Fix: Check use_clone() instead of worker in run_as

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>

diff --git a/src/common/runas.c b/src/common/runas.c
index 42ca55266ca43767b38c9e2af46cef74efd6933f..3a1de0a3acdd2b3613d715d48f404c3a60eb9eeb 100644 (file)
--- a/src/common/runas.c
+++ b/src/common/runas.c
@@ -30,6 +30,7 @@
 #include <fcntl.h>
 #include <sched.h>
 #include <sys/signal.h>
+#include <assert.h>
 
 #include <common/common.h>
 #include <common/utils.h>
@@ -364,7 +365,6 @@ int run_as_cmd(struct run_as_worker *worker,
        ssize_t readlen, writelen;
        struct run_as_ret recvret;
 
-       pthread_mutex_lock(&worker_lock);
        /*
         * If we are non-root, we can only deal with our own uid.
         */
@@ -410,7 +410,6 @@ int run_as_cmd(struct run_as_worker *worker,
        }
 
 end:
-       pthread_mutex_unlock(&worker_lock);
        errno = recvret._errno;
        return recvret.ret;
 }
@@ -442,15 +441,17 @@ end:
 }
 
 static
-int run_as(struct run_as_worker *worker,
-               enum run_as_cmd cmd,
-               struct run_as_data *data, uid_t uid, gid_t gid)
+int run_as(enum run_as_cmd cmd, struct run_as_data *data, uid_t uid, gid_t gid)
 {
        int ret;
 
-       if (worker) {
+       if (use_clone()) {
                DBG("Using run_as worker");
-               ret = run_as_cmd(worker, cmd, data, uid, gid);
+               pthread_mutex_lock(&worker_lock);
+               assert(global_worker);
+               ret = run_as_cmd(global_worker, cmd, data, uid, gid);
+               pthread_mutex_unlock(&worker_lock);
+
        } else {
                DBG("Using run_as without worker");
                ret = run_as_noworker(cmd, data, uid, gid);
@@ -461,7 +462,6 @@ int run_as(struct run_as_worker *worker,
 LTTNG_HIDDEN
 int run_as_mkdir_recursive(const char *path, mode_t mode, uid_t uid, gid_t gid)
 {
-       struct run_as_worker *worker = global_worker;
        struct run_as_data data;
 
        DBG3("mkdir() recursive %s with mode %d for uid %d and gid %d",
@@ -469,13 +469,12 @@ int run_as_mkdir_recursive(const char *path, mode_t mode, uid_t uid, gid_t gid)
        strncpy(data.u.mkdir.path, path, PATH_MAX - 1);
        data.u.mkdir.path[PATH_MAX - 1] = '\0';
        data.u.mkdir.mode = mode;
-       return run_as(worker, RUN_AS_MKDIR_RECURSIVE, &data, uid, gid);
+       return run_as(RUN_AS_MKDIR_RECURSIVE, &data, uid, gid);
 }
 
 LTTNG_HIDDEN
 int run_as_mkdir(const char *path, mode_t mode, uid_t uid, gid_t gid)
 {
-       struct run_as_worker *worker = global_worker;
        struct run_as_data data;
 
        DBG3("mkdir() %s with mode %d for uid %d and gid %d",
@@ -483,7 +482,7 @@ int run_as_mkdir(const char *path, mode_t mode, uid_t uid, gid_t gid)
        strncpy(data.u.mkdir.path, path, PATH_MAX - 1);
        data.u.mkdir.path[PATH_MAX - 1] = '\0';
        data.u.mkdir.mode = mode;
-       return run_as(worker, RUN_AS_MKDIR, &data, uid, gid);
+       return run_as(RUN_AS_MKDIR, &data, uid, gid);
 }
 
 /*
@@ -493,7 +492,6 @@ int run_as_mkdir(const char *path, mode_t mode, uid_t uid, gid_t gid)
 LTTNG_HIDDEN
 int run_as_open(const char *path, int flags, mode_t mode, uid_t uid, gid_t gid)
 {
-       struct run_as_worker *worker = global_worker;
        struct run_as_data data;
 
        DBG3("open() %s with flags %X mode %d for uid %d and gid %d",
@@ -502,33 +500,31 @@ int run_as_open(const char *path, int flags, mode_t mode, uid_t uid, gid_t gid)
        data.u.open.path[PATH_MAX - 1] = '\0';
        data.u.open.flags = flags;
        data.u.open.mode = mode;
-       return run_as(worker, RUN_AS_OPEN, &data, uid, gid);
+       return run_as(RUN_AS_OPEN, &data, uid, gid);
 }
 
 LTTNG_HIDDEN
 int run_as_unlink(const char *path, uid_t uid, gid_t gid)
 {
-       struct run_as_worker *worker = global_worker;
        struct run_as_data data;
 
        DBG3("unlink() %s with for uid %d and gid %d",
                        path, uid, gid);
        strncpy(data.u.unlink.path, path, PATH_MAX - 1);
        data.u.unlink.path[PATH_MAX - 1] = '\0';
-       return run_as(worker, RUN_AS_UNLINK, &data, uid, gid);
+       return run_as(RUN_AS_UNLINK, &data, uid, gid);
 }
 
 LTTNG_HIDDEN
 int run_as_rmdir_recursive(const char *path, uid_t uid, gid_t gid)
 {
-       struct run_as_worker *worker = global_worker;
        struct run_as_data data;
 
        DBG3("rmdir_recursive() %s with for uid %d and gid %d",
                        path, uid, gid);
        strncpy(data.u.rmdir_recursive.path, path, PATH_MAX - 1);
        data.u.rmdir_recursive.path[PATH_MAX - 1] = '\0';
-       return run_as(worker, RUN_AS_RMDIR_RECURSIVE, &data, uid, gid);
+       return run_as(RUN_AS_RMDIR_RECURSIVE, &data, uid, gid);
 }
 
 LTTNG_HIDDEN
@@ -540,7 +536,13 @@ int run_as_create_worker(char *procname)
        struct run_as_ret recvret;
        struct run_as_worker *worker;
 
+       pthread_mutex_lock(&worker_lock);
+       assert(!global_worker);
        if (!use_clone()) {
+               /*
+                * Don't initialize a worker, all run_as tasks will be performed
+                * in the current process.
+                */
                ret = 0;
                goto end;
        }
@@ -564,6 +566,8 @@ int run_as_create_worker(char *procname)
        } else if (pid == 0) {
                /* Child */
 
+               /* The child has no use for this lock. */
+               pthread_mutex_unlock(&worker_lock);
                /* Just close, no shutdown. */
                if (close(worker->sockpair[0])) {
                        PERROR("close");
@@ -600,6 +604,7 @@ int run_as_create_worker(char *procname)
                global_worker = worker;
        }
 end:
+       pthread_mutex_unlock(&worker_lock);
        return ret;
 
        /* Error handling. */
@@ -615,6 +620,7 @@ error_fork:
        }
 error_sock:
        free(worker);
+       pthread_mutex_unlock(&worker_lock);
        return ret;
 }
 
@@ -625,8 +631,9 @@ void run_as_destroy_worker(void)
        int status;
        pid_t pid;
 
+       pthread_mutex_lock(&worker_lock);
        if (!worker) {
-               return;
+               goto end;
        }
        /* Close unix socket */
        if (lttcomm_close_unix_sock(worker->sockpair[0])) {
@@ -640,4 +647,6 @@ void run_as_destroy_worker(void)
        }
        free(worker);
        global_worker = NULL;
+end:
+       pthread_mutex_unlock(&worker_lock);
 }