1 // SPDX-License-Identifier: GPL-2.0 2 /* Copyright (c) 2022 Meta Platforms, Inc. and affiliates. */ 3 #include <test_progs.h> 4 5 #define _SDT_HAS_SEMAPHORES 1 6 #include "../sdt.h" 7 8 #include "test_usdt.skel.h" 9 #include "test_urandom_usdt.skel.h" 10 11 int lets_test_this(int); 12 13 static volatile int idx = 2; 14 static volatile __u64 bla = 0xFEDCBA9876543210ULL; 15 static volatile short nums[] = {-1, -2, -3, -4}; 16 17 static volatile struct { 18 int x; 19 signed char y; 20 } t1 = { 1, -127 }; 21 22 #define SEC(name) __attribute__((section(name), used)) 23 24 unsigned short test_usdt0_semaphore SEC(".probes"); 25 unsigned short test_usdt3_semaphore SEC(".probes"); 26 unsigned short test_usdt12_semaphore SEC(".probes"); 27 28 static void __always_inline trigger_func(int x) { 29 long y = 42; 30 31 if (test_usdt0_semaphore) 32 STAP_PROBE(test, usdt0); 33 if (test_usdt3_semaphore) 34 STAP_PROBE3(test, usdt3, x, y, &bla); 35 if (test_usdt12_semaphore) { 36 STAP_PROBE12(test, usdt12, 37 x, x + 1, y, x + y, 5, 38 y / 7, bla, &bla, -9, nums[x], 39 nums[idx], t1.y); 40 } 41 } 42 43 static void subtest_basic_usdt(void) 44 { 45 LIBBPF_OPTS(bpf_usdt_opts, opts); 46 struct test_usdt *skel; 47 struct test_usdt__bss *bss; 48 int err, i; 49 50 skel = test_usdt__open_and_load(); 51 if (!ASSERT_OK_PTR(skel, "skel_open")) 52 return; 53 54 bss = skel->bss; 55 bss->my_pid = getpid(); 56 57 err = test_usdt__attach(skel); 58 if (!ASSERT_OK(err, "skel_attach")) 59 goto cleanup; 60 61 /* usdt0 won't be auto-attached */ 62 opts.usdt_cookie = 0xcafedeadbeeffeed; 63 skel->links.usdt0 = bpf_program__attach_usdt(skel->progs.usdt0, 64 0 /*self*/, "/proc/self/exe", 65 "test", "usdt0", &opts); 66 if (!ASSERT_OK_PTR(skel->links.usdt0, "usdt0_link")) 67 goto cleanup; 68 69 trigger_func(1); 70 71 ASSERT_EQ(bss->usdt0_called, 1, "usdt0_called"); 72 ASSERT_EQ(bss->usdt3_called, 1, "usdt3_called"); 73 ASSERT_EQ(bss->usdt12_called, 1, "usdt12_called"); 74 75 ASSERT_EQ(bss->usdt0_cookie, 0xcafedeadbeeffeed, "usdt0_cookie"); 76 ASSERT_EQ(bss->usdt0_arg_cnt, 0, "usdt0_arg_cnt"); 77 ASSERT_EQ(bss->usdt0_arg_ret, -ENOENT, "usdt0_arg_ret"); 78 ASSERT_EQ(bss->usdt0_arg_size, -ENOENT, "usdt0_arg_size"); 79 80 /* auto-attached usdt3 gets default zero cookie value */ 81 ASSERT_EQ(bss->usdt3_cookie, 0, "usdt3_cookie"); 82 ASSERT_EQ(bss->usdt3_arg_cnt, 3, "usdt3_arg_cnt"); 83 84 ASSERT_EQ(bss->usdt3_arg_rets[0], 0, "usdt3_arg1_ret"); 85 ASSERT_EQ(bss->usdt3_arg_rets[1], 0, "usdt3_arg2_ret"); 86 ASSERT_EQ(bss->usdt3_arg_rets[2], 0, "usdt3_arg3_ret"); 87 ASSERT_EQ(bss->usdt3_args[0], 1, "usdt3_arg1"); 88 ASSERT_EQ(bss->usdt3_args[1], 42, "usdt3_arg2"); 89 ASSERT_EQ(bss->usdt3_args[2], (uintptr_t)&bla, "usdt3_arg3"); 90 ASSERT_EQ(bss->usdt3_arg_sizes[0], 4, "usdt3_arg1_size"); 91 ASSERT_EQ(bss->usdt3_arg_sizes[1], 8, "usdt3_arg2_size"); 92 ASSERT_EQ(bss->usdt3_arg_sizes[2], 