trace-cmd: Use glob() library call to enable events

Use of the glob() library call makes the enabling of events
more robust.

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

1 files changed, 130 insertions, 27 deletions

diff --git a/trace-cmd.c b/trace-cmd.c
index d13cb15..00caf53 100644
--- a/trace-cmd.c
+++ b/trace-cmd.c
@@ -32,6 +32,7 @@
 #include <unistd.h>
 #include <ctype.h>
 #include <errno.h>
+#include <glob.h>
 
 #include "trace-local.h"
 #include "version.h"
@@ -359,31 +360,102 @@ static void set_option(const char *option)
         fclose(fp);
 }
 
+static void old_enable_events(const char *name)
+{
+        char *path;
+        FILE *fp;
+        int ret;
+
+        if (strcmp(name, "all") == 0)
+                name = "*:*";
+
+        /* need to use old way */
+        path = get_tracing_file("set_event");
+        fp = fopen(path, "w");
+        if (!fp)
+                die("opening '%s'", path);
+        put_tracing_file(path);
+
+        ret = fwrite(name, 1, strlen(name), fp);
+        if (ret < 0)
+                die("bad event '%s'", name);
+
+        ret = fwrite("\n", 1, 1, fp);
+        if (ret < 0)
+                die("bad event '%s'", name);
+
+        fclose(fp);
+
+        return;
+}
+
+static int enable_glob(const char *name)
+{
+        glob_t globbuf;
+        FILE *fp;
+        char *path;
+        char *str;
+        int len;
+        int ret;
+        int i;
+        int count = 0;
+
+        len = strlen(name) + strlen("events//enable") + 1;
+        str = malloc_or_die(len);
+        snprintf(str, len, "events/%s/enable", name);
+        path = get_tracing_file(str);
+        free(str);
+
+        globbuf.gl_offs = 0;
+        printf("path = %s\n", path);
+        ret = glob(path, GLOB_ONLYDIR, NULL, &globbuf);
+        put_tracing_file(path);
+        if (ret < 0)
+                return 0;
+
+        for (i = 0; i < globbuf.gl_pathc; i++) {
+                path = globbuf.gl_pathv[i];
+
+                fp = fopen(path, "w");
+                if (!fp)
+                        die("writing to '%s'", path);
+                ret = fwrite("1", 1, 1, fp);
+                fclose(fp);
+                if (ret < 0)
+                        die("writing to '%s'", path);
+
+                count++;
+        }
+        globfree(&globbuf);
+        return count;
+}
+
 static void enable_event(const char *name)
 {
         struct stat st;
         FILE *fp;
         char *path;
+        char *str;
+        char *ptr;
+        int len;
         int ret;
+        int ret2;
+
+        /* Check if the kernel has the events/enable file */
+        path = get_tracing_file("events/enable");
+        ret = stat(path, &st);
+        if (ret < 0) {
+                put_tracing_file(path);
+                /* old kernel */
+                old_enable_events(name);
+                return;
+        }
 
         fprintf(stderr, "enable %s\n", name);
-        if (strcmp(name, "all") == 0) {
-                path = get_tracing_file("events/enable");
 
-                ret = stat(path, &st);
-                if (ret < 0) {
-                        put_tracing_file(path);
-                        /* need to use old way */
-                        path = get_tracing_file("set_event");
-                        fp = fopen(path, "w");
-                        if (!fp)
-                                die("writing to '%s'", path);
-                        put_tracing_file(path);
-                        fwrite("*:*\n", 4, 1, fp);
-                        fclose(fp);
-                        return;
-                }
+        /* We allow the user to use "all" to enable all events */
 
+        if (strcmp(name, "all") == 0) {
                 fp = fopen(path, "w");
                 if (!fp)
                         die("writing to '%s'", path);
@@ -395,18 +467,49 @@ static void enable_event(const char *name)
                 return;
         }
 
-        path = get_tracing_file("set_event");
-        fp = fopen(path, "a");
-        if (!fp)
-                die("writing to '%s'", path);
-        put_tracing_file(path);
-        ret = fwrite(name, 1, strlen(name), fp);
-        if (ret < 0)
-                die("bad event '%s'", name);
-        ret = fwrite("\n", 1, 1, fp);
-        if (ret < 0)
-                die("bad event '%s'", name);
-        fclose(fp);
+        ptr = strchr(name, ':');
+
+        if (ptr) {
+                len = ptr - name;
+                str = strdup(name);
+                if (!str)
+                        die("could not allocate memory");
+                str[len] = 0;
+                ptr++;
+                if (!strlen(ptr) || strcmp(ptr, "*") == 0) {
+                        ret = enable_glob(str);
+                        free(str);
+                        put_tracing_file(path);
+                        if (!ret)
+                                goto fail;
+                        return;
+                }
+
+                str[len] = '/';
+
+                ret = enable_glob(str);
+                free(str);
+                if (!ret)
+                        die("No events enabled with %s", name);
+                return;
+        }
+
+        /* No ':' so enable all matching systems and events */
+        ret = enable_glob(name);
+
+        len = strlen(name) + strlen("*/") + 1;
+        str = malloc_or_die(len);
+        snprintf(str, len, "*/%s", name);
+        ret2 = enable_glob(str);
+        free(str);
+
+        if (!ret && !ret2)
+                goto fail;
+
+        return;
+ fail:
+        die("No events enabled with %s", name);
+
 }
 
 static void disable_event(const char *name)