From a8605aef813f8eb3ef4b80d32cba6a671ef8deb0 Mon Sep 17 00:00:00 2001
From: Judith Lebzelter <judith@osdl.org>
Date: Fri, 8 Dec 2006 02:36:23 -0800
Subject: [PATCH] [PATCH] use generic BUG for ppc

Switch ppc over to using the generic BUG implementation.

Signed-off-by: Judith Lebzelter <judith@osdl.org>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: Michael Ellerman <michael@ellerman.id.au>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
---
 arch/ppc/Kconfig        |  5 ++++
 arch/ppc/kernel/traps.c | 64 ++++-------------------------------------
 2 files changed, 11 insertions(+), 58 deletions(-)

diff --git a/arch/ppc/Kconfig b/arch/ppc/Kconfig
index edf71a4ecc9..f76a146cff1 100644
--- a/arch/ppc/Kconfig
+++ b/arch/ppc/Kconfig
@@ -52,6 +52,11 @@ config ARCH_MAY_HAVE_PC_FDC
 	bool
 	default y
 
+config GENERIC_BUG
+	bool
+	default y
+	depends on BUG
+
 source "init/Kconfig"
 
 menu "Processor"
diff --git a/arch/ppc/kernel/traps.c b/arch/ppc/kernel/traps.c
index 2f835b9e95e..810f7aa72e9 100644
--- a/arch/ppc/kernel/traps.c
+++ b/arch/ppc/kernel/traps.c
@@ -28,6 +28,7 @@
 #include <linux/init.h>
 #include <linux/module.h>
 #include <linux/prctl.h>
+#include <linux/bug.h>
 
 #include <asm/pgtable.h>
 #include <asm/uaccess.h>
@@ -559,64 +560,9 @@ static void emulate_single_step(struct pt_regs *regs)
 	}
 }
 
-/*
- * Look through the list of trap instructions that are used for BUG(),
- * BUG_ON() and WARN_ON() and see if we hit one.  At this point we know
- * that the exception was caused by a trap instruction of some kind.
- * Returns 1 if we should continue (i.e. it was a WARN_ON) or 0
- * otherwise.
- */
-extern struct bug_entry __start___bug_table[], __stop___bug_table[];
-
-#ifndef CONFIG_MODULES
-#define module_find_bug(x)	NULL
-#endif
-
-struct bug_entry *find_bug(unsigned long bugaddr)
-{
-	struct bug_entry *bug;
-
-	for (bug = __start___bug_table; bug < __stop___bug_table; ++bug)
-		if (bugaddr == bug->bug_addr)
-			return bug;
-	return module_find_bug(bugaddr);
-}
-
-int check_bug_trap(struct pt_regs *regs)
+int is_valid_bugaddr(unsigned long addr)
 {
-	struct bug_entry *bug;
-	unsigned long addr;
-
-	if (regs->msr & MSR_PR)
-		return 0;	/* not in kernel */
-	addr = regs->nip;	/* address of trap instruction */
-	if (addr < PAGE_OFFSET)
-		return 0;
-	bug = find_bug(regs->nip);
-	if (bug == NULL)
-		return 0;
-	if (bug->line & BUG_WARNING_TRAP) {
-		/* this is a WARN_ON rather than BUG/BUG_ON */
-#ifdef CONFIG_XMON
-		xmon_printf(KERN_ERR "Badness in %s at %s:%ld\n",
-		       bug->function, bug->file,
-		       bug->line & ~BUG_WARNING_TRAP);
-#endif /* CONFIG_XMON */		
-		printk(KERN_ERR "Badness in %s at %s:%ld\n",
-		       bug->function, bug->file,
-		       bug->line & ~BUG_WARNING_TRAP);
-		dump_stack();
-		return 1;
-	}
-#ifdef CONFIG_XMON
-	xmon_printf(KERN_CRIT "kernel BUG in %s at %s:%ld!\n",
-	       bug->function, bug->file, bug->line);
-	xmon(regs);
-#endif /* CONFIG_XMON */
-	printk(KERN_CRIT "kernel BUG in %s at %s:%ld!\n",
-	       bug->function, bug->file, bug->line);
-
-	return 0;
+	return addr >= PAGE_OFFSET;
 }
 
 void program_check_exception(struct pt_regs *regs)
@@ -671,7 +617,9 @@ void program_check_exception(struct pt_regs *regs)
 		/* trap exception */
 		if (debugger_bpt(regs))
 			return;
-		if (check_bug_trap(regs)) {
+
+		if (!(regs->msr & MSR_PR) &&  /* not user-mode */
+		    report_bug(regs->nip) == BUG_TRAP_TYPE_WARN) {
 			regs->nip += 4;
 			return;
 		}
-- 
2.41.1