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Message-Id: <20221014170905.64069-6-adrian.hunter@intel.com>
Date: Fri, 14 Oct 2022 20:09:03 +0300
From: Adrian Hunter <adrian.hunter@...el.com>
To: Arnaldo Carvalho de Melo <acme@...nel.org>
Cc: Jiri Olsa <jolsa@...hat.com>, Namhyung Kim <namhyung@...nel.org>,
Ian Rogers <irogers@...gle.com>, linux-kernel@...r.kernel.org,
linux-perf-users@...r.kernel.org
Subject: [PATCH 5/7] perf test: test_intel_pt.sh: Add jitdump test
Add a test for decoding self-modifying code using a jitdump file.
The test creates a workload that uses self-modifying code and generates its
own jitdump file. The result is processed with perf inject --jit and
checked for decoding errors.
Note the test will fail without patch "perf inject: Fix GEN_ELF_TEXT_OFFSET
for jit" applied.
Signed-off-by: Adrian Hunter <adrian.hunter@...el.com>
---
tools/perf/tests/shell/test_intel_pt.sh | 162 ++++++++++++++++++++++++
1 file changed, 162 insertions(+)
diff --git a/tools/perf/tests/shell/test_intel_pt.sh b/tools/perf/tests/shell/test_intel_pt.sh
index 79dde57b561d..e0bf75981b9c 100755
--- a/tools/perf/tests/shell/test_intel_pt.sh
+++ b/tools/perf/tests/shell/test_intel_pt.sh
@@ -22,6 +22,7 @@ outfile="${temp_dir}/test-out.txt"
errfile="${temp_dir}/test-err.txt"
workload="${temp_dir}/workload"
awkscript="${temp_dir}/awkscript"
+jitdump_workload="${temp_dir}/jitdump_workload"
cleanup()
{
@@ -50,6 +51,13 @@ perf_record_no_decode()
perf record -B -N --no-bpf-event "$@"
}
+# perf record for testing should not need BPF events
+perf_record_no_bpf()
+{
+ # Options for no BPF events
+ perf record --no-bpf-event "$@"
+}
+
have_workload=false
cat << _end_of_file_ | /usr/bin/cc -o "${workload}" -xc - -pthread && have_workload=true
#include <time.h>
@@ -269,6 +277,159 @@ test_per_thread()
return 0
}
+test_jitdump()
+{
+ echo "--- Test tracing self-modifying code that uses jitdump ---"
+
+ script_path=$(realpath "$0")
+ script_dir=$(dirname "$script_path")
+ jitdump_incl_dir="${script_dir}/../../util"
+ jitdump_h="${jitdump_incl_dir}/jitdump.h"
+
+ if [ ! -e "${jitdump_h}" ] ; then
+ echo "SKIP: Include file jitdump.h not found"
+ return 2
+ fi
+
+ if [ -z "${have_jitdump_workload}" ] ; then
+ have_jitdump_workload=false
+ # Create a workload that uses self-modifying code and generates its own jitdump file
+ cat <<- "_end_of_file_" | /usr/bin/cc -o "${jitdump_workload}" -I "${jitdump_incl_dir}" -xc - -pthread && have_jitdump_workload=true
+ #define _GNU_SOURCE
+ #include <sys/mman.h>
+ #include <sys/types.h>
+ #include <stddef.h>
+ #include <stdio.h>
+ #include <stdint.h>
+ #include <unistd.h>
+ #include <string.h>
+
+ #include "jitdump.h"
+
+ #define CHK_BYTE 0x5a
+
+ static inline uint64_t rdtsc(void)
+ {
+ unsigned int low, high;
+
+ asm volatile("rdtsc" : "=a" (low), "=d" (high));
+
+ return low | ((uint64_t)high) << 32;
+ }
+
+ static FILE *open_jitdump(void)
+ {
+ struct jitheader header = {
+ .magic = JITHEADER_MAGIC,
+ .version = JITHEADER_VERSION,
+ .total_size = sizeof(header),
+ .pid = getpid(),
+ .timestamp = rdtsc(),
