From: "H. Peter Anvin" <hpa@zytor.com>
To: Arnd Bergmann <arnd@arndb.de>
Cc: "H.J. Lu" <hjl.tools@gmail.com>,
Linus Torvalds <torvalds@linux-foundation.org>,
"H. Peter Anvin" <hpa@kernel.org>,
linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org,
mingo@kernel.org, tglx@linutronix.de,
Paul Mundt <lethal@linux-sh.org>,
David Howells <dhowells@redhat.com>
Subject: Re: [PATCH 08/10] Use __kernel_ulong_t in struct msqid64_ds
Date: Sat, 19 May 2012 16:47:47 -0700 [thread overview]
Message-ID: <4FB83123.3020402@zytor.com> (raw)
In-Reply-To: <201205182121.02706.arnd@arndb.de>
On 05/18/2012 02:21 PM, Arnd Bergmann wrote:
> On Friday 18 May 2012, H.J. Lu wrote:
>> Since x32 uses the same kernel interface as x86-64 with a few
>> exceptions. The current kernel header files with
>>
>> #ifdef __x86_64__
>> # define __BITS_PER_LONG 64
>> #else
>> # define __BITS_PER_LONG 32
>> #endif
>>
>> #if __BITS_PER_LONG == 64
>> Define x86-64 types
>> #endif
>>
>> work fine for x32 even if long for x32 is 32 bits. If __BITS_PER_LONG
>> is changed to 32 for x32, many types in kernel header files will be
>> wrong for x32.
>>
>
> A lot of things are broken if __BITS_PER_LONG is set to 64 in x32 user
> space. It was specifically introduced to get around places in exported
> headers that incorrectly used '#ifdef CONFIG_64BIT' to define a user
> space structure, so that we can depend on whatever the user sees
> in bitmasks and other data structures.
>
I'm not entirely sure I follow the above statement, as it seems
contradict itself. Either way, I would agree, __BITS_PER_LONG should be
32 in x32 space and if there are places where that is wrong then we need
to fix them.
Fortunately x32 is littleendian, so no "littleendian bitmask on a
bigendian architecture" drain bamage...
-hpa
next prev parent reply other threads:[~2012-05-19 23:48 UTC|newest]
Thread overview: 77+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-05-17 22:13 [RFC PATCH 00/10] Use __kernel_[u]long_t for x32 user space compatibility H.J. Lu
2012-05-17 22:13 ` H.J. Lu
2012-05-17 22:13 ` [PATCH 01/10] Use __kernel_long_t in struct timex H.J. Lu
2012-05-17 22:13 ` H.J. Lu
2012-05-17 22:32 ` Linus Torvalds
2012-05-17 22:41 ` H. Peter Anvin
2012-05-17 22:50 ` H. Peter Anvin
2012-05-17 22:50 ` H. Peter Anvin
2012-05-17 22:50 ` Linus Torvalds
2012-05-17 22:55 ` H. Peter Anvin
2012-05-17 22:58 ` Linus Torvalds
2012-05-17 22:56 ` Linus Torvalds
2012-05-17 22:57 ` H. Peter Anvin
2012-05-17 23:51 ` David Daney
2012-05-17 22:13 ` [PATCH 02/10] Use __kernel_ulong_t in struct shm_info H.J. Lu
2012-05-17 22:13 ` [PATCH 03/10] Use __kernel_[u]long_t in linux/resource.h H.J. Lu
2012-05-17 22:13 ` H.J. Lu
2012-05-17 22:13 ` [PATCH 04/10] Use __kernel_long_t in struct msgbuf H.J. Lu
2012-05-17 22:13 ` H.J. Lu
2012-05-17 22:13 ` [PATCH 05/10] Use __kernel_long_t in struct mq_attr H.J. Lu
2012-05-17 22:13 ` H.J. Lu
2012-05-17 22:13 ` [PATCH 06/10] Use __kernel_ulong_t in x86 struct semid64_ds H.J. Lu
2012-05-17 22:13 ` [PATCH 07/10] Use __kernel_ulong_t in struct shmid64_ds/shminfo64 H.J. Lu
2012-05-17 22:13 ` H.J. Lu
2012-05-17 22:13 ` [PATCH 08/10] Use __kernel_ulong_t in struct msqid64_ds H.J. Lu
2012-05-17 22:13 ` H.J. Lu
2012-05-17 23:51 ` H. Peter Anvin
2012-05-18 0:07 ` Linus Torvalds
2012-05-18 0:07 ` Linus Torvalds
2012-05-18 0:14 ` H. Peter Anvin
2012-05-18 0:14 ` H. Peter Anvin
2012-05-18 0:22 ` Linus Torvalds
2012-05-18 0:27 ` H. Peter Anvin
2012-05-18 0:41 ` Linus Torvalds
2012-05-18 21:31 ` Arnd Bergmann
2012-05-18 21:41 ` H. Peter Anvin
2012-05-18 21:58 ` Arnd Bergmann
2012-05-18 22:08 ` H. Peter Anvin
2012-05-19 7:56 ` Arnd Bergmann
2012-05-19 14:35 ` Al Viro
2012-05-18 11:44 ` David Howells
2012-05-18 0:29 ` David Daney
2012-05-18 0:31 ` H. Peter Anvin
2012-05-18 0:45 ` David Daney
2012-05-18 0:37 ` H. Peter Anvin
2012-05-18 15:03 ` Chris Metcalf
2012-05-18 3:21 ` H. Peter Anvin
2012-05-18 3:39 ` H.J. Lu
2012-05-18 3:43 ` H.J. Lu
2012-05-18 3:47 ` H.J. Lu
2012-05-18 3:49 ` Linus Torvalds
2012-05-18 3:55 ` H. Peter Anvin
2012-05-18 3:59 ` H.J. Lu
2012-05-18 4:05 ` Linus Torvalds
2012-05-18 4:13 ` H.J. Lu
2012-05-18 21:21 ` Arnd Bergmann
2012-05-19 23:47 ` H. Peter Anvin [this message]
2012-05-20 1:32 ` H.J. Lu
2012-05-20 1:32 ` H.J. Lu
2012-05-20 2:08 ` H. Peter Anvin
2012-05-20 2:08 ` H. Peter Anvin
2012-05-18 3:56 ` H.J. Lu
2012-05-18 21:06 ` H. Peter Anvin
2012-05-18 11:53 ` David Howells
2012-05-18 12:06 ` H.J. Lu
2012-05-18 12:06 ` H.J. Lu
2012-05-17 22:13 ` [PATCH 09/10] Use __kernel_ulong_t in struct ipc64_perm H.J. Lu
2012-05-17 22:13 ` H.J. Lu
2012-05-17 22:13 ` [PATCH 10/10] Use __kernel_[u]long_t in x86-64 struct stat H.J. Lu
2012-05-17 23:07 ` [RFC PATCH 00/10] Use __kernel_[u]long_t for x32 user space compatibility David Daney
2012-05-17 23:07 ` David Daney
2012-05-17 23:11 ` H. Peter Anvin
2012-05-17 23:25 ` David Daney
2012-05-17 23:31 ` H. Peter Anvin
2012-05-18 0:19 ` Mike Frysinger
2012-05-18 0:21 ` H. Peter Anvin
2012-05-18 0:38 ` Mike Frysinger
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