Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  ftrace: Revert 8ab2b7efd ftrace: Remove unnecessary disabling of irqs
  kprobes/trace: Fix kprobe selftest for gcc 4.6
  ftrace: Fix possible undefined return code
  oprofile, dcookies: Fix possible circular locking dependency
  oprofile: Fix locking dependency in sync_start()
  oprofile: Free potentially owned tasks in case of errors
  oprofile, x86: Add comments to IBS LVT offset initialization

kernel/trace/ftrace.c

@@ -2740,7 +2740,7 @@ static int ftrace_process_regex(struct ftrace_hash *hash,
 {
 	char *func, *command, *next = buff;
 	struct ftrace_func_command *p;
-	int ret;
+	int ret = -EINVAL;
 
 	func = strsep(&next, ":");
 
@@ -3330,6 +3330,7 @@ static int ftrace_process_locs(struct module *mod,
 {
 	unsigned long *p;
 	unsigned long addr;
+	unsigned long flags;
 
 	mutex_lock(&ftrace_lock);
 	p = start;
@@ -3346,7 +3347,13 @@ static int ftrace_process_locs(struct module *mod,
 		ftrace_record_ip(addr);
 	}
 
+	/*
+	 * Disable interrupts to prevent interrupts from executing
+	 * code that is being modified.
+	 */
+	local_irq_save(flags);
 	ftrace_update_code(mod);
+	local_irq_restore(flags);
 	mutex_unlock(&ftrace_lock);
 
 	return 0;

kernel/trace/trace_kprobe.c

@@ -1870,8 +1870,12 @@ fs_initcall(init_kprobe_trace);
 
 #ifdef CONFIG_FTRACE_STARTUP_TEST
 
-static int kprobe_trace_selftest_target(int a1, int a2, int a3,
-					int a4, int a5, int a6)
+/*
+ * The "__used" keeps gcc from removing the function symbol
+ * from the kallsyms table.
+ */
+static __used int kprobe_trace_selftest_target(int a1, int a2, int a3,
+					       int a4, int a5, int a6)
 {
 	return a1 + a2 + a3 + a4 + a5 + a6;
 }