projects/linux·blob master · refs

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1#!/bin/bash
2# Test that perf report includes file offsets and event type names in diagnostic messages.
3# SPDX-License-Identifier: GPL-2.0
4#
5# The file_offset diagnostic series adds "at offset 0x...: TYPE (N)"
6# to all skip/stop/error messages. This test corrupts an event's size
7# field in a perf.data file, then verifies the resulting warning
8# includes the file offset and event type.
9
10err=0
11
12cleanup() {
13 [ -n "${perfdata}" ] && rm -f "${perfdata}" "${perfdata}.old"
14 rm -f "${corrupted}" "${stderrfile}"
15 trap - EXIT TERM INT
16}
17trap 'cleanup; exit 1' TERM INT
18trap cleanup EXIT
19
20perfdata=$(mktemp /tmp/__perf_test.perf.data.XXXXX) || exit 2
21corrupted=$(mktemp /tmp/__perf_test.perf.data.XXXXX) || exit 2
22stderrfile=$(mktemp /tmp/__perf_test.perf.data.XXXXX) || exit 2
23
24if ! perf record -o "${perfdata}" -- perf test -w noploop 2>/dev/null; then
25 echo "Skip: perf record failed"
26 cleanup
27 exit 2
28fi
29
30# Find the file offset of the first MMAP2 event via perf report -D.
31# Format: "timestamp 0xOFFSET [0xSIZE]: PERF_RECORD_MMAP2 ..."
32mmap2_line=$(perf report -D -i "${perfdata}" 2>/dev/null | grep "PERF_RECORD_MMAP2" | head -1)
33if [ -z "${mmap2_line}" ]; then
34 echo "Skip: no MMAP2 events found in perf.data"
35 cleanup
36 exit 2
37fi
38
39mmap2_offset=$(echo "${mmap2_line}" | awk '{print $2}')
40mmap2_offset_dec=$((mmap2_offset))
41
42# Copy the file and corrupt the MMAP2 event's size field.
43# perf_event_header layout: type(u32) misc(u16) size(u16)
44# Set size to 16 — below the MMAP2 minimum, which triggers
45# the "event size too small" warning.
46#
47# perf.data uses native byte order, so write the u16 in the
48# host's endianness to work on both LE and BE architectures.
49cp "${perfdata}" "${corrupted}"
50if printf '\x01\x02' | od -A n -t x2 | grep -q "0201"; then
51 # Little-endian
52 printf '\x10\x00'
53else
54 # Big-endian
55 printf '\x00\x10'
56fi | dd of="${corrupted}" bs=1 seek=$((mmap2_offset_dec + 6)) conv=notrunc 2>/dev/null
57
58perf report -i "${corrupted}" --stdio > /dev/null 2> "${stderrfile}"
59
60# Check that warnings include "at offset 0x..."
61if grep -q "at offset 0x" "${stderrfile}"; then
62 echo "File offset in diagnostics [Success]"
63else
64 echo "File offset in diagnostics [Failed: no 'at offset 0x...' found]"
65 echo " stderr was:"
66 head -5 "${stderrfile}"
67 err=1
68fi
69
70# Check that the event type name and numeric id appear: "MMAP2 (10)"
71if grep -q "MMAP2 (10)" "${stderrfile}"; then
72 echo "Event type name in diagnostics [Success]"
73else
74 echo "Event type name in diagnostics [Failed: no 'MMAP2 (10)' found]"
75 echo " stderr was:"
76 head -5 "${stderrfile}"
77 err=1
78fi
79
80# Check that the reported offset matches the actual corruption point
81if grep -q "at offset ${mmap2_offset}:" "${stderrfile}"; then
82 echo "Correct offset reported [Success]"
83else
84 echo "Correct offset reported [Failed: expected offset ${mmap2_offset}]"
85 echo " stderr was:"
86 head -5 "${stderrfile}"
87 err=1
88fi
89
90cleanup
91exit ${err}