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Re: [PATCH] [BZ #19371] Properly handle x32 syscall

From: "Dmitry V. Levin" <ldv at altlinux dot org>
To: GNU C Library <libc-alpha at sourceware dot org>
Date: Wed, 16 Dec 2015 20:37:33 +0300
Subject: Re: [PATCH] [BZ #19371] Properly handle x32 syscall
Authentication-results: sourceware.org; auth=none
References: <20151216150139 dot GA24629 at gmail dot com> <20151216171211 dot GG238 at brightrain dot aerifal dot cx>

On Wed, Dec 16, 2015 at 12:12:12PM -0500, Rich Felker wrote:
> On Wed, Dec 16, 2015 at 07:01:39AM -0800, H.J. Lu wrote:
> > X32 syscall() may return 64-bit integer as lseek, time and times.  Its
> > return type should be __syscall_slong_t instead of long int.  We need
> > to properly return 64-bit error value.
> 
> Where is this actually needed?

On linux x32, at least lseek, time, and times syscalls return values that
cannot be properly stored in a 32-bit long int.  If libc syscall wrapper
is unable to forward values returned by these syscalls, you hardly can use
such a syscall wrapper with __NR_lseek, __NR_time, or __NR_times.

-- 
ldv

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References:
- [PATCH] [BZ #19371] Properly handle x32 syscall
  - From: H.J. Lu
- Re: [PATCH] [BZ #19371] Properly handle x32 syscall
  - From: Rich Felker

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