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From: Peter Zijlstra <peterz@infradead.org>
To: Torvald Riegel <triegel@redhat.com>
Cc: paulmck@linux.vnet.ibm.com,
	Linus Torvalds <torvalds@linux-foundation.org>,
	Alec Teal <a.teal@warwick.ac.uk>,
	Will Deacon <will.deacon@arm.com>,
	Ramana Radhakrishnan <Ramana.Radhakrishnan@arm.com>,
	David Howells <dhowells@redhat.com>,
	"linux-arch@vger.kernel.org" <linux-arch@vger.kernel.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"akpm@linux-foundation.org" <akpm@linux-foundation.org>,
	"mingo@kernel.org" <mingo@kernel.org>,
	"gcc@gcc.gnu.org" <gcc@gcc.gnu.org>
Subject: Re: [RFC][PATCH 0/5] arch: atomic rework
Date: Tue, 18 Feb 2014 22:52:56 +0100	[thread overview]
Message-ID: <20140218215256.GW14089@laptop.programming.kicks-ass.net> (raw)
In-Reply-To: <1392759615.18779.8429.camel@triegel.csb>

> > 4.	Some drivers allow user-mode code to mmap() some of their
> > 	state.  Any changes undertaken by the user-mode code would
> > 	be invisible to the compiler.
> 
> A good point, but a compiler that doesn't try to (incorrectly) assume
> something about the semantics of mmap will simply see that the mmap'ed
> data will escape to stuff if can't analyze, so it will not be able to
> make a proof.
> 
> This is different from, for example, malloc(), which is guaranteed to
> return "fresh" nonaliasing memory.

The kernel side of this is different.. it looks like 'normal' memory, we
just happen to allow it to end up in userspace too.

But on that point; how do you tell the compiler the difference between
malloc() and mmap()? Is that some function attribute?

  reply	other threads:[~2014-02-18 21:53 UTC|newest]

Thread overview: 299+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-02-06 13:48 Peter Zijlstra
2014-02-06 13:48 ` [RFC][PATCH 1/5] ia64: Fix up smp_mb__{before,after}_clear_bit Peter Zijlstra
2014-02-06 13:48 ` [RFC][PATCH 2/5] arc,hexagon: Delete asm/barrier.h Peter Zijlstra
2014-02-06 13:48 ` [RFC][PATCH 3/5] arch: s/smp_mb__(before|after)_(atomic|clear)_(dec,inc,bit)/smp_mb__\1/g Peter Zijlstra
2014-02-06 19:12   ` Paul E. McKenney
2014-02-07  9:52     ` Will Deacon
2014-02-06 13:48 ` [RFC][PATCH 4/5] arch: Generic atomic.h cleanup Peter Zijlstra
2014-02-06 17:49   ` Will Deacon
2014-02-06 13:48 ` [RFC][PATCH 5/5] arch: Sanitize atomic_t bitwise ops Peter Zijlstra
2014-02-06 14:43   ` Geert Uytterhoeven
2014-02-06 16:14     ` Peter Zijlstra
2014-02-06 16:53   ` Linus Torvalds
2014-02-06 17:52     ` Peter Zijlstra
2014-02-06 17:56       ` Linus Torvalds
2014-02-06 18:09         ` Peter Zijlstra
2014-02-06 18:25 ` [RFC][PATCH 0/5] arch: atomic rework David Howells
2014-02-06 18:30   ` Peter Zijlstra
2014-02-06 18:42   ` Paul E. McKenney
2014-02-06 18:55   ` Ramana Radhakrishnan
2014-02-06 18:59     ` Will Deacon
2014-02-06 19:27       ` Paul E. McKenney
2014-02-06 21:17         ` Torvald Riegel
2014-02-06 22:11           ` Paul E. McKenney
2014-02-06 23:44             ` Torvald Riegel
2014-02-07  4:20               ` Paul E. McKenney
2014-02-07  7:44                 ` Peter Zijlstra
2014-02-07 16:50                   ` Paul E. McKenney
2014-02-07 16:55                     ` Will Deacon
2014-02-07 17:06                       ` Peter Zijlstra
2014-02-07 17:13                         ` Will Deacon
2014-02-07 17:20                           ` Peter Zijlstra
2014-02-07 18:03                           ` Paul E. McKenney
2014-02-07 17:46                         ` Joseph S. Myers
2014-02-07 18:43                         ` Torvald Riegel
2014-02-07 18:02                       ` Paul E. McKenney
2014-02-10  0:27                         ` Torvald Riegel
2014-02-10  0:56                           ` Linus Torvalds
2014-02-10  1:16                             ` Torvald Riegel
2014-02-10  1:24                               ` Linus Torvalds
2014-02-10  1:46                                 ` Torvald Riegel
2014-02-10  2:04                                   ` Linus Torvalds
2014-02-10  3:21                           ` Paul E. McKenney
2014-02-10  3:45                           ` Paul E. McKenney
2014-02-10 11:46                           ` Peter Zijlstra
2014-02-10 19:09                           ` Linus Torvalds
2014-02-11 15:59                             ` Paul E. McKenney
2014-02-12  6:06                               ` Torvald Riegel
2014-02-12  9:19                                 ` Peter Zijlstra
2014-02-12 17:42                                   ` Paul E. McKenney
2014-02-12 18:12                                     ` Peter Zijlstra
2014-02-17 18:18                                       ` Paul E. McKenney
2014-02-17 20:39                                         ` Richard Biener
2014-02-17 22:14                                           ` Paul E. McKenney
2014-02-17 22:27                                             ` Torvald Riegel
2014-02-14  5:07                                   ` Torvald Riegel
2014-02-14  9:50                                     ` Peter Zijlstra
2014-02-14 19:19                                       ` Torvald Riegel
2014-02-12 17:39                                 ` Paul E. McKenney
2014-02-12  5:39                             ` Torvald Riegel
2014-02-12 18:07                               ` Paul E. McKenney
2014-02-12 20:22                                 ` Linus Torvalds
2014-02-13  0:23                                   ` Paul E. McKenney
2014-02-13 20:03                                     ` Torvald Riegel
2014-02-14  2:01                                       ` Paul E. McKenney
2014-02-14  4:43                                         ` Torvald Riegel
2014-02-14 17:29                                           ` Paul E. McKenney
2014-02-14 19:21                                             ` Torvald Riegel
2014-02-14 19:50                                             ` Linus Torvalds
2014-02-14 20:02                                               ` Linus Torvalds
2014-02-15  2:08                                                 ` Paul E. McKenney
2014-02-15  2:44                                                   ` Linus Torvalds
2014-02-15  2:48                                                     ` Linus Torvalds
