[PATCH 06/11] ftrace: add ftrace warn on to disable ftrace

[Steven Rostedt]

Add ftrace warn on to disable ftrace as well as report a warning.

Signed-off-by: Steven Rostedt <srostedt@xxxxxxxxxx>
---
 kernel/trace/ftrace.c |   29 ++++++++++++++++++++++-------
 1 file changed, 22 insertions(+), 7 deletions(-)

Index: linux-compile.git/kernel/trace/ftrace.c
===================================================================
--- linux-compile.git.orig/kernel/trace/ftrace.c	2008-10-22 13:17:29.000000000 -0400
+++ linux-compile.git/kernel/trace/ftrace.c	2008-10-22 13:20:11.000000000 -0400
@@ -32,6 +32,24 @@
 
 #include "trace.h"
 
+#define FTRACE_WARN_ON(cond)			\
+	do {					\
+		if (unlikely(cond)) {		\
+			WARN_ON(1);		\
+			ftrace_kill();		\
+		}				\
+	} while (0)
+
+#define FTRACE_WARN_ON_ONCE(cond)		\
+	do {					\
+		static int once;		\
+		if (unlikely(cond) && !once) {	\
+			once++;			\
+			WARN_ON(1);		\
+			ftrace_kill();		\
+		}				\
+	} while (0)
+
 /* ftrace_enabled is a method to turn ftrace on or off */
 int ftrace_enabled __read_mostly;
 static int last_ftrace_enabled;
@@ -358,10 +376,8 @@ static struct dyn_ftrace *ftrace_alloc_d
 		rec = ftrace_free_records;
 
 		if (unlikely(!(rec->flags & FTRACE_FL_FREE))) {
-			WARN_ON_ONCE(1);
+			FTRACE_WARN_ON_ONCE(1);
 			ftrace_free_records = NULL;
-			ftrace_disabled = 1;
-			ftrace_enabled = 0;
 			return NULL;
 		}
 
@@ -410,7 +426,7 @@ ftrace_record_ip(unsigned long ip)
 
 	key = hash_long(ip, FTRACE_HASHBITS);
 
-	WARN_ON_ONCE(key >= FTRACE_HASHSIZE);
+	FTRACE_WARN_ON_ONCE(key >= FTRACE_HASHSIZE);
 
 	if (ftrace_ip_in_hash(ip, key))
 		goto out;
@@ -600,7 +616,7 @@ ftrace_code_disable(struct dyn_ftrace *r
 
 	ret = ftrace_modify_code(ip, call, nop);
 	if (ret) {
-		WARN_ON_ONCE(1);
+		FTRACE_WARN_ON_ONCE(1);
 		pr_info("ftrace failed to modify ");
 		print_ip_sym(ip);
 		print_ip_ins(" expected: ", call);
@@ -1660,8 +1676,7 @@ static int ftraced(void *ignore)
 					ftrace_update_cnt != 1 ? "s" : "",
 					ftrace_update_tot_cnt,
 					usecs, usecs != 1 ? "s" : "");
-				ftrace_disabled = 1;
-				WARN_ON_ONCE(1);
+				FTRACE_WARN_ON_ONCE(1);
 			}
 		}
 		mutex_unlock(&ftraced_lock);

-- 
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