From e317c02235db79ed94106e9f2c0855cb9e8cecbc Mon Sep 17 00:00:00 2001
From: David Daney <ddaney@avtrex.com>
Date: Tue, 23 Sep 2008 00:08:45 -0700
Subject: [PATCH] --- yaml --- r: 111135 b: refs/heads/master c:
 b67b2b703047bfaf62687ca64c9486599b609ef0 h: refs/heads/master i:   111133:
 c71926548ec4de1961cc917f89976cfe8be6bcc5   111131:
 0f7416cb5c9cc197ab63789724947d6d9c6ad1c2   111127:
 137acbd8b7aa70e3c41a0381ca245ea9e573d5c2   111119:
 3b033e607a128a760dfef39ae146d297c6257d77   111103:
 b9bf35609ab82767317c61cbec95ac4c00b49718 v: v3

---
 [refs]                         |  2 +-
 trunk/arch/mips/kernel/genex.S |  4 ++++
 trunk/arch/mips/kernel/traps.c | 24 +++++++++++++++++++-----
 3 files changed, 24 insertions(+), 6 deletions(-)

diff --git a/[refs] b/[refs]
index 54c1da7ea49e..b17b10f66f3d 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 654f57bfb467996fb730eae96dc30ea4de989fdc
+refs/heads/master: b67b2b703047bfaf62687ca64c9486599b609ef0
diff --git a/trunk/arch/mips/kernel/genex.S b/trunk/arch/mips/kernel/genex.S
index 01dcbe38fa01..757d48f0d80f 100644
--- a/trunk/arch/mips/kernel/genex.S
+++ b/trunk/arch/mips/kernel/genex.S
@@ -453,7 +453,11 @@ NESTED(nmi_handler, PT_SIZE, sp)
 	BUILD_HANDLER tr tr sti silent			/* #13 */
 	BUILD_HANDLER fpe fpe fpe silent		/* #15 */
 	BUILD_HANDLER mdmx mdmx sti silent		/* #22 */
+#ifdef 	CONFIG_HARDWARE_WATCHPOINTS
+	BUILD_HANDLER watch watch sti silent		/* #23 */
+#else
 	BUILD_HANDLER watch watch sti verbose		/* #23 */
+#endif
 	BUILD_HANDLER mcheck mcheck cli verbose		/* #24 */
 	BUILD_HANDLER mt mt sti silent			/* #25 */
 	BUILD_HANDLER dsp dsp sti silent		/* #26 */
diff --git a/trunk/arch/mips/kernel/traps.c b/trunk/arch/mips/kernel/traps.c
index b602ac6eb47d..80b9e070c207 100644
--- a/trunk/arch/mips/kernel/traps.c
+++ b/trunk/arch/mips/kernel/traps.c
@@ -42,6 +42,7 @@
 #include <asm/tlbdebug.h>
 #include <asm/traps.h>
 #include <asm/uaccess.h>
+#include <asm/watch.h>
 #include <asm/mmu_context.h>
 #include <asm/types.h>
 #include <asm/stacktrace.h>
@@ -912,13 +913,26 @@ asmlinkage void do_mdmx(struct pt_regs *regs)
 
 asmlinkage void do_watch(struct pt_regs *regs)
 {
+	u32 cause;
+
 	/*
-	 * We use the watch exception where available to detect stack
-	 * overflows.
+	 * Clear WP (bit 22) bit of cause register so we don't loop
+	 * forever.
 	 */
-	dump_tlb_all();
-	show_regs(regs);
-	panic("Caught WATCH exception - probably caused by stack overflow.");
+	cause = read_c0_cause();
+	cause &= ~(1 << 22);
+	write_c0_cause(cause);
+
+	/*
+	 * If the current thread has the watch registers loaded, save
+	 * their values and send SIGTRAP.  Otherwise another thread
+	 * left the registers set, clear them and continue.
+	 */
+	if (test_tsk_thread_flag(current, TIF_LOAD_WATCH)) {
+		mips_read_watch_registers();
+		force_sig(SIGTRAP, current);
+	} else
+		mips_clear_watch_registers();
 }
 
 asmlinkage void do_mcheck(struct pt_regs *regs)