2014-02-15  6:35                                                       ` Paul E. McKenney
2014-02-15  6:58                                                         ` Paul E. McKenney
2014-02-15 18:07                                                     ` Torvald Riegel
2014-02-17 18:59                                                       ` Joseph S. Myers
2014-02-17 19:19                                                         ` Will Deacon
2014-02-17 19:41                                                         ` Torvald Riegel
2014-02-17 23:12                                                           ` Joseph S. Myers
2014-02-15 17:45                                                 ` Torvald Riegel
2014-02-15 18:49                                                   ` Linus Torvalds
2014-02-17 19:55                                                     ` Torvald Riegel
2014-02-17 20:18                                                       ` Linus Torvalds
2014-02-17 21:21                                                         ` Torvald Riegel
2014-02-17 22:02                                                           ` Linus Torvalds
2014-02-17 22:25                                                             ` Torvald Riegel
2014-02-17 22:47                                                               ` Linus Torvalds
2014-02-17 23:41                                                                 ` Torvald Riegel
2014-02-18  0:18                                                                   ` Linus Torvalds
2014-02-18  1:26                                                                     ` Paul E. McKenney
2014-02-18 15:38                                                                     ` Torvald Riegel
2014-02-18 16:55                                                                       ` Paul E. McKenney
2014-02-18 19:57                                                                         ` Torvald Riegel
2014-02-17 23:10                                                         ` Alec Teal
2014-02-18  0:05                                                           ` Linus Torvalds
2014-02-18 15:31                                                             ` Torvald Riegel
2014-02-18 16:49                                                               ` Linus Torvalds
2014-02-18 17:16                                                                 ` Paul E. McKenney
2014-02-18 18:23                                                                   ` Peter Sewell
2014-02-18 19:00                                                                     ` Linus Torvalds
2014-02-18 19:42                                                                     ` Paul E. McKenney
2014-02-18 21:40                                                                   ` Torvald Riegel
2014-02-18 21:52                                                                     ` Peter Zijlstra [this message]
2014-02-19  9:52                                                                       ` Torvald Riegel
2014-02-18 22:58                                                                     ` Paul E. McKenney
2014-02-19 10:59                                                                       ` Torvald Riegel
2014-02-19 15:14                                                                         ` Paul E. McKenney
2014-02-19 17:55                                                                           ` Torvald Riegel
2014-02-19 22:12                                                                             ` Paul E. McKenney
2014-02-18 21:21                                                                 ` Torvald Riegel
2014-02-18 21:40                                                                   ` Peter Zijlstra
2014-02-18 21:47                                                                     ` Torvald Riegel
2014-02-19 15:23                                                                       ` David Lang
2014-02-19 18:11                                                                         ` Torvald Riegel
2014-02-18 21:47                                                                   ` Peter Zijlstra
2014-02-19 11:07                                                                     ` Torvald Riegel
2014-02-19 11:42                                                                       ` Peter Zijlstra
2014-02-18 22:14                                                                   ` Linus Torvalds
2014-02-19 14:40                                                                     ` Torvald Riegel
2014-02-19 19:49                                                                       ` Linus Torvalds
2014-02-18  3:00                                                         ` Paul E. McKenney
2014-02-18  3:24                                                           ` Linus Torvalds
2014-02-18  3:42                                                             ` Linus Torvalds
2014-02-18  5:22                                                               ` Paul E. McKenney
2014-02-18 16:17                                                               ` Torvald Riegel
2014-02-18 17:44                                                                 ` Linus Torvalds
2014-02-18 19:40                                                                   ` Paul E. McKenney
2014-02-18 19:47                                                                   ` Torvald Riegel
2014-02-20  0:53                                                                     ` Linus Torvalds
2014-02-20  4:01                                                                       ` Paul E. McKenney
2014-02-20  4:43                                                                         ` Linus Torvalds
2014-02-20  8:30                                                                           ` Paul E. McKenney
2014-02-20  9:20                                                                             ` Paul E. McKenney
2014-02-20 17:01                                                                             ` Linus Torvalds
2014-02-20 18:11                                                                               ` Paul E. McKenney
