return daemon(nochdir, noclose);
}
+bool qemu_write_pidfile(const char *path, Error **errp)
+{
+ int fd;
+ char pidstr[32];
+
+ while (1) {
+ struct stat a, b;
+ struct flock lock = {
+ .l_type = F_WRLCK,
+ .l_whence = SEEK_SET,
+ .l_len = 0,
+ };
+
+ fd = qemu_open(path, O_CREAT | O_WRONLY, S_IRUSR | S_IWUSR);
+ if (fd == -1) {
+ error_setg_errno(errp, errno, "Cannot open pid file");
+ return false;
+ }
+
+ if (fstat(fd, &b) < 0) {
+ error_setg_errno(errp, errno, "Cannot stat file");
+ goto fail_close;
+ }
+
+ if (fcntl(fd, F_SETLK, &lock)) {
+ error_setg_errno(errp, errno, "Cannot lock pid file");
+ goto fail_close;
+ }
+
+ /*
+ * Now make sure the path we locked is the same one that now
+ * exists on the filesystem.
+ */
+ if (stat(path, &a) < 0) {
+ /*
+ * PID file disappeared, someone else must be racing with
+ * us, so try again.
+ */
+ close(fd);
+ continue;
+ }
+
+ if (a.st_ino == b.st_ino) {
+ break;
+ }
+
+ /*
+ * PID file was recreated, someone else must be racing with
+ * us, so try again.
+ */
+ close(fd);
+ }
+
+ if (ftruncate(fd, 0) < 0) {
+ error_setg_errno(errp, errno, "Failed to truncate pid file");
+ goto fail_unlink;
+ }
+
+ snprintf(pidstr, sizeof(pidstr), FMT_pid "\n", getpid());
+ if (write(fd, pidstr, strlen(pidstr)) != strlen(pidstr)) {
+ error_setg(errp, "Failed to write pid file");
+ goto fail_unlink;
+ }
+
+ return true;
+
+fail_unlink:
+ unlink(path);
+fail_close:
+ close(fd);
+ return false;
+}
+
void *qemu_oom_check(void *ptr)
{
if (ptr == NULL) {
}
/* alloc shared memory pages */
-void *qemu_anon_ram_alloc(size_t size, uint64_t *alignment)
+void *qemu_anon_ram_alloc(size_t size, uint64_t *alignment, bool shared)
{
size_t align = QEMU_VMALLOC_ALIGN;
- void *ptr = qemu_ram_mmap(-1, size, align, false);
+ void *ptr = qemu_ram_mmap(-1, size, align, shared);
if (ptr == MAP_FAILED) {
return NULL;
void qemu_anon_ram_free(void *ptr, size_t size)
{
trace_qemu_anon_ram_free(ptr, size);
- qemu_ram_munmap(ptr, size);
+ qemu_ram_munmap(-1, ptr, size);
}
void qemu_set_block(int fd)
{
int f;
f = fcntl(fd, F_GETFL);
- fcntl(fd, F_SETFL, f & ~O_NONBLOCK);
+ assert(f != -1);
+ f = fcntl(fd, F_SETFL, f & ~O_NONBLOCK);
+ assert(f != -1);
}
void qemu_set_nonblock(int fd)
{
int f;
f = fcntl(fd, F_GETFL);
- fcntl(fd, F_SETFL, f | O_NONBLOCK);
+ assert(f != -1);
+ f = fcntl(fd, F_SETFL, f | O_NONBLOCK);
+#ifdef __OpenBSD__
+ if (f == -1) {
+ /*
+ * Previous to OpenBSD 6.3, fcntl(F_SETFL) is not permitted on
+ * memory devices and sets errno to ENODEV.
+ * It's OK if we fail to set O_NONBLOCK on devices like /dev/null,
+ * because they will never block anyway.
+ */
+ assert(errno == ENODEV);
+ }
+#else
+ assert(f != -1);
+#endif
}
int socket_set_fast_reuse(int fd)
}
}
+uint64_t qemu_get_pmem_size(const char *filename, Error **errp)
+{
+ struct stat st;
+
+ if (stat(filename, &st) < 0) {
+ error_setg(errp, "unable to stat pmem file \"%s\"", filename);
+ return 0;
+ }
+
+#if defined(__linux__)
+ /* Special handling for devdax character devices */
+ if (S_ISCHR(st.st_mode)) {
+ char *subsystem_path = NULL;
+ char *subsystem = NULL;
+ char *size_path = NULL;
+ char *size_str = NULL;
+ uint64_t ret = 0;
+
+ subsystem_path = g_strdup_printf("/sys/dev/char/%d:%d/subsystem",
+ major(st.st_rdev), minor(st.st_rdev));
+ subsystem = g_file_read_link(subsystem_path, NULL);
+ if (!subsystem) {
+ error_setg(errp, "unable to read subsystem for pmem file \"%s\"",
+ filename);
+ goto devdax_err;
+ }
+
+ if (!g_str_has_suffix(subsystem, "/dax")) {
+ error_setg(errp, "pmem file \"%s\" is not a dax device", filename);
+ goto devdax_err;
+ }
+
+ size_path = g_strdup_printf("/sys/dev/char/%d:%d/size",
+ major(st.st_rdev), minor(st.st_rdev));
+ if (!g_file_get_contents(size_path, &size_str, NULL, NULL)) {
+ error_setg(errp, "unable to read size for pmem file \"%s\"",
+ size_path);
+ goto devdax_err;
+ }
+
+ ret = g_ascii_strtoull(size_str, NULL, 0);
+
+devdax_err:
+ g_free(size_str);
+ g_free(size_path);
+ g_free(subsystem);
+ g_free(subsystem_path);
+ return ret;
+ }
+#endif /* defined(__linux__) */
+
+ return st.st_size;
+}
char *qemu_get_pid_name(pid_t pid)
{
void *qemu_alloc_stack(size_t *sz)
{
void *ptr, *guardpage;
+ int flags;
#ifdef CONFIG_DEBUG_STACK_USAGE
void *ptr2;
#endif
/* allocate one extra page for the guard page */
*sz += pagesz;
- ptr = mmap(NULL, *sz, PROT_READ | PROT_WRITE,
- MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
+ flags = MAP_PRIVATE | MAP_ANONYMOUS;
+#if defined(MAP_STACK) && defined(__OpenBSD__)
+ /* Only enable MAP_STACK on OpenBSD. Other OS's such as
+ * Linux/FreeBSD/NetBSD have a flag with the same name
+ * but have differing functionality. OpenBSD will SEGV
+ * if it spots execution with a stack pointer pointing
+ * at memory that was not allocated with MAP_STACK.
+ */
+ flags |= MAP_STACK;
+#endif
+
+ ptr = mmap(NULL, *sz, PROT_READ | PROT_WRITE, flags, -1, 0);
if (ptr == MAP_FAILED) {
perror("failed to allocate memory for stack");
abort();
projects / mirror_qemu.git / blobdiff