strace/lseek.c
Dmitry V. Levin 38a34c9349 Add copyright headers to some files which lack them
Before this change, all files that exist since 20th century had
copyright headers, while most files that appeared later didn't.  This
change fixes the inconsistency by adding missing copyright headers.

It doesn't mean that copyright headers became maintained.  In my view,
git history provides much better information on this subject and is much
more accurate than copyright headers.
2015-12-17 17:56:48 +00:00

121 lines
4.3 KiB
C

/*
* Copyright (c) 1991, 1992 Paul Kranenburg <pk@cs.few.eur.nl>
* Copyright (c) 1993 Branko Lankester <branko@hacktic.nl>
* Copyright (c) 1993, 1994, 1995, 1996 Rick Sladkey <jrs@world.std.com>
* Copyright (c) 1996-1999 Wichert Akkerman <wichert@cistron.nl>
* Copyright (c) 2002-2005 Roland McGrath <roland@redhat.com>
* Copyright (c) 2009 Andreas Schwab <schwab@redhat.com>
* Copyright (c) 2012 H.J. Lu <hongjiu.lu@intel.com>
* Copyright (c) 2013 Denys Vlasenko <vda.linux@googlemail.com>
* Copyright (c) 2014-2015 Dmitry V. Levin <ldv@altlinux.org>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "defs.h"
#include "xlat/whence_codes.h"
/* Linux kernel has exactly one version of lseek:
* fs/read_write.c::SYSCALL_DEFINE3(lseek, unsigned, fd, off_t, offset, unsigned, origin)
* In kernel, off_t is always the same as (kernel's) long
* (see include/uapi/asm-generic/posix_types.h),
* which means that on x32 we need to use tcp->ext_arg[N] to get offset argument.
* Use test/x32_lseek.c to test lseek decoding.
*/
#if defined(LINUX_MIPSN32) || defined(X32)
SYS_FUNC(lseek)
{
long long offset;
int whence;
printfd(tcp, tcp->u_arg[0]);
# ifdef X32
/* tcp->ext_arg is not initialized for i386 personality */
if (current_personality == 1)
offset = tcp->u_arg[1];
else
# endif
offset = tcp->ext_arg[1];
whence = tcp->u_arg[2];
if (whence == SEEK_SET)
tprintf(", %llu, ", offset);
else
tprintf(", %lld, ", offset);
printxval(whence_codes, whence, "SEEK_???");
return RVAL_DECODED | RVAL_LUDECIMAL;
}
#else
SYS_FUNC(lseek)
{
long offset;
int whence;
printfd(tcp, tcp->u_arg[0]);
offset = tcp->u_arg[1];
whence = tcp->u_arg[2];
if (whence == SEEK_SET)
tprintf(", %lu, ", offset);
else
tprintf(", %ld, ", offset);
printxval(whence_codes, whence, "SEEK_???");
return RVAL_DECODED | RVAL_UDECIMAL;
}
#endif
/* llseek syscall takes explicitly two ulong arguments hi, lo,
* rather than one 64-bit argument for which LONG_LONG works
* appropriate for the native byte order.
*
* See kernel's fs/read_write.c::SYSCALL_DEFINE5(llseek, ...)
*
* hi,lo are "unsigned longs" and combined exactly this way in kernel:
* ((loff_t) hi << 32) | lo
* Note that for architectures with kernel's long wider than userspace long
* (such as x32), combining code will use *kernel's*, i.e. *wide* longs
* for hi and lo. We would need to use tcp->ext_arg[N] on x32...
* ...however, x32 (and x86_64) does not _have_ llseek syscall as such.
*/
SYS_FUNC(llseek)
{
if (entering(tcp)) {
printfd(tcp, tcp->u_arg[0]);
if (tcp->u_arg[4] == SEEK_SET)
tprintf(", %llu, ",
((long long) tcp->u_arg[1]) << 32 |
(unsigned long long) (unsigned) tcp->u_arg[2]);
else
tprintf(", %lld, ",
((long long) tcp->u_arg[1]) << 32 |
(unsigned long long) (unsigned) tcp->u_arg[2]);
} else {
printnum_int64(tcp, tcp->u_arg[3], "%" PRIu64);
tprints(", ");
printxval(whence_codes, tcp->u_arg[4], "SEEK_???");
}
return 0;
}