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16#include "qemu/osdep.h"
17#include "qemu-common.h"
18#include "qemu/thread.h"
19
20#include <sys/syscall.h>
21
22struct sigfd_compat_info
23{
24 sigset_t mask;
25 int fd;
26};
27
28static void *sigwait_compat(void *opaque)
29{
30 struct sigfd_compat_info *info = opaque;
31
32 while (1) {
33 int sig;
34 int err;
35
36 err = sigwait(&info->mask, &sig);
37 if (err != 0) {
38 if (errno == EINTR) {
39 continue;
40 } else {
41 return NULL;
42 }
43 } else {
44 struct qemu_signalfd_siginfo buffer;
45 size_t offset = 0;
46
47 memset(&buffer, 0, sizeof(buffer));
48 buffer.ssi_signo = sig;
49
50 while (offset < sizeof(buffer)) {
51 ssize_t len;
52
53 len = write(info->fd, (char *)&buffer + offset,
54 sizeof(buffer) - offset);
55 if (len == -1 && errno == EINTR)
56 continue;
57
58 if (len <= 0) {
59 return NULL;
60 }
61
62 offset += len;
63 }
64 }
65 }
66}
67
68static int qemu_signalfd_compat(const sigset_t *mask)
69{
70 struct sigfd_compat_info *info;
71 QemuThread thread;
72 int fds[2];
73
74 info = malloc(sizeof(*info));
75 if (info == NULL) {
76 errno = ENOMEM;
77 return -1;
78 }
79
80 if (pipe(fds) == -1) {
81 free(info);
82 return -1;
83 }
84
85 qemu_set_cloexec(fds[0]);
86 qemu_set_cloexec(fds[1]);
87
88 memcpy(&info->mask, mask, sizeof(*mask));
89 info->fd = fds[1];
90
91 qemu_thread_create(&thread, "signalfd_compat", sigwait_compat, info,
92 QEMU_THREAD_DETACHED);
93
94 return fds[0];
95}
96
97int qemu_signalfd(const sigset_t *mask)
98{
99#if defined(CONFIG_SIGNALFD)
100 int ret;
101
102 ret = syscall(SYS_signalfd, -1, mask, _NSIG / 8);
103 if (ret != -1) {
104 qemu_set_cloexec(ret);
105 return ret;
106 }
107#endif
108
109 return qemu_signalfd_compat(mask);
110}
111