From 28477fb1ed1a00c67b382ae8f37f35708e3bf5dd Mon Sep 17 00:00:00 2001
From: Dave Kleikamp <shaggy@linux.vnet.ibm.com>
Date: Wed, 8 Jul 2009 13:46:18 +0000
Subject: [PATCH] powerpc: Fix booke user_disable_single_step()
On booke processors, gdb is seeing spurious SIGTRAPs when setting a
watchpoint.
user_disable_single_step() simply quits when the DAC is non-zero. It should
be clearing the DBCR0_IC and DBCR0_BT bits from the dbcr0 register and
TIF_SINGLESTEP from the thread flag.
Signed-off-by: Dave Kleikamp <shaggy@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
---
arch/powerpc/kernel/ptrace.c | 17 +++++++++--------
1 file changed, 9 insertions(+), 8 deletions(-)
diff --git a/arch/powerpc/kernel/ptrace.c b/arch/powerpc/kernel/ptrace.c
index 9fa2c7dcd05a..ef149880c145 100644
--- a/arch/powerpc/kernel/ptrace.c
+++ b/arch/powerpc/kernel/ptrace.c
@@ -736,15 +736,16 @@ void user_disable_single_step(struct task_struct *task)
{
struct pt_regs *regs = task->thread.regs;
-
-#if defined(CONFIG_BOOKE)
- /* If DAC then do not single step, skip */
- if (task->thread.dabr)
- return;
-#endif
-
if (regs != NULL) {
-#if defined(CONFIG_40x) || defined(CONFIG_BOOKE)
+#if defined(CONFIG_BOOKE)
+ /* If DAC don't clear DBCRO_IDM or MSR_DE */
+ if (task->thread.dabr)
+ task->thread.dbcr0 &= ~(DBCR0_IC | DBCR0_BT);
+ else {
+ task->thread.dbcr0 &= ~(DBCR0_IC | DBCR0_BT | DBCR0_IDM);
+ regs->msr &= ~MSR_DE;
+ }
+#elif defined(CONFIG_40x)
task->thread.dbcr0 &= ~(DBCR0_IC | DBCR0_BT | DBCR0_IDM);
regs->msr &= ~MSR_DE;
#else
--
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