rseq/selftests: Provide basic test

"basic_test" only asserts that RSEQ works moderately correctly. E.g.
that the CPUID pointer works.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Joel Fernandes <joelaf@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dave Watson <davejwatson@fb.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Shuah Khan <shuahkh@osg.samsung.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: linux-kselftest@vger.kernel.org
Cc: "H . Peter Anvin" <hpa@zytor.com>
Cc: Chris Lameter <cl@linux.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Andrew Hunter <ahh@google.com>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: "Paul E . McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Paul Turner <pjt@google.com>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Ben Maurer <bmaurer@fb.com>
Cc: linux-api@vger.kernel.org
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lkml.kernel.org/r/20180602124408.8430-14-mathieu.desnoyers@efficios.com

diff --git a/tools/testing/selftests/rseq/basic_test.c b/tools/testing/selftests/rseq/basic_test.c
new file mode 100644 (file)
index 0000000..d8efbfb
--- /dev/null
+++ b/tools/testing/selftests/rseq/basic_test.c
@@ -0,0 +1,56 @@
+// SPDX-License-Identifier: LGPL-2.1
+/*
+ * Basic test coverage for critical regions and rseq_current_cpu().
+ */
+
+#define _GNU_SOURCE
+#include <assert.h>
+#include <sched.h>
+#include <signal.h>
+#include <stdio.h>
+#include <string.h>
+#include <sys/time.h>
+
+#include "rseq.h"
+
+void test_cpu_pointer(void)
+{
+       cpu_set_t affinity, test_affinity;
+       int i;
+
+       sched_getaffinity(0, sizeof(affinity), &affinity);
+       CPU_ZERO(&test_affinity);
+       for (i = 0; i < CPU_SETSIZE; i++) {
+               if (CPU_ISSET(i, &affinity)) {
+                       CPU_SET(i, &test_affinity);
+                       sched_setaffinity(0, sizeof(test_affinity),
+                                       &test_affinity);
+                       assert(sched_getcpu() == i);
+                       assert(rseq_current_cpu() == i);
+                       assert(rseq_current_cpu_raw() == i);
+                       assert(rseq_cpu_start() == i);
+                       CPU_CLR(i, &test_affinity);
+               }
+       }
+       sched_setaffinity(0, sizeof(affinity), &affinity);
+}
+
+int main(int argc, char **argv)
+{
+       if (rseq_register_current_thread()) {
+               fprintf(stderr, "Error: rseq_register_current_thread(...) failed(%d): %s\n",
+                       errno, strerror(errno));
+               goto init_thread_error;
+       }
+       printf("testing current cpu\n");
+       test_cpu_pointer();
+       if (rseq_unregister_current_thread()) {
+               fprintf(stderr, "Error: rseq_unregister_current_thread(...) failed(%d): %s\n",
+                       errno, strerror(errno));
+               goto init_thread_error;
+       }
+       return 0;
+
+init_thread_error:
+       return -1;
+}