parse-events: Always allocate comm for pevent_register_comm()

The function pevent_register_comm() will allocate its own comm
depending on when you execute it. This is stupid and likely to
cause bugs.

Make it always allocate its own comm and also change the parameter
name to accept const char *.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

3 files changed, 13 insertions, 5 deletions

diff --git a/parse-events.c b/parse-events.c
index a959ebc..beab8f3 100644
--- a/parse-events.c
+++ b/parse-events.c
@@ -225,8 +225,13 @@ static int add_new_comm(struct pevent *pevent, char *comm, int pid)
         const struct cmdline *cmdline;
         struct cmdline key;
 
-        if (!pid)
+        if (!comm)
+                die("malloc comm");
+
+        if (!pid) {
+                free(comm);
                 return 0;
+        }
 
         /* avoid duplicates */
         key.pid = pid;
@@ -246,6 +251,7 @@ static int add_new_comm(struct pevent *pevent, char *comm, int pid)
 
         cmdlines[pevent->cmdline_count].pid = pid;
         cmdlines[pevent->cmdline_count].comm = comm;
+        if (cmdlines[pevent->cmdline_count].comm)
         pevent->cmdline_count++;
 
         qsort(cmdlines, pevent->cmdline_count, sizeof(*cmdlines), cmdline_cmp);
@@ -263,15 +269,17 @@ static int add_new_comm(struct pevent *pevent, char *comm, int pid)
  * This adds a mapping to search for command line names with
  * a given pid. The comm is duplicated.
  */
-int pevent_register_comm(struct pevent *pevent, char *comm, int pid)
+int pevent_register_comm(struct pevent *pevent, const char *comm, int pid)
 {
         struct cmdline_list *item;
 
         if (pevent->cmdlines)
-                return add_new_comm(pevent, comm, pid);
+                return add_new_comm(pevent, strdup(comm), pid);
 
         item = malloc_or_die(sizeof(*item));
         item->comm = strdup(comm);
+        if (!item->comm)
+                die("malloc comm");
         item->pid = pid;
         item->next = pevent->cmdlist;
 
diff --git a/parse-events.h b/parse-events.h
index 38ddf95..4732acf 100644
--- a/parse-events.h
+++ b/parse-events.h
@@ -428,7 +428,7 @@ enum trace_flag_type {
         TRACE_FLAG_SOFTIRQ              = 0x10,
 };
 
-int pevent_register_comm(struct pevent *pevent, char *comm, int pid);
+int pevent_register_comm(struct pevent *pevent, const char *comm, int pid);
 int pevent_register_function(struct pevent *pevent, char *name,
                              unsigned long long addr, char *mod);
 int pevent_register_print_string(struct pevent *pevent, char *fmt,
diff --git a/trace-graph.c b/trace-graph.c
index 7225880..2ddd283 100644
--- a/trace-graph.c
+++ b/trace-graph.c
@@ -1134,7 +1134,7 @@ int trace_graph_check_sched_switch(struct graph_info *ginfo,
                  */
                 if (!pevent_pid_is_registered(ginfo->pevent, *pid))
                         pevent_register_comm(ginfo->pevent,
-                                             strdup(*comm), *pid);
+                                             *comm, *pid);
         }
 
         return ret;