1 /* Copyright (C) 1996-1998,2001,2002,2003,2006 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
3 Contributed by Ulrich Drepper <drepper@cygnus.com>, 1996.
4
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
9
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
14
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, see
17 <http://www.gnu.org/licenses/>. */
18
19 #include <features.h>
20
21 #ifdef __USE_XOPEN2K
22
23 #include <sys/syscall.h>
24 #include <sys/select.h>
25 #include <sys/time.h>
26 #include <signal.h>
27 #include <cancel.h>
28
29 #if defined(__UCLIBC_USE_TIME64__)
30 #include "internal/time64_helpers.h"
31 #endif
32
__NC(pselect)33 static int __NC(pselect)(int nfds, fd_set *readfds, fd_set *writefds,
34 fd_set *exceptfds, const struct timespec *timeout,
35 const sigset_t *sigmask)
36 {
37 #if defined(__NR_pselect6) || defined(__NR_pselect6_time64)
38 /* The Linux kernel can in some situations update the timeout value.
39 * We do not want that so use a local variable.
40 */
41 struct timespec _ts;
42
43 /* Note: the system call expects 7 values but on most architectures
44 we can only pass in 6 directly. If there is an architecture with
45 support for more parameters a new version of this file needs to
46 be created. */
47 struct {
48 __kernel_ulong_t ss;
49 __kernel_size_t ss_len;
50 } data;
51
52 if (timeout != NULL) {
53 _ts = *timeout;
54 timeout = &_ts;
55 }
56
57 if (sigmask != NULL) {
58 data.ss = (__kernel_ulong_t) sigmask;
59 data.ss_len = __SYSCALL_SIGSET_T_SIZE;
60
61 sigmask = (void *)&data;
62 }
63 #if defined(__UCLIBC_USE_TIME64__) && defined(__NR_pselect6_time64)
64 return INLINE_SYSCALL(pselect6_time64, 6, nfds, readfds, writefds, exceptfds, TO_TS64_P(timeout), sigmask);
65 #else
66 return INLINE_SYSCALL(pselect6, 6, nfds, readfds, writefds, exceptfds, timeout, sigmask);
67 #endif
68 #else
69 struct timeval tval;
70 int retval;
71 sigset_t savemask;
72
73 /* Change nanosecond number to microseconds. This might mean losing
74 precision and therefore the `pselect` should be available. But
75 for now it is hardly found. */
76 if (timeout != NULL)
77 TIMESPEC_TO_TIMEVAL (&tval, timeout);
78
79 /* The setting and restoring of the signal mask and the select call
80 should be an atomic operation. This can't be done without kernel
81 help. */
82 if (sigmask != NULL)
83 sigprocmask (SIG_SETMASK, sigmask, &savemask);
84
85 /* The comment below does not apply on uClibc, since we use __select_nocancel */
86 /* Note the pselect() is a cancellation point. But since we call
87 select() which itself is a cancellation point we do not have
88 to do anything here. */
89 retval = __NC(select)(nfds, readfds, writefds, exceptfds,
90 timeout != NULL ? &tval : NULL);
91
92 if (sigmask != NULL)
93 sigprocmask (SIG_SETMASK, &savemask, NULL);
94
95 return retval;
96 #endif
97 }
98
99 CANCELLABLE_SYSCALL(int, pselect, (int nfds, fd_set *readfds, fd_set *writefds, fd_set *exceptfds,
100 const struct timespec *timeout, const sigset_t *sigmask),
101 (nfds, readfds, writefds, exceptfds, timeout, sigmask))
102
103 #endif
104