sleep() warning in do_page_fault() or, worse, deadlock
> on the pte lock when TLB ops broadcasting is enabled (ARM11MPCore or A15
> together with workaround for erratum 798181).
>
> Catalin Marinas (5):
>   arm: Move asm macro get_thread_info to asm/assembler.h
>   arm: Add {inc,dec}_preempt_count asm macros
>   arm: Disable preemption in iwmmxt_task_enable()
>   arm: Disable preemption in crunch_task_enable()
>   arm: Enable IRQs before attempting to read user space in __und_usr
>
>  arch/arm/include/asm/assembler.h   | 42 ++++++++++++++++++++++++++++++++++++++
>  arch/arm/kernel/entry-armv.S       | 11 ++++++----
>  arch/arm/kernel/entry-header.S     | 11 ----------
>  arch/arm/kernel/iwmmxt.S           | 15 ++++++++++----
>  arch/arm/mach-ep93xx/crunch-bits.S | 13 +++++++++---
>  arch/arm/vfp/entry.S               | 28 ++++++++-----------------
>  arch/arm/vfp/vfphw.S               | 19 ++++++-----------
>  7 files changed, 84 insertions(+), 55 deletions(-)

Tested-by: Arun KS<getarunks at gmail.com>

Thanks,
Arun
>
>
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