warn: consolidate warn_slowpath and warn_on_slowpath

From 7aaa8478fe22e944adf185e465fa07799b87e573 Mon Sep 17 00:00:00 2001

From acdc8771dfaf6e8236b9122364301f65f46d4b59 Mon Sep 17 00:00:00 2001

From 7aaa8478fe22e944adf185e465fa07799b87e573 Mon Sep 17 00:00:00 2001
From: Arjan van de Ven <[email protected]>
Date: Fri, 28 Nov 2008 08:30:46 -0800
Subject: [PATCH] warn: consolidate warn_slowpath and warn_on_slowpath

warn_slowpath is a superset of warn_on_slowpath; just have warn_on_slowpath call warn_slowpath with a NULL 3rd argument.

Signed-off-by Arjan van de Ven <[email protected]>

---
 kernel/panic.c |   32 ++++++++++++--------------------
 1 files changed, 12 insertions(+), 20 deletions(-)

kernel/panic.c +6 -20

index d1ac662..2b913aa 100644
@@ -324,23 +324,6 @@ void oops_exit(void)
 }
 
 #ifdef WANT_WARN_ON_SLOWPATH
-void warn_on_slowpath(const char *file, int line)
-{
-	char function[KSYM_SYMBOL_LEN];
-	unsigned long caller = (unsigned long) __builtin_return_address(0);
-	sprint_symbol(function, caller);
-
-	printk(KERN_WARNING "------------[ cut here ]------------\n");
-	printk(KERN_WARNING "WARNING: at %s:%d %s()\n", file,
-		line, function);
-	print_modules();
-	dump_stack();
-	print_oops_end_marker();
-	add_taint(TAINT_WARN);
-}
-EXPORT_SYMBOL(warn_on_slowpath);
-
-
 void warn_slowpath(const char *file, int line, const char *fmt, ...)
 {
 	va_list args;

@@ -351,9 +334,12 @@ void warn_slowpath(const char *file, int line, const char *fmt, ...)
 	printk(KERN_WARNING "------------[ cut here ]------------\n");
 	printk(KERN_WARNING "WARNING: at %s:%d %s()\n", file,
 		line, function);
-	va_start(args, fmt);
-	vprintk(fmt, args);
-	va_end(args);
+
+	if (fmt) {
+		va_start(args, fmt);
+		vprintk(fmt, args);
+		va_end(args);
+	}
 
 	print_modules();
 	dump_stack();

From ec5679e513305f1411753e5f5489935bd638af23 Mon Sep 17 00:00:00 2001

From acdc8771dfaf6e8236b9122364301f65f46d4b59 Mon Sep 17 00:00:00 2001
From: Arjan van de Ven <[email protected]>
Date: Fri, 28 Nov 2008 08:32:44 -0800
Subject: [PATCH] warn: print the DMI board info name in a WARN/WARN_ON

it's very useful for many low level WARN_ON's to find out which motherboard has the broken BIOS etc... this patch adds a printk to the WARN_ON code for this.
On architectures without DMI, gcc should optimize the code out.

Signed-off-by Arjan van de Ven <[email protected]>

---
 kernel/panic.c |    5 +++++
 1 files changed, 5 insertions(+), 0 deletions(-)

kernel/panic.c +2 -0

index 2b913aa..9c1b7e0 100644
@@ -21,6 +21,7 @@
 #include <linux/debug_locks.h>
 #include <linux/random.h>
 #include <linux/kallsyms.h>
+#include <linux/dmi.h>
 
 int panic_on_oops;
 static unsigned long tainted_mask;

@@ -328,12 +329,16 @@ void warn_slowpath(const char *file, int line, const char *fmt, ...)
 {
 	va_list args;
 	char function[KSYM_SYMBOL_LEN];
+	const char *board;
 	unsigned long caller = (unsigned long)__builtin_return_address(0);
 	sprint_symbol(function, caller);

Quoted 34 lines · Arjan van de Ven

From acdc8771dfaf6e8236b9122364301f65f46d4b59 Mon Sep 17 00:00:00 2001
From: Arjan van de Ven <[email protected]>
Date: Fri, 28 Nov 2008 08:32:44 -0800
Subject: [PATCH] warn: print the DMI board info name in a WARN/WARN_ON

it's very useful for many low level WARN_ON's to find out which motherboard has the broken BIOS etc... this patch adds a printk to the WARN_ON code for this.
On architectures without DMI, gcc should optimize the code out.

Signed-off-by Arjan van de Ven <[email protected]>

---
 kernel/panic.c |    5 +++++
 1 files changed, 5 insertions(+), 0 deletions(-)

kernel/panic.c +2 -0

index 2b913aa..9c1b7e0 100644
@@ -21,6 +21,7 @@
 #include <linux/debug_locks.h>
 #include <linux/random.h>
 #include <linux/kallsyms.h>
+#include <linux/dmi.h>
 
 int panic_on_oops;
 static unsigned long tainted_mask;

@@ -328,12 +329,16 @@ void warn_slowpath(const char *file, int line, const char *fmt, ...)
 {
 	va_list args;
 	char function[KSYM_SYMBOL_LEN];
+	const char *board;
 	unsigned long caller = (unsigned long)__builtin_return_address(0);
 	sprint_symbol(function, caller);

kernel/panic.c void warn_slowpath(const char *file, int line, const char *fmt, ...) · line 344

Quoted 10 lines

kernel/panic.c +3 -0

 
 	printk(KERN_WARNING "------------[ cut here ]------------\n");
 	printk(KERN_WARNING "WARNING: at %s:%d %s()\n", file,
 		line, function);
+	board = dmi_get_system_info(DMI_PRODUCT_NAME);
+	if (board)
+		printk(KERN_WARNING "Hardware name: %s\n", board);
 
 	if (fmt) {
 		va_start(args, fmt);

nice idea - applied to tip/core/debug.

On architectures (or systems) where there's no DMI_PRODUCT_NAME string available, we'll print nothing. It's also a simple lockless call so can be called from any context.

Andrew, any objections?