--- /dev/null
+/*
+ * Asynchronous teardown
+ *
+ * Copyright IBM, Corp. 2022
+ *
+ * Authors:
+ * Claudio Imbrenda <imbrenda@linux.ibm.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or (at your
+ * option) any later version. See the COPYING file in the top-level directory.
+ *
+ */
+
+#include "qemu/osdep.h"
+#include <dirent.h>
+#include <sys/prctl.h>
+#include <sched.h>
+
+#include "qemu/async-teardown.h"
+
+#ifdef _SC_THREAD_STACK_MIN
+#define CLONE_STACK_SIZE sysconf(_SC_THREAD_STACK_MIN)
+#else
+#define CLONE_STACK_SIZE 16384
+#endif
+
+static pid_t the_ppid;
+
+/*
+ * Close all open file descriptors.
+ */
+static void close_all_open_fd(void)
+{
+ struct dirent *de;
+ int fd, dfd;
+ DIR *dir;
+
+#ifdef CONFIG_CLOSE_RANGE
+ int r = close_range(0, ~0U, 0);
+ if (!r) {
+ /* Success, no need to try other ways. */
+ return;
+ }
+#endif
+
+ dir = opendir("/proc/self/fd");
+ if (!dir) {
+ /* If /proc is not mounted, there is nothing that can be done. */
+ return;
+ }
+ /* Avoid closing the directory. */
+ dfd = dirfd(dir);
+
+ for (de = readdir(dir); de; de = readdir(dir)) {
+ fd = atoi(de->d_name);
+ if (fd != dfd) {
+ close(fd);
+ }
+ }
+ closedir(dir);
+}
+
+static void hup_handler(int signal)
+{
+ /* Check every second if this process has been reparented. */
+ while (the_ppid == getppid()) {
+ /* sleep() is safe to use in a signal handler. */
+ sleep(1);
+ }
+
+ /* At this point the parent process has terminated completely. */
+ _exit(0);
+}
+
+static int async_teardown_fn(void *arg)
+{
+ struct sigaction sa = { .sa_handler = hup_handler };
+ sigset_t hup_signal;
+ char name[16];
+
+ /* Set a meaningful name for this process. */
+ snprintf(name, 16, "cleanup/%d", the_ppid);
+ prctl(PR_SET_NAME, (unsigned long)name);
+
+ /*
+ * Close all file descriptors that might have been inherited from the
+ * main qemu process when doing clone, needed to make libvirt happy.
+ * Not using close_range for increased compatibility with older kernels.
+ */
+ close_all_open_fd();
+
+ /* Set up a handler for SIGHUP and unblock SIGHUP. */
+ sigaction(SIGHUP, &sa, NULL);
+ sigemptyset(&hup_signal);
+ sigaddset(&hup_signal, SIGHUP);
+ sigprocmask(SIG_UNBLOCK, &hup_signal, NULL);
+
+ /* Ask to receive SIGHUP when the parent dies. */
+ prctl(PR_SET_PDEATHSIG, SIGHUP);
+
+ /*
+ * Sleep forever, unless the parent process has already terminated. The
+ * only interruption can come from the SIGHUP signal, which in normal
+ * operation is received when the parent process dies.
+ */
+ if (the_ppid == getppid()) {
+ pause();
+ }
+
+ /* At this point the parent process has terminated completely. */
+ _exit(0);
+}
+
+/*
+ * Allocate a new stack of a reasonable size, and return a pointer to its top.
+ */
+static void *new_stack_for_clone(void)
+{
+ size_t stack_size = CLONE_STACK_SIZE;
+ char *stack_ptr;
+
+ /* Allocate a new stack and get a pointer to its top. */
+ stack_ptr = qemu_alloc_stack(&stack_size);
+#if !defined(HOST_HPPA)
+ /* The top is at the end of the area, except on HPPA. */
+ stack_ptr += stack_size;
+#endif
+
+ return stack_ptr;
+}
+
+/*
+ * Block all signals, start (clone) a new process sharing the address space
+ * with qemu (CLONE_VM), then restore signals.
+ */
+void init_async_teardown(void)
+{
+ sigset_t all_signals, old_signals;
+
+ the_ppid = getpid();
+
+ sigfillset(&all_signals);
+ sigprocmask(SIG_BLOCK, &all_signals, &old_signals);
+ clone(async_teardown_fn, new_stack_for_clone(), CLONE_VM, NULL);
+ sigprocmask(SIG_SETMASK, &old_signals, NULL);
+}
system_ss.add(when: seccomp, if_true: files('qemu-seccomp.c'))
system_ss.add(when: fdt, if_true: files('device_tree.c'))
+system_ss.add(when: 'CONFIG_LINUX', if_true: files('async-teardown.c'))
+++ /dev/null
-/*
- * Asynchronous teardown
- *
- * Copyright IBM, Corp. 2022
- *
- * Authors:
- * Claudio Imbrenda <imbrenda@linux.ibm.com>
- *
- * This work is licensed under the terms of the GNU GPL, version 2 or (at your
- * option) any later version. See the COPYING file in the top-level directory.
