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Subject: Re: [PATCH 0/9] [v3] x86, pkeys: two protection keys bug fixes
To:     Ingo Molnar <mingo@kernel.org>,
        Dave Hansen <dave.hansen@linux.intel.com>
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From:   Dave Hansen <dave.hansen@intel.com>
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Date:   Mon, 30 Apr 2018 08:30:43 -0700
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On 04/28/2018 12:05 AM, Ingo Molnar wrote:
> In the above kernel that was missing the PROT_EXEC fix I was repeatedly running 
> the 64-bit and 32-bit testcases as non-root and as root as well, until I got a 
> hang in the middle of a 32-bit test running as root:
> 
>   test  7 PASSED (iteration 19)
>   test  8 PASSED (iteration 19)
>   test  9 PASSED (iteration 19)
> 
>   < test just hangs here >

For the hang, there is a known issue with the use of printf() in the
signal handler and a resulting deadlock.  I *thought* there was a patch
merged to fix this from Ram Pai or one of the other IBM folks.