From 95f60084acbcee6c466256cf26eb52191fad9edc Mon Sep 17 00:00:00 2001 From: Alexander Shishkin Date: Thu, 15 Sep 2016 18:13:50 +0300 Subject: [PATCH] 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 Signed-off-by: Alexander Shishkin Acked-by: Peter Zijlstra Cc: Arnaldo Carvalho de Melo Cc: Arnaldo Carvalho de Melo Cc: Jiri Olsa Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Stephane Eranian Cc: Thomas Gleixner Cc: Vince Weaver 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 --- arch/x86/events/intel/pt.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/x86/events/intel/pt.c b/arch/x86/events/intel/pt.c index 04bb5fb5a8d7..5ec0100e3fc6 100644 --- a/arch/x86/events/intel/pt.c +++ b/arch/x86/events/intel/pt.c @@ -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; -- 2.20.1