1 files changed, 52 insertions, 20 deletions

diff --git a/arch/powerpc/kernel/ptrace/ptrace-noadv.c b/arch/powerpc/kernel/ptrace/ptrace-noadv.c
index f87e7c5c3bf3..697c7e4b5877 100644
--- a/arch/powerpc/kernel/ptrace/ptrace-noadv.c
+++ b/arch/powerpc/kernel/ptrace/ptrace-noadv.c
@@ -44,7 +44,7 @@ void ppc_gethwdinfo(struct ppc_debug_info *dbginfo)
 	dbginfo->version = 1;
 	dbginfo->num_instruction_bps = 0;
 	if (ppc_breakpoint_available())
-		dbginfo->num_data_bps = 1;
+		dbginfo->num_data_bps = nr_wp_slots();
 	else
 		dbginfo->num_data_bps = 0;
 	dbginfo->num_condition_regs = 0;
@@ -67,11 +67,16 @@ int ptrace_get_debugreg(struct task_struct *child, unsigned long addr,
 	/* We only support one DABR and no IABRS at the moment */
 	if (addr > 0)
 		return -EINVAL;
-	dabr_fake = ((child->thread.hw_brk.address & (~HW_BRK_TYPE_DABR)) |
-		     (child->thread.hw_brk.type & HW_BRK_TYPE_DABR));
+	dabr_fake = ((child->thread.hw_brk[0].address & (~HW_BRK_TYPE_DABR)) |
+		     (child->thread.hw_brk[0].type & HW_BRK_TYPE_DABR));
 	return put_user(dabr_fake, datalp);
 }
 
+/*
+ * ptrace_set_debugreg() fakes DABR and DABR is only one. So even if
+ * internal hw supports more than one watchpoint, we support only one
+ * watchpoint with this interface.
+ */
 int ptrace_set_debugreg(struct task_struct *task, unsigned long addr, unsigned long data)
 {
 #ifdef CONFIG_HAVE_HW_BREAKPOINT
@@ -137,7 +142,7 @@ int ptrace_set_debugreg(struct task_struct *task, unsigned long addr, unsigned l
 			return ret;
 
 		thread->ptrace_bps[0] = bp;
-		thread->hw_brk = hw_brk;
+		thread->hw_brk[0] = hw_brk;
 		return 0;
 	}
 
@@ -159,12 +164,37 @@ int ptrace_set_debugreg(struct task_struct *task, unsigned long addr, unsigned l
 	if (set_bp && (!ppc_breakpoint_available()))
 		return -ENODEV;
 #endif /* CONFIG_HAVE_HW_BREAKPOINT */
-	task->thread.hw_brk = hw_brk;
+	task->thread.hw_brk[0] = hw_brk;
 	return 0;
 }
 
+#ifdef CONFIG_HAVE_HW_BREAKPOINT
+static int find_empty_ptrace_bp(struct thread_struct *thread)
+{
+	int i;
+
+	for (i = 0; i < nr_wp_slots(); i++) {
+		if (!thread->ptrace_bps[i])
+			return i;
+	}
+	return -1;
+}
+#endif
+
+static int find_empty_hw_brk(struct thread_struct *thread)
+{
+	int i;
+
+	for (i = 0; i < nr_wp_slots(); i++) {
+		if (!thread->hw_brk[i].address)
+			return i;
+	}
+	return -1;
+}
+
 long ppc_set_hwdebug(struct task_struct *child, struct ppc_hw_breakpoint *bp_info)
 {
+	int i;
 #ifdef CONFIG_HAVE_HW_BREAKPOINT
 	int len = 0;
 	struct thread_struct *thread = &child->thread;
@@ -186,7 +216,7 @@ long ppc_set_hwdebug(struct task_struct *child, struct ppc_hw_breakpoint *bp_inf
 	if ((unsigned long)bp_info->addr >= TASK_SIZE)
 		return -EIO;
 
-	brk.address = bp_info->addr & ~HW_BREAKPOINT_ALIGN;
+	brk.address = ALIGN_DOWN(bp_info->addr, HW_BREAKPOINT_SIZE);
 	brk.type = HW_BRK_TYPE_TRANSLATE;
 	brk.len = DABR_MAX_LEN;
 	if (bp_info->trigger_type & PPC_BREAKPOINT_TRIGGER_READ)
@@ -200,8 +230,9 @@ long ppc_set_hwdebug(struct task_struct *child, struct ppc_hw_breakpoint *bp_inf
 		len = 1;
 	else
 		return -EINVAL;
-	bp = thread->ptrace_bps[0];
-	if (bp)
+
+	i = find_empty_ptrace_bp(thread);
+	if (i < 0)
 		return -ENOSPC;
 
 	/* Create a new breakpoint request if one doesn't exist already */
@@ -211,27 +242,28 @@ long ppc_set_hwdebug(struct task_struct *child, struct ppc_hw_breakpoint *bp_inf
 	arch_bp_generic_fields(brk.type, &attr.bp_type);
 
 	bp = register_user_hw_breakpoint(&attr, ptrace_triggered, NULL, child);
-	thread->ptrace_bps[0] = bp;
+	thread->ptrace_bps[i] = bp;
 	if (IS_ERR(bp)) {
-		thread->ptrace_bps[0] = NULL;
+		thread->ptrace_bps[i] = NULL;
 		return PTR_ERR(bp);
 	}
 
-	return 1;
+	return i + 1;
 #endif /* CONFIG_HAVE_HW_BREAKPOINT */
 
 	if (bp_info->addr_mode != PPC_BREAKPOINT_MODE_EXACT)
 		return -EINVAL;
 
-	if (child->thread.hw_brk.address)
+	i = find_empty_hw_brk(&child->thread);
+	if (i < 0)
 		return -ENOSPC;
 
 	if (!ppc_breakpoint_available())
 		return -ENODEV;
 
-	child->thread.hw_brk = brk;
+	child->thread.hw_brk[i] = brk;
 
-	return 1;
+	return i + 1;
 }
 
 long ppc_del_hwdebug(struct task_struct *child, long data)
@@ -241,24 +273,24 @@ long ppc_del_hwdebug(struct task_struct *child, long data)
 	struct thread_struct *thread = &child->thread;
 	struct perf_event *bp;
 #endif /* CONFIG_HAVE_HW_BREAKPOINT */
-	if (data != 1)
+	if (data < 1 || data > nr_wp_slots())
 		return -EINVAL;
 
 #ifdef CONFIG_HAVE_HW_BREAKPOINT
-	bp = thread->ptrace_bps[0];
+	bp = thread->ptrace_bps[data - 1];
 	if (bp) {
 		unregister_hw_breakpoint(bp);
-		thread->ptrace_bps[0] = NULL;
+		thread->ptrace_bps[data - 1] = NULL;
 	} else {
 		ret = -ENOENT;
 	}
 	return ret;
 #else /* CONFIG_HAVE_HW_BREAKPOINT */
-	if (child->thread.hw_brk.address == 0)
+	if (child->thread.hw_brk[data - 1].address == 0)
 		return -ENOENT;
 
-	child->thread.hw_brk.address = 0;
-	child->thread.hw_brk.type = 0;
+	child->thread.hw_brk[data - 1].address = 0;
+	child->thread.hw_brk[data - 1].type = 0;
 #endif /* CONFIG_HAVE_HW_BREAKPOINT */
 
 	return 0;