rseq/selftests: Fix: Namespace gettid() for compatibility with glibc 2.30

commit 8df34c56 upstream.

glibc 2.30 introduces gettid() in public headers, which clashes with
the internal static definition within rseq selftests.

Rename gettid() to rseq_gettid() to eliminate this symbol name clash.
Reported-by: Tommi T. Rantala <tommi.t.rantala@nokia.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Shuah Khan <skhan@linuxfoundation.org>
Cc: Tommi T. Rantala <tommi.t.rantala@nokia.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: "Paul E. McKenney" <paulmck@linux.ibm.com>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: "H . Peter Anvin" <hpa@zytor.com>
Cc: Paul Turner <pjt@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: <stable@vger.kernel.org>	# v4.18+
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

tools/testing/selftests/rseq/param_test.c

@@ -15,7 +15,7 @@
 #include <errno.h>
 #include <stddef.h>
 
-static inline pid_t gettid(void)
+static inline pid_t rseq_gettid(void)
 {
 	return syscall(__NR_gettid);
 }
@@ -373,11 +373,12 @@ void *test_percpu_spinlock_thread(void *arg)
 		rseq_percpu_unlock(&data->lock, cpu);
 #ifndef BENCHMARK
 		if (i != 0 && !(i % (reps / 10)))
-			printf_verbose("tid %d: count %lld\n", (int) gettid(), i);
+			printf_verbose("tid %d: count %lld\n",
+				       (int) rseq_gettid(), i);
 #endif
 	}
 	printf_verbose("tid %d: number of rseq abort: %d, signals delivered: %u\n",
-		       (int) gettid(), nr_abort, signals_delivered);
+		       (int) rseq_gettid(), nr_abort, signals_delivered);
 	if (!opt_disable_rseq && thread_data->reg &&
 	    rseq_unregister_current_thread())
 		abort();
@@ -454,11 +455,12 @@ void *test_percpu_inc_thread(void *arg)
 		} while (rseq_unlikely(ret));
 #ifndef BENCHMARK
 		if (i != 0 && !(i % (reps / 10)))
-			printf_verbose("tid %d: count %lld\n", (int) gettid(), i);
+			printf_verbose("tid %d: count %lld\n",
+				       (int) rseq_gettid(), i);
 #endif
 	}
 	printf_verbose("tid %d: number of rseq abort: %d, signals delivered: %u\n",
-		       (int) gettid(), nr_abort, signals_delivered);
+		       (int) rseq_gettid(), nr_abort, signals_delivered);
 	if (!opt_disable_rseq && thread_data->reg &&
 	    rseq_unregister_current_thread())
 		abort();
@@ -605,7 +607,7 @@ void *test_percpu_list_thread(void *arg)
 	}
 
 	printf_verbose("tid %d: number of rseq abort: %d, signals delivered: %u\n",
-		       (int) gettid(), nr_abort, signals_delivered);
+		       (int) rseq_gettid(), nr_abort, signals_delivered);
 	if (!opt_disable_rseq && rseq_unregister_current_thread())
 		abort();
 
@@ -796,7 +798,7 @@ void *test_percpu_buffer_thread(void *arg)
 	}
 
 	printf_verbose("tid %d: number of rseq abort: %d, signals delivered: %u\n",
-		       (int) gettid(), nr_abort, signals_delivered);
+		       (int) rseq_gettid(), nr_abort, signals_delivered);
 	if (!opt_disable_rseq && rseq_unregister_current_thread())
 		abort();
 
@@ -1011,7 +1013,7 @@ void *test_percpu_memcpy_buffer_thread(void *arg)
 	}
 
 	printf_verbose("tid %d: number of rseq abort: %d, signals delivered: %u\n",
-		       (int) gettid(), nr_abort, signals_delivered);
+		       (int) rseq_gettid(), nr_abort, signals_delivered);
 	if (!opt_disable_rseq && rseq_unregister_current_thread())
 		abort();