S390: Optimize stpcpy and wcpcpy.
[glibc.git] / hurd / catch-signal.c
blob1f10b89e27c8ca08a296e4c4f63f50accf41f08f
1 /* Convenience function to catch expected signals during an operation.
2 Copyright (C) 1996-2015 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
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.
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.
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/>. */
19 #include <hurd/signal.h>
20 #include <hurd/sigpreempt.h>
21 #include <string.h>
22 #include <assert.h>
24 error_t
25 hurd_catch_signal (sigset_t sigset,
26 unsigned long int first, unsigned long int last,
27 error_t (*operate) (struct hurd_signal_preemptor *),
28 sighandler_t handler)
30 /* We need to restore the signal mask, because otherwise the
31 signal-handling code will have blocked the caught signal and for
32 instance calling hurd_catch_signal again would then dump core. */
33 sigjmp_buf buf;
34 void throw (int signo, long int sigcode, struct sigcontext *scp)
35 { siglongjmp (buf, scp->sc_error ?: EGRATUITOUS); }
37 struct hurd_signal_preemptor preemptor =
39 sigset, first, last,
40 NULL, handler == SIG_ERR ? (sighandler_t) &throw : handler,
43 struct hurd_sigstate *const ss = _hurd_self_sigstate ();
44 error_t error;
46 if (handler != SIG_ERR)
47 /* Not our handler; don't bother saving state. */
48 error = 0;
49 else
50 /* This returns again with nonzero value when we preempt a signal. */
51 error = sigsetjmp (buf, 1);
53 if (error == 0)
55 /* Install a signal preemptor for the thread. */
56 __spin_lock (&ss->lock);
57 preemptor.next = ss->preemptors;
58 ss->preemptors = &preemptor;
59 __spin_unlock (&ss->lock);
61 /* Try the operation that might crash. */
62 (*operate) (&preemptor);
65 /* Either FUNCTION completed happily and ERROR is still zero, or it hit
66 an expected signal and `throw' made setjmp return the signal error
67 code in ERROR. Now we can remove the preemptor and return. */
69 __spin_lock (&ss->lock);
70 assert (ss->preemptors == &preemptor);
71 ss->preemptors = preemptor.next;
72 __spin_unlock (&ss->lock);
74 return error;
78 error_t
79 hurd_safe_memset (void *dest, int byte, size_t nbytes)
81 error_t operate (struct hurd_signal_preemptor *preemptor)
83 memset (dest, byte, nbytes);
84 return 0;
86 return hurd_catch_signal (sigmask (SIGBUS) | sigmask (SIGSEGV),
87 (vm_address_t) dest, (vm_address_t) dest + nbytes,
88 &operate, SIG_ERR);
92 error_t
93 hurd_safe_copyout (void *dest, const void *src, size_t nbytes)
95 error_t operate (struct hurd_signal_preemptor *preemptor)
97 memcpy (dest, src, nbytes);
98 return 0;
100 return hurd_catch_signal (sigmask (SIGBUS) | sigmask (SIGSEGV),
101 (vm_address_t) dest, (vm_address_t) dest + nbytes,
102 &operate, SIG_ERR);
105 error_t
106 hurd_safe_copyin (void *dest, const void *src, size_t nbytes)
108 error_t operate (struct hurd_signal_preemptor *preemptor)
110 memcpy (dest, src, nbytes);
111 return 0;
113 return hurd_catch_signal (sigmask (SIGBUS) | sigmask (SIGSEGV),
114 (vm_address_t) src, (vm_address_t) src + nbytes,
115 &operate, SIG_ERR);
118 error_t
119 hurd_safe_memmove (void *dest, const void *src, size_t nbytes)
121 jmp_buf buf;
122 void throw (int signo, long int sigcode, struct sigcontext *scp)
123 { longjmp (buf, scp->sc_error ?: EGRATUITOUS); }
125 struct hurd_signal_preemptor src_preemptor =
127 sigmask (SIGBUS) | sigmask (SIGSEGV),
128 (vm_address_t) src, (vm_address_t) src + nbytes,
129 NULL, (sighandler_t) &throw,
131 struct hurd_signal_preemptor dest_preemptor =
133 sigmask (SIGBUS) | sigmask (SIGSEGV),
134 (vm_address_t) dest, (vm_address_t) dest + nbytes,
135 NULL, (sighandler_t) &throw,
136 &src_preemptor
139 struct hurd_sigstate *const ss = _hurd_self_sigstate ();
140 error_t error;
142 /* This returns again with nonzero value when we preempt a signal. */
143 error = setjmp (buf);
145 if (error == 0)
147 /* Install a signal preemptor for the thread. */
148 __spin_lock (&ss->lock);
149 src_preemptor.next = ss->preemptors;
150 ss->preemptors = &dest_preemptor;
151 __spin_unlock (&ss->lock);
153 /* Do the copy; it might fault. */
154 memmove (dest, src, nbytes);
157 /* Either memmove completed happily and ERROR is still zero, or it hit
158 an expected signal and `throw' made setjmp return the signal error
159 code in ERROR. Now we can remove the preemptor and return. */
161 __spin_lock (&ss->lock);
162 assert (ss->preemptors == &dest_preemptor);
163 ss->preemptors = src_preemptor.next;
164 __spin_unlock (&ss->lock);
166 return error;