[PATCH 07/12 v3] ftrace: add ftrace warn on to disable ftrace

Steven Rostedt
2008-10-23T13:40:17Z

[-- Attachment #1: ftrace-disable-warn-on.patch --]
[-- Type: text/plain, Size: 2596 bytes --]

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

[ Thanks to Andrew Morton for suggesting using the WARN_ON return value ]

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
---
kernel/trace/ftrace.c | 29 +++++++++++++++++++----------
1 file changed, 19 insertions(+), 10 deletions(-)

Index: linux-compile.git/kernel/trace/ftrace.c
===================================================================
--- linux-compile.git.orig/kernel/trace/ftrace.c 2008-10-22 15:58:35.000000000 -0400
+++ linux-compile.git/kernel/trace/ftrace.c 2008-10-22 16:05:30.000000000 -0400
@@ -32,6 +32,18 @@

#include "trace.h"

+#define FTRACE_WARN_ON(cond) \
+ do { \
+ if (WARN_ON(cond)) \
+ ftrace_kill(); \
+ } while (0)
+
+#define FTRACE_WARN_ON_ONCE(cond) \
+ do { \
+ if (WARN_ON_ONCE(cond)) \
+ 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 +370,8 @@ 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 +420,7 @@ 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;
@@ -602,12 +612,12 @@ ftrace_code_disable(struct dyn_ftrace *r
if (ret) {
switch (ret) {
case -EFAULT:
- WARN_ON_ONCE(1);
+ FTRACE_WARN_ON_ONCE(1);
pr_info("ftrace faulted on modifying ");
print_ip_sym(ip);
break;
case -EINVAL:
- WARN_ON_ONCE(1);
+ FTRACE_WARN_ON_ONCE(1);
pr_info("ftrace failed to modify ");
print_ip_sym(ip);
print_ip_ins(" expected: ", call);
@@ -616,12 +626,12 @@ ftrace_code_disable(struct dyn_ftrace *r
printk(KERN_CONT "\n");
break;
case -EPERM:
- WARN_ON_ONCE(1);
+ FTRACE_WARN_ON_ONCE(1);
pr_info("ftrace faulted on writing ");
print_ip_sym(ip);
break;
default:
- WARN_ON_ONCE(1);
+ FTRACE_WARN_ON_ONCE(1);
pr_info("ftrace faulted on unknown error ");
print_ip_sym(ip);
}
@@ -1679,8 +1689,7 @@ 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);

--