Cleanup: avoid duplicating userspace-probe desc twice

In userspace probe location _copy functions, we duplicate the strings
(e.g. function name, provider name, etc.) before passing those new
strings to the *_create_no_check function. But this function also duplicates
those strings.

To remove this double duplication, we remove the calls to lttng_strndup() in
the _copy functions and pass the pointers to those strings directly to
the _create_no_check functions.

Also, we now don't call open() needlessly when calling the
_create_no_check functions from the _copy functions as we need to
manually set a duplicated fd (using dup(2)) to avoid file unlink race.

Fixes Coverity resource leak issues: 1395196, 1395192, 1395205, 1395211
and 1395214
Signed-off-by: Francis Deslauriers <francis.deslauriers@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>

diff --git a/src/common/userspace-probe.c b/src/common/userspace-probe.c
index 7f038f5b53ec8a0e76d77df6c121542dbb3129f9..6331ff13574e9f03e14a4dc426284fe97390e526 100644 (file)
--- a/src/common/userspace-probe.c
+++ b/src/common/userspace-probe.c
@@ -402,26 +402,23 @@ lttng_userspace_probe_location_function_copy(
        enum lttng_userspace_probe_location_lookup_method_type lookup_type;
        struct lttng_userspace_probe_location *new_location = NULL;
        struct lttng_userspace_probe_location_lookup_method *lookup_method = NULL;
-       char *binary_path = NULL;
-       char *function_name = NULL;
+       const char *binary_path = NULL;
+       const char *function_name = NULL;
        int fd;
 
        assert(location);
        assert(location->type == LTTNG_USERSPACE_PROBE_LOCATION_TYPE_FUNCTION);
 
-        /* Duplicate probe location fields */
-       binary_path =
-               lttng_strndup(lttng_userspace_probe_location_function_get_binary_path(location),
-                               LTTNG_PATH_MAX);
+        /* Get probe location fields */
+       binary_path = lttng_userspace_probe_location_function_get_binary_path(location);
        if (!binary_path) {
+               ERR("Userspace probe binary path is NULL");
                goto error;
        }
 
-       function_name =
-               lttng_strndup(lttng_userspace_probe_location_function_get_function_name(location),
-                               LTTNG_SYMBOL_NAME_LEN);
+       function_name = lttng_userspace_probe_location_function_get_function_name(location);
        if (!function_name) {
-               PERROR("Error duplicating function name string");
+               ERR("Userspace probe function name is NULL");
                goto error;
        }
 
@@ -453,7 +450,7 @@ lttng_userspace_probe_location_function_copy(
 
        /* Create the probe_location */
        new_location = lttng_userspace_probe_location_function_create_no_check(
-                       binary_path, function_name, lookup_method, true);
+                       binary_path, function_name, lookup_method, false);
        if (!new_location) {
                goto destroy_lookup_method;
        }
@@ -474,8 +471,6 @@ close_fd:
                PERROR("Error closing duplicated file descriptor in error path");
        }
 error:
-       free(function_name);
-       free(binary_path);
        new_location = NULL;
 end:
        return new_location;
@@ -488,43 +483,37 @@ lttng_userspace_probe_location_tracepoint_copy(
        enum lttng_userspace_probe_location_lookup_method_type lookup_type;
        struct lttng_userspace_probe_location *new_location = NULL;
        struct lttng_userspace_probe_location_lookup_method *lookup_method = NULL;
-       char *binary_path = NULL;
-       char *probe_name = NULL;
-       char *provider_name = NULL;
+       const char *binary_path = NULL;
+       const char *probe_name = NULL;
+       const char *provider_name = NULL;
        int fd;
 
        assert(location);
        assert(location->type == LTTNG_USERSPACE_PROBE_LOCATION_TYPE_TRACEPOINT);
 
-        /* Duplicate probe location fields */
-       binary_path =
-               lttng_strndup(lttng_userspace_probe_location_tracepoint_get_binary_path(location),
-                               LTTNG_PATH_MAX);
+        /* Get probe location fields */
+       binary_path = lttng_userspace_probe_location_tracepoint_get_binary_path(location);
        if (!binary_path) {
-               PERROR("lttng_strndup");
+               ERR("Userspace probe binary path is NULL");
                goto error;
        }
 
-       probe_name =
-               lttng_strndup(lttng_userspace_probe_location_tracepoint_get_probe_name(location),
-                               LTTNG_SYMBOL_NAME_LEN);
+       probe_name = lttng_userspace_probe_location_tracepoint_get_probe_name(location);
        if (!probe_name) {
-               PERROR("lttng_strndup");
+               ERR("Userspace probe probe name is NULL");
                goto error;
        }
 
-       provider_name =
-               lttng_strndup(lttng_userspace_probe_location_tracepoint_get_provider_name(location),
-                               LTTNG_SYMBOL_NAME_LEN);
+       provider_name = lttng_userspace_probe_location_tracepoint_get_provider_name(location);
        if (!provider_name) {
-               PERROR("lttng_strndup");
+               ERR("Userspace probe provider name is NULL");
                goto error;
        }
 
        /* Duplicate the binary fd */
        fd = dup(lttng_userspace_probe_location_tracepoint_get_binary_fd(location));
        if (fd == -1) {
-               PERROR("dup");
+               PERROR("Error duplicating file descriptor to binary");
                goto error;
        }
 
@@ -549,7 +538,7 @@ lttng_userspace_probe_location_tracepoint_copy(
 
        /* Create the probe_location */
        new_location = lttng_userspace_probe_location_tracepoint_create_no_check(
-                       binary_path, provider_name, probe_name, lookup_method, true);
+                       binary_path, provider_name, probe_name, lookup_method, false);
        if (!new_location) {
                goto destroy_lookup_method;
        }
@@ -567,12 +556,9 @@ destroy_lookup_method:
        lttng_userspace_probe_location_lookup_method_destroy(lookup_method);
 close_fd:
        if (close(fd) < 0) {
-               PERROR("close");
+               PERROR("Error closing duplicated file descriptor in error path");
        }
 error:
-       free(provider_name);
-       free(probe_name);
-       free(binary_path);
        new_location = NULL;
 end:
        return new_location;