1 /* SPDX-License-Identifier: BSD-3-Clause 2 * Copyright (c) Intel Corporation. 3 * All rights reserved. 4 */ 5 6 #include "spdk/stdinc.h" 7 8 #include "spdk/env.h" 9 #include "spdk/string.h" 10 #include "spdk/trace.h" 11 #include "spdk/util.h" 12 #include "spdk/barrier.h" 13 #include "spdk/log.h" 14 15 static int g_trace_fd = -1; 16 static char g_shm_name[64]; 17 18 struct spdk_trace_histories *g_trace_histories; 19 20 static inline struct spdk_trace_entry * 21 get_trace_entry(struct spdk_trace_history *history, uint64_t offset) 22 { 23 return &history->entries[offset & (history->num_entries - 1)]; 24 } 25 26 void 27 _spdk_trace_record(uint64_t tsc, uint16_t tpoint_id, uint16_t poller_id, uint32_t size, 28 uint64_t object_id, int num_args, ...) 29 { 30 struct spdk_trace_history *lcore_history; 31 struct spdk_trace_entry *next_entry; 32 struct spdk_trace_entry_buffer *buffer; 33 struct spdk_trace_tpoint *tpoint; 34 struct spdk_trace_argument *argument; 35 unsigned lcore, i, offset, num_entries, arglen, argoff, curlen; 36 uint64_t intval; 37 void *argval; 38 va_list vl; 39 40 lcore = spdk_env_get_current_core(); 41 if (lcore >= SPDK_TRACE_MAX_LCORE) { 42 return; 43 } 44 45 lcore_history = spdk_get_per_lcore_history(g_trace_histories, lcore); 46 if (tsc == 0) { 47 tsc = spdk_get_ticks(); 48 } 49 50 lcore_history->tpoint_count[tpoint_id]++; 51 52 tpoint = &g_trace_flags->tpoint[tpoint_id]; 53 /* Make sure that the number of arguments passed matches tracepoint definition */ 54 if (tpoint->num_args != num_args) { 55 assert(0 && "Unexpected number of tracepoint arguments"); 56 return; 57 } 58 59 /* Get next entry index in the circular buffer */ 60 next_entry = get_trace_entry(lcore_history, lcore_history->next_entry); 61 next_entry->tsc = tsc; 62 next_entry->tpoint_id = tpoint_id; 63 next_entry->poller_id = poller_id; 64 next_entry->size = size; 65 next_entry->object_id = object_id; 66 67 num_entries = 1; 68 buffer = (struct spdk_trace_entry_buffer *)next_entry; 69 /* The initial offset needs to be adjusted by the fields present in the first entry 70 * (poller_id, size, etc.). 71 */ 72 offset = offsetof(struct spdk_trace_entry, args) - 73 offsetof(struct spdk_trace_entry_buffer, data); 74 75 va_start(vl, num_args); 76 for (i = 0; i < tpoint->num_args; ++i) { 77 argument = &tpoint->args[i]; 78 switch (argument->type) { 79 case SPDK_TRACE_ARG_TYPE_STR: 80 argval = va_arg(vl, void *); 81 arglen = strnlen((const char *)argval, argument->size - 1) + 1; 82 break; 83 case SPDK_TRACE_ARG_TYPE_INT: 84 case SPDK_TRACE_ARG_TYPE_PTR: 85 intval = va_arg(vl, uint64_t); 86 argval = &intval; 87 arglen = sizeof(uint