Re: [PATCH v3 3/3] sched, x86: Check that we're on the right stack in schedule and __might_sleep

[Andy Lutomirski]

On Wed, Nov 19, 2014 at 10:40 AM, Linus Torvalds
<torvalds@xxxxxxxxxxxxxxxxxxxx> wrote:
> On Tue, Nov 18, 2014 at 3:15 PM, Andy Lutomirski <luto@xxxxxxxxxxxxxx> wrote:
>> On x86, sleeping while on an IST or irq stack has a surprisingly
>> good chance of working, but it can also fail dramatically.  Add an
>> arch hook to allow schedule and __might_sleep to catch sleeping on
>> the wrong stack.
>
> Why doesn't the normal in_interrupt() test catch this?

It catches scheduling on an irq stack, assuming that all of the
irq_count stuff is working correctly.  I don't think it catches
sleeping on an IST stack.

--Andy

>
>           Linus



-- 
Andy Lutomirski
AMA Capital Management, LLC
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