8, "usdt3_arg3_size"); 93 94 /* auto-attached usdt12 gets default zero cookie value */ 95 ASSERT_EQ(bss->usdt12_cookie, 0, "usdt12_cookie"); 96 ASSERT_EQ(bss->usdt12_arg_cnt, 12, "usdt12_arg_cnt"); 97 98 ASSERT_EQ(bss->usdt12_args[0], 1, "usdt12_arg1"); 99 ASSERT_EQ(bss->usdt12_args[1], 1 + 1, "usdt12_arg2"); 100 ASSERT_EQ(bss->usdt12_args[2], 42, "usdt12_arg3"); 101 ASSERT_EQ(bss->usdt12_args[3], 42 + 1, "usdt12_arg4"); 102 ASSERT_EQ(bss->usdt12_args[4], 5, "usdt12_arg5"); 103 ASSERT_EQ(bss->usdt12_args[5], 42 / 7, "usdt12_arg6"); 104 ASSERT_EQ(bss->usdt12_args[6], bla, "usdt12_arg7"); 105 ASSERT_EQ(bss->usdt12_args[7], (uintptr_t)&bla, "usdt12_arg8"); 106 ASSERT_EQ(bss->usdt12_args[8], -9, "usdt12_arg9"); 107 ASSERT_EQ(bss->usdt12_args[9], nums[1], "usdt12_arg10"); 108 ASSERT_EQ(bss->usdt12_args[10], nums[idx], "usdt12_arg11"); 109 ASSERT_EQ(bss->usdt12_args[11], t1.y, "usdt12_arg12"); 110 111 int usdt12_expected_arg_sizes[12] = { 4, 4, 8, 8, 4, 8, 8, 8, 4, 2, 2, 1 }; 112 113 for (i = 0; i < 12; i++) 114 ASSERT_EQ(bss->usdt12_arg_sizes[i], usdt12_expected_arg_sizes[i], "usdt12_arg_size"); 115 116 /* trigger_func() is marked __always_inline, so USDT invocations will be 117 * inlined in two different places, meaning that each USDT will have 118 * at least 2 different places to be attached to. This verifies that 119 * bpf_program__attach_usdt() handles this properly and attaches to 120 * all possible places of USDT invocation. 121 */ 122 trigger_func(2); 123 124 ASSERT_EQ(bss->usdt0_called, 2, "usdt0_called"); 125 ASSERT_EQ(bss->usdt3_called, 2, "usdt3_called"); 126 ASSERT_EQ(bss->usdt12_called, 2, "usdt12_called"); 127 128 /* only check values that depend on trigger_func()'s input value */ 129 ASSERT_EQ(bss->usdt3_args[0], 2, "usdt3_arg1"); 130 131 ASSERT_EQ(bss->usdt12_args[0], 2, "usdt12_arg1"); 132 ASSERT_EQ(bss->usdt12_args[1], 2 + 1, "usdt12_arg2"); 133 ASSERT_EQ(bss->usdt12_args[3], 42 + 2, "usdt12_arg4"); 134 ASSERT_EQ(bss->usdt12_args[9], nums[2], "usdt12_arg10"); 135 136 /* detach and re-attach usdt3 */ 137 bpf_link__destroy(skel->links.usdt3); 138 139 opts.usdt_cookie = 0xBADC00C51E; 140 skel->links.usdt3 = bpf_program__attach_usdt(skel->progs.usdt3, -1 /* any pid */, 141 "/proc/self/exe", "test", "usdt3", &opts); 142 if (!ASSERT_OK_PTR(skel->links.usdt3, "usdt3_reattach")) 143 goto cleanup; 144 145 trigger_func(3); 146 147 ASSERT_EQ(bss->usdt3_called, 3, "usdt3_called"); 148 /* this time usdt3 has custom cookie */ 149 ASSERT_EQ(bss->usdt3_cookie, 0xBADC00C51E, "usdt3_cookie"); 150 ASSERT_EQ(bss->usdt3_arg_cnt, 3, "usdt3_arg_cnt"); 151 152 ASSERT_EQ(bss->usdt3_arg_rets[0], 0, "usdt3_arg1_ret"); 153 ASSERT_EQ(bss->usdt3_arg_rets[1], 0, "usdt3_arg2_ret"); 154 ASSERT_EQ(bss->usdt3_arg_rets[2], 0, "usdt3_arg3_ret"); 155 ASSERT_EQ(bss->usdt3_args[0], 3, "usdt3_arg1"); 156 ASSERT_EQ(bss->usdt3_args[1], 42, "usdt3_arg2"); 157 