2014-02-20 18:32                                                                                 ` Linus Torvalds
2014-02-20 18:53                                                                                   ` Torvald Riegel
2014-02-20 19:09                                                                                     ` Linus Torvalds
2014-02-22 18:53                                                                                       ` Torvald Riegel
2014-02-22 21:53                                                                                         ` Linus Torvalds
2014-02-23  0:39                                                                                           ` Paul E. McKenney
2014-02-23  3:50                                                                                             ` Linus Torvalds
2014-02-23  6:34                                                                                               ` Paul E. McKenney
2014-02-23 19:31                                                                                                 ` Linus Torvalds
2014-02-24  1:16                                                                                                   ` Paul E. McKenney
2014-02-24  1:35                                                                                                     ` Linus Torvalds
2014-02-24  4:59                                                                                                       ` Paul E. McKenney
2014-02-24  5:25                                                                                                         ` Linus Torvalds
2014-02-24 15:57                                                                                                   ` Linus Torvalds
2014-02-24 16:27                                                                                                     ` Richard Biener
2014-02-24 16:37                                                                                                       ` Linus Torvalds
2014-02-24 16:40                                                                                                         ` Linus Torvalds
2014-02-24 16:55                                                                                                         ` Michael Matz
2014-02-24 17:28                                                                                                           ` Paul E. McKenney
2014-02-24 17:57                                                                                                             ` Paul E. McKenney
2014-02-26 17:39                                                                                                             ` Torvald Riegel
2014-02-24 17:38                                                                                                           ` Linus Torvalds
2014-02-24 18:12                                                                                                             ` Paul E. McKenney
2014-02-26 17:34                                                                                                             ` Torvald Riegel
2014-02-24 17:21                                                                                                     ` Paul E. McKenney
2014-02-24 18:14                                                                                                       ` Linus Torvalds
2014-02-24 18:53                                                                                                         ` Paul E. McKenney
2014-02-24 19:54                                                                                                           ` Linus Torvalds
2014-02-24 22:37                                                                                                             ` Paul E. McKenney
2014-02-24 23:35                                                                                                               ` Linus Torvalds
2014-02-25  6:00                                                                                                                 ` Paul E. McKenney
2014-02-26  1:47                                                                                                                   ` Linus Torvalds
2014-02-26  5:12                                                                                                                     ` Paul E. McKenney
2014-02-25  6:05                                                                                                                 ` Linus Torvalds
2014-02-26  0:15                                                                                                                   ` Paul E. McKenney
2014-02-26  3:32                                                                                                                     ` Jeff Law
2014-02-26  5:23                                                                                                                       ` Paul E. McKenney
2014-02-27 15:37                                                                                                             ` Torvald Riegel
2014-02-27 17:01                                                                                                               ` Linus Torvalds
2014-02-27 19:06                                                                                                                 ` Paul E. McKenney
2014-02-27 19:47                                                                                                                   ` Linus Torvalds
2014-02-27 20:53                                                                                                                     ` Paul E. McKenney
2014-03-01  0:50                                                                                                                       ` Paul E. McKenney
2014-03-01 10:06                                                                                                                         ` Peter Sewell
