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authorSteven Rostedt <srostedt@redhat.com>2012-06-05 17:44:25 +0400
committerSteven Rostedt <rostedt@goodmis.org>2012-07-19 21:18:22 +0400
commitccf3672d530170c98c734dfc5db07d64bcbad2ad (patch)
tree0cbe9a0856429412b9e026baf77cec9e117c6896 /include/linux/ftrace.h
parent2f5f6ad9390c1ebbf738d130dbfe80b60eaa167e (diff)
downloadlinux-ccf3672d530170c98c734dfc5db07d64bcbad2ad.tar.xz
ftrace: Consolidate arch dependent functions with 'list' function
As the function tracer starts to get more features, the support for theses features will spread out throughout the different architectures over time. These features boil down to what each arch does in the mcount trampoline (the ftrace_caller). Currently there's two features that are not the same throughout the archs. 1) Support to stop function tracing before the callback 2) passing of the ftrace ops Both of these require placing an indirect function to support the features if the mcount trampoline does not. On a side note, for all architectures, when more than one callback is registered to the function tracer, an intermediate 'list' function is called by the mcount trampoline to iterate through the callbacks that are registered. Instead of making a separate function for each of these features, and requiring several indirect calls, just use the single 'list' function as the intermediate, to handle all cases. If an arch does not support the 'stop function tracing' or the passing of ftrace ops, just force it to use the list function that will handle the features required. This makes the code cleaner and simpler and removes a lot of #ifdefs in the code. Link: http://lkml.kernel.org/r/20120612225424.495625483@goodmis.org Reviewed-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Diffstat (limited to 'include/linux/ftrace.h')
-rw-r--r--include/linux/ftrace.h13
1 files changed, 13 insertions, 0 deletions
diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h
index 2d5964119885..3651fdc3bec9 100644
--- a/include/linux/ftrace.h
+++ b/include/linux/ftrace.h
@@ -27,6 +27,19 @@
#define ARCH_SUPPORTS_FTRACE_OPS 0
#endif
+/*
+ * If the arch's mcount caller does not support all of ftrace's
+ * features, then it must call an indirect function that
+ * does. Or at least does enough to prevent any unwelcomed side effects.
+ */
+#if !defined(CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST) || \
+ !ARCH_SUPPORTS_FTRACE_OPS
+# define FTRACE_FORCE_LIST_FUNC 1
+#else
+# define FTRACE_FORCE_LIST_FUNC 0
+#endif
+
+
struct module;
struct ftrace_hash;