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From: Dave Hansen <dave@sr71.net>
To: Mel Gorman <mgorman@techsingularity.net>
Cc: linux-kernel@vger.kernel.org, x86@kernel.org,
	linux-api@vger.kernel.org, linux-arch@vger.kernel.org,
	linux-mm@kvack.org, torvalds@linux-foundation.org,
	akpm@linux-foundation.org, dave.hansen@linux.intel.com,
	arnd@arndb.de, hughd@google.com, viro@zeniv.linux.org.uk
Subject: Re: [PATCH 1/9] x86, pkeys: add fault handling for PF_PK page fault bit
Date: Thu, 7 Jul 2016 08:42:00 -0700	[thread overview]
Message-ID: <577E7848.3060908@sr71.net> (raw)
In-Reply-To: <20160707144027.GX11498@techsingularity.net>

On 07/07/2016 07:40 AM, Mel Gorman wrote:
> On Thu, Jul 07, 2016 at 05:47:20AM -0700, Dave Hansen wrote:
>> From: Dave Hansen <dave.hansen@linux.intel.com>
>> PF_PK means that a memory access violated the protection key
>> access restrictions.  It is unconditionally an access_error()
>> because the permissions set on the VMA don't matter (the PKRU
>> value overrides it), and we never "resolve" PK faults (like
>> how a COW can "resolve write fault).
>>
>> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
> 
> An access fault gets propgated as SEGV_PKUERR. What happens if glibc
> does not recognise it?

It passes it through to the handler without any side-effects.  I don't
think it does anything differently with SEGV_* codes that it knows about
vs. unknown ones.  The only negative side-effect that I can think of is
that it won't have a nice error message for it.

  reply	other threads:[~2016-07-07 15:42 UTC|newest]

Thread overview: 47+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-07-07 12:47 [PATCH 0/9] [REVIEW-REQUEST] [v4] System Calls for Memory Protection Keys Dave Hansen
2016-07-07 12:47 ` [PATCH 1/9] x86, pkeys: add fault handling for PF_PK page fault bit Dave Hansen
2016-07-07 14:40   ` Mel Gorman
2016-07-07 15:42     ` Dave Hansen [this message]
2016-07-07 12:47 ` [PATCH 2/9] mm: implement new pkey_mprotect() system call Dave Hansen
2016-07-07 14:40   ` Mel Gorman
2016-07-07 16:51     ` Dave Hansen
2016-07-08 10:15       ` Mel Gorman
2016-07-07 12:47 ` [PATCH 3/9] x86, pkeys: make mprotect_key() mask off additional vm_flags Dave Hansen
2016-07-07 12:47 ` [PATCH 4/9] x86: wire up mprotect_key() system call Dave Hansen
2016-07-07 12:47 ` [PATCH 5/9] x86, pkeys: allocation/free syscalls Dave Hansen
2016-07-07 14:40   ` Mel Gorman
2016-07-07 15:38     ` Dave Hansen
2016-07-07 12:47 ` [PATCH 6/9] x86, pkeys: add pkey set/get syscalls Dave Hansen
2016-07-07 14:45   ` Mel Gorman
2016-07-07 17:33     ` Dave Hansen
2016-07-08  7:18       ` Ingo Molnar
2016-07-08 16:32         ` Dave Hansen
2016-07-09  8:37           ` Ingo Molnar
2016-07-11  4:25             ` Andy Lutomirski
2016-07-11  7:35               ` Ingo Molnar
2016-07-11 14:28                 ` Dave Hansen
2016-07-12  7:13                   ` Ingo Molnar
2016-07-12 15:39                     ` Dave Hansen
2016-07-11 14:50                 ` Andy Lutomirski
2016-07-11 14:34               ` Dave Hansen
2016-07-11 14:45                 ` Andy Lutomirski
2016-07-11 15:48                   ` Dave Hansen
2016-07-12 16:32                     ` Andy Lutomirski
2016-07-12 17:12                       ` Dave Hansen
2016-07-12 22:55                         ` Andy Lutomirski
2016-07-13  7:56                       ` Ingo Molnar
2016-07-13 18:43                         ` Andy Lutomirski
2016-07-14  8:07                           ` Ingo Molnar
2016-07-18  4:43                             ` Andy Lutomirski
2016-07-18  9:56                               ` Ingo Molnar
2016-07-18 18:02             ` Dave Hansen
2016-07-18 20:12             ` Dave Hansen
2016-07-08 19:26         ` Dave Hansen
2016-07-08 10:22       ` Mel Gorman
2016-07-07 12:47 ` [PATCH 7/9] generic syscalls: wire up memory protection keys syscalls Dave Hansen
2016-07-07 12:47 ` [PATCH 8/9] pkeys: add details of system call use to Documentation/ Dave Hansen
2016-07-07 12:47 ` [PATCH 9/9] x86, pkeys: add self-tests Dave Hansen
2016-07-07 14:47 ` [PATCH 0/9] [REVIEW-REQUEST] [v4] System Calls for Memory Protection Keys Mel Gorman
2016-07-08 18:38 ` Hugh Dickins
  -- strict thread matches above, loose matches on Subject: below --
2016-06-09  0:01 [PATCH 0/9] [v3] " Dave Hansen
2016-06-09  0:01 ` [PATCH 1/9] x86, pkeys: add fault handling for PF_PK page fault bit Dave Hansen
2016-06-07 20:47 [PATCH 0/9] [v2] System Calls for Memory Protection Keys Dave Hansen
2016-06-07 20:47 ` [PATCH 1/9] x86, pkeys: add fault handling for PF_PK page fault bit Dave Hansen

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