Commit-ID: 5a99d99e3310a565b0cf63f785b347be9ee0da45
Gitweb: https://git.kernel.org/tip/5a99d99e3310a565b0cf63f785b347be9ee0da45
Author: Adrian Hunter <adrian.hunter@xxxxxxxxx>
AuthorDate: Wed, 6 Feb 2019 12:39:44 +0200
Committer: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
CommitDate: Wed, 6 Feb 2019 10:27:00 -0300
perf intel-pt: Fix overlap calculation for padding
Auxtrace records might have up to 7 bytes of padding appended. Adjust
the overlap accordingly.
Signed-off-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Link: http://lkml.kernel.org/r/20190206103947.15750-3-adrian.hunter@xxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
.../perf/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' */
|