Add Intel PT full trace mode basic test case

This test will do Intel PT full trace mode with test case PID to check if enable/stop/trace generation works with Intel PT.

---
 runtest/tracing                             |   1 +
 testcases/kernel/tracing/pt_test/.gitignore |   1 +
 testcases/kernel/tracing/pt_test/Makefile   |   6 ++
 testcases/kernel/tracing/pt_test/pt_test.c  | 153 ++++++++++++++++++++++++++++
 4 files changed, 161 insertions(+)
 create mode 100644 testcases/kernel/tracing/pt_test/.gitignore
 create mode 100644 testcases/kernel/tracing/pt_test/Makefile
 create mode 100644 testcases/kernel/tracing/pt_test/pt_test.c

index 8285eeb43..504132d70 100644
@@ -3,3 +3,4 @@ ftrace_regression01	ftrace_regression01.sh
 ftrace_regression02	ftrace_regression02.sh
 ftrace-stress-test	ftrace_stress_test.sh 90
 dynamic_debug01		dynamic_debug01.sh
+pt_full_trace_basic pt_test

new file mode 100644
index 000000000..96efc142d
@@ -0,0 +1 @@
+/pt_test

new file mode 100644
index 000000000..5ea7d67db
@@ -0,0 +1,6 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
+
+top_srcdir		?= ../../../..
+
+include $(top_srcdir)/include/mk/testcases.mk
+include $(top_srcdir)/include/mk/generic_leaf_target.mk

2.14.1

Hi!
Pushed with following changes, thanks.

index d46d7726e..517427992 100644
@@ -7,7 +7,10 @@
 
 /*
  * This test will check if Intel PT(Intel Processer Trace) full trace mode is
- * working. It is only applied on X86 platforms.
+ * working.
+ *
+ * Intel CPU of 5th-generation Core (Broadwell) or newer is required for the test.
+ *
  * kconfig requirement: CONFIG_PERF_EVENTS
  */
 

I found out that the perf manual says we need at least broadwell to run the test, so I documented it here (and I had to borow recent enough machine to check the test, since the newest I have is Ivy Bridge).

@@ -93,11 +96,11 @@ static void intel_pt_full_trace_check(void)
/* stop tracing */
SAFE_IOCTL(fde, PERF_EVENT_IOC_DISABLE);

- // check if there is some trace generated
+ /* check if there is some trace generated */
pmp = (struct perf_event_mmap_page *)bufm[0]; aux_head = *(volatile uint64_t *)&pmp->aux_head; if (aux_head == 0) {
- tst_res(TFAIL, "There is no trace, so failed!");
+ tst_res(TFAIL, "There is no trace!");
return;
}

@@ -109,10 +112,13 @@ static void setup(void)
struct perf_event_attr attr = {};

buhsz = 2 * PAGESIZE;
- if (tst_dir_is_empty(INTEL_PT_PATH, 1))
- tst_brk(TCONF, "PT not enabled, please check kconfig!");
+ if (access(INTEL_PT_PATH, F_OK)) {
+ tst_brk(TCONF,
+ "Requires Intel Core 5th+ generation (Broadwell and newer)"
+ " and CONFIG_PERF_EVENTS enabled.");
+ }

The tst_dir_is_empty() does not work here because the directory does not exists, at least on my machines, if the CPU does not support PT.

We usually use acess() with F_OK in these cases.

- //set attr for Intel PT trace
+ /* set attr for Intel PT trace */
attr.type = intel_pt_pmu_value(INTEL_PT_PMU_TYPE);
attr.read_format = PERF_FORMAT_ID | PERF_FORMAT_TOTAL_TIME_RUNNING |
PERF_FORMAT_TOTAL_TIME_ENABLED;
@@ -124,7 +130,7 @@ static void setup(void)
attr.exclude_user = 0;
attr.mmap = 1;

- //only get trace for own pid
+ /* only get trace for own pid */
fde = tst_syscall(__NR_perf_event_open, &attr, 0, -1, -1, 0); if (fde < 0) {
tst_res(TINFO, "Open Intel PT event failed!");

Cyril Hrubis
[email protected]