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perf/x86/intel/pt: Fix an off-by-one in address filter configuration
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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>
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Alexander Shishkin authored and Ingo Molnar committed Sep 16, 2016
1 parent cecf623 commit 95f6008
Showing 1 changed file with 2 additions and 2 deletions.
4 changes: 2 additions & 2 deletions arch/x86/events/intel/pt.c
Original file line number Diff line number Diff line change
Expand Up @@ -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))
Expand Down Expand Up @@ -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;
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