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#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)
int
sys_lseek(struct tcb *tcp)
{
long long offset;
int whence;
if (entering(tcp)) {
printfd(tcp, tcp->u_arg[0]);
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_LUDECIMAL;
}
#else
int
sys_lseek(struct tcb *tcp)
{
long offset;
int whence;
if (entering(tcp)) {
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_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.
*/
int
sys_llseek(struct tcb *tcp)
{
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 {
long long off;
if (syserror(tcp) || umove(tcp, tcp->u_arg[3], &off) < 0)
tprintf("%#lx, ", tcp->u_arg[3]);
else
tprintf("[%llu], ", off);
printxval(whence_codes, tcp->u_arg[4], "SEEK_???");
}
return 0;
}
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