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authorHuang Ying <ying.huang@intel.com>2008-08-15 00:40:25 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2008-08-15 08:35:42 -0700
commit9bdeb7b5d34f197dea7859d24475943395ffea5e (patch)
treef2db04f16f95ac713bb35d9c0dc8626a294d6d60 /include
parent73bd9c72a29be1e8de008186eea55d333a938804 (diff)
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kexec jump: __ftrace_enabled_save/restore
Add __ftrace_enabled_save/restore, used to disable ftrace for a while. Now, this is used by kexec jump, which need a version without lock, for general situation, a locked version should be used. Signed-off-by: Huang Ying <ying.huang@intel.com> Cc: Pavel Machek <pavel@ucw.cz> Cc: "Rafael J. Wysocki" <rjw@sisk.pl> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include')
-rw-r--r--include/linux/ftrace.h21
1 files changed, 21 insertions, 0 deletions
diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h
index f368d041e02..bb384068272 100644
--- a/include/linux/ftrace.h
+++ b/include/linux/ftrace.h
@@ -98,6 +98,27 @@ static inline void tracer_disable(void)
#endif
}
+/* Ftrace disable/restore without lock. Some synchronization mechanism
+ * must be used to prevent ftrace_enabled to be changed between
+ * disable/restore. */
+static inline int __ftrace_enabled_save(void)
+{
+#ifdef CONFIG_FTRACE
+ int saved_ftrace_enabled = ftrace_enabled;
+ ftrace_enabled = 0;
+ return saved_ftrace_enabled;
+#else
+ return 0;
+#endif
+}
+
+static inline void __ftrace_enabled_restore(int enabled)
+{
+#ifdef CONFIG_FTRACE
+ ftrace_enabled = enabled;
+#endif
+}
+
#ifdef CONFIG_FRAME_POINTER
/* TODO: need to fix this for ARM */
# define CALLER_ADDR0 ((unsigned long)__builtin_return_address(0))