perf event: perf_event_ops->attr() manipulates only an evlist

[firefly-linux-kernel-4.4.55.git] / tools / perf / util / debugfs.c

diff --git a/tools/perf/util/debugfs.c b/tools/perf/util/debugfs.c
index a88fefc0cc0ada1afdbf8fc133cca9f8d49fe5a3..ffc35e748e89e1a93110f3b987bf371e50d5b4c4 100644 (file)
--- a/tools/perf/util/debugfs.c
+++ b/tools/perf/util/debugfs.c
@@ -2,8 +2,12 @@
 #include "debugfs.h"
 #include "cache.h"
 
+#include <linux/kernel.h>
+#include <sys/mount.h>
+
 static int debugfs_premounted;
-static char debugfs_mountpoint[MAX_PATH+1];
+char debugfs_mountpoint[PATH_MAX + 1] = "/sys/kernel/debug";
+char tracing_events_path[PATH_MAX + 1] = "/sys/kernel/debug/tracing/events";
 
 static const char *debugfs_known_mountpoints[] = {
        "/sys/kernel/debug/",
@@ -62,11 +66,9 @@ const char *debugfs_find_mountpoint(void)
        /* give up and parse /proc/mounts */
        fp = fopen("/proc/mounts", "r");
        if (fp == NULL)
-               die("Can't open /proc/mounts for read");
+               return NULL;
 
-       while (fscanf(fp, "%*s %"
-                     STR(MAX_PATH)
-                     "s %99s %*s %*d %*d\n",
+       while (fscanf(fp, "%*s %" STR(PATH_MAX) "s %99s %*s %*d %*d\n",
                      debugfs_mountpoint, type) == 2) {
                if (strcmp(type, "debugfs") == 0)
                        break;
@@ -106,6 +108,12 @@ int debugfs_valid_entry(const char *path)
        return 0;
 }
 
+static void debugfs_set_tracing_events_path(const char *mountpoint)
+{
+       snprintf(tracing_events_path, sizeof(tracing_events_path), "%s/%s",
+                mountpoint, "tracing/events");
+}
+
 /* mount the debugfs somewhere if it's not mounted */
 
 char *debugfs_mount(const char *mountpoint)
@@ -113,7 +121,7 @@ char *debugfs_mount(const char *mountpoint)
        /* see if it's already mounted */
        if (debugfs_find_mountpoint()) {
                debugfs_premounted = 1;
-               return debugfs_mountpoint;
+               goto out;
        }
 
        /* if not mounted and no argument */
@@ -129,12 +137,19 @@ char *debugfs_mount(const char *mountpoint)
                return NULL;
 
        /* save the mountpoint */
-       strncpy(debugfs_mountpoint, mountpoint, sizeof(debugfs_mountpoint));
        debugfs_found = 1;
-
+       strncpy(debugfs_mountpoint, mountpoint, sizeof(debugfs_mountpoint));
+out:
+       debugfs_set_tracing_events_path(debugfs_mountpoint);
        return debugfs_mountpoint;
 }
 
+void debugfs_set_path(const char *mountpoint)
+{
+       snprintf(debugfs_mountpoint, sizeof(debugfs_mountpoint), "%s", mountpoint);
+       debugfs_set_tracing_events_path(mountpoint);
+}
+
 /* umount the debugfs */
 
 int debugfs_umount(void)
@@ -158,7 +173,7 @@ int debugfs_umount(void)
 
 int debugfs_write(const char *entry, const char *value)
 {
-       char path[MAX_PATH+1];
+       char path[PATH_MAX + 1];
        int ret, count;
        int fd;
 
@@ -203,7 +218,7 @@ int debugfs_write(const char *entry, const char *value)
  */
 int debugfs_read(const char *entry, char *buffer, size_t size)
 {
-       char path[MAX_PATH+1];
+       char path[PATH_MAX + 1];
        int ret;
        int fd;