2014-03-01 14:03                                                                                                                           ` Paul E. McKenney
2014-03-02 10:05                                                                                                                             ` Peter Sewell
2014-03-02 23:20                                                                                                                               ` Paul E. McKenney
2014-03-02 23:44                                                                                                                                 ` Peter Sewell
2014-03-03  4:25                                                                                                                                   ` Paul E. McKenney
2014-03-03 20:44                                                                                                                               ` Torvald Riegel
2014-03-04 22:11                                                                                                                                 ` Peter Sewell
2014-03-05 17:15                                                                                                                                   ` Torvald Riegel
2014-03-05 18:37                                                                                                                                     ` Peter Sewell
2014-03-03 18:55                                                                                                                         ` Torvald Riegel
2014-03-03 19:20                                                                                                                           ` Paul E. McKenney
2014-03-03 20:46                                                                                                                             ` Torvald Riegel
2014-03-04 19:00                                                                                                                               ` Paul E. McKenney
2014-03-04 21:35                                                                                                                                 ` Paul E. McKenney
2014-03-05 16:54                                                                                                                                   ` Torvald Riegel
2014-03-05 18:15                                                                                                                                     ` Paul E. McKenney
2014-03-07 18:33                                                                                                                                       ` Torvald Riegel
2014-03-07 19:11                                                                                                                                         ` Paul E. McKenney
2014-03-05 16:26                                                                                                                                 ` Torvald Riegel
2014-03-05 18:01                                                                                                                                   ` Paul E. McKenney
2014-03-07 17:45                                                                                                                                     ` Torvald Riegel
2014-03-07 19:02                                                                                                                                       ` Paul E. McKenney
2014-03-03 18:59                                                                                                                     ` Torvald Riegel
2014-03-03 15:36                                                                                                                 ` Torvald Riegel
2014-02-27 17:50                                                                                                               ` Paul E. McKenney
2014-02-27 19:22                                                                                                                 ` Paul E. McKenney
2014-02-28  1:02                                                                                                                 ` Paul E. McKenney
2014-03-03 19:01                                                                                                                 ` Torvald Riegel
2014-02-20 18:56                                                                                   ` Paul E. McKenney
2014-02-20 19:45                                                                                     ` Linus Torvalds
2014-02-20 22:10                                                                                       ` Paul E. McKenney
2014-02-20 22:52                                                                                         ` Linus Torvalds
2014-02-21 18:35                                                                                           ` Michael Matz
2014-02-21 19:13                                                                                             ` Paul E. McKenney
2014-02-21 22:10                                                                                               ` Joseph S. Myers
2014-02-21 22:37                                                                                                 ` Paul E. McKenney
2014-02-26 13:09                                                                                                 ` Torvald Riegel
2014-02-26 18:43                                                                                                   ` Joseph S. Myers
2014-02-27  0:52                                                                                                     ` Torvald Riegel
2014-02-24 13:55                                                                                               ` Michael Matz
2014-02-24 17:40                                                                                                 ` Paul E. McKenney
2014-02-26 13:04                                                                                               ` Torvald Riegel
