From: Adrian Hunter adrian.hunter@intel.com

Auxtrace records might have up to 7 bytes of padding appended. Adjust the overlap accordingly.

Signed-off-by: Adrian Hunter adrian.hunter@intel.com Cc: Jiri Olsa jolsa@redhat.com Cc: stable@vger.kernel.org Link: http://lkml.kernel.org/r/20190206103947.15750-3-adrian.hunter@intel.com Signed-off-by: Arnaldo Carvalho de Melo acme@redhat.com --- .../util/intel-pt-decoder/intel-pt-decoder.c | 36 +++++++++++++++++-- 1 file changed, 34 insertions(+), 2 deletions(-)

diff --git a/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c b/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c index 4503f3ca45ab..ecd25cdc1d3e 100644 --- a/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c +++ b/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c @@ -26,6 +26,7 @@

#include "../cache.h" #include "../util.h" +#include "../auxtrace.h"

#include "intel-pt-insn-decoder.h" #include "intel-pt-pkt-decoder.h" @@ -2575,6 +2576,34 @@ static int intel_pt_tsc_cmp(uint64_t tsc1, uint64_t tsc2) } }

+#define MAX_PADDING (PERF_AUXTRACE_RECORD_ALIGNMENT - 1) + +/** + * adj_for_padding - adjust overlap to account for padding. + * @buf_b: second buffer + * @buf_a: first buffer + * @len_a: size of first buffer + * + * @buf_a might have up to 7 bytes of padding appended. Adjust the overlap + * accordingly. + * + * Return: A pointer into @buf_b from where non-overlapped data starts + */ +static unsigned char *adj_for_padding(unsigned char *buf_b, + unsigned char *buf_a, size_t len_a) +{ + unsigned char *p = buf_b - MAX_PADDING; + unsigned char *q = buf_a + len_a - MAX_PADDING; + int i; + + for (i = MAX_PADDING; i; i--, p++, q++) { + if (*p != *q) + break; + } + + return p; +} + /** * intel_pt_find_overlap_tsc - determine start of non-overlapped trace data * using TSC. @@ -2625,8 +2654,11 @@ static unsigned char *intel_pt_find_overlap_tsc(unsigned char *buf_a,

/* Same TSC, so buffers are consecutive */ if (!cmp && rem_b >= rem_a) { + unsigned char *start; + *consecutive = true; - return buf_b + len_b - (rem_b - rem_a); + start = buf_b + len_b - (rem_b - rem_a); + return adj_for_padding(start, buf_a, len_a); } if (cmp < 0) return buf_b; /* tsc_a < tsc_b => no overlap */ @@ -2689,7 +2721,7 @@ unsigned char *intel_pt_find_overlap(unsigned char *buf_a, size_t len_a, found = memmem(buf_a, len_a, buf_b, len_a); if (found) { *consecutive = true; - return buf_b + len_a; + return adj_for_padding(buf_b + len_a, buf_a, len_a); }

/* Try again at next PSB in buffer 'a' */