[LTP] [PATCH] tracing/intel_pt: Fix build on older userspace.

[Cyril Hrubis]

Older userspace linux headers do not have aux_* fields struct
perf_event_mmap_page. This commit disables the test build if older
headers were detected, the alternative would be adding a fallback
definition to LTP but I doubt that it's worth the effort.

Signed-off-by: Cyril Hrubis <chrubis@suse.cz>
CC: Ammy Yi <ammy.yi@intel.com>
---
 configure.ac                               |  1 +
 m4/ltp-perf_event.m4                       | 13 +++++++++++++
 testcases/kernel/tracing/pt_test/pt_test.c |  7 +++++++
 3 files changed, 21 insertions(+)
 create mode 100644 m4/ltp-perf_event.m4

diff --git a/configure.ac b/configure.ac
index 0f0d8c17a..e81d2add5 100644
--- a/configure.ac
+++ b/configure.ac
@@ -229,6 +229,7 @@ LTP_CHECK_X_TABLES
 LTP_CHECK_ATOMIC_MEMORY_MODEL
 LTP_CHECK_TPACKET_V3
 LTP_DETECT_HOST_CPU
+LTP_CHECK_PERF_EVENT
 
 if test "x$with_numa" = xyes; then
 	LTP_CHECK_SYSCALL_NUMA
diff --git a/m4/ltp-perf_event.m4 b/m4/ltp-perf_event.m4
new file mode 100644
index 000000000..109ad4935
--- /dev/null
+++ b/m4/ltp-perf_event.m4
@@ -0,0 +1,13 @@
+dnl
+dnl Copyright (c) 2018 Cyril Hrubis <chrubis@suse.cz>
+dnl
+dnl SPDX-License-Identifier: GPL-2.0-or-later
+dnl
+
+dnl
+dnl LTP_CHECK_PERF_EVENT
+dnl ----------------------------
+dnl
+AC_DEFUN([LTP_CHECK_PERF_EVENT],[
+AC_CHECK_MEMBERS([struct perf_event_mmap_page.aux_head],,,[#include <linux/perf_event.h>])
+])
diff --git a/testcases/kernel/tracing/pt_test/pt_test.c b/testcases/kernel/tracing/pt_test/pt_test.c
index 517427992..abf575d37 100644
--- a/testcases/kernel/tracing/pt_test/pt_test.c
+++ b/testcases/kernel/tracing/pt_test/pt_test.c
@@ -20,6 +20,9 @@
 #include <stdio.h>
 #include "tst_test.h"
 #include "lapi/syscalls.h"
+#include "config.h"
+
+#ifdef HAVE_STRUCT_PERF_EVENT_MMAP_PAGE_AUX_HEAD
 
 #define PAGESIZE 4096
 #define INTEL_PT_MEMSIZE (17*PAGESIZE)
@@ -157,3 +160,7 @@ static struct tst_test test = {
 	.cleanup = cleanup,
 	.needs_root = 1,
 };
+
+#else
+TST_TEST_TCONF("missing aux_* fields in struct perf_event_mmap_page");
+#endif /* HAVE_STRUCT_PERF_EVENT_MMAP_PAGE_AUX_HEAD */
-- 
2.16.4