1 // SPDX-License-Identifier: GPL-2.0 2 #define _GNU_SOURCE 3 #include <linux/compiler.h> 4 #include <asm/barrier.h> 5 #include <test_progs.h> 6 #include <sys/mman.h> 7 #include <sys/epoll.h> 8 #include <time.h> 9 #include <sched.h> 10 #include <signal.h> 11 #include <pthread.h> 12 #include <sys/sysinfo.h> 13 #include <linux/perf_event.h> 14 #include <linux/ring_buffer.h> 15 #include "test_ringbuf.lskel.h" 16 17 #define EDONE 7777 18 19 static int duration = 0; 20 21 struct sample { 22 int pid; 23 int seq; 24 long value; 25 char comm[16]; 26 }; 27 28 static int sample_cnt; 29 30 static void atomic_inc(int *cnt) 31 { 32 __atomic_add_fetch(cnt, 1, __ATOMIC_SEQ_CST); 33 } 34 35 static int atomic_xchg(int *cnt, int val) 36 { 37 return __atomic_exchange_n(cnt, val, __ATOMIC_SEQ_CST); 38 } 39 40 static int process_sample(void *ctx, void *data, size_t len) 41 { 42 struct sample *s = data; 43 44 atomic_inc(&sample_cnt); 45 46 switch (s->seq) { 47 case 0: 48 CHECK(s->value != 333, "sample1_value", "exp %ld, got %ld\n", 49 333L, s->value); 50 return 0; 51 case 1: 52 CHECK(s->value != 777, "sample2_value", "exp %ld, got %ld\n", 53 777L, s->value); 54 return -EDONE; 55 default: 56 /* we don't care about the rest */ 57 return 0; 58 } 59 } 60 61 static struct test_ringbuf *skel; 62 static struct ring_buffer *ringbuf; 63 64 static void trigger_samples() 65 { 66 skel->bss->dropped = 0; 67 skel->bss->total = 0; 68 skel->bss->discarded = 0; 69 70 /* trigger exactly two samples */ 71 skel->bss->value = 333; 72 syscall(__NR_getpgid); 73 skel->bss->value = 777; 74 syscall(__NR_getpgid); 75 } 76 77 static void *poll_thread(void *input) 78 { 79 long timeout = (long)input; 80 81 return (void *)(long)ring_buffer__poll(ringbuf, timeout); 82 } 83 84 void test_ringbuf(void) 85 { 86 const size_t rec_sz = BPF_RINGBUF_HDR_SZ + sizeof(struct sample); 87 pthread_t thread; 88 long bg_ret = -1; 89 int err, cnt, rb_fd; 90 int page_size = getpagesize(); 91 void *mmap_ptr, *tmp_ptr; 92 93 skel = test_ringbuf__open(); 94 if (CHECK(!skel, "skel_open", "skeleton open failed\n")) 95 return; 96 97 skel->maps.ringbuf.max_entries = page_size; 98 99 err = test_ringbuf__load(skel); 100 if (CHECK(err != 0, "skel_load", "skeleton load failed\n")) 101 goto cleanup; 102 103 rb_fd = bpf_map__fd(skel->maps.ringbuf); 104 /* good read/write cons_pos */ 105 mmap_ptr = mmap(NULL, page_size, PROT_READ | PROT_WRITE, MAP_SHARED, rb_fd, 0); 106 ASSERT_OK_PTR(mmap_ptr, "rw_cons_pos"); 107 tmp_ptr = mremap(mmap_ptr, page_size, 2 * page_size, MREMAP_MAYMOVE); 108 if (!ASSERT_ERR_PTR(tmp_ptr, "rw_extend")) 109 goto cleanup; 110 ASSERT_ERR(mprotect(mmap_ptr, page_size, PROT_EXEC), "exec_cons_pos_protect"); 111 ASSERT_OK(munmap(mmap_ptr, page_size), "unmap_rw"); 112 113 /* bad writeable prod_pos */ 114 mmap_ptr = mmap(NULL, page_size, PROT_WRITE, MAP_SHARED, rb_fd, page_size); 115 err = -errno; 116 ASSERT_ERR_PTR(mmap_ptr, "wr_prod_pos"); 117 ASSERT_EQ(err, -EPERM, "wr_prod_pos_err"); 118 119 /* bad writeable data pages */ 120 mmap_ptr = mmap(NULL, page_size, PROT_WRITE, MAP_SHARED, rb_fd, 2 * page_size); 121 err = -errno; 122 ASSERT_ERR_PTR(mmap_ptr, "wr_data_page_one"); 123 ASSERT_EQ(err, -EPERM, "wr_data_page_one_err"); 124 mmap_ptr = mmap(NULL, page_size, PROT_WRITE, MAP_SHARED, rb_fd, 3 * page_size); 125 ASSERT_ERR_PTR(mmap_ptr, "wr_data_page_two"); 126 mmap_ptr = mmap(NULL, 2 * page_size, PROT_WRITE, MAP_SHARED, rb_fd, 2 * page_size); 127 ASSERT_ERR_PTR(mmap_ptr, "wr_data_page_all"); 128 129 /* good read-only pages */ 130 mmap_ptr = mmap(NULL, 4 * page_size, PROT_READ, MAP_SHARED, rb_fd, 0); 131 if (!ASSERT_OK_PTR(mmap_ptr, "ro_prod_pos")) 132 goto cleanup; 133 134 ASSERT_ERR(mprotect(mmap_ptr, 4 * page_size, PROT_WRITE), "write_protect"); 135 ASSERT_ERR(mprotect(mmap_ptr, 4 * page_size, PROT_EXEC), "exec_protect"); 136 ASSERT_ERR_PTR(mremap(mmap_ptr, 0, 4 * page_size, MREMAP_MAYMOVE), "ro_remap"); 137 ASSERT_OK(munmap(mmap_ptr, 4 * page_size), "unmap_ro"); 138 139 /* good read-only pages with initial offset */ 140 mmap_ptr = mmap(NULL, page_size, PROT_READ, MAP_SHARED, rb_fd, page_size); 141 if (!ASSERT_OK_PTR(mmap_ptr, "ro_prod_pos")) 142 goto cleanup; 143 144 ASSERT_ERR(mprotect(mmap_ptr, page_size, PROT_WRITE), "write_protect"); 145 ASSERT_ERR(mprotect(mmap_ptr, page_size, PROT_EXEC), "exec_protect"); 146 ASSERT_ERR_PTR(mremap(mmap_ptr, 0, 3 * page_size, MREMAP_MAYMOVE), "ro_remap"); 147 ASSERT_OK(munmap(mmap_ptr, page_size), "unmap_ro"); 148 149 /* only trigger BPF program for current process */ 150 skel->bss->pid = getpid(); 151 152 ringbuf = ring_buffer__new(skel->maps.ringbuf.map_fd, 153 process_sample, NULL, NULL); 154 if (CHECK(!ringbuf, "ringbuf_create", "failed to create ringbuf\n")) 155 goto cleanup; 156 157 err = test_ringbuf__attach(skel); 158 if (CHECK(err, "skel_attach", "skeleton attachment failed: %d\n", err)) 159 goto cleanup; 160 161 trigger_samples(); 162 163 /* 2 submitted + 1 discarded records */ 164 CHECK(skel->bss->avail_data != 3 * rec_sz, 165 "err_avail_size", "exp %ld, got %ld\n", 166 3L * rec_sz, skel->bss->avail_data); 167 CHECK(skel->bss->ring_size != page_size, 168 "err_ring_size", "exp %ld, got %ld\n", 169 (long)page_size, skel->bss->ring_size); 170 CHECK(skel->bss->cons_pos != 0, 171 "err_cons_pos", "exp %ld, got %ld\n", 172 0L, skel->bss->cons_pos); 173 CHECK(skel->bss->prod_pos != 3 * rec_sz, 174 "err_prod_pos", "exp %ld, got %ld\n", 175 3L * rec_sz, skel->bss->prod_pos); 176 177 /* poll for samples */ 178 err = ring_buffer__poll(ringbuf, -1); 179 180 /* -EDONE is used as an indicator that we are done */ 181 if (CHECK(err != -EDONE, "err_done", "done err: %d\n", err)) 182 goto cleanup; 183 cnt = atomic_xchg(&sample_cnt, 0); 184 CHECK(cnt != 2, "cnt", "exp %d samples, got %d\n", 2, cnt); 185 186 /* we expect extra polling to return nothing */ 187 err = ring_buffer__poll(ringbuf, 0); 188 if (CHECK(err != 0, "extra_samples", "poll result: %d\n", err)) 189 goto cleanup; 190 cnt = atomic_xchg(&sample_cnt, 0); 191 CHECK(cnt != 0, "cnt", "exp %d samples, got %d\n", 0, cnt); 192 193 CHECK(skel->bss->dropped != 0, "err_dropped", "exp %ld, got %ld\n", 194 0L, skel->bss->dropped); 195 CHECK(skel->bss->total != 2, "err_total", "exp %ld, got %ld\n", 196 2L, skel->bss->total); 197 CHECK(skel->bss->discarded != 1, "err_discarded", "exp %ld, got %ld\n", 198 1L, skel->bss->discarded); 199 200 /* now validate consumer position is updated and returned */ 201 trigger_samples(); 202 CHECK(skel->bss->cons_pos != 3 * rec_sz, 203 "err_cons_pos", "exp %ld, got %ld\n", 204 3L * rec_sz, skel->bss->cons_pos); 205 err = ring_buffer__poll(ringbuf, -1); 206 CHECK(err <= 0, "poll_err", "err %d\n", err); 207 cnt = atomic_xchg(&sample_cnt, 0); 208 CHECK(cnt != 2, "cnt", "exp %d samples, got %d\n", 2, cnt); 209 210 /* start poll in background w/ long timeout */ 211 err = pthread_create(&thread, NULL, poll_thread, (void *)(long)10000); 212 if (CHECK(err, "bg_poll", "pthread_create failed: %d\n", err)) 213 goto cleanup; 214 215 /* turn off notifications now */ 216 skel->bss->flags = BPF_RB_NO_WAKEUP; 217 218 /* give background thread a bit of a time */ 219 usleep(50000); 220 trigger_samples(); 221 /* sleeping arbitrarily is bad, but no better way to know that 222 * epoll_wait() **DID NOT** unblock in background thread 223 */ 224 usleep(50000); 225 /* background poll should still be blocked */ 226 err = pthread_tryjoin_np(thread, (void **)&bg_ret); 227 if (CHECK(err != EBUSY, "try_join", "err %d\n", err)) 228 goto cleanup; 229 230 /* BPF side did everything right */ 231 CHECK(skel->bss->dropped != 0, "err_dropped", "exp %ld, got %ld\n", 232 0L, skel->bss->dropped); 233 CHECK(skel->bss->total != 2, "err_total", "exp %ld, got %ld\n", 234 2L, skel->bss->total); 235 CHECK(skel->bss->discarded != 1, "err_discarded", "exp %ld, got %ld\n", 236 1L, skel->bss->discarded); 237 cnt = atomic_xchg(&sample_cnt, 0); 238 CHECK(cnt != 0, "cnt", "exp %d samples, got %d\n", 0, cnt); 239 240 /* clear flags to return to "adaptive" notification mode */ 241 skel->bss->flags = 0; 242 243 /* produce new samples, no notification should be triggered, because 244 * consumer is now behind 245 */ 246 trigger_samples(); 247 248 /* background poll should still be blocked */ 249 err = pthread_tryjoin_np(thread, (void **)&bg_ret); 250 if (CHECK(err != EBUSY, "try_join", "err %d\n", err)) 251 goto cleanup; 252 253 /* still no samples, because consumer is behind */ 254 cnt = atomic_xchg(&sample_cnt, 0); 255 CHECK(cnt != 0, "cnt", "exp %d samples, got %d\n", 0, cnt); 256 257 skel->bss->dropped = 0; 258 skel->bss->total = 0; 259 skel->bss->discarded = 0; 260 261 skel->bss->value = 333; 262 syscall(__NR_getpgid); 263 /* now force notifications */ 264 skel->bss->flags = BPF_RB_FORCE_WAKEUP; 265 skel->bss->value = 777; 266 syscall(__NR_getpgid); 267 268 /* now we should get a pending notification */ 269 usleep(50000); 270 err = pthread_tryjoin_np(thread, (void **)&bg_ret); 271 if (CHECK(err, "join_bg", "err %d\n", err)) 272 goto cleanup; 273 274 if (CHECK(bg_ret <= 0, "bg_ret", "epoll_wait result: %ld", bg_ret)) 275 goto cleanup; 276 277 /* due to timing variations, there could still be non-notified 278 * samples, so consume them here to collect all the samples 279 */ 280 err = ring_buffer__consume(ringbuf); 281 CHECK(err < 0, "rb_consume", "failed: %d\b", err); 282 283 /* 3 rounds, 2 samples each */ 284 cnt = atomic_xchg(&sample_cnt, 0); 285 CHECK(cnt != 6, "cnt", "exp %d samples, got %d\n", 6, cnt); 286 287 /* BPF side did everything right */ 288 CHECK(skel->bss->dropped != 0, "err_dropped", "exp %ld, got %ld\n", 289 0L, skel->bss->dropped); 290 CHECK(skel->bss->total != 2, "err_total", "exp %ld, got %ld\n", 291 2L, skel->bss->total); 292 CHECK(skel->bss->discarded != 1, "err_discarded", "exp %ld, got %ld\n", 293 1L, skel->bss->discarded); 294 295 test_ringbuf__detach(skel); 296 cleanup: 297 ring_buffer__free(ringbuf); 298 test_ringbuf__destroy(skel); 299 } 300