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1 | bcdf9b4d | aliguori | /*
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2 | bcdf9b4d | aliguori | * signalfd/eventfd compatibility
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3 | bcdf9b4d | aliguori | *
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4 | bcdf9b4d | aliguori | * Copyright IBM, Corp. 2008
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5 | bcdf9b4d | aliguori | *
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6 | bcdf9b4d | aliguori | * Authors:
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7 | bcdf9b4d | aliguori | * Anthony Liguori <aliguori@us.ibm.com>
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8 | bcdf9b4d | aliguori | *
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9 | bcdf9b4d | aliguori | * This work is licensed under the terms of the GNU GPL, version 2. See
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10 | bcdf9b4d | aliguori | * the COPYING file in the top-level directory.
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11 | bcdf9b4d | aliguori | *
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12 | bcdf9b4d | aliguori | */
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13 | bcdf9b4d | aliguori | |
14 | bcdf9b4d | aliguori | #include "qemu-common.h" |
15 | bcdf9b4d | aliguori | #include "compatfd.h" |
16 | bcdf9b4d | aliguori | |
17 | bcdf9b4d | aliguori | #include <sys/syscall.h> |
18 | bcdf9b4d | aliguori | #include <pthread.h> |
19 | bcdf9b4d | aliguori | |
20 | bcdf9b4d | aliguori | struct sigfd_compat_info
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21 | bcdf9b4d | aliguori | { |
22 | bcdf9b4d | aliguori | sigset_t mask; |
23 | bcdf9b4d | aliguori | int fd;
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24 | bcdf9b4d | aliguori | }; |
25 | bcdf9b4d | aliguori | |
26 | bcdf9b4d | aliguori | static void *sigwait_compat(void *opaque) |
27 | bcdf9b4d | aliguori | { |
28 | bcdf9b4d | aliguori | struct sigfd_compat_info *info = opaque;
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29 | bcdf9b4d | aliguori | int err;
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30 | bcdf9b4d | aliguori | sigset_t all; |
31 | bcdf9b4d | aliguori | |
32 | bcdf9b4d | aliguori | sigfillset(&all); |
33 | bcdf9b4d | aliguori | sigprocmask(SIG_BLOCK, &all, NULL);
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34 | bcdf9b4d | aliguori | |
35 | bcdf9b4d | aliguori | do {
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36 | bcdf9b4d | aliguori | siginfo_t siginfo; |
37 | bcdf9b4d | aliguori | |
38 | bcdf9b4d | aliguori | err = sigwaitinfo(&info->mask, &siginfo); |
39 | bcdf9b4d | aliguori | if (err == -1 && errno == EINTR) { |
40 | bcdf9b4d | aliguori | err = 0;
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41 | bcdf9b4d | aliguori | continue;
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42 | bcdf9b4d | aliguori | } |
43 | bcdf9b4d | aliguori | |
44 | bcdf9b4d | aliguori | if (err > 0) { |
45 | bcdf9b4d | aliguori | char buffer[128]; |
46 | bcdf9b4d | aliguori | size_t offset = 0;
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47 | bcdf9b4d | aliguori | |
48 | bcdf9b4d | aliguori | memcpy(buffer, &err, sizeof(err));
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49 | bcdf9b4d | aliguori | while (offset < sizeof(buffer)) { |
50 | bcdf9b4d | aliguori | ssize_t len; |
51 | bcdf9b4d | aliguori | |
52 | bcdf9b4d | aliguori | len = write(info->fd, buffer + offset, |
53 | bcdf9b4d | aliguori | sizeof(buffer) - offset);
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54 | bcdf9b4d | aliguori | if (len == -1 && errno == EINTR) |
55 | bcdf9b4d | aliguori | continue;
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56 | bcdf9b4d | aliguori | |
57 | bcdf9b4d | aliguori | if (len <= 0) { |
58 | bcdf9b4d | aliguori | err = -1;
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59 | bcdf9b4d | aliguori | break;
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60 | bcdf9b4d | aliguori | } |
61 | bcdf9b4d | aliguori | |
62 | bcdf9b4d | aliguori | offset += len; |
63 | bcdf9b4d | aliguori | } |
64 | bcdf9b4d | aliguori | } |
65 | bcdf9b4d | aliguori | } while (err >= 0); |
66 | bcdf9b4d | aliguori | |
67 | bcdf9b4d | aliguori | return NULL; |
68 | bcdf9b4d | aliguori | } |
69 | bcdf9b4d | aliguori | |
70 | bcdf9b4d | aliguori | static int qemu_signalfd_compat(const sigset_t *mask) |
71 | bcdf9b4d | aliguori | { |
72 | bcdf9b4d | aliguori | pthread_attr_t attr; |
73 | bcdf9b4d | aliguori | pthread_t tid; |
74 | bcdf9b4d | aliguori | struct sigfd_compat_info *info;
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75 | bcdf9b4d | aliguori | int fds[2]; |
76 | bcdf9b4d | aliguori | |
77 | bcdf9b4d | aliguori | info = malloc(sizeof(*info));
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78 | bcdf9b4d | aliguori | if (info == NULL) { |
79 | bcdf9b4d | aliguori | errno = ENOMEM; |
80 | bcdf9b4d | aliguori | return -1; |
81 | bcdf9b4d | aliguori | } |
82 | bcdf9b4d | aliguori | |
83 | bcdf9b4d | aliguori | if (pipe(fds) == -1) { |
84 | bcdf9b4d | aliguori | free(info); |
85 | bcdf9b4d | aliguori | return -1; |
86 | bcdf9b4d | aliguori | } |
87 | bcdf9b4d | aliguori | |
88 | bcdf9b4d | aliguori | memcpy(&info->mask, mask, sizeof(*mask));
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89 | bcdf9b4d | aliguori | info->fd = fds[1];
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90 | bcdf9b4d | aliguori | |
91 | bcdf9b4d | aliguori | pthread_attr_init(&attr); |
92 | bcdf9b4d | aliguori | pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED); |
93 | bcdf9b4d | aliguori | |
94 | bcdf9b4d | aliguori | pthread_create(&tid, &attr, sigwait_compat, info); |
95 | bcdf9b4d | aliguori | |
96 | bcdf9b4d | aliguori | pthread_attr_destroy(&attr); |
97 | bcdf9b4d | aliguori | |
98 | bcdf9b4d | aliguori | return fds[0]; |
99 | bcdf9b4d | aliguori | } |
100 | bcdf9b4d | aliguori | |
101 | bcdf9b4d | aliguori | int qemu_signalfd(const sigset_t *mask) |
102 | bcdf9b4d | aliguori | { |
103 | bcdf9b4d | aliguori | #if defined(SYS_signalfd)
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104 | bcdf9b4d | aliguori | int ret;
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105 | bcdf9b4d | aliguori | |
106 | bcdf9b4d | aliguori | ret = syscall(SYS_signalfd, -1, mask, _NSIG / 8); |
107 | bcdf9b4d | aliguori | if (!(ret == -1 && errno == ENOSYS)) |
108 | bcdf9b4d | aliguori | return ret;
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109 | bcdf9b4d | aliguori | #endif
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110 | bcdf9b4d | aliguori | |
111 | bcdf9b4d | aliguori | return qemu_signalfd_compat(mask);
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112 | bcdf9b4d | aliguori | } |
113 | bcdf9b4d | aliguori | |
114 | bcdf9b4d | aliguori | int qemu_eventfd(int *fds) |
115 | bcdf9b4d | aliguori | { |
116 | bcdf9b4d | aliguori | #if defined(SYS_eventfd)
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117 | bcdf9b4d | aliguori | int ret;
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118 | bcdf9b4d | aliguori | |
119 | bcdf9b4d | aliguori | ret = syscall(SYS_eventfd, 0);
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120 | bcdf9b4d | aliguori | if (ret >= 0) { |
121 | bcdf9b4d | aliguori | fds[0] = fds[1] = ret; |
122 | bcdf9b4d | aliguori | return 0; |
123 | bcdf9b4d | aliguori | } else if (!(ret == -1 && errno == ENOSYS)) |
124 | bcdf9b4d | aliguori | return ret;
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125 | bcdf9b4d | aliguori | #endif
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126 | bcdf9b4d | aliguori | |
127 | bcdf9b4d | aliguori | return pipe(fds);
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128 | bcdf9b4d | aliguori | } |