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From: Jeff Law <law@redhat.com>
To: Richard Guenther <richard.guenther@gmail.com>
Cc: Andi Kleen <andi@firstfloor.org>,
	Andreas Schwab <schwab@linux-m68k.org>, Jim <jim876@xs4all.nl>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	gcc@gcc.gnu.org
Subject: Re: gcc 4.5.1 / as 2.20.51.0.11 miscompiling drivers/char/i8k.c ?
Date: Mon, 15 Nov 2010 21:10:49 -0700	[thread overview]
Message-ID: <4CE20449.4050403@redhat.com> (raw)
In-Reply-To: <AANLkTi=piiT5MCWYvw+4wQPx=e8uVrQmY0Lw+=mnabK_@mail.gmail.com>

On 11/15/10 16:07, Richard Guenther wrote:
>>
>> If the address of the auto isn't taken, then why is the object in memory to
>> begin with (with the obvious exception for aggregates).
> Exactly sort of my point.  If people pass the address of&x to an asm
> and modify&x + 8 expecting the "adjacent" stack location to be changed
> I want to tell them that's not a supported way to get to another stack
> variable (even if they clobber "memory").  Or consider the C-decl guy
> who wants to access adjacent parameters by address arithmetic on
> the address of the first param ...
Well, in that case, I think we can easily say that the programmer has 
gone off the deep end and has entered the realm of undefined behavior.

Presumably we rooted out all relevant instances of the latter over the 
last 20 years...  It was fairly common in the past, but I doubt anyone 
worth caring about is still writing code assuming they can take the 
address of parameter A, offset it and get parameters B, C, D, etc.

jeff

  reply	other threads:[~2010-11-16  4:11 UTC|newest]

