3 #include "xlat/whence_codes.h"
5 /* Linux kernel has exactly one version of lseek:
6 * fs/read_write.c::SYSCALL_DEFINE3(lseek, unsigned, fd, off_t, offset, unsigned, origin)
7 * In kernel, off_t is always the same as (kernel's) long
8 * (see include/uapi/asm-generic/posix_types.h),
9 * which means that on x32 we need to use tcp->ext_arg[N] to get offset argument.
10 * Use test/x32_lseek.c to test lseek decoding.
12 #if defined(LINUX_MIPSN32) || defined(X32)
14 sys_lseek(struct tcb *tcp)
20 printfd(tcp, tcp->u_arg[0]);
21 offset = tcp->ext_arg[1];
22 whence = tcp->u_arg[2];
23 if (whence == SEEK_SET)
24 tprintf(", %llu, ", offset);
26 tprintf(", %lld, ", offset);
27 printxval(whence_codes, whence, "SEEK_???");
29 return RVAL_LUDECIMAL;
33 sys_lseek(struct tcb *tcp)
39 printfd(tcp, tcp->u_arg[0]);
40 offset = tcp->u_arg[1];
41 whence = tcp->u_arg[2];
42 if (whence == SEEK_SET)
43 tprintf(", %lu, ", offset);
45 tprintf(", %ld, ", offset);
46 printxval(whence_codes, whence, "SEEK_???");
52 /* llseek syscall takes explicitly two ulong arguments hi, lo,
53 * rather than one 64-bit argument for which LONG_LONG works
54 * appropriate for the native byte order.
56 * See kernel's fs/read_write.c::SYSCALL_DEFINE5(llseek, ...)
58 * hi,lo are "unsigned longs" and combined exactly this way in kernel:
59 * ((loff_t) hi << 32) | lo
60 * Note that for architectures with kernel's long wider than userspace long
61 * (such as x32), combining code will use *kernel's*, i.e. *wide* longs
62 * for hi and lo. We would need to use tcp->ext_arg[N] on x32...
63 * ...however, x32 (and x86_64) does not _have_ llseek syscall as such.
66 sys_llseek(struct tcb *tcp)
69 printfd(tcp, tcp->u_arg[0]);
70 if (tcp->u_arg[4] == SEEK_SET)
72 ((long long) tcp->u_arg[1]) << 32 |
73 (unsigned long long) (unsigned) tcp->u_arg[2]);
76 ((long long) tcp->u_arg[1]) << 32 |
77 (unsigned long long) (unsigned) tcp->u_arg[2]);
81 if (syserror(tcp) || umove(tcp, tcp->u_arg[3], &off) < 0)
82 tprintf("%#lx, ", tcp->u_arg[3]);
84 tprintf("[%llu], ", off);
85 printxval(whence_codes, tcp->u_arg[4], "SEEK_???");