+ .flags = JITDUMP_FLAGS_ARCH_TIMESTAMP,
+ };
+ char filename[256];
+ FILE *f;
+ void *m;
+
+ snprintf(filename, sizeof(filename), "jit-%d.dump", getpid());
+ f = fopen(filename, "w+");
+ if (!f)
+ goto err;
+ /* Create an MMAP event for the jitdump file. That is how perf tool finds it. */
+ m = mmap(0, 4096, PROT_READ | PROT_EXEC, MAP_PRIVATE, fileno(f), 0);
+ if (m == MAP_FAILED)
+ goto err_close;
+ munmap(m, 4096);
+ if (fwrite(&header,sizeof(header),1,f) != 1)
+ goto err_close;
+ return f;
+
+ err_close:
+ fclose(f);
+ err:
+ return NULL;
+ }
+
+ static int write_jitdump(FILE *f, void *addr, const uint8_t *dat, size_t sz, uint64_t *idx)
+ {
+ struct jr_code_load rec = {
+ .p.id = JIT_CODE_LOAD,
+ .p.total_size = sizeof(rec) + sz,
+ .p.timestamp = rdtsc(),
+ .pid = getpid(),
+ .tid = gettid(),
+ .vma = (unsigned long)addr,
+ .code_addr = (unsigned long)addr,
+ .code_size = sz,
+ .code_index = ++*idx,
+ };
+
+ if (fwrite(&rec,sizeof(rec),1,f) != 1 ||
+ fwrite(dat, sz, 1, f) != 1)
+ return -1;
+ return 0;
+ }
+
+ static void close_jitdump(FILE *f)
+ {
+ fclose(f);
+ }
+
+ int main()
+ {
+ /* Get a memory page to store executable code */
+ void *addr = mmap(0, 4096, PROT_WRITE | PROT_EXEC, MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);
+ /* Code to execute: mov CHK_BYTE, %eax ; ret */
+ uint8_t dat[] = {0xb8, CHK_BYTE, 0x00, 0x00, 0x00, 0xc3};
+ FILE *f = open_jitdump();
+ uint64_t idx = 0;
+ int ret = 1;
+
+ if (!f)
+ return 1;
+ /* Copy executable code to executable memory page */
+ memcpy(addr, dat, sizeof(dat));
+ /* Record it in the jitdump file */
+ if (write_jitdump(f, addr, dat, sizeof(dat), &idx))
+ goto out_close;
+ /* Call it */
+ ret = ((int (*)(void))addr)() - CHK_BYTE;
+ out_close:
+ close_jitdump(f);
+ return ret;
+ }
+ _end_of_file_
+ fi
+
+ if ! $have_jitdump_workload ; then
+ echo "SKIP: No jitdump workload"
+ return 2
+ fi
+
+ # Change to temp_dir so jitdump collateral files go there
+ cd "${temp_dir}"
+ perf_record_no_bpf -o "${tmpfile}" -e intel_pt//u "${jitdump_workload}"
+ perf inject -i "${tmpfile}" -o "${perfdatafile}" --jit
+ decode_br_cnt=$(perf script -i "${perfdatafile}" --itrace=b | wc -l)
+ # Note that overflow and lost errors are suppressed for the error count
+ decode_err_cnt=$(perf script -i "${perfdatafile}" --itrace=e-o-l | grep -ci error)
+ cd -
+ # Should be thousands of branches
+ if [ "${decode_br_cnt}" -lt 1000 ] ; then
+ echo "Decode failed, only ${decode_br_cnt} branches"
+ return 1
+ fi
+ # Should be no errors
+ if [ "${decode_err_cnt}" -ne 0 ] ; then
+ echo "Decode failed, ${decode_err_cnt} errors"
+ perf script -i "${perfdatafile}" --itrace=e-o-l
+ return 1
+ fi
+
+ echo OK
+ return 0
+}
+
count_result()
{
if [ "$1" -eq 2 ] ; then
@@ -286,6 +447,7 @@ ret=0
test_system_wide_side_band || ret=$? ; count_result $ret ; ret=0
test_per_thread "" "" || ret=$? ; count_result $ret ; ret=0
test_per_thread "k" "(incl. kernel) " || ret=$? ; count_result $ret ; ret=0
+test_jitdump || ret=$? ; count_result $ret ; ret=0
cleanup
--
2.25.1
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