Commit 0bb7a95f authored Jan 16, 2010 by Luca Barbieri Committed by Ingo Molnar Jan 17, 2010

hw-breakpoints, perf: Fix broken mmiotrace due to dr6 by reference change



Commit 62edab90 (from June 2009
but merged in 2.6.33) changes notify_die to pass dr6 by
reference.

However, it forgets to fix the check for DR_STEP in kmmio.c,
breaking mmiotrace. It also passes a wrong value to the post
handler.

This simple fix makes mmiotrace work again.

Signed-off-by: Luca Barbieri <luca@luca-barbieri.com>
Acked-by: K.Prasad <prasad@linux.vnet.ibm.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <1263634770-14578-1-git-send-email-luca@luca-barbieri.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

parent 8f06d7e6

arch/x86/mm/kmmio.c

+4 −3

Original line number	Diff line number	Diff line
		@@ -538,14 +538,15 @@ static int
		kmmio_die_notifier(struct notifier_block nb, unsigned long val, void args)
		{
		struct die_args *arg = args;
		unsigned long* dr6_p = (unsigned long *)ERR_PTR(arg->err);

		if (val == DIE_DEBUG && (arg->err & DR_STEP))
		if (post_kmmio_handler(arg->err, arg->regs) == 1) {
		if (val == DIE_DEBUG && (*dr6_p & DR_STEP))
		if (post_kmmio_handler(*dr6_p, arg->regs) == 1) {
		/*
		* Reset the BS bit in dr6 (pointed by args->err) to
		* denote completion of processing
		*/
		((unsigned long )ERR_PTR(arg->err)) &= ~DR_STEP;
		*dr6_p &= ~DR_STEP;
		return NOTIFY_STOP;
		}

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