[PATCH 1/2] Make lib/bug.c WARN implementation match the kernel/panic.c one

[PATCH 1/2] Make lib/bug.c WARN implementation match the kernel/panic.c one

[Anton Blanchard]

There are a few issues with the exception based WARN implementation in
lib/bug.c:

- Inconsistent printk flags. The "cut here" line is printed at KERN_EMERG, so
  the console and all logged in users see the single line:

------------[ cut here ]------------

  for each WARN. Fix this so we print everything at KERN_WARNING to match the
  kernel/panic.c version.

- The lib/bug.c WARN would print "Badness at". Change it to match the
  kernel/panic.c version which prints "WARNING: at". 

- Print the list of modules, similar to kernel/panic.c of modules, similar to
  kernel/panic.c

Signed-off-by: Anton Blanchard <anton@samba.org>
---

Index: linux-2.6/lib/bug.c
===================================================================
--- linux-2.6.orig/lib/bug.c	2010-06-26 06:09:59.000000000 +1000
+++ linux-2.6/lib/bug.c	2010-06-26 06:24:28.000000000 +1000
@@ -136,8 +136,6 @@ enum bug_trap_type report_bug(unsigned l
 
 	bug = find_bug(bugaddr);
 
-	printk(KERN_EMERG "------------[ cut here ]------------\n");
-
 	file = NULL;
 	line = 0;
 	warning = 0;
@@ -156,19 +154,24 @@ enum bug_trap_type report_bug(unsigned l
 
 	if (warning) {
 		/* this is a WARN_ON rather than BUG/BUG_ON */
+		printk(KERN_WARNING "------------[ cut here ]------------\n");
+
 		if (file)
-			printk(KERN_ERR "Badness at %s:%u\n",
+			printk(KERN_WARNING "WARNING: at %s:%u\n",
 			       file, line);
 		else
-			printk(KERN_ERR "Badness at %p "
+			printk(KERN_WARNING "WARNING: at %p "
 			       "[verbose debug info unavailable]\n",
 			       (void *)bugaddr);
 
+        	print_modules();
 		show_regs(regs);
 		add_taint(BUG_GET_TAINT(bug));
 		return BUG_TRAP_TYPE_WARN;
 	}
 
+	printk(KERN_EMERG "------------[ cut here ]------------\n");
+
 	if (file)
 		printk(KERN_CRIT "kernel BUG at %s:%u!\n",
 		       file, line);

[PATCH 2/2] Add oops end marker to lib/bug.c WARN implementation

[Anton Blanchard]

We are missing the oops end marker for the exception based WARN implementation
in lib/bug.c. This is useful for logfile analysis tools.

Signed-off-by: Anton Blanchard <anton@samba.org>
---

Index: linux-2.6/include/linux/kernel.h
===================================================================
--- linux-2.6.orig/include/linux/kernel.h	2010-06-26 06:29:35.000000000 +1000
+++ linux-2.6/include/linux/kernel.h	2010-06-26 06:30:27.000000000 +1000
@@ -177,6 +177,7 @@ NORET_TYPE void panic(const char * fmt, 
 	__attribute__ ((NORET_AND format (printf, 1, 2))) __cold;
 extern void oops_enter(void);
 extern void oops_exit(void);
+void print_oops_end_marker(void);
 extern int oops_may_print(void);
 NORET_TYPE void do_exit(long error_code)
 	ATTRIB_NORET;
Index: linux-2.6/kernel/panic.c
===================================================================
--- linux-2.6.orig/kernel/panic.c	2010-06-26 06:29:35.000000000 +1000
+++ linux-2.6/kernel/panic.c	2010-06-26 06:30:05.000000000 +1000
@@ -344,7 +344,7 @@ static int init_oops_id(void)
 }
 late_initcall(init_oops_id);
 
-static void print_oops_end_marker(void)
+void print_oops_end_marker(void)
 {
 	init_oops_id();
 	printk(KERN_WARNING "---[ end trace %016llx ]---\n",
Index: linux-2.6/lib/bug.c
===================================================================
--- linux-2.6.orig/lib/bug.c	2010-06-26 06:29:35.000000000 +1000
+++ linux-2.6/lib/bug.c	2010-06-26 06:31:28.000000000 +1000
@@ -166,6 +166,7 @@ enum bug_trap_type report_bug(unsigned l
 
         	print_modules();
 		show_regs(regs);
+		print_oops_end_marker();
 		add_taint(BUG_GET_TAINT(bug));
 		return BUG_TRAP_TYPE_WARN;
 	}

Re: [PATCH 1/2] Make lib/bug.c WARN implementation match the kernel/panic.c one

[Kirill A. Shutemov]

On Sun, Jun 27, 2010 at 05:10:59AM +1000, Anton Blanchard wrote:
> 
> There are a few issues with the exception based WARN implementation in
> lib/bug.c:
> 
> - Inconsistent printk flags. The "cut here" line is printed at KERN_EMERG, so
>   the console and all logged in users see the single line:
> 
> ------------[ cut here ]------------
> 
>   for each WARN. Fix this so we print everything at KERN_WARNING to match the
>   kernel/panic.c version.
> 
> - The lib/bug.c WARN would print "Badness at". Change it to match the
>   kernel/panic.c version which prints "WARNING: at". 
> 
> - Print the list of modules, similar to kernel/panic.c of modules, similar to
>   kernel/panic.c
> 
> Signed-off-by: Anton Blanchard <anton@samba.org>
> ---
> 
> Index: linux-2.6/lib/bug.c
> ===================================================================
> --- linux-2.6.orig/lib/bug.c	2010-06-26 06:09:59.000000000 +1000
> +++ linux-2.6/lib/bug.c	2010-06-26 06:24:28.000000000 +1000
> @@ -136,8 +136,6 @@ enum bug_trap_type report_bug(unsigned l
>  
>  	bug = find_bug(bugaddr);
>  
> -	printk(KERN_EMERG "------------[ cut here ]------------\n");
> -
>  	file = NULL;
>  	line = 0;
>  	warning = 0;
> @@ -156,19 +154,24 @@ enum bug_trap_type report_bug(unsigned l
>  
>  	if (warning) {
>  		/* this is a WARN_ON rather than BUG/BUG_ON */
> +		printk(KERN_WARNING "------------[ cut here ]------------\n");
> +
>  		if (file)
> -			printk(KERN_ERR "Badness at %s:%u\n",
> +			printk(KERN_WARNING "WARNING: at %s:%u\n",
>  			       file, line);
>  		else
> -			printk(KERN_ERR "Badness at %p "
> +			printk(KERN_WARNING "WARNING: at %p "
>  			       "[verbose debug info unavailable]\n",
>  			       (void *)bugaddr);
>  
> +        	print_modules();
>  		show_regs(regs);
>  		add_taint(BUG_GET_TAINT(bug));
>  		return BUG_TRAP_TYPE_WARN;
>  	}
>  
> +	printk(KERN_EMERG "------------[ cut here ]------------\n");
> +

Hm... Why do you use KERN_EMERG here?

>  	if (file)
>  		printk(KERN_CRIT "kernel BUG at %s:%u!\n",
>  		       file, line);
> --
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-- 
 Kirill A. Shutemov