Complete change of the source directory tree

[lttng-tools.git] / lttng-sessiond / shm.c

diff --git a/lttng-sessiond/shm.c b/lttng-sessiond/shm.c
deleted file mode 100644 (file)
index 7dac165..0000000
--- a/lttng-sessiond/shm.c
+++ /dev/null
@@ -1,160 +0,0 @@
-/*
- * Copyright (C)  2011 - David Goulet <david.goulet@polymtl.ca>
- *                       Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
- *
- * This program is free software; you can redistribute it and/or modify it
- * under the terms of the GNU General Public License as published by the Free
- * Software Foundation; only version 2 of the License.
- *
- * This program is distributed in the hope that it will be useful, but WITHOUT
- * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
- * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
- * more details.
- *
- * You should have received a copy of the GNU General Public License along with
- * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
- * Place - Suite 330, Boston, MA  02111-1307, USA.
- */
-
-#define _GNU_SOURCE
-#include <fcntl.h>
-#include <limits.h>
-#include <sys/mman.h>
-#include <sys/stat.h>
-#include <sys/types.h>
-#include <sys/wait.h>
-#include <unistd.h>
-#include <urcu.h>
-
-#include <lttngerr.h>
-
-#include "shm.h"
-
-/*
- * Using fork to set umask in the child process (not multi-thread safe). We
- * deal with the shm_open vs ftruncate race (happening when the sessiond owns
- * the shm and does not let everybody modify it, to ensure safety against
- * shm_unlink) by simply letting the mmap fail and retrying after a few
- * seconds. For global shm, everybody has rw access to it until the sessiond
- * starts.
- */
-static int get_wait_shm(char *shm_path, size_t mmap_size, int global)
-{
-       int wait_shm_fd, ret;
-       mode_t mode;
-
-       /* Default permissions */
-       mode = S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP;
-
-       /* Change owner of the shm path */
-       if (global) {
-               ret = chown(shm_path, 0, 0);
-               if (ret < 0) {
-                       if (errno != ENOENT) {
-                               perror("chown wait shm");
-                               goto error;
-                       }
-               }
-
-               /*
-                * If global session daemon, any application can register so the shm
-                * needs to be set in read-only mode for others.
-                */
-               mode |= S_IROTH;
-       } else {
-               ret = chown(shm_path, getuid(), getgid());
-               if (ret < 0) {
-                       if (errno != ENOENT) {
-                               perror("chown wait shm");
-                               goto error;
-                       }
-               }
-       }
-
-       /*
-        * Set permissions to the shm even if we did not create the shm.
-        */
-       ret = chmod(shm_path, mode);
-       if (ret < 0) {
-               if (errno != ENOENT) {
-                       perror("chmod wait shm");
-                       goto error;
-               }
-       }
-
-       /*
-        * We're alone in a child process, so we can modify the process-wide
-        * umask.
-        */
-       umask(~mode);
-
-       /*
-        * Try creating shm (or get rw access). We don't do an exclusive open,
-        * because we allow other processes to create+ftruncate it concurrently.
-        */
-       wait_shm_fd = shm_open(shm_path, O_RDWR | O_CREAT, mode);
-       if (wait_shm_fd < 0) {
-               perror("shm_open wait shm");
-               goto error;
-       }
-
-       ret = ftruncate(wait_shm_fd, mmap_size);
-       if (ret < 0) {
-               perror("ftruncate wait shm");
-               exit(EXIT_FAILURE);
-       }
-
-       ret = fchmod(wait_shm_fd, mode);
-       if (ret < 0) {
-               perror("fchmod");
-               exit(EXIT_FAILURE);
-       }
-
-       DBG("Got the wait shm fd %d", wait_shm_fd);
-
-       return wait_shm_fd;
-
-error:
-       DBG("Failing to get the wait shm fd");
-
-       return -1;
-}
-
-/*
- * Return the wait shm mmap for UST application notification. The global
- * variable is used to indicate if the the session daemon is global
- * (root:tracing) or running with an unprivileged user.
- *
- * This returned value is used by futex_wait_update() in futex.c to WAKE all
- * waiters which are UST application waiting for a session daemon.
- */
-char *shm_ust_get_mmap(char *shm_path, int global)
-{
-       size_t mmap_size = sysconf(_SC_PAGE_SIZE);
-       int wait_shm_fd, ret;
-       char *wait_shm_mmap;
-
-       wait_shm_fd = get_wait_shm(shm_path, mmap_size, global);
-       if (wait_shm_fd < 0) {
-               goto error;
-       }
-
-       wait_shm_mmap = mmap(NULL, mmap_size, PROT_WRITE | PROT_READ,
-                       MAP_SHARED, wait_shm_fd, 0);
-
-       /* close shm fd immediately after taking the mmap reference */
-       ret = close(wait_shm_fd);
-       if (ret) {
-               perror("Error closing fd");
-       }
-
-       if (wait_shm_mmap == MAP_FAILED) {
-               DBG("mmap error (can be caused by race with ust).");
-               goto error;
-       }
-
-       return wait_shm_mmap;
-
-error:
-       return NULL;
-}