1 files changed, 137 insertions, 0 deletions
diff --git a/tools/testing/selftests/bpf/prog_tests/perf_skip.c b/tools/testing/selftests/bpf/prog_tests/perf_skip.c
new file mode 100644
index 000000000000..37d8618800e4
--- /dev/null
+++ b/tools/testing/selftests/bpf/prog_tests/perf_skip.c
@@ -0,0 +1,137 @@
+// SPDX-License-Identifier: GPL-2.0
+#define _GNU_SOURCE
+
+#include <test_progs.h>
+#include "test_perf_skip.skel.h"
+#include <linux/compiler.h>
+#include <linux/hw_breakpoint.h>
+#include <sys/mman.h>
+
+#ifndef TRAP_PERF
+#define TRAP_PERF 6
+#endif
+
+int sigio_count, sigtrap_count;
+
+static void handle_sigio(int sig __always_unused)
+{
+	++sigio_count;
+}
+
+static void handle_sigtrap(int signum __always_unused,
+			   siginfo_t *info,
+			   void *ucontext __always_unused)
+{
+	ASSERT_EQ(info->si_code, TRAP_PERF, "si_code");
+	++sigtrap_count;
+}
+
+static noinline int test_function(void)
+{
+	asm volatile ("");
+	return 0;
+}
+
+void serial_test_perf_skip(void)
+{
+	struct sigaction action = {};
+	struct sigaction previous_sigtrap;
+	sighandler_t previous_sigio = SIG_ERR;
+	struct test_perf_skip *skel = NULL;
+	struct perf_event_attr attr = {};
+	int perf_fd = -1;
+	int err;
+	struct f_owner_ex owner;
+	struct bpf_link *prog_link = NULL;
+
+	action.sa_flags = SA_SIGINFO | SA_NODEFER;
+	action.sa_sigaction = handle_sigtrap;
+	sigemptyset(&action.sa_mask);
+	if (!ASSERT_OK(sigaction(SIGTRAP, &action, &previous_sigtrap), "sigaction"))
+		return;
+
+	previous_sigio = signal(SIGIO, handle_sigio);
+	if (!ASSERT_NEQ(previous_sigio, SIG_ERR, "signal"))
+		goto cleanup;
+
+	skel = test_perf_skip__open_and_load();
+	if (!ASSERT_OK_PTR(skel, "skel_load"))
+		goto cleanup;
+
+	attr.type = PERF_TYPE_BREAKPOINT;
+	attr.size = sizeof(attr);
+	attr.bp_type = HW_BREAKPOINT_X;
+	attr.bp_addr = (uintptr_t)test_function;
+	attr.bp_len = sizeof(long);
+	attr.sample_period = 1;
+	attr.sample_type = PERF_SAMPLE_IP;
+	attr.pinned = 1;
+	attr.exclude_kernel = 1;
+	attr.exclude_hv = 1;
+	attr.precise_ip = 3;
+	attr.sigtrap = 1;
+	attr.remove_on_exec = 1;
+
+	perf_fd = syscall(__NR_perf_event_open, &attr, 0, -1, -1, 0);
+	if (perf_fd < 0 && (errno == ENOENT || errno == EOPNOTSUPP)) {
+		printf("SKIP:no PERF_TYPE_BREAKPOINT/HW_BREAKPOINT_X\n");
+		test__skip();
+		goto cleanup;
+	}
+	if (!ASSERT_OK(perf_fd < 0, "perf_event_open"))
+		goto cleanup;
+
+	/* Configure the perf event to signal on sample. */
+	err = fcntl(perf_fd, F_SETFL, O_ASYNC);
+	if (!ASSERT_OK(err, "fcntl(F_SETFL, O_ASYNC)"))
+		goto cleanup;
+
+	owner.type = F_OWNER_TID;
+	owner.pid = syscall(__NR_gettid);
+	err = fcntl(perf_fd, F_SETOWN_EX, &owner);
+	if (!ASSERT_OK(err, "fcntl(F_SETOWN_EX)"))
+		goto cleanup;
+
+	/* Allow at most one sample. A sample rejected by bpf should
+	 * not count against this.
+	 */
+	err = ioctl(perf_fd, PERF_EVENT_IOC_REFRESH, 1);
+	if (!ASSERT_OK(err, "ioctl(PERF_EVENT_IOC_REFRESH)"))
+		goto cleanup;
+
+	prog_link = bpf_program__attach_perf_event(skel->progs.handler, perf_fd);
+	if (!ASSERT_OK_PTR(prog_link, "bpf_program__attach_perf_event"))
+		goto cleanup;
+
+	/* Configure the bpf program to suppress the sample. */
+	skel->bss->ip = (uintptr_t)test_function;
+	test_function();
+
+	ASSERT_EQ(sigio_count, 0, "sigio_count");
+	ASSERT_EQ(sigtrap_count, 0, "sigtrap_count");
+
+	/* Configure the bpf program to allow the sample. */
+	skel->bss->ip = 0;
+	test_function();
+
+	ASSERT_EQ(sigio_count, 1, "sigio_count");
+	ASSERT_EQ(sigtrap_count, 1, "sigtrap_count");
+
+	/* Test that the sample above is the only one allowed (by perf, not
+	 * by bpf)
+	 */
+	test_function();
+
+	ASSERT_EQ(sigio_count, 1, "sigio_count");
+	ASSERT_EQ(sigtrap_count, 1, "sigtrap_count");
+
+cleanup:
+	bpf_link__destroy(prog_link);
+	if (perf_fd >= 0)
+		close(perf_fd);
+	test_perf_skip__destroy(skel);
+
+	if (previous_sigio != SIG_ERR)
+		signal(SIGIO, previous_sigio);
+	sigaction(SIGTRAP, &previous_sigtrap, NULL);
+}