diff options
Diffstat (limited to 'tools/testing/selftests/perf_events/mmap.c')
| -rw-r--r-- | tools/testing/selftests/perf_events/mmap.c | 236 |
1 files changed, 236 insertions, 0 deletions
diff --git a/tools/testing/selftests/perf_events/mmap.c b/tools/testing/selftests/perf_events/mmap.c new file mode 100644 index 000000000000..ea0427aac1f9 --- /dev/null +++ b/tools/testing/selftests/perf_events/mmap.c @@ -0,0 +1,236 @@ +// SPDX-License-Identifier: GPL-2.0-only +#define _GNU_SOURCE + +#include <dirent.h> +#include <sched.h> +#include <stdbool.h> +#include <stdio.h> +#include <unistd.h> + +#include <sys/ioctl.h> +#include <sys/mman.h> +#include <sys/syscall.h> +#include <sys/types.h> + +#include <linux/perf_event.h> + +#include "../kselftest_harness.h" + +#define RB_SIZE 0x3000 +#define AUX_SIZE 0x10000 +#define AUX_OFFS 0x4000 + +#define HOLE_SIZE 0x1000 + +/* Reserve space for rb, aux with space for shrink-beyond-vma testing. */ +#define REGION_SIZE (2 * RB_SIZE + 2 * AUX_SIZE) +#define REGION_AUX_OFFS (2 * RB_SIZE) + +#define MAP_BASE 1 +#define MAP_AUX 2 + +#define EVENT_SRC_DIR "/sys/bus/event_source/devices" + +FIXTURE(perf_mmap) +{ + int fd; + void *ptr; + void *region; +}; + +FIXTURE_VARIANT(perf_mmap) +{ + bool aux; + unsigned long ptr_size; +}; + +FIXTURE_VARIANT_ADD(perf_mmap, rb) +{ + .aux = false, + .ptr_size = RB_SIZE, +}; + +FIXTURE_VARIANT_ADD(perf_mmap, aux) +{ + .aux = true, + .ptr_size = AUX_SIZE, +}; + +static bool read_event_type(struct dirent *dent, __u32 *type) +{ + char typefn[512]; + FILE *fp; + int res; + + snprintf(typefn, sizeof(typefn), "%s/%s/type", EVENT_SRC_DIR, dent->d_name); + fp = fopen(typefn, "r"); + if (!fp) + return false; + + res = fscanf(fp, "%u", type); + fclose(fp); + return res > 0; +} + +FIXTURE_SETUP(perf_mmap) +{ + struct perf_event_attr attr = { + .size = sizeof(attr), + .disabled = 1, + .exclude_kernel = 1, + .exclude_hv = 1, + }; + struct perf_event_attr attr_ok = {}; + unsigned int eacces = 0, map = 0; + struct perf_event_mmap_page *rb; + struct dirent *dent; + void *aux, *region; + DIR *dir; + + self->ptr = NULL; + + dir = opendir(EVENT_SRC_DIR); + if (!dir) + SKIP(return, "perf not available."); + + region = mmap(NULL, REGION_SIZE, PROT_NONE, MAP_ANON | MAP_PRIVATE, -1, 0); + ASSERT_NE(region, MAP_FAILED); + self->region = region; + + // Try to find a suitable event on this system + while ((dent = readdir(dir))) { + int fd; + + if (!read_event_type(dent, &attr.type)) + continue; + + fd = syscall(SYS_perf_event_open, &attr, 0, -1, -1, 0); + if (fd < 0) { + if (errno == EACCES) + eacces++; + continue; + } + + // Check whether the event supports mmap() + rb = mmap(region, RB_SIZE, PROT_READ | PROT_WRITE, MAP_SHARED | MAP_FIXED, fd, 0); + if (rb == MAP_FAILED) { + close(fd); + continue; + } + + if (!map) { + // Save the event in case that no AUX capable event is found + attr_ok = attr; + map = MAP_BASE; + } + + if (!variant->aux) + continue; + + rb->aux_offset = AUX_OFFS; + rb->aux_size = AUX_SIZE; + + // Check whether it supports a AUX buffer + aux = mmap(region + REGION_AUX_OFFS, AUX_SIZE, PROT_READ | PROT_WRITE, + MAP_SHARED | MAP_FIXED, fd, AUX_OFFS); + if (aux == MAP_FAILED) { + munmap(rb, RB_SIZE); + close(fd); + continue; + } + + attr_ok = attr; + map = MAP_AUX; + munmap(aux, AUX_SIZE); + munmap(rb, RB_SIZE); + close(fd); + break; + } + closedir(dir); + + if (!map) { + if (!eacces) + SKIP(return, "No mappable perf event found."); + else + SKIP(return, "No permissions for perf_event_open()"); + } + + self->fd = syscall(SYS_perf_event_open, &attr_ok, 0, -1, -1, 0); + ASSERT_NE(self->fd, -1); + + rb = mmap(region, RB_SIZE, PROT_READ | PROT_WRITE, MAP_SHARED | MAP_FIXED, self->fd, 0); + ASSERT_NE(rb, MAP_FAILED); + + if (!variant->aux) { + self->ptr = rb; + return; + } + + if (map != MAP_AUX) + SKIP(return, "No AUX event found."); + + rb->aux_offset = AUX_OFFS; + rb->aux_size = AUX_SIZE; + aux = mmap(region + REGION_AUX_OFFS, AUX_SIZE, PROT_READ | PROT_WRITE, + MAP_SHARED | MAP_FIXED, self->fd, AUX_OFFS); + ASSERT_NE(aux, MAP_FAILED); + self->ptr = aux; +} + +FIXTURE_TEARDOWN(perf_mmap) +{ + ASSERT_EQ(munmap(self->region, REGION_SIZE), 0); + if (self->fd != -1) + ASSERT_EQ(close(self->fd), 0); +} + +TEST_F(perf_mmap, remap) +{ + void *tmp, *ptr = self->ptr; + unsigned long size = variant->ptr_size; + + // Test the invalid remaps + ASSERT_EQ(mremap(ptr, size, HOLE_SIZE, MREMAP_MAYMOVE), MAP_FAILED); + ASSERT_EQ(mremap(ptr + HOLE_SIZE, size, HOLE_SIZE, MREMAP_MAYMOVE), MAP_FAILED); + ASSERT_EQ(mremap(ptr + size - HOLE_SIZE, HOLE_SIZE, size, MREMAP_MAYMOVE), MAP_FAILED); + // Shrink the end of the mapping such that we only unmap past end of the VMA, + // which should succeed and poke a hole into the PROT_NONE region + ASSERT_NE(mremap(ptr + size - HOLE_SIZE, size, HOLE_SIZE, MREMAP_MAYMOVE), MAP_FAILED); + + // Remap the whole buffer to a new address + tmp = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_SHARED | MAP_ANONYMOUS, -1, 0); + ASSERT_NE(tmp, MAP_FAILED); + + // Try splitting offset 1 hole size into VMA, this should fail + ASSERT_EQ(mremap(ptr + HOLE_SIZE, size - HOLE_SIZE, size - HOLE_SIZE, + MREMAP_MAYMOVE | MREMAP_FIXED, tmp), MAP_FAILED); + // Remapping the whole thing should succeed fine + ptr = mremap(ptr, size, size, MREMAP_MAYMOVE | MREMAP_FIXED, tmp); + ASSERT_EQ(ptr, tmp); + ASSERT_EQ(munmap(tmp, size), 0); +} + +TEST_F(perf_mmap, unmap) +{ + unsigned long size = variant->ptr_size; + + // Try to poke holes into the mappings + ASSERT_NE(munmap(self->ptr, HOLE_SIZE), 0); + ASSERT_NE(munmap(self->ptr + HOLE_SIZE, HOLE_SIZE), 0); + ASSERT_NE(munmap(self->ptr + size - HOLE_SIZE, HOLE_SIZE), 0); +} + +TEST_F(perf_mmap, map) +{ + unsigned long size = variant->ptr_size; + + // Try to poke holes into the mappings by mapping anonymous memory over it + ASSERT_EQ(mmap(self->ptr, HOLE_SIZE, PROT_READ | PROT_WRITE, + MAP_PRIVATE | MAP_ANON | MAP_FIXED, -1, 0), MAP_FAILED); + ASSERT_EQ(mmap(self->ptr + HOLE_SIZE, HOLE_SIZE, PROT_READ | PROT_WRITE, + MAP_PRIVATE | MAP_ANON | MAP_FIXED, -1, 0), MAP_FAILED); + ASSERT_EQ(mmap(self->ptr + size - HOLE_SIZE, HOLE_SIZE, PROT_READ | PROT_WRITE, + MAP_PRIVATE | MAP_ANON | MAP_FIXED, -1, 0), MAP_FAILED); +} + +TEST_HARNESS_MAIN |