ASSERT_EQ(bss->usdt3_args[2], (uintptr_t)&bla, "usdt3_arg3"); 158 159 cleanup: 160 test_usdt__destroy(skel); 161 } 162 163 unsigned short test_usdt_100_semaphore SEC(".probes"); 164 unsigned short test_usdt_300_semaphore SEC(".probes"); 165 unsigned short test_usdt_400_semaphore SEC(".probes"); 166 167 #define R10(F, X) F(X+0); F(X+1);F(X+2); F(X+3); F(X+4); \ 168 F(X+5); F(X+6); F(X+7); F(X+8); F(X+9); 169 #define R100(F, X) R10(F,X+ 0);R10(F,X+10);R10(F,X+20);R10(F,X+30);R10(F,X+40); \ 170 R10(F,X+50);R10(F,X+60);R10(F,X+70);R10(F,X+80);R10(F,X+90); 171 172 /* carefully control that we get exactly 100 inlines by preventing inlining */ 173 static void __always_inline f100(int x) 174 { 175 STAP_PROBE1(test, usdt_100, x); 176 } 177 178 __weak void trigger_100_usdts(void) 179 { 180 R100(f100, 0); 181 } 182 183 /* we shouldn't be able to attach to test:usdt2_300 USDT as we don't have as 184 * many slots for specs. It's important that each STAP_PROBE2() invocation 185 * (after untolling) gets different arg spec due to compiler inlining i as 186 * a constant 187 */ 188 static void __always_inline f300(int x) 189 { 190 STAP_PROBE1(test, usdt_300, x); 191 } 192 193 __weak void trigger_300_usdts(void) 194 { 195 R100(f300, 0); 196 R100(f300, 100); 197 R100(f300, 200); 198 } 199 200 static void __always_inline f400(int x __attribute__((unused))) 201 { 202 STAP_PROBE1(test, usdt_400, 400); 203 } 204 205 /* this time we have 400 different USDT call sites, but they have uniform 206 * argument location, so libbpf's spec string deduplication logic should keep 207 * spec count use very small and so we should be able to attach to all 400 208 * call sites 209 */ 210 __weak void trigger_400_usdts(void) 211 { 212 R100(f400, 0); 213 R100(f400, 100); 214 R100(f400, 200); 215 R100(f400, 300); 216 } 217 218 static void subtest_multispec_usdt(void) 219 { 220 LIBBPF_OPTS(bpf_usdt_opts, opts); 221 struct test_usdt *skel; 222 struct test_usdt__bss *bss; 223 int err, i; 224 225 skel = test_usdt__open_and_load(); 226 if (!ASSERT_OK_PTR(skel, "skel_open")) 227 return; 228 229 bss = skel->bss; 230 bss->my_pid = getpid(); 231 232 err = test_usdt__attach(skel); 233 if (!ASSERT_OK(err, "skel_attach")) 234 goto cleanup; 235 236 /* usdt_100 is auto-attached and there are 100 inlined call sites, 237 * let's validate that all of them are properly attached to and 238 * handled from BPF side 239 */ 240 trigger_100_usdts(); 241 242 ASSERT_EQ(bss->usdt_100_called, 100, "usdt_100_called"); 243 ASSERT_EQ(bss->usdt_100_sum, 99 * 100 / 2, "usdt_100_sum"); 244 245 /* Stress test free spec ID tracking. By default libbpf allows up to 246 * 256 specs to be used, so if we don't return free spec IDs back 247 * after few detachments and re-attachments we should run out of 248 * available spec IDs. 249 */ 250 for (i = 0; i < 2; i++) { 251 bpf_link__destroy(skel->links.usdt_100); 252 253 