2014-02-26 18:27                                                                                                 ` Paul E. McKenney
2014-02-20 18:44                                                                                 ` Torvald Riegel
2014-02-20 18:56                                                                                   ` Paul E. McKenney
2014-02-20 18:23                                                                               ` Torvald Riegel
     [not found]                                                                               ` <CAHWkzRQZ8+gOGMFNyTKjFNzpUv6d_J1G9KL0x_iCa=YCgvEojQ@mail.gmail.com>
2014-02-21 19:16                                                                                 ` Linus Torvalds
2014-02-21 19:41                                                                                   ` Linus Torvalds
2014-02-21 19:48                                                                                     ` Peter Sewell
     [not found]                                                                                   ` <CAHWkzRSO82jU-9dtTEjHaW2FeLcEqdZXxp5Q8cmVTTT9uhZQYw@mail.gmail.com>
2014-02-21 20:22                                                                                     ` Linus Torvalds
     [not found]                                                                                 ` <CAHWkzRRxqhH+DnuQHu9bM4ywGBen3oqtT8W4Xqt1CFAHy2WQRg@mail.gmail.com>
2014-02-21 19:24                                                                                   ` Paul E. McKenney
2014-02-20 17:54                                                                             ` Torvald Riegel
2014-02-20 18:11                                                                               ` Paul E. McKenney
2014-02-20 17:49                                                                           ` Torvald Riegel
2014-02-20 18:25                                                                             ` Linus Torvalds
2014-02-20 19:02                                                                               ` Linus Torvalds
2014-02-20 19:06                                                                                 ` Linus Torvalds
2014-02-20 17:26                                                                         ` Torvald Riegel
2014-02-20 18:18                                                                           ` Paul E. McKenney
2014-02-22 18:30                                                                             ` Torvald Riegel
2014-02-22 20:17                                                                               ` Paul E. McKenney
2014-02-20 17:14                                                                       ` Torvald Riegel
2014-02-20 17:34                                                                         ` Linus Torvalds
2014-02-20 18:12                                                                           ` Torvald Riegel
2014-02-20 18:26                                                                           ` Paul E. McKenney
2014-02-18  5:01                                                             ` Paul E. McKenney
2014-02-18 15:56                                                           ` Torvald Riegel
2014-02-18 16:51                                                             ` Paul E. McKenney
2014-02-17 20:23                                                       ` Paul E. McKenney
2014-02-17 21:05                                                         ` Torvald Riegel
2014-02-15 17:30                                               ` Torvald Riegel
2014-02-15 19:15                                                 ` Linus Torvalds
2014-02-17 22:09                                                   ` Torvald Riegel
2014-02-17 22:32                                                     ` Linus Torvalds
2014-02-17 23:17                                                       ` Torvald Riegel
2014-02-18  0:09                                                         ` Linus Torvalds
2014-02-18 15:46                                                           ` Torvald Riegel
2014-02-10 11:48                         ` Peter Zijlstra
2014-02-10 11:49                           ` Will Deacon
2014-02-10 12:05                             ` Peter Zijlstra
2014-02-10 15:04                             ` Paul E. McKenney
2014-02-10 16:22                               ` Will Deacon
2014-02-07 18:44                     ` Torvald Riegel
2014-02-10  0:06                 ` Torvald Riegel
2014-02-10  3:51                   ` Paul E. McKenney
2014-02-12  5:13                     ` Torvald Riegel
2014-02-12 18:26                       ` Paul E. McKenney
2014-02-06 21:09       ` Torvald Riegel
2014-02-06 21:55         ` Paul E. McKenney
2014-02-06 22:58           ` Torvald Riegel
2014-02-07  4:06             ` Paul E. McKenney
2014-02-07  9:13               ` Torvald Riegel
2014-02-07 16:44                 ` Paul E. McKenney
2014-02-06 22:13         ` Joseph S. Myers
2014-02-06 23:25           ` Torvald Riegel
2014-02-06 23:33             ` Joseph S. Myers
2014-02-07 12:01         ` Will Deacon
2014-02-07 16:47           ` Paul E. McKenney
2014-02-06 19:21   ` Linus Torvalds
     [not found] ` <52F93B7C.2090304@tilera.com>
     [not found]   ` <20140210205719.GY5002@laptop.programming.kicks-ass.net>
2014-02-10 21:08     ` Chris Metcalf
2014-02-10 21:14       ` Peter Zijlstra
2014-02-18 12:12 Peter Sewell
2014-02-18 12:53 ` Peter Zijlstra
2014-02-18 16:08   ` Peter Sewell
2014-02-18 14:56 ` Paul E. McKenney
2014-02-18 15:16   ` Mark Batty
2014-02-18 17:17     ` Paul E. McKenney
2014-02-18 15:33   ` Peter Sewell
2014-02-18 16:47     ` Paul E. McKenney
2014-02-18 17:38 ` Linus Torvalds
2014-02-18 18:21   ` Peter Sewell
2014-02-18 18:49     ` Linus Torvalds
2014-02-18 19:47       ` Paul E. McKenney
2014-02-18 20:46     ` Torvald Riegel
2014-02-18 20:43 ` Torvald Riegel
2014-02-18 21:29   ` Paul E. McKenney
2014-02-18 23:48   ` Peter Sewell
2014-02-19  9:46     ` Torvald Riegel
2014-02-26  3:06 George Spelvin
2014-02-26  5:22 ` Paul E. McKenney

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