#define _LGPL_SOURCE
#include <sys/types.h>
#include <sys/socket.h>
-#include <sys/prctl.h>
#include <sys/mman.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <usterr-signal-safe.h>
#include "tracepoint-internal.h"
#include "ltt-tracer-core.h"
+#include "compat.h"
/*
* Has lttng ust comm constructor been called ?
int register_app_to_sessiond(int socket)
{
ssize_t ret;
- int prctl_ret;
struct {
uint32_t major;
uint32_t minor;
reg_msg.uid = getuid();
reg_msg.gid = getgid();
reg_msg.bits_per_long = CAA_BITS_PER_LONG;
- prctl_ret = prctl(PR_GET_NAME, (unsigned long) reg_msg.name, 0, 0, 0);
- if (prctl_ret) {
- ERR("Error executing prctl");
- return -errno;
- }
+ lttng_ust_getprocname(reg_msg.name);
ret = ustcomm_send_unix_sock(socket, ®_msg, sizeof(reg_msg));
if (ret >= 0 && ret != sizeof(reg_msg))
const struct lttng_ust_objd_ops *ops;
struct ustcomm_ust_reply lur;
int shm_fd, wait_fd;
+ union ust_args args;
ust_lock();
default:
if (ops->cmd)
ret = ops->cmd(lum->handle, lum->cmd,
- (unsigned long) &lum->u);
+ (unsigned long) &lum->u,
+ &args);
else
ret = -ENOSYS;
break;
* Special-case reply to send stream info.
* Use lum.u output.
*/
- lur.u.stream.memory_map_size = lum->u.stream.memory_map_size;
- shm_fd = lum->u.stream.shm_fd;
- wait_fd = lum->u.stream.wait_fd;
+ lur.u.stream.memory_map_size = *args.stream.memory_map_size;
+ shm_fd = *args.stream.shm_fd;
+ wait_fd = *args.stream.wait_fd;
break;
case LTTNG_UST_METADATA:
case LTTNG_UST_CHANNEL:
- lur.u.channel.memory_map_size = lum->u.channel.memory_map_size;
- shm_fd = lum->u.channel.shm_fd;
- wait_fd = lum->u.channel.wait_fd;
+ lur.u.channel.memory_map_size = *args.channel.memory_map_size;
+ shm_fd = *args.channel.shm_fd;
+ wait_fd = *args.channel.wait_fd;
break;
case LTTNG_UST_TRACER_VERSION:
lur.u.version = lum->u.version;
goto error;
}
}
+ /*
+ * We still have the memory map reference, and the fds have been
+ * sent to the sessiond. We can therefore close those fds. Note
+ * that we keep the write side of the wait_fd open, but close
+ * the read side.
+ */
+ if (lur.ret_code == USTCOMM_OK) {
+ switch (lum->cmd) {
+ case LTTNG_UST_STREAM:
+ if (shm_fd >= 0) {
+ ret = close(shm_fd);
+ if (ret) {
+ PERROR("Error closing stream shm_fd");
+ }
+ *args.stream.shm_fd = -1;
+ }
+ if (wait_fd >= 0) {
+ ret = close(wait_fd);
+ if (ret) {
+ PERROR("Error closing stream wait_fd");
+ }
+ *args.stream.wait_fd = -1;
+ }
+ break;
+ case LTTNG_UST_METADATA:
+ case LTTNG_UST_CHANNEL:
+ if (shm_fd >= 0) {
+ ret = close(shm_fd);
+ if (ret) {
+ PERROR("Error closing channel shm_fd");
+ }
+ *args.channel.shm_fd = -1;
+ }
+ if (wait_fd >= 0) {
+ ret = close(wait_fd);
+ if (ret) {
+ PERROR("Error closing channel wait_fd");
+ }
+ *args.channel.wait_fd = -1;
+ }
+ break;
+ }
+ }
+
error:
ust_unlock();
return ret;
}
static
-void cleanup_sock_info(struct sock_info *sock_info)
+void cleanup_sock_info(struct sock_info *sock_info, int exiting)
{
int ret;
sock_info->root_handle = -1;
}
sock_info->constructor_sem_posted = 0;
- if (sock_info->wait_shm_mmap) {
+ /*
+ * When called from process exit, we allow this memory map to be
+ * released by the OS at exit(), because removing it prior to
+ * this can cause a segmentation fault when using the
+ * futex_async timer-based fallback. And we cannot join those
+ * threads because sys_futex does not react to the cancellation
+ * request.
+ *
+ * So we actually _do_ release it only after a fork, since all
+ * threads have vanished anyway.
+ */
+ if (!exiting && sock_info->wait_shm_mmap) {
ret = munmap(sock_info->wait_shm_mmap, sysconf(_SC_PAGE_SIZE));
if (ret) {
ERR("Error unmapping wait shm");
* shared memory map will have been created.
*/
pid = wait(&status);
- if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) {
+ if (pid < 0 || !WIFEXITED(status) || WEXITSTATUS(status) != 0) {
wait_shm_fd = -1;
goto end;
}
"Please upgrade your kernel "
"(fix is commit 9ea71503a8ed9184d2d0b8ccc4d269d05f7940ae in Linux kernel "
"mainline). LTTng-UST will use polling mode fallback.");
- PERROR("futex");
+ if (ust_debug())
+ PERROR("futex");
}
}
}
static
void lttng_ust_cleanup(int exiting)
{
- cleanup_sock_info(&global_apps);
+ cleanup_sock_info(&global_apps, exiting);
if (local_apps.allowed) {
- cleanup_sock_info(&local_apps);
+ cleanup_sock_info(&local_apps, exiting);
}
lttng_ust_abi_exit();
lttng_ust_events_exit();
ERR("Error cancelling local ust listener thread");
}
}
+ /*
+ * We cannot join the threads because they might be waiting on
+ * sys_futex. Simply let the OS exit() clean up those threads.
+ */
lttng_ust_cleanup(1);
}
projects / lttng-ust.git / blobdiff