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authorAdrian Hunter <adrian.hunter@intel.com>2019-02-06 12:39:44 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2019-03-23 13:19:53 +0100
commit4f7c16b5ef874199d9e2acfafdb7f0ff203cc1e8 (patch)
tree995df857186781ab879886cf113fbab161589d26
parent300ef83e733e5b51821b4f9ddbf66782d171f88f (diff)
perf intel-pt: Fix overlap calculation for padding
commit 5a99d99e3310a565b0cf63f785b347be9ee0da45 upstream. 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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--tools/perf/util/intel-pt-decoder/intel-pt-decoder.c36
1 files 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 f64c62e20540..94764efb0a6a 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"
@@ -2350,6 +2351,34 @@ 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.
@@ -2400,8 +2429,11 @@ 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 */
@@ -2464,7 +2496,7 @@ 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' */