skel->links.usdt_100 = bpf_program__attach_usdt(skel->progs.usdt_100, -1, 254 "/proc/self/exe", 255 "test", "usdt_100", NULL); 256 if (!ASSERT_OK_PTR(skel->links.usdt_100, "usdt_100_reattach")) 257 goto cleanup; 258 259 bss->usdt_100_sum = 0; 260 trigger_100_usdts(); 261 262 ASSERT_EQ(bss->usdt_100_called, (i + 1) * 100 + 100, "usdt_100_called"); 263 ASSERT_EQ(bss->usdt_100_sum, 99 * 100 / 2, "usdt_100_sum"); 264 } 265 266 /* Now let's step it up and try to attach USDT that requires more than 267 * 256 attach points with different specs for each. 268 * Note that we need trigger_300_usdts() only to actually have 300 269 * USDT call sites, we are not going to actually trace them. 270 */ 271 trigger_300_usdts(); 272 273 /* we'll reuse usdt_100 BPF program for usdt_300 test */ 274 bpf_link__destroy(skel->links.usdt_100); 275 skel->links.usdt_100 = bpf_program__attach_usdt(skel->progs.usdt_100, -1, "/proc/self/exe", 276 "test", "usdt_300", NULL); 277 err = -errno; 278 if (!ASSERT_ERR_PTR(skel->links.usdt_100, "usdt_300_bad_attach")) 279 goto cleanup; 280 ASSERT_EQ(err, -E2BIG, "usdt_300_attach_err"); 281 282 /* let's check that there are no "dangling" BPF programs attached due 283 * to partial success of the above test:usdt_300 attachment 284 */ 285 bss->usdt_100_called = 0; 286 bss->usdt_100_sum = 0; 287 288 f300(777); /* this is 301st instance of usdt_300 */ 289 290 ASSERT_EQ(bss->usdt_100_called, 0, "usdt_301_called"); 291 ASSERT_EQ(bss->usdt_100_sum, 0, "usdt_301_sum"); 292 293 /* This time we have USDT with 400 inlined invocations, but arg specs 294 * should be the same across all sites, so libbpf will only need to 295 * use one spec and thus we'll be able to attach 400 uprobes 296 * successfully. 297 * 298 * Again, we are reusing usdt_100 BPF program. 299 */ 300 skel->links.usdt_100 = bpf_program__attach_usdt(skel->progs.usdt_100, -1, 301 "/proc/self/exe", 302 "test", "usdt_400", NULL); 303 if (!ASSERT_OK_PTR(skel->links.usdt_100, "usdt_400_attach")) 304 goto cleanup; 305 306 trigger_400_usdts(); 307 308 ASSERT_EQ(bss->usdt_100_called, 400, "usdt_400_called"); 309 ASSERT_EQ(bss->usdt_100_sum, 400 * 400, "usdt_400_sum"); 310 311 cleanup: 312 test_usdt__destroy(skel); 313 } 314 315 static FILE *urand_spawn(int *pid) 316 { 317 FILE *f; 318 319 /* urandom_read's stdout is wired into f */ 320 f = popen("./urandom_read 1 report-pid", "r"); 321 if (!f) 322 return NULL; 323 324 if (fscanf(f, "%d", pid) != 1) { 325 pclose(f); 326 errno = EINVAL; 327 return NULL; 328 } 329 330 return f; 331 } 332 333 static int urand_trigger(FILE **urand_pipe) 334 { 335 int exit_code; 336 337 /* pclose() waits for child process to exit and returns their exit code */ 338 exit_code = pclose(*urand_pipe); 339 *urand_pipe = NULL; 340 341 return exit_code; 342 } 343 344 static void subtest_urandom_usdt(bool auto_attach) 345 { 346 struct test_urandom_usdt *skel; 