* 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 free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License, version 2 only,
+ * as published by the Free Software Foundation.
*
* 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
+ * 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.
+ * 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.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#define _GNU_SOURCE
#include <unistd.h>
#include <fcntl.h>
#include <sched.h>
-#include <sys/mman.h>
+#include <sys/signal.h>
#include <common/error.h>
+#include <common/compat/mman.h>
+#include <common/compat/clone.h>
#include "runas.h"
#define MAP_STACK 0
#endif
+#ifdef __FreeBSD__
+/* FreeBSD MAP_STACK always return -ENOMEM */
+#define LTTNG_MAP_STACK 0
+#else
+#define LTTNG_MAP_STACK MAP_STACK
+#endif
+
+#ifndef MAP_GROWSDOWN
+#define MAP_GROWSDOWN 0
+#endif
+
+#ifndef MAP_ANONYMOUS
+#define MAP_ANONYMOUS MAP_ANON
+#endif
+
struct run_as_data {
int (*cmd)(void *data);
void *data;
static
int child_run_as(void *_data)
{
+ int ret;
struct run_as_data *data = _data;
- size_t writelen, writeleft, index;
+ ssize_t writelen;
+ size_t writeleft, index;
union {
int i;
char c[sizeof(int)];
} sendret;
- int ret;
/*
* Child: it is safe to drop egid and euid while sharing the
writeleft = sizeof(sendret);
index = 0;
do {
- writelen = write(data->retval_pipe, &sendret.c[index],
- writeleft);
+ do {
+ writelen = write(data->retval_pipe, &sendret.c[index],
+ writeleft);
+ } while (writelen < 0 && errno == EINTR);
if (writelen < 0) {
PERROR("write");
return EXIT_FAILURE;
}
static
-int run_as(int (*cmd)(void *data), void *data, uid_t uid, gid_t gid)
+int run_as_clone(int (*cmd)(void *data), void *data, uid_t uid, gid_t gid)
{
struct run_as_data run_as_data;
int ret = 0;
run_as_data.retval_pipe = retval_pipe[1]; /* write end */
child_stack = mmap(NULL, RUNAS_CHILD_STACK_SIZE,
PROT_WRITE | PROT_READ,
- MAP_PRIVATE | MAP_GROWSDOWN | MAP_ANONYMOUS | MAP_STACK,
+ MAP_PRIVATE | MAP_GROWSDOWN | MAP_ANONYMOUS | LTTNG_MAP_STACK,
-1, 0);
if (child_stack == MAP_FAILED) {
PERROR("mmap");
* Pointing to the middle of the stack to support architectures
* where the stack grows up (HPPA).
*/
- pid = clone(child_run_as, child_stack + (RUNAS_CHILD_STACK_SIZE / 2),
- CLONE_FILES | SIGCHLD,
- &run_as_data, NULL);
+ pid = lttng_clone_files(child_run_as, child_stack + (RUNAS_CHILD_STACK_SIZE / 2),
+ &run_as_data);
if (pid < 0) {
PERROR("clone");
retval.i = pid;
return retval.i;
}
+/*
+ * To be used on setups where gdb has issues debugging programs using
+ * clone/rfork. Note that this is for debuging ONLY, and should not be
+ * considered secure.
+ */
+static
+int run_as_noclone(int (*cmd)(void *data), void *data, uid_t uid, gid_t gid)
+{
+ int ret;
+ mode_t old_mask;
+
+ old_mask = umask(0);
+ ret = cmd(data);
+ umask(old_mask);
+
+ return ret;
+}
+
+static
+int run_as(int (*cmd)(void *data), void *data, uid_t uid, gid_t gid)
+{
+ if (!getenv("LTTNG_DEBUG_NOCLONE")) {
+ int ret;
+
+ DBG("Using run_as_clone");
+ pthread_mutex_lock(<tng_libc_state_lock);
+ ret = run_as_clone(cmd, data, uid, gid);
+ pthread_mutex_unlock(<tng_libc_state_lock);
+ return ret;
+ } else {
+ DBG("Using run_as_noclone");
+ return run_as_noclone(cmd, data, uid, gid);
+ }
+}
+
+__attribute__((visibility("hidden")))
int run_as_mkdir_recursive(const char *path, mode_t mode, uid_t uid, gid_t gid)
{
struct run_as_mkdir_data data;
return run_as(_mkdir_recursive, &data, uid, gid);
}
+__attribute__((visibility("hidden")))
int run_as_mkdir(const char *path, mode_t mode, uid_t uid, gid_t gid)
{
struct run_as_mkdir_data data;
* Note: open_run_as is currently not working. We'd need to pass the fd
* opened in the child to the parent.
*/
+__attribute__((visibility("hidden")))
int run_as_open(const char *path, int flags, mode_t mode, uid_t uid, gid_t gid)
{
struct run_as_open_data data;