1/*
2 * os-posix-lib.c
3 *
4 * Copyright (c) 2003-2008 Fabrice Bellard
5 * Copyright (c) 2010 Red Hat, Inc.
6 *
7 * QEMU library functions on POSIX which are shared between QEMU and
8 * the QEMU tools.
9 *
10 * Permission is hereby granted, free of charge, to any person obtaining a copy
11 * of this software and associated documentation files (the "Software"), to deal
12 * in the Software without restriction, including without limitation the rights
13 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
14 * copies of the Software, and to permit persons to whom the Software is
15 * furnished to do so, subject to the following conditions:
16 *
17 * The above copyright notice and this permission notice shall be included in
18 * all copies or substantial portions of the Software.
19 *
20 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
21 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
22 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
23 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
24 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
25 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
26 * THE SOFTWARE.
27 */
28
29/* The following block of code temporarily renames the daemon() function so the
30   compiler does not see the warning associated with it in stdlib.h on OSX */
31#ifdef __APPLE__
32#define daemon qemu_fake_daemon_function
33#include <stdlib.h>
34#undef daemon
35extern int daemon(int, int);
36#endif
37
38#if defined(__linux__) && (defined(__x86_64__) || defined(__arm__))
39   /* Use 2 MiB alignment so transparent hugepages can be used by KVM.
40      Valgrind does not support alignments larger than 1 MiB,
41      therefore we need special code which handles running on Valgrind. */
42#  define QEMU_VMALLOC_ALIGN (512 * 4096)
43#elif defined(__linux__) && defined(__s390x__)
44   /* Use 1 MiB (segment size) alignment so gmap can be used by KVM. */
45#  define QEMU_VMALLOC_ALIGN (256 * 4096)
46#else
47#  define QEMU_VMALLOC_ALIGN getpagesize()
48#endif
49
50#include "config-host.h"
51#ifndef CONFIG_ANDROID
52#include <glib/gprintf.h>
53#endif
54
55#include "config-host.h"
56#include "sysemu/sysemu.h"
57#include "trace.h"
58#include "qemu/sockets.h"
59#include <sys/mman.h>
60
61#ifdef CONFIG_LINUX
62#include <sys/syscall.h>
63#endif
64
65int qemu_get_thread_id(void)
66{
67#if defined(__linux__)
68    return syscall(SYS_gettid);
69#else
70    return getpid();
71#endif
72}
73
74int qemu_daemon(int nochdir, int noclose)
75{
76    return daemon(nochdir, noclose);
77}
78
79void *qemu_oom_check(void *ptr)
80{
81    if (ptr == NULL) {
82        fprintf(stderr, "Failed to allocate memory: %s\n", strerror(errno));
83        abort();
84    }
85    return ptr;
86}
87
88void *qemu_memalign(size_t alignment, size_t size)
89{
90    void *ptr;
91#if defined(_POSIX_C_SOURCE) && !defined(__sun__)
92    int ret;
93    ret = posix_memalign(&ptr, alignment, size);
94    if (ret != 0) {
95        fprintf(stderr, "Failed to allocate %zu B: %s\n",
96                size, strerror(ret));
97        abort();
98    }
99#elif defined(CONFIG_BSD)
100    ptr = qemu_oom_check(valloc(size));
101#else
102    ptr = qemu_oom_check(memalign(alignment, size));
103#endif
104    //trace_qemu_memalign(alignment, size, ptr);
105    return ptr;
106}
107
108/* alloc shared memory pages */
109void *qemu_vmalloc(size_t size)
110{
111    return qemu_memalign(getpagesize(), size);
112}
113
114/* alloc shared memory pages */
115void *qemu_anon_ram_alloc(size_t size)
116{
117    size_t align = QEMU_VMALLOC_ALIGN;
118    size_t total = size + align - getpagesize();
119    void *ptr = mmap(0, total, PROT_READ | PROT_WRITE,