Thread overview: 129+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-11-06 11:15 gcc 4.5.1 / as 2.20.51.0.11 miscompiling drivers/char/i8k.c ? Jim
2010-11-07 21:31 ` Andi Kleen
2010-11-07 22:41   ` Andreas Schwab
2010-11-07 23:03     ` Andi Kleen
2010-11-08 10:49       ` Richard Guenther
2010-11-08 11:20         ` Andi Kleen
2010-11-08 11:20           ` Richard Guenther
2010-11-08 11:47             ` Paul Koning
2010-11-08 11:53               ` Jakub Jelinek
2010-11-08 12:20           ` Michael Matz
2010-11-08 18:39           ` Dave Korn
2010-11-09 13:00             ` Michael Matz
2010-11-09 13:48               ` Andi Kleen
2010-11-09 13:57                 ` Andreas Schwab
2010-11-09 16:43                   ` Jim
2010-11-13 11:13                     ` [PATCH] i8k: Tell gcc that *regs gets clobbered Jim Bos
2010-11-15  0:52                     ` gcc 4.5.1 / as 2.20.51.0.11 miscompiling drivers/char/i8k.c ? James Cloos
2010-11-15  3:21                       ` Linus Torvalds
2010-11-15  8:56                         ` Jakub Jelinek
2010-11-15  9:12                           ` Andi Kleen
2010-11-15  9:20                           ` Jakub Jelinek
2010-11-15 10:03                           ` Jakub Jelinek
2010-11-15 10:54                             ` Andi Kleen
2010-11-15 11:16                               ` Jakub Jelinek
2010-11-15 11:37                                 ` Andi Kleen
2010-11-15 17:36                                   ` Jim Bos
2010-11-15 17:44                                     ` Jakub Jelinek
2010-11-15 18:17                                       ` Jim Bos
2010-11-15 18:26                                         ` Jakub Jelinek
2010-11-15 19:10                                           ` Jim Bos
2010-11-15 16:04                                 ` Linus Torvalds
2010-11-15 17:40                                   ` Jim Bos
2010-11-15 18:08                                     ` Linus Torvalds
2010-11-15 18:30                                       ` Jim Bos
2010-11-15 18:37                                         ` Jim Bos
2010-11-15 18:56                                         ` Linus Torvalds
2010-11-15 18:58                                         ` Jakub Jelinek
2010-11-15 19:12                                           ` Jakub Jelinek
2010-11-15 19:21                                             ` Linus Torvalds
2010-11-15 19:51                                               ` Jakub Jelinek
2010-11-15 20:22                                                 ` Jim Bos
2011-06-03 13:05                                                   ` 2.6.39.1 immediately reboots/resets on EFI system Jim Bos
2011-06-03 13:33                                                     ` Matthew Garrett
2011-06-03 14:26                                                       ` Jim Bos
2011-06-03 14:46                                                         ` Matthew Garrett
2011-06-05 10:40                                                           ` Jim Bos
2011-06-05 12:57                                                             ` Maarten Lankhorst
2011-06-06 15:01                                                           ` Maarten Lankhorst
2011-06-06 15:40                                                             ` Jim Bos
2011-06-06 15:44                                                             ` Matthew Garrett
2011-06-06 15:27                                                         ` Maarten Lankhorst
2011-06-06 16:11                                                           ` Jim Bos
2011-06-06 16:43                                                             ` Maarten Lankhorst
2011-06-07  0:19                                                               ` Yinghai Lu
2011-06-07  1:41                                                                 ` Matthew Garrett
2011-06-07  2:05                                                                   ` Yinghai Lu
2011-06-07  8:25                                                                     ` Maarten Lankhorst
2011-06-07 15:14                                                                       ` Yinghai Lu
2011-06-07  9:08                                                                     ` Maarten Lankhorst
2011-06-07 12:22                                                                       ` Maarten Lankhorst
2011-06-07 22:25                                                                         ` Yinghai Lu
2011-06-08 16:44                                                                           ` Jim Bos
2011-06-08 19:17                                                                             ` Yinghai Lu
2011-06-08 19:23                                                                               ` Matthew Garrett
2011-06-08 19:27                                                                                 ` Yinghai Lu
2011-06-08 19:29                                                                                   ` Matthew Garrett
2011-06-08 19:35                                                                                     ` Yinghai Lu
2011-06-08 19:38                                                                                       ` Matthew Garrett
2011-06-08 19:46                                                                                         ` Yinghai Lu
2011-06-08 19:52                                                                                           ` Matthew Garrett
2011-06-08 19:48                                                                                         ` Yinghai Lu
2011-06-08 19:52                                                                                           ` Matthew Garrett
2011-06-08 20:03                                                                                             ` Yinghai Lu
2011-06-08 20:09                                                                                               ` Matthew Garrett
2011-06-08 20:23                                                                                                 ` Yinghai Lu
2011-06-08 20:30                                                                                                   ` Matthew Garrett
2011-06-08 20:36                                                                                                     ` Yinghai Lu
2011-06-08 20:42                                                                                                       ` Matthew Garrett
2011-06-08 20:46                                                                                                         ` Yinghai Lu
2011-06-08 21:06                                                                                                           ` Matthew Garrett
2011-06-08 21:06                                                                                                         ` Linus Torvalds
2011-06-08 21:28                                                                                                           ` Matthew Garrett
2011-06-08 21:31                                                                                                             ` H. Peter Anvin
2011-06-08 21:36                                                                                                               ` Matthew Garrett
2011-06-08 21:31                                                                                                             ` Linus Torvalds
2011-06-08 21:42                                                                                                               ` Matthew Garrett
2011-06-08 21:51                                                                                                               ` H. Peter Anvin
2011-06-08 22:57                                                                                                                 ` Linus Torvalds
2011-06-08 23:54                                                                                                                   ` Maarten Lankhorst
2011-06-08 21:38                                                                                                             ` Yinghai Lu
2011-06-10 16:47                                                                       ` Matthew Garrett
2011-06-10 17:51                                                                         ` Maarten Lankhorst
2011-06-10 17:54                                                                           ` Matthew Garrett
2011-06-10 22:45                                                                             ` Maarten Lankhorst
2011-06-10 22:58                                                                               ` Yinghai Lu
2011-06-10 23:03                                                                                 ` Matthew Garrett
2011-06-10 23:17                                                                                   ` Greg KH
2011-06-10 23:22                                                                                     ` Maarten Lankhorst
2011-06-10 23:25                                                                                     ` H. Peter Anvin
2011-06-10 23:26                                                                                   ` Yinghai Lu
2011-06-10 23:32                                                                                     ` H. Peter Anvin
2011-06-10 23:55                                                                                       ` Yinghai Lu
2011-06-11  0:00                                                                                         ` H. Peter Anvin
2011-06-11  0:19                                                                                           ` Yinghai Lu
2011-06-14 18:06                                                                                             ` H. Peter Anvin
2011-06-11 15:29                                                                                     ` Matthew Garrett
2011-06-10 23:00                                                                               ` Yinghai Lu
2011-06-13 16:47                                                                               ` Matthew Garrett
2011-06-13 17:52                                                                                 ` Maarten Lankhorst
2011-06-13 18:00                                                                                   ` Matthew Garrett
2011-06-13 18:14                                                                                     ` Maarten Lankhorst
2011-06-13 18:17                                                                                       ` Matthew Garrett
2011-06-13 18:23                                                                                         ` Maarten Lankhorst
2011-06-13 18:33                                                                                           ` Matthew Garrett
2011-06-13 18:45                                                                                             ` Maarten Lankhorst
2011-06-14 14:34                                                                                             ` Maarten Lankhorst
2011-06-14 14:50                                                                                             ` Maarten Lankhorst
2011-06-14 14:55                                                                                               ` Matthew Garrett
2010-11-15 22:43                                                 ` gcc 4.5.1 / as 2.20.51.0.11 miscompiling drivers/char/i8k.c ? Andi Kleen
2010-11-15 22:46                                                   ` Jakub Jelinek
2010-11-15 19:53                                             ` Richard Henderson
2010-11-15 10:24                           ` Richard Guenther
2010-11-15 18:45         ` Jeff Law
2010-11-15 19:04           ` Linus Torvalds
2010-11-15 22:07           ` Richard Guenther
2010-11-15 22:58             ` Jeff Law
2010-11-15 23:07               ` Richard Guenther
2010-11-16  4:10                 ` Jeff Law [this message]
2010-11-15 18:42     ` Jeff Law

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