Commit 95f60084 authored Sep 15, 2016 by Alexander Shishkin Committed by Ingo Molnar Sep 16, 2016

perf/x86/intel/pt: Fix an off-by-one in address filter configuration



PT address filter configuration requires that a range is specified by
its first and last address, but at the moment we're obtaining the end
of the range by adding user specified size to its start, which is off
by one from what it actually needs to be.

Fix this and make sure that zero-sized filters don't pass the filter
validation.

Reported-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: stable@vger.kernel.org # v4.7
Cc: stable@vger.kernel.org#v4.7
Cc: vince@deater.net
Link: http://lkml.kernel.org/r/20160915151352.21306-2-alexander.shishkin@linux.intel.com


Signed-off-by: Ingo Molnar <mingo@kernel.org>

parent cecf6235

arch/x86/events/intel/pt.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -1081,7 +1081,7 @@ static int pt_event_addr_filters_validate(struct list_head *filters)

		list_for_each_entry(filter, filters, entry) {
		/* PT doesn't support single address triggers */
		if (!filter->range)
		if (!filter->range \|\| !filter->size)
		return -EOPNOTSUPP;

		if (!filter->inode && !kernel_ip(filter->offset))
		@@ -1111,7 +1111,7 @@ static void pt_event_addr_filters_sync(struct perf_event *event)
		} else {
		/* apply the offset */
		msr_a = filter->offset + offs[range];
		msr_b = filter->size + msr_a;
		msr_b = filter->size + msr_a - 1;
		}

		filters->filter[range].msr_a = msr_a;