120                     MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);
121    size_t offset = QEMU_ALIGN_UP((uintptr_t)ptr, align) - (uintptr_t)ptr;
122
123    if (ptr == MAP_FAILED) {
124        return NULL;
125    }
126
127    ptr += offset;
128    total -= offset;
129
130    if (offset > 0) {
131        munmap(ptr - offset, offset);
132    }
133    if (total > size) {
134        munmap(ptr + size, total - size);
135    }
136
137    //trace_qemu_anon_ram_alloc(size, ptr);
138    return ptr;
139}
140
141void qemu_vfree(void *ptr)
142{
143    //trace_qemu_vfree(ptr);
144    free(ptr);
145}
146
147void qemu_anon_ram_free(void *ptr, size_t size)
148{
149    //trace_qemu_anon_ram_free(ptr, size);
150    if (ptr) {
151        munmap(ptr, size);
152    }
153}
154
155void qemu_set_block(int fd)
156{
157    int f;
158    f = fcntl(fd, F_GETFL);
159    fcntl(fd, F_SETFL, f & ~O_NONBLOCK);
160}
161
162void qemu_set_nonblock(int fd)
163{
164    int f;
165    f = fcntl(fd, F_GETFL);
166    fcntl(fd, F_SETFL, f | O_NONBLOCK);
167}
168
169int socket_set_fast_reuse(int fd)
170{
171#ifdef CONFIG_ANDROID
172    return socket_set_xreuseaddr(fd);
173#else
174    int val = 1, ret;
175
176    ret = qemu_setsockopt(fd, SOL_SOCKET, SO_REUSEADDR,
177                     (const char *)&val, sizeof(val));
178
179    assert(ret == 0);
180
181    return ret;
182#endif
183}
184
185void qemu_set_cloexec(int fd)
186{
187    int f;
188    f = fcntl(fd, F_GETFD);
189    fcntl(fd, F_SETFD, f | FD_CLOEXEC);
190}
191
192/*
193 * Creates a pipe with FD_CLOEXEC set on both file descriptors
194 */
195int qemu_pipe(int pipefd[2])
196{
197    int ret;
198
199#ifdef CONFIG_PIPE2
200    ret = pipe2(pipefd, O_CLOEXEC);
201    if (ret != -1 || errno != ENOSYS) {
202        return ret;
203    }
204#endif
205    ret = pipe(pipefd);
206    if (ret == 0) {
207        qemu_set_cloexec(pipefd[0]);
208        qemu_set_cloexec(pipefd[1]);
209    }
210
211    return ret;
212}
213
214int qemu_utimens(const char *path, const struct timespec *times)
215{
216    struct timeval tv[2], tv_now;
217    struct stat st;
218    int i;
219#ifdef CONFIG_UTIMENSAT
220    int ret;
221
222    ret = utimensat(AT_FDCWD, path, times, AT_SYMLINK_NOFOLLOW);
223    if (ret != -1 || errno != ENOSYS) {
224        return ret;
225    }
226#endif
227    /* Fallback: use utimes() instead of utimensat() */
228
229    /* happy if special cases */
230    if (times[0].tv_nsec == UTIME_OMIT && times[1].tv_nsec == UTIME_OMIT) {
231        return 0;
232    }
233    if (times[0].tv_nsec == UTIME_NOW && times[1].tv_nsec == UTIME_NOW) {
234        return utimes(path, NULL);
235    }
236
237    /* prepare for hard cases */
238    if (times[0].tv_nsec == UTIME_NOW || times[1].tv_nsec == UTIME_NOW) {
239        gettimeofday(&tv_now, NULL);
240    }
241    if (times[0].tv_nsec == UTIME_OMIT || times[1].tv_nsec == UTIME_OMIT) {
242        stat(path, &st);
243    }
244
245    for (i = 0; i < 2; i++) {
246        if (times[i].tv_nsec == UTIME_NOW) {
247            tv[i].tv_sec = tv_now.tv_sec;
248            tv[i].tv_usec = tv_now.tv_usec;
249        } else if (times[i].tv_nsec == UTIME_OMIT) {
250            tv[i].tv_sec = (i == 0) ? st.st_atime : st.st_mtime;
251            tv[i].tv_usec = 0;
252        } else {
253            tv[i].tv_sec = times[i].tv_sec;
254            tv[i].tv_usec = times[i].tv_nsec / 1000;
255        }
256    }
257
258    return utimes(path, &tv[0]);
259}
260
261char *
262qemu_get_local_state_pathname(const char *relative_pathname)
263{
264#ifdef CONFIG_ANDROID
265    return NULL;
266#else
267    return g_strdup_printf("%s/%s", CONFIG_QEMU_LOCALSTATEDIR,
268                           relative_pathname);
269#endif
270}
271