347 struct test_urandom_usdt__bss *bss; 348 struct bpf_link *l; 349 FILE *urand_pipe = NULL; 350 int err, urand_pid = 0; 351 352 skel = test_urandom_usdt__open_and_load(); 353 if (!ASSERT_OK_PTR(skel, "skel_open")) 354 return; 355 356 urand_pipe = urand_spawn(&urand_pid); 357 if (!ASSERT_OK_PTR(urand_pipe, "urand_spawn")) 358 goto cleanup; 359 360 bss = skel->bss; 361 bss->urand_pid = urand_pid; 362 363 if (auto_attach) { 364 err = test_urandom_usdt__attach(skel); 365 if (!ASSERT_OK(err, "skel_auto_attach")) 366 goto cleanup; 367 } else { 368 l = bpf_program__attach_usdt(skel->progs.urand_read_without_sema, 369 urand_pid, "./urandom_read", 370 "urand", "read_without_sema", NULL); 371 if (!ASSERT_OK_PTR(l, "urand_without_sema_attach")) 372 goto cleanup; 373 skel->links.urand_read_without_sema = l; 374 375 l = bpf_program__attach_usdt(skel->progs.urand_read_with_sema, 376 urand_pid, "./urandom_read", 377 "urand", "read_with_sema", NULL); 378 if (!ASSERT_OK_PTR(l, "urand_with_sema_attach")) 379 goto cleanup; 380 skel->links.urand_read_with_sema = l; 381 382 l = bpf_program__attach_usdt(skel->progs.urandlib_read_without_sema, 383 urand_pid, "./liburandom_read.so", 384 "urandlib", "read_without_sema", NULL); 385 if (!ASSERT_OK_PTR(l, "urandlib_without_sema_attach")) 386 goto cleanup; 387 skel->links.urandlib_read_without_sema = l; 388 389 l = bpf_program__attach_usdt(skel->progs.urandlib_read_with_sema, 390 urand_pid, "./liburandom_read.so", 391 "urandlib", "read_with_sema", NULL); 392 if (!ASSERT_OK_PTR(l, "urandlib_with_sema_attach")) 393 goto cleanup; 394 skel->links.urandlib_read_with_sema = l; 395 396 } 397 398 /* trigger urandom_read USDTs */ 399 ASSERT_OK(urand_trigger(&urand_pipe), "urand_exit_code"); 400 401 ASSERT_EQ(bss->urand_read_without_sema_call_cnt, 1, "urand_wo_sema_cnt"); 402 ASSERT_EQ(bss->urand_read_without_sema_buf_sz_sum, 256, "urand_wo_sema_sum"); 403 404 ASSERT_EQ(bss->urand_read_with_sema_call_cnt, 1, "urand_w_sema_cnt"); 405 ASSERT_EQ(bss->urand_read_with_sema_buf_sz_sum, 256, "urand_w_sema_sum"); 406 407 ASSERT_EQ(bss->urandlib_read_without_sema_call_cnt, 1, "urandlib_wo_sema_cnt"); 408 ASSERT_EQ(bss->urandlib_read_without_sema_buf_sz_sum, 256, "urandlib_wo_sema_sum"); 409 410 ASSERT_EQ(bss->urandlib_read_with_sema_call_cnt, 1, "urandlib_w_sema_cnt"); 411 ASSERT_EQ(bss->urandlib_read_with_sema_buf_sz_sum, 256, "urandlib_w_sema_sum"); 412 413 cleanup: 414 if (urand_pipe) 415 pclose(urand_pipe); 416 test_urandom_usdt__destroy(skel); 417 } 418 419 void test_usdt(void) 420 { 421 if (test__start_subtest("basic")) 422 subtest_basic_usdt(); 423 if (test__start_subtest("multispec")) 424 subtest_multispec_usdt(); 425 if (test__start_subtest("urand_auto_attach")) 426 subtest_urandom_usdt(true /* auto_attach */); 427 if (test__start_subtest("urand_pid_attach")) 428 subtest_urandom_usdt(false /* auto_attach */); 429 } 430