commit 9422de3e953d0e60eb95f5430a9dd803eec1c6d7
author Michael Neuling <mikey@neuling.org> Thu Dec 20 14:06:44 2012 +0000
committer Benjamin Herrenschmidt <benh@kernel.crashing.org> Thu Jan 10 17:01:44 2013 +1100
tree 7255a4a2b873a0c3daf7b312a0845202edf6b2d5
parent a8190a59e7440a7e3f7c0889d72a13e157988b3c

powerpc: Hardware breakpoints rewrite to handle non DABR breakpoint registers

This is a rewrite so that we don't assume we are using the DABR throughout the
code.  We now use the arch_hw_breakpoint to store the breakpoint in a generic
manner in the thread_struct, rather than storing the raw DABR value.

The ptrace GET/SET_DEBUGREG interface currently passes the raw DABR in from
userspace.  We keep this functionality, so that future changes (like the POWER8
DAWR), will still fake the DABR to userspace.

Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

arch/powerpc/kernel/signal.c

diff --git a/arch/powerpc/kernel/signal.c b/arch/powerpc/kernel/signal.c
index 3b99711..1f26956 100644
--- a/arch/powerpc/kernel/signal.c
+++ b/arch/powerpc/kernel/signal.c
@@ -130,8 +130,9 @@
 	 * user space. The DABR will have been cleared if it
 	 * triggered inside the kernel.
 	 */
-	if (current->thread.dabr)
-		set_dabr(current->thread.dabr, current->thread.dabrx);
+	if (current->thread.hw_brk.address &&
+		current->thread.hw_brk.type)
+		set_break(&current->thread.hw_brk);
 #endif
 	/* Re-enable the breakpoints for the signal stack */
 	thread_change_pc(current, regs);