Merge remote-tracking branch 'remotes/pmaydell/tags/pull-target-arm-20210330' into...
[qemu/ar7.git] / util / compatfd.c
blobee47dd808977d089dc92baed486fed5e3f3200f3
1 /*
2 * signalfd/eventfd compatibility
4 * Copyright IBM, Corp. 2008
6 * Authors:
7 * Anthony Liguori <aliguori@us.ibm.com>
9 * This work is licensed under the terms of the GNU GPL, version 2. See
10 * the COPYING file in the top-level directory.
12 * Contributions after 2012-01-13 are licensed under the terms of the
13 * GNU GPL, version 2 or (at your option) any later version.
16 #include "qemu/osdep.h"
17 #include "qemu/thread.h"
19 #if defined(CONFIG_SIGNALFD)
20 #include <sys/syscall.h>
21 #endif
23 struct sigfd_compat_info
25 sigset_t mask;
26 int fd;
29 static void *sigwait_compat(void *opaque)
31 struct sigfd_compat_info *info = opaque;
33 while (1) {
34 int sig;
35 int err;
37 err = sigwait(&info->mask, &sig);
38 if (err != 0) {
39 if (errno == EINTR) {
40 continue;
41 } else {
42 return NULL;
44 } else {
45 struct qemu_signalfd_siginfo buffer;
46 size_t offset = 0;
48 memset(&buffer, 0, sizeof(buffer));
49 buffer.ssi_signo = sig;
51 while (offset < sizeof(buffer)) {
52 ssize_t len;
54 len = write(info->fd, (char *)&buffer + offset,
55 sizeof(buffer) - offset);
56 if (len == -1 && errno == EINTR)
57 continue;
59 if (len <= 0) {
60 return NULL;
63 offset += len;
69 static int qemu_signalfd_compat(const sigset_t *mask)
71 struct sigfd_compat_info *info;
72 QemuThread thread;
73 int fds[2];
75 info = malloc(sizeof(*info));
76 if (info == NULL) {
77 errno = ENOMEM;
78 return -1;
81 if (pipe(fds) == -1) {
82 free(info);
83 return -1;
86 qemu_set_cloexec(fds[0]);
87 qemu_set_cloexec(fds[1]);
89 memcpy(&info->mask, mask, sizeof(*mask));
90 info->fd = fds[1];
92 qemu_thread_create(&thread, "signalfd_compat", sigwait_compat, info,
93 QEMU_THREAD_DETACHED);
95 return fds[0];
98 int qemu_signalfd(const sigset_t *mask)
100 #if defined(CONFIG_SIGNALFD)
101 int ret;
103 ret = syscall(SYS_signalfd, -1, mask, _NSIG / 8);
104 if (ret != -1) {
105 qemu_set_cloexec(ret);
106 return ret;
108 #endif
110 return qemu_signalfd_compat(mask);