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* [PATCH] Fix BUG(), BUG_ON() handling
@ 2007-04-12 11:02 Atsushi Nemoto
  2007-04-18 14:25 ` Ralf Baechle
  0 siblings, 1 reply; 2+ messages in thread
From: Atsushi Nemoto @ 2007-04-12 11:02 UTC (permalink / raw)
  To: linux-mips; +Cc: ralf

With commit 63dc68a8cf60cb110b147dab1704d990808b39e2, kernel can not
handle BUG() and BUG_ON() properly since get_user() returns false for
kernel code.  Use __get_user() to skip unnecessary access_ok().  This
patch also make BRK_BUG code encoded in the TNE instruction.

Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
---
diff --git a/arch/mips/kernel/traps.c b/arch/mips/kernel/traps.c
index 7d76a85..56a770c 100644
--- a/arch/mips/kernel/traps.c
+++ b/arch/mips/kernel/traps.c
@@ -650,7 +650,7 @@ asmlinkage void do_bp(struct pt_regs *regs)
 	unsigned int opcode, bcode;
 	siginfo_t info;
 
-	if (get_user(opcode, (unsigned int __user *) exception_epc(regs)))
+	if (__get_user(opcode, (unsigned int __user *) exception_epc(regs)))
 		goto out_sigsegv;
 
 	/*
@@ -700,7 +700,7 @@ asmlinkage void do_tr(struct pt_regs *regs)
 	unsigned int opcode, tcode = 0;
 	siginfo_t info;
 
-	if (get_user(opcode, (unsigned int __user *) exception_epc(regs)))
+	if (__get_user(opcode, (unsigned int __user *) exception_epc(regs)))
 		goto out_sigsegv;
 
 	/* Immediate versions don't provide a code.  */
diff --git a/include/asm-mips/bug.h b/include/asm-mips/bug.h
index 4d560a5..7eb63de 100644
--- a/include/asm-mips/bug.h
+++ b/include/asm-mips/bug.h
@@ -18,7 +18,8 @@ do {									\
 
 #define BUG_ON(condition)						\
 do {									\
-	__asm__ __volatile__("tne $0, %0" : : "r" (condition));		\
+	__asm__ __volatile__("tne $0, %0, %1"				\
+			     : : "r" (condition), "i" (BRK_BUG));	\
 } while (0)
 
 #define HAVE_ARCH_BUG_ON

^ permalink raw reply related	[flat|nested] 2+ messages in thread

* Re: [PATCH] Fix BUG(), BUG_ON() handling
  2007-04-12 11:02 [PATCH] Fix BUG(), BUG_ON() handling Atsushi Nemoto
@ 2007-04-18 14:25 ` Ralf Baechle
  0 siblings, 0 replies; 2+ messages in thread
From: Ralf Baechle @ 2007-04-18 14:25 UTC (permalink / raw)
  To: Atsushi Nemoto; +Cc: linux-mips

On Thu, Apr 12, 2007 at 08:02:54PM +0900, Atsushi Nemoto wrote:

> With commit 63dc68a8cf60cb110b147dab1704d990808b39e2, kernel can not
> handle BUG() and BUG_ON() properly since get_user() returns false for
> kernel code.  Use __get_user() to skip unnecessary access_ok().  This
> patch also make BRK_BUG code encoded in the TNE instruction.

Thanks, applied to 2.6.20-stable and master.

  Ralf

^ permalink raw reply	[flat|nested] 2+ messages in thread

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2007-04-12 11:02 [PATCH] Fix BUG(), BUG_ON() handling Atsushi Nemoto
2007-04-18 14:25 ` Ralf Baechle

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