1 /* 2 * proc_info_list_kthreads 3 * 4 * list 64 bit thread ids of kernel_task 5 */ 6 7 #include <stdio.h> 8 #include <stdlib.h> 9 #include <assert.h> 10 #include <err.h> 11 12 #include <libproc.h> 13 #include <strings.h> 14 #include <darwintest.h> 15 #include <TargetConditionals.h> 16 17 T_GLOBAL_META(T_META_RUN_CONCURRENTLY(true)); 18 19 #if TARGET_OS_OSX 20 #define _ASROOT false 21 #else 22 #define _ASROOT true 23 #endif 24 25 #define MAX_TRIES 20 26 #define EXTRA_THREADS 15 27 28 T_DECL(proc_info_list_kthreads, 29 "Test to verify PROC_PIDLISTTHREADIDS returns kernel thread IDs for pid 0", 30 T_META_ASROOT(_ASROOT), 31 T_META_CHECK_LEAKS(false), 32 T_META_TAG_VM_PREFERRED, 33 T_META_ENABLED(false /* rdar://133956230 */)) 34 { 35 int buf_used = 0; 36 37 int thread_count = 0; 38 uint64_t *thread_list = NULL; 39 40 /* 41 * To use PROC_PIDLISTTHREADIDS, we must pass a buffer of uint64_t's for each thread ID. 42 * However, there is a TOCTOU race between asking for the thread count 43 * and asking for the array of identifiers. 44 * 45 * Because the process could have allocated more threads since last we asked 46 * how many threads there are, we instead pass an extra slot in the array, 47 * and try again if it used that slot. 48 */ 49 50 int attempt = 1; 51 while (!thread_count && (attempt < MAX_TRIES)) { 52 struct proc_taskinfo ti; 53 54 buf_used = proc_pidinfo(0, PROC_PIDTASKINFO, 0, &ti, sizeof(ti)); 55 56 T_QUIET; T_WITH_ERRNO; T_ASSERT_GT(buf_used, 0, "proc_pidinfo(PROC_PIDTASKINFO) returned a value > 0"); 57 T_QUIET; T_ASSERT_EQ(buf_used, (int)sizeof(ti), "proc_pidinfo(PROC_PIDTASKINFO) returned size %d == %lu", buf_used, sizeof(ti)); 58 59 T_LOG("The kernel says it has %d threads", ti.pti_threadnum); 60 61 int expected_size = ti.pti_threadnum * (int)sizeof(uint64_t); 62 /* tack on five extra to detect newly allocated threads */ 63 int allocated_size = expected_size + EXTRA_THREADS * (int)sizeof(uint64_t); 64 uint64_t *thread_list_tmp = malloc((size_t)allocated_size); 65 T_QUIET; T_WITH_ERRNO; T_ASSERT_NOTNULL(thread_list_tmp, "malloc(size = %d) failed", allocated_size); 66 67 buf_used = proc_pidinfo(0, PROC_PIDLISTTHREADIDS, 0, thread_list_tmp, (int)allocated_size); 68 T_LOG("proc_pidinfo(PROC_PIDLISTTHREADIDS) buf_used = %d, expected_size = %d", buf_used, expected_size); 69 70 if (buf_used == 0) { 71 T_WITH_ERRNO; T_ASSERT_FAIL("proc_pidinfo(PROC_PIDLISTTHREADIDS) failed"); 72 } 73 if (buf_used == expected_size) { 74 /* success, we found the expected number of threads */ 75 thread_list = thread_list_tmp; 76 thread_count = expected_size / (int)sizeof(uint64_t); 77 } else if (buf_used < expected_size) { 78 /* there were fewer threads than we expected, fix up the allocation */ 79 thread_list = realloc(thread_list_tmp, (size_t)buf_used); 80 thread_count = buf_used / (int)sizeof(uint64_t); 81 T_QUIET; T_WITH_ERRNO; T_ASSERT_NOTNULL(thread_list, "realloc(size = %d) failed", buf_used); 82 } else if (buf_used > expected_size) { 83 if (buf_used < allocated_size) { 84 thread_list = realloc(thread_list_tmp, (size_t)buf_used); 85 thread_count = buf_used / (int)sizeof(uint64_t); 86 T_QUIET; T_WITH_ERRNO; T_ASSERT_NOTNULL(thread_list, "realloc(size = %d) failed", buf_used); 87 } else { 88 /* 89 * it used all the extra slots, meaning there are more 90 * threads than we thought, try again! 91 */ 92 T_LOG("expected %d threads, but saw an extra thread: %d", 93 expected_size / (int)sizeof(uint64_t), buf_used / (int)sizeof(uint64_t)); 94 free(thread_list_tmp); 95 } 96 } 97 attempt++; 98 } 99 T_QUIET; T_ASSERT_LE(attempt, MAX_TRIES, "attempt <= MAX_TRIES"); 100 T_QUIET; T_ASSERT_NOTNULL(thread_list, "thread_list != NULL"); 101 T_QUIET; T_ASSERT_GT(thread_count, 0, "thread_count > 0"); 102 103 struct proc_threadinfo pthinfo_64; 104 for (int i = 0; i < thread_count; i++) { 105 bzero(&pthinfo_64, sizeof(struct proc_threadinfo)); 106 int retval = proc_pidinfo(0, PROC_PIDTHREADID64INFO, thread_list[i], 107 (void *)&pthinfo_64, (uint32_t)sizeof(pthinfo_64)); 108 T_QUIET; T_WITH_ERRNO; T_EXPECT_GT(retval, 0, "proc_pidinfo(PROC_PIDTASKINFO) returned %d", retval); 109 T_QUIET; T_EXPECT_EQ(retval, (int)sizeof(pthinfo_64), "proc_pidinfo(PROC_PIDTASKINFO) returned size %d == %lu", 110 retval, sizeof(pthinfo_64)); 111 } 112 } 113