Merge remote-tracking branch 'torvalds/master' into perf/core

[linux-2.6-microblaze.git] / tools / perf / util / probe-file.c

diff --git a/tools/perf/util/probe-file.c b/tools/perf/util/probe-file.c
index 5227354..f9a6cbc 100644 (file)
--- a/tools/perf/util/probe-file.c
+++ b/tools/perf/util/probe-file.c
@@ -22,6 +22,7 @@
 #include "symbol.h"
 #include "strbuf.h"
 #include <api/fs/tracing_path.h>
+#include <api/fs/fs.h>
 #include "probe-event.h"
 #include "probe-file.h"
 #include "session.h"
@@ -31,44 +32,78 @@
 /* 4096 - 2 ('\n' + '\0') */
 #define MAX_CMDLEN 4094
 
-static void print_open_warning(int err, bool uprobe)
+static bool print_common_warning(int err, bool readwrite)
 {
-       char sbuf[STRERR_BUFSIZE];
+       if (err == -EACCES)
+               pr_warning("No permission to %s tracefs.\nPlease %s\n",
+                          readwrite ? "write" : "read",
+                          readwrite ? "run this command again with sudo." :
+                                      "try 'sudo mount -o remount,mode=755 /sys/kernel/tracing/'");
+       else
+               return false;
 
-       if (err == -ENOENT) {
-               const char *config;
+       return true;
+}
 
-               if (uprobe)
-                       config = "CONFIG_UPROBE_EVENTS";
-               else
-                       config = "CONFIG_KPROBE_EVENTS";
+static bool print_configure_probe_event(int kerr, int uerr)
+{
+       const char *config, *file;
+
+       if (kerr == -ENOENT && uerr == -ENOENT) {
+               file = "{k,u}probe_events";
+               config = "CONFIG_KPROBE_EVENTS=y and CONFIG_UPROBE_EVENTS=y";
+       } else if (kerr == -ENOENT) {
+               file = "kprobe_events";
+               config = "CONFIG_KPROBE_EVENTS=y";
+       } else if (uerr == -ENOENT) {
+               file = "uprobe_events";
+               config = "CONFIG_UPROBE_EVENTS=y";
+       } else
+               return false;
 
-               pr_warning("%cprobe_events file does not exist"
-                          " - please rebuild kernel with %s.\n",
-                          uprobe ? 'u' : 'k', config);
-       } else if (err == -ENOTSUP)
-               pr_warning("Tracefs or debugfs is not mounted.\n");
+       if (!debugfs__configured() && !tracefs__configured())
+               pr_warning("Debugfs or tracefs is not mounted\n"
+                          "Please try 'sudo mount -t tracefs nodev /sys/kernel/tracing/'\n");
        else
-               pr_warning("Failed to open %cprobe_events: %s\n",
-                          uprobe ? 'u' : 'k',
-                          str_error_r(-err, sbuf, sizeof(sbuf)));
+               pr_warning("%s/%s does not exist.\nPlease rebuild kernel with %s.\n",
+                          tracing_path_mount(), file, config);
+
+       return true;
+}
+
+static void print_open_warning(int err, bool uprobe, bool readwrite)
+{
+       char sbuf[STRERR_BUFSIZE];
+
+       if (print_common_warning(err, readwrite))
+               return;
+
+       if (print_configure_probe_event(uprobe ? 0 : err, uprobe ? err : 0))
+               return;
+
+       pr_warning("Failed to open %s/%cprobe_events: %s\n",
+                  tracing_path_mount(), uprobe ? 'u' : 'k',
+                  str_error_r(-err, sbuf, sizeof(sbuf)));
 }
 
-static void print_both_open_warning(int kerr, int uerr)
+static void print_both_open_warning(int kerr, int uerr, bool readwrite)
 {
-       /* Both kprobes and uprobes are disabled, warn it. */
-       if (kerr == -ENOTSUP && uerr == -ENOTSUP)
-               pr_warning("Tracefs or debugfs is not mounted.\n");
-       else if (kerr == -ENOENT && uerr == -ENOENT)
-               pr_warning("Please rebuild kernel with CONFIG_KPROBE_EVENTS "
-                          "or/and CONFIG_UPROBE_EVENTS.\n");
-       else {
-               char sbuf[STRERR_BUFSIZE];
-               pr_warning("Failed to open kprobe events: %s.\n",
+       char sbuf[STRERR_BUFSIZE];
+
+       if (kerr == uerr && print_common_warning(kerr, readwrite))
+               return;
+
+       if (print_configure_probe_event(kerr, uerr))
+               return;
+
+       if (kerr < 0)
+               pr_warning("Failed to open %s/kprobe_events: %s.\n",
+                          tracing_path_mount(),
                           str_error_r(-kerr, sbuf, sizeof(sbuf)));
-               pr_warning("Failed to open uprobe events: %s.\n",
+       if (uerr < 0)
+               pr_warning("Failed to open %s/uprobe_events: %s.\n",
+                          tracing_path_mount(),
                           str_error_r(-uerr, sbuf, sizeof(sbuf)));
-       }
 }
 
 int open_trace_file(const char *trace_file, bool readwrite)
@@ -109,7 +144,7 @@ int probe_file__open(int flag)
        else
                fd = open_kprobe_events(flag & PF_FL_RW);
        if (fd < 0)
-               print_open_warning(fd, flag & PF_FL_UPROBE);
+               print_open_warning(fd, flag & PF_FL_UPROBE, flag & PF_FL_RW);
 
        return fd;
 }
@@ -122,7 +157,7 @@ int probe_file__open_both(int *kfd, int *ufd, int flag)
        *kfd = open_kprobe_events(flag & PF_FL_RW);
        *ufd = open_uprobe_events(flag & PF_FL_RW);
        if (*kfd < 0 && *ufd < 0) {
-               print_both_open_warning(*kfd, *ufd);
+               print_both_open_warning(*kfd, *ufd, flag & PF_FL_RW);
                return *kfd;
        }