[PATCH 4/8] hw-breakpoints: Check disabled breakpoints again

[Frederic Weisbecker <fweisbec@gmail.com>]

We stopped checking disabled breakpoints because we weren't
allowing breakpoints on NULL addresses. And gdb tends to set
NULL addresses on inactive breakpoints.

But refusing NULL addresses was actually a regression that has
been fixed now. There is no reason anymore to not validate
inactive breakpoint settings.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: Paul Mundt <lethal@linux-sh.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Cc: K. Prasad <prasad@linux.vnet.ibm.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Jason Wessel <jason.wessel@windriver.com>
Cc: Ingo Molnar <mingo@elte.hu>
---
 kernel/hw_breakpoint.c |   12 +-----------
 1 files changed, 1 insertions(+), 11 deletions(-)

diff --git a/kernel/hw_breakpoint.c b/kernel/hw_breakpoint.c
index 03808ed..9ed9ae3 100644
--- a/kernel/hw_breakpoint.c
+++ b/kernel/hw_breakpoint.c
@@ -316,17 +316,7 @@ int register_perf_hw_breakpoint(struct perf_event *bp)
 	if (ret)
 		return ret;
 
-	/*
-	 * Ptrace breakpoints can be temporary perf events only
-	 * meant to reserve a slot. In this case, it is created disabled and
-	 * we don't want to check the params right now (as we put a null addr)
-	 * But perf tools create events as disabled and we want to check
-	 * the params for them.
-	 * This is a quick hack that will be removed soon, once we remove
-	 * the tmp breakpoints from ptrace
-	 */
-	if (!bp->attr.disabled || !bp->overflow_handler)
-		ret = arch_validate_hwbkpt_settings(bp, bp->ctx->task);
+	ret = arch_validate_hwbkpt_settings(bp, bp->ctx->task);
 
 	/* if arch_validate_hwbkpt_settings() fails then release bp slot */
 	if (ret)
-- 
1.6.2.3