- *
- */
-
-#include "qemu/osdep.h"
-#include <dirent.h>
-#include <sys/prctl.h>
-#include <sched.h>
-
-#include "qemu/async-teardown.h"
-
-#ifdef _SC_THREAD_STACK_MIN
-#define CLONE_STACK_SIZE sysconf(_SC_THREAD_STACK_MIN)
-#else
-#define CLONE_STACK_SIZE 16384
-#endif
-
-static pid_t the_ppid;
-
-/*
- * Close all open file descriptors.
- */
-static void close_all_open_fd(void)
-{
- struct dirent *de;
- int fd, dfd;
- DIR *dir;
-
-#ifdef CONFIG_CLOSE_RANGE
- int r = close_range(0, ~0U, 0);
- if (!r) {
- /* Success, no need to try other ways. */
- return;
- }
-#endif
-
- dir = opendir("/proc/self/fd");
- if (!dir) {
- /* If /proc is not mounted, there is nothing that can be done. */
- return;
- }
- /* Avoid closing the directory. */
- dfd = dirfd(dir);
-
- for (de = readdir(dir); de; de = readdir(dir)) {
- fd = atoi(de->d_name);
- if (fd != dfd) {
- close(fd);
- }
- }
- closedir(dir);
-}
-
-static void hup_handler(int signal)
-{
- /* Check every second if this process has been reparented. */
- while (the_ppid == getppid()) {
- /* sleep() is safe to use in a signal handler. */
- sleep(1);
- }
-
- /* At this point the parent process has terminated completely. */
- _exit(0);
-}
-
-static int async_teardown_fn(void *arg)
-{
- struct sigaction sa = { .sa_handler = hup_handler };
- sigset_t hup_signal;
- char name[16];
-
- /* Set a meaningful name for this process. */
- snprintf(name, 16, "cleanup/%d", the_ppid);
- prctl(PR_SET_NAME, (unsigned long)name);
-
- /*
- * Close all file descriptors that might have been inherited from the
- * main qemu process when doing clone, needed to make libvirt happy.
- * Not using close_range for increased compatibility with older kernels.
- */
- close_all_open_fd();
-
- /* Set up a handler for SIGHUP and unblock SIGHUP. */
- sigaction(SIGHUP, &sa, NULL);
- sigemptyset(&hup_signal);
- sigaddset(&hup_signal, SIGHUP);
- sigprocmask(SIG_UNBLOCK, &hup_signal, NULL);
-
- /* Ask to receive SIGHUP when the parent dies. */
- prctl(PR_SET_PDEATHSIG, SIGHUP);
-
- /*
- * Sleep forever, unless the parent process has already terminated. The
- * only interruption can come from the SIGHUP signal, which in normal
- * operation is received when the parent process dies.
- */
- if (the_ppid == getppid()) {
- pause();
- }
-
- /* At this point the parent process has terminated completely. */
- _exit(0);
-}
-
-/*
- * Allocate a new stack of a reasonable size, and return a pointer to its top.
- */
-static void *new_stack_for_clone(void)
-{
- size_t stack_size = CLONE_STACK_SIZE;
- char *stack_ptr;
-
- /* Allocate a new stack and get a pointer to its top. */
- stack_ptr = qemu_alloc_stack(&stack_size);
-#if !defined(HOST_HPPA)
- /* The top is at the end of the area, except on HPPA. */
- stack_ptr += stack_size;
-#endif
-
- return stack_ptr;
-}
-
-/*
- * Block all signals, start (clone) a new process sharing the address space
- * with qemu (CLONE_VM), then restore signals.
- */
-void init_async_teardown(void)
-{
- sigset_t all_signals, old_signals;
-
- the_ppid = getpid();
-
- sigfillset(&all_signals);
- sigprocmask(SIG_BLOCK, &all_signals, &old_signals);
- clone(async_teardown_fn, new_stack_for_clone(), CLONE_VM, NULL);
- sigprocmask(SIG_SETMASK, &old_signals, NULL);
-}
if not config_host_data.get('CONFIG_ATOMIC64')
util_ss.add(files('atomic64.c'))
endif
-util_ss.add(when: 'CONFIG_LINUX', if_true: files('async-teardown.c'))
util_ss.add(when: 'CONFIG_POSIX', if_true: files('aio-posix.c'))
util_ss.add(when: 'CONFIG_POSIX', if_true: files('fdmon-poll.c'))
if config_host_data.get('CONFIG_EPOLL_CREATE1')
projects / mirror_qemu.git / commitdiff