|
| 1 | +// SPDX-License-Identifier: GPL-2.0-only |
| 2 | +#define _GNU_SOURCE |
| 3 | + |
| 4 | +#include <dirent.h> |
| 5 | +#include <sched.h> |
| 6 | +#include <stdbool.h> |
| 7 | +#include <stdio.h> |
| 8 | +#include <unistd.h> |
| 9 | + |
| 10 | +#include <sys/ioctl.h> |
| 11 | +#include <sys/mman.h> |
| 12 | +#include <sys/syscall.h> |
| 13 | +#include <sys/types.h> |
| 14 | + |
| 15 | +#include <linux/perf_event.h> |
| 16 | + |
| 17 | +#include "../kselftest_harness.h" |
| 18 | + |
| 19 | +#define RB_SIZE 0x3000 |
| 20 | +#define AUX_SIZE 0x10000 |
| 21 | +#define AUX_OFFS 0x4000 |
| 22 | + |
| 23 | +#define HOLE_SIZE 0x1000 |
| 24 | + |
| 25 | +/* Reserve space for rb, aux with space for shrink-beyond-vma testing. */ |
| 26 | +#define REGION_SIZE (2 * RB_SIZE + 2 * AUX_SIZE) |
| 27 | +#define REGION_AUX_OFFS (2 * RB_SIZE) |
| 28 | + |
| 29 | +#define MAP_BASE 1 |
| 30 | +#define MAP_AUX 2 |
| 31 | + |
| 32 | +#define EVENT_SRC_DIR "/sys/bus/event_source/devices" |
| 33 | + |
| 34 | +FIXTURE(perf_mmap) |
| 35 | +{ |
| 36 | + int fd; |
| 37 | + void *ptr; |
| 38 | + void *region; |
| 39 | +}; |
| 40 | + |
| 41 | +FIXTURE_VARIANT(perf_mmap) |
| 42 | +{ |
| 43 | + bool aux; |
| 44 | + unsigned long ptr_size; |
| 45 | +}; |
| 46 | + |
| 47 | +FIXTURE_VARIANT_ADD(perf_mmap, rb) |
| 48 | +{ |
| 49 | + .aux = false, |
| 50 | + .ptr_size = RB_SIZE, |
| 51 | +}; |
| 52 | + |
| 53 | +FIXTURE_VARIANT_ADD(perf_mmap, aux) |
| 54 | +{ |
| 55 | + .aux = true, |
| 56 | + .ptr_size = AUX_SIZE, |
| 57 | +}; |
| 58 | + |
| 59 | +static bool read_event_type(struct dirent *dent, __u32 *type) |
| 60 | +{ |
| 61 | + char typefn[512]; |
| 62 | + FILE *fp; |
| 63 | + int res; |
| 64 | + |
| 65 | + snprintf(typefn, sizeof(typefn), "%s/%s/type", EVENT_SRC_DIR, dent->d_name); |
| 66 | + fp = fopen(typefn, "r"); |
| 67 | + if (!fp) |
| 68 | + return false; |
| 69 | + |
| 70 | + res = fscanf(fp, "%u", type); |
| 71 | + fclose(fp); |
| 72 | + return res > 0; |
| 73 | +} |
| 74 | + |
| 75 | +FIXTURE_SETUP(perf_mmap) |
| 76 | +{ |
| 77 | + struct perf_event_attr attr = { |
| 78 | + .size = sizeof(attr), |
| 79 | + .disabled = 1, |
| 80 | + .exclude_kernel = 1, |
| 81 | + .exclude_hv = 1, |
| 82 | + }; |
| 83 | + struct perf_event_attr attr_ok = {}; |
| 84 | + unsigned int eacces = 0, map = 0; |
| 85 | + struct perf_event_mmap_page *rb; |
| 86 | + struct dirent *dent; |
| 87 | + void *aux, *region; |
| 88 | + DIR *dir; |
| 89 | + |
| 90 | + self->ptr = NULL; |
| 91 | + |
| 92 | + dir = opendir(EVENT_SRC_DIR); |
| 93 | + if (!dir) |
| 94 | + SKIP(return, "perf not available."); |
| 95 | + |
| 96 | + region = mmap(NULL, REGION_SIZE, PROT_NONE, MAP_ANON | MAP_PRIVATE, -1, 0); |
| 97 | + ASSERT_NE(region, MAP_FAILED); |
| 98 | + self->region = region; |
| 99 | + |
| 100 | + // Try to find a suitable event on this system |
| 101 | + while ((dent = readdir(dir))) { |
| 102 | + int fd; |
| 103 | + |
| 104 | + if (!read_event_type(dent, &attr.type)) |
| 105 | + continue; |
| 106 | + |
| 107 | + fd = syscall(SYS_perf_event_open, &attr, 0, -1, -1, 0); |
| 108 | + if (fd < 0) { |
| 109 | + if (errno == EACCES) |
| 110 | + eacces++; |
| 111 | + continue; |
| 112 | + } |
| 113 | + |
| 114 | + // Check whether the event supports mmap() |
| 115 | + rb = mmap(region, RB_SIZE, PROT_READ | PROT_WRITE, MAP_SHARED | MAP_FIXED, fd, 0); |
| 116 | + if (rb == MAP_FAILED) { |
| 117 | + close(fd); |
| 118 | + continue; |
| 119 | + } |
| 120 | + |
| 121 | + if (!map) { |
| 122 | + // Save the event in case that no AUX capable event is found |
| 123 | + attr_ok = attr; |
| 124 | + map = MAP_BASE; |
| 125 | + } |
| 126 | + |
| 127 | + if (!variant->aux) |
| 128 | + continue; |
| 129 | + |
| 130 | + rb->aux_offset = AUX_OFFS; |
| 131 | + rb->aux_size = AUX_SIZE; |
| 132 | + |
| 133 | + // Check whether it supports a AUX buffer |
| 134 | + aux = mmap(region + REGION_AUX_OFFS, AUX_SIZE, PROT_READ | PROT_WRITE, |
| 135 | + MAP_SHARED | MAP_FIXED, fd, AUX_OFFS); |
| 136 | + if (aux == MAP_FAILED) { |
| 137 | + munmap(rb, RB_SIZE); |
| 138 | + close(fd); |
| 139 | + continue; |
| 140 | + } |
| 141 | + |
| 142 | + attr_ok = attr; |
| 143 | + map = MAP_AUX; |
| 144 | + munmap(aux, AUX_SIZE); |
| 145 | + munmap(rb, RB_SIZE); |
| 146 | + close(fd); |
| 147 | + break; |
| 148 | + } |
| 149 | + closedir(dir); |
| 150 | + |
| 151 | + if (!map) { |
| 152 | + if (!eacces) |
| 153 | + SKIP(return, "No mappable perf event found."); |
| 154 | + else |
| 155 | + SKIP(return, "No permissions for perf_event_open()"); |
| 156 | + } |
| 157 | + |
| 158 | + self->fd = syscall(SYS_perf_event_open, &attr_ok, 0, -1, -1, 0); |
| 159 | + ASSERT_NE(self->fd, -1); |
| 160 | + |
| 161 | + rb = mmap(region, RB_SIZE, PROT_READ | PROT_WRITE, MAP_SHARED | MAP_FIXED, self->fd, 0); |
| 162 | + ASSERT_NE(rb, MAP_FAILED); |
| 163 | + |
| 164 | + if (!variant->aux) { |
| 165 | + self->ptr = rb; |
| 166 | + return; |
| 167 | + } |
| 168 | + |
| 169 | + if (map != MAP_AUX) |
| 170 | + SKIP(return, "No AUX event found."); |
| 171 | + |
| 172 | + rb->aux_offset = AUX_OFFS; |
| 173 | + rb->aux_size = AUX_SIZE; |
| 174 | + aux = mmap(region + REGION_AUX_OFFS, AUX_SIZE, PROT_READ | PROT_WRITE, |
| 175 | + MAP_SHARED | MAP_FIXED, self->fd, AUX_OFFS); |
| 176 | + ASSERT_NE(aux, MAP_FAILED); |
| 177 | + self->ptr = aux; |
| 178 | +} |
| 179 | + |
| 180 | +FIXTURE_TEARDOWN(perf_mmap) |
| 181 | +{ |
| 182 | + ASSERT_EQ(munmap(self->region, REGION_SIZE), 0); |
| 183 | + if (self->fd != -1) |
| 184 | + ASSERT_EQ(close(self->fd), 0); |
| 185 | +} |
| 186 | + |
| 187 | +TEST_F(perf_mmap, remap) |
| 188 | +{ |
| 189 | + void *tmp, *ptr = self->ptr; |
| 190 | + unsigned long size = variant->ptr_size; |
| 191 | + |
| 192 | + // Test the invalid remaps |
| 193 | + ASSERT_EQ(mremap(ptr, size, HOLE_SIZE, MREMAP_MAYMOVE), MAP_FAILED); |
| 194 | + ASSERT_EQ(mremap(ptr + HOLE_SIZE, size, HOLE_SIZE, MREMAP_MAYMOVE), MAP_FAILED); |
| 195 | + ASSERT_EQ(mremap(ptr + size - HOLE_SIZE, HOLE_SIZE, size, MREMAP_MAYMOVE), MAP_FAILED); |
| 196 | + // Shrink the end of the mapping such that we only unmap past end of the VMA, |
| 197 | + // which should succeed and poke a hole into the PROT_NONE region |
| 198 | + ASSERT_NE(mremap(ptr + size - HOLE_SIZE, size, HOLE_SIZE, MREMAP_MAYMOVE), MAP_FAILED); |
| 199 | + |
| 200 | + // Remap the whole buffer to a new address |
| 201 | + tmp = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_SHARED | MAP_ANONYMOUS, -1, 0); |
| 202 | + ASSERT_NE(tmp, MAP_FAILED); |
| 203 | + |
| 204 | + // Try splitting offset 1 hole size into VMA, this should fail |
| 205 | + ASSERT_EQ(mremap(ptr + HOLE_SIZE, size - HOLE_SIZE, size - HOLE_SIZE, |
| 206 | + MREMAP_MAYMOVE | MREMAP_FIXED, tmp), MAP_FAILED); |
| 207 | + // Remapping the whole thing should succeed fine |
| 208 | + ptr = mremap(ptr, size, size, MREMAP_MAYMOVE | MREMAP_FIXED, tmp); |
| 209 | + ASSERT_EQ(ptr, tmp); |
| 210 | + ASSERT_EQ(munmap(tmp, size), 0); |
| 211 | +} |
| 212 | + |
| 213 | +TEST_F(perf_mmap, unmap) |
| 214 | +{ |
| 215 | + unsigned long size = variant->ptr_size; |
| 216 | + |
| 217 | + // Try to poke holes into the mappings |
| 218 | + ASSERT_NE(munmap(self->ptr, HOLE_SIZE), 0); |
| 219 | + ASSERT_NE(munmap(self->ptr + HOLE_SIZE, HOLE_SIZE), 0); |
| 220 | + ASSERT_NE(munmap(self->ptr + size - HOLE_SIZE, HOLE_SIZE), 0); |
| 221 | +} |
| 222 | + |
| 223 | +TEST_F(perf_mmap, map) |
| 224 | +{ |
| 225 | + unsigned long size = variant->ptr_size; |
| 226 | + |
| 227 | + // Try to poke holes into the mappings by mapping anonymous memory over it |
| 228 | + ASSERT_EQ(mmap(self->ptr, HOLE_SIZE, PROT_READ | PROT_WRITE, |
| 229 | + MAP_PRIVATE | MAP_ANON | MAP_FIXED, -1, 0), MAP_FAILED); |
| 230 | + ASSERT_EQ(mmap(self->ptr + HOLE_SIZE, HOLE_SIZE, PROT_READ | PROT_WRITE, |
| 231 | + MAP_PRIVATE | MAP_ANON | MAP_FIXED, -1, 0), MAP_FAILED); |
| 232 | + ASSERT_EQ(mmap(self->ptr + size - HOLE_SIZE, HOLE_SIZE, PROT_READ | PROT_WRITE, |
| 233 | + MAP_PRIVATE | MAP_ANON | MAP_FIXED, -1, 0), MAP_FAILED); |
| 234 | +} |
| 235 | + |
| 236 | +TEST_HARNESS_MAIN |
0 commit comments