From patchwork Tue May 14 16:16:03 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Steven Rostedt X-Patchwork-Id: 13664273 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 521BC1802B6; Tue, 14 May 2024 16:16:06 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1715703366; cv=none; b=rpSPCyLTkOBgkK28LP3vuKc/n2UrfucN5qpaZKeOjZ4fgROgjnyQdtFBFFEZ4iIS9A0ENptzWHpulPHnGdMzhPhlTRu6j7jmorw3SRVo8vFsCZxRGCiR62+s/5jUtXuWZmTYEAjK08xzRQ975JSFF2r2+1sWVaZVg4DliRI4kRs= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1715703366; c=relaxed/simple; bh=la4S4bMz86ZXBnocupQ7o1X9/ENjncUXQ6HGRcJwpCk=; h=Message-ID:Date:From:To:Cc:Subject:References:MIME-Version: Content-Type; b=I/zMJ3cM480AX/rawFjV0CX5QaQjOAd0phRJ8Thl02S5AsnJpo4s4pKMXSmJvzPNDOU0Sotjb/SqIyFAP7lvPan8rjH5cmSqjtptCeIX4KRgjAlU7AsjD4BKIMl74OXUEm7iPC4gkxKc7U+xJ59HotIU/rNRuBE6VwzEVhU11gI= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 Received: by smtp.kernel.org (Postfix) with ESMTPSA id 29E46C4AF0C; Tue, 14 May 2024 16:16:06 +0000 (UTC) Received: from rostedt by gandalf with local (Exim 4.97) (envelope-from ) id 1s6upK-00000003tE9-3m1D; Tue, 14 May 2024 12:16:30 -0400 Message-ID: <20240514161630.757077802@goodmis.org> User-Agent: quilt/0.68 Date: Tue, 14 May 2024 12:16:03 -0400 From: Steven Rostedt To: linux-kernel@vger.kernel.org Cc: Masami Hiramatsu , Mark Rutland , Mathieu Desnoyers , Andrew Morton , Shuah Khan , Shuah Khan , linux-kselftest@vger.kernel.org, Muhammad Usama Anjum , Vincent Donnefort Subject: [for-next][PATCH 5/6] ring-buffer/selftest: Add ring-buffer mapping test References: <20240514161558.664348429@goodmis.org> Precedence: bulk X-Mailing-List: linux-kselftest@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 From: Vincent Donnefort Map a ring-buffer, validate the meta-page before and after emitting few events. Also check ring-buffer mapping boundaries and finally ensure the tracing snapshot is mutually exclusive. Link: https://lore.kernel.org/linux-trace-kernel/20240510140435.3550353-6-vdonnefort@google.com Cc: Shuah Khan Cc: Shuah Khan Cc: linux-kselftest@vger.kernel.org Acked-by: Muhammad Usama Anjum Signed-off-by: Vincent Donnefort Signed-off-by: Steven Rostedt (Google) --- .../testing/selftests/ring-buffer/.gitignore | 1 + tools/testing/selftests/ring-buffer/Makefile | 8 + tools/testing/selftests/ring-buffer/config | 2 + .../testing/selftests/ring-buffer/map_test.c | 294 ++++++++++++++++++ 4 files changed, 305 insertions(+) create mode 100644 tools/testing/selftests/ring-buffer/.gitignore create mode 100644 tools/testing/selftests/ring-buffer/Makefile create mode 100644 tools/testing/selftests/ring-buffer/config create mode 100644 tools/testing/selftests/ring-buffer/map_test.c diff --git a/tools/testing/selftests/ring-buffer/.gitignore b/tools/testing/selftests/ring-buffer/.gitignore new file mode 100644 index 000000000000..3aed1a2a6c67 --- /dev/null +++ b/tools/testing/selftests/ring-buffer/.gitignore @@ -0,0 +1 @@ +map_test diff --git a/tools/testing/selftests/ring-buffer/Makefile b/tools/testing/selftests/ring-buffer/Makefile new file mode 100644 index 000000000000..627c5fa6d1ab --- /dev/null +++ b/tools/testing/selftests/ring-buffer/Makefile @@ -0,0 +1,8 @@ +# SPDX-License-Identifier: GPL-2.0 +CFLAGS += -Wl,-no-as-needed -Wall +CFLAGS += $(KHDR_INCLUDES) +CFLAGS += -D_GNU_SOURCE + +TEST_GEN_PROGS = map_test + +include ../lib.mk diff --git a/tools/testing/selftests/ring-buffer/config b/tools/testing/selftests/ring-buffer/config new file mode 100644 index 000000000000..d936f8f00e78 --- /dev/null +++ b/tools/testing/selftests/ring-buffer/config @@ -0,0 +1,2 @@ +CONFIG_FTRACE=y +CONFIG_TRACER_SNAPSHOT=y diff --git a/tools/testing/selftests/ring-buffer/map_test.c b/tools/testing/selftests/ring-buffer/map_test.c new file mode 100644 index 000000000000..a9006fa7097e --- /dev/null +++ b/tools/testing/selftests/ring-buffer/map_test.c @@ -0,0 +1,294 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Ring-buffer memory mapping tests + * + * Copyright (c) 2024 Vincent Donnefort + */ +#include +#include +#include +#include +#include +#include + +#include + +#include +#include + +#include "../user_events/user_events_selftests.h" /* share tracefs setup */ +#include "../kselftest_harness.h" + +#define TRACEFS_ROOT "/sys/kernel/tracing" + +static int __tracefs_write(const char *path, const char *value) +{ + int fd, ret; + + fd = open(path, O_WRONLY | O_TRUNC); + if (fd < 0) + return fd; + + ret = write(fd, value, strlen(value)); + + close(fd); + + return ret == -1 ? -errno : 0; +} + +static int __tracefs_write_int(const char *path, int value) +{ + char *str; + int ret; + + if (asprintf(&str, "%d", value) < 0) + return -1; + + ret = __tracefs_write(path, str); + + free(str); + + return ret; +} + +#define tracefs_write_int(path, value) \ + ASSERT_EQ(__tracefs_write_int((path), (value)), 0) + +#define tracefs_write(path, value) \ + ASSERT_EQ(__tracefs_write((path), (value)), 0) + +static int tracefs_reset(void) +{ + if (__tracefs_write_int(TRACEFS_ROOT"/tracing_on", 0)) + return -1; + if (__tracefs_write(TRACEFS_ROOT"/trace", "")) + return -1; + if (__tracefs_write(TRACEFS_ROOT"/set_event", "")) + return -1; + if (__tracefs_write(TRACEFS_ROOT"/current_tracer", "nop")) + return -1; + + return 0; +} + +struct tracefs_cpu_map_desc { + struct trace_buffer_meta *meta; + int cpu_fd; +}; + +int tracefs_cpu_map(struct tracefs_cpu_map_desc *desc, int cpu) +{ + int page_size = getpagesize(); + char *cpu_path; + void *map; + + if (asprintf(&cpu_path, + TRACEFS_ROOT"/per_cpu/cpu%d/trace_pipe_raw", + cpu) < 0) + return -ENOMEM; + + desc->cpu_fd = open(cpu_path, O_RDONLY | O_NONBLOCK); + free(cpu_path); + if (desc->cpu_fd < 0) + return -ENODEV; + + map = mmap(NULL, page_size, PROT_READ, MAP_SHARED, desc->cpu_fd, 0); + if (map == MAP_FAILED) + return -errno; + + desc->meta = (struct trace_buffer_meta *)map; + + return 0; +} + +void tracefs_cpu_unmap(struct tracefs_cpu_map_desc *desc) +{ + munmap(desc->meta, desc->meta->meta_page_size); + close(desc->cpu_fd); +} + +FIXTURE(map) { + struct tracefs_cpu_map_desc map_desc; + bool umount; +}; + +FIXTURE_VARIANT(map) { + int subbuf_size; +}; + +FIXTURE_VARIANT_ADD(map, subbuf_size_4k) { + .subbuf_size = 4, +}; + +FIXTURE_VARIANT_ADD(map, subbuf_size_8k) { + .subbuf_size = 8, +}; + +FIXTURE_SETUP(map) +{ + int cpu = sched_getcpu(); + cpu_set_t cpu_mask; + bool fail, umount; + char *message; + + if (getuid() != 0) + SKIP(return, "Skipping: %s", "Please run the test as root"); + + if (!tracefs_enabled(&message, &fail, &umount)) { + if (fail) { + TH_LOG("Tracefs setup failed: %s", message); + ASSERT_FALSE(fail); + } + SKIP(return, "Skipping: %s", message); + } + + self->umount = umount; + + ASSERT_GE(cpu, 0); + + ASSERT_EQ(tracefs_reset(), 0); + + tracefs_write_int(TRACEFS_ROOT"/buffer_subbuf_size_kb", variant->subbuf_size); + + ASSERT_EQ(tracefs_cpu_map(&self->map_desc, cpu), 0); + + /* + * Ensure generated events will be found on this very same ring-buffer. + */ + CPU_ZERO(&cpu_mask); + CPU_SET(cpu, &cpu_mask); + ASSERT_EQ(sched_setaffinity(0, sizeof(cpu_mask), &cpu_mask), 0); +} + +FIXTURE_TEARDOWN(map) +{ + tracefs_reset(); + + if (self->umount) + tracefs_unmount(); + + tracefs_cpu_unmap(&self->map_desc); +} + +TEST_F(map, meta_page_check) +{ + struct tracefs_cpu_map_desc *desc = &self->map_desc; + int cnt = 0; + + ASSERT_EQ(desc->meta->entries, 0); + ASSERT_EQ(desc->meta->overrun, 0); + ASSERT_EQ(desc->meta->read, 0); + + ASSERT_EQ(desc->meta->reader.id, 0); + ASSERT_EQ(desc->meta->reader.read, 0); + + ASSERT_EQ(ioctl(desc->cpu_fd, TRACE_MMAP_IOCTL_GET_READER), 0); + ASSERT_EQ(desc->meta->reader.id, 0); + + tracefs_write_int(TRACEFS_ROOT"/tracing_on", 1); + for (int i = 0; i < 16; i++) + tracefs_write_int(TRACEFS_ROOT"/trace_marker", i); +again: + ASSERT_EQ(ioctl(desc->cpu_fd, TRACE_MMAP_IOCTL_GET_READER), 0); + + ASSERT_EQ(desc->meta->entries, 16); + ASSERT_EQ(desc->meta->overrun, 0); + ASSERT_EQ(desc->meta->read, 16); + + ASSERT_EQ(desc->meta->reader.id, 1); + + if (!(cnt++)) + goto again; +} + +TEST_F(map, data_mmap) +{ + struct tracefs_cpu_map_desc *desc = &self->map_desc; + unsigned long meta_len, data_len; + void *data; + + meta_len = desc->meta->meta_page_size; + data_len = desc->meta->subbuf_size * desc->meta->nr_subbufs; + + /* Map all the available subbufs */ + data = mmap(NULL, data_len, PROT_READ, MAP_SHARED, + desc->cpu_fd, meta_len); + ASSERT_NE(data, MAP_FAILED); + munmap(data, data_len); + + /* Map all the available subbufs - 1 */ + data_len -= desc->meta->subbuf_size; + data = mmap(NULL, data_len, PROT_READ, MAP_SHARED, + desc->cpu_fd, meta_len); + ASSERT_NE(data, MAP_FAILED); + munmap(data, data_len); + + /* Overflow the available subbufs by 1 */ + meta_len += desc->meta->subbuf_size * 2; + data = mmap(NULL, data_len, PROT_READ, MAP_SHARED, + desc->cpu_fd, meta_len); + ASSERT_EQ(data, MAP_FAILED); +} + +FIXTURE(snapshot) { + bool umount; +}; + +FIXTURE_SETUP(snapshot) +{ + bool fail, umount; + struct stat sb; + char *message; + + if (getuid() != 0) + SKIP(return, "Skipping: %s", "Please run the test as root"); + + if (stat(TRACEFS_ROOT"/snapshot", &sb)) + SKIP(return, "Skipping: %s", "snapshot not available"); + + if (!tracefs_enabled(&message, &fail, &umount)) { + if (fail) { + TH_LOG("Tracefs setup failed: %s", message); + ASSERT_FALSE(fail); + } + SKIP(return, "Skipping: %s", message); + } + + self->umount = umount; +} + +FIXTURE_TEARDOWN(snapshot) +{ + __tracefs_write(TRACEFS_ROOT"/events/sched/sched_switch/trigger", + "!snapshot"); + tracefs_reset(); + + if (self->umount) + tracefs_unmount(); +} + +TEST_F(snapshot, excludes_map) +{ + struct tracefs_cpu_map_desc map_desc; + int cpu = sched_getcpu(); + + ASSERT_GE(cpu, 0); + tracefs_write(TRACEFS_ROOT"/events/sched/sched_switch/trigger", + "snapshot"); + ASSERT_EQ(tracefs_cpu_map(&map_desc, cpu), -EBUSY); +} + +TEST_F(snapshot, excluded_by_map) +{ + struct tracefs_cpu_map_desc map_desc; + int cpu = sched_getcpu(); + + ASSERT_EQ(tracefs_cpu_map(&map_desc, cpu), 0); + + ASSERT_EQ(__tracefs_write(TRACEFS_ROOT"/events/sched/sched_switch/trigger", + "snapshot"), -EBUSY); + ASSERT_EQ(__tracefs_write(TRACEFS_ROOT"/snapshot", + "1"), -EBUSY); +} + +TEST_HARNESS_MAIN