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authorSteven Rostedt <rostedt@goodmis.org>2008-08-14 15:45:08 -0400
committerIngo Molnar <mingo@elte.hu>2008-10-14 10:34:44 +0200
commit68bf21aa15c85d2e9b623dcda2b1ed8893275fa1 (patch)
tree54d4d4f7e8311b77f3166a8807a635347d479081 /include
parent8da3821ba5634497da63d58a69e24a97697c4a2b (diff)
ftrace: mcount call site on boot nops core
This is the infrastructure to the converting the mcount call sites recorded by the __mcount_loc section into nops on boot. It also allows for using these sites to enable tracing as normal. When the __mcount_loc section is used, the "ftraced" kernel thread is disabled. This uses the current infrastructure to record the mcount call sites as well as convert them to nops. The mcount function is kept as a stub on boot up and not converted to the ftrace_record_ip function. We use the ftrace_record_ip to only record from the table. This patch does not handle modules. That comes with a later patch. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'include')
-rw-r--r--include/asm-x86/ftrace.h10
-rw-r--r--include/linux/ftrace.h6
2 files changed, 16 insertions, 0 deletions
diff --git a/include/asm-x86/ftrace.h b/include/asm-x86/ftrace.h
index be0e004ad14..1bb6f9bbe1a 100644
--- a/include/asm-x86/ftrace.h
+++ b/include/asm-x86/ftrace.h
@@ -7,6 +7,16 @@
#ifndef __ASSEMBLY__
extern void mcount(void);
+
+static inline unsigned long ftrace_call_adjust(unsigned long addr)
+{
+ /*
+ * call mcount is "e8 <4 byte offset>"
+ * The addr points to the 4 byte offset and the caller of this
+ * function wants the pointer to e8. Simply subtract one.
+ */
+ return addr - 1;
+}
#endif
#endif /* CONFIG_FTRACE */
diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h
index bb384068272..d4d6ab453b7 100644
--- a/include/linux/ftrace.h
+++ b/include/linux/ftrace.h
@@ -162,4 +162,10 @@ static inline void
ftrace_special(unsigned long arg1, unsigned long arg2, unsigned long arg3) { }
#endif
+#ifdef CONFIG_FTRACE_MCOUNT_RECORD
+extern void ftrace_init(void);
+#else
+static inline void ftrace_init(void) { }
+#endif
+
#endif /* _LINUX_FTRACE_H */