Author | Tokens | Token Proportion | Commits | Commit Proportion |
---|---|---|---|---|
Vincent Donnefort | 1280 | 100.00% | 1 | 100.00% |
Total | 1280 | 1 |
// SPDX-License-Identifier: GPL-2.0 /* * Ring-buffer memory mapping tests * * Copyright (c) 2024 Vincent Donnefort <vdonnefort@google.com> */ #include <fcntl.h> #include <sched.h> #include <stdbool.h> #include <stdio.h> #include <stdlib.h> #include <unistd.h> #include <linux/trace_mmap.h> #include <sys/mman.h> #include <sys/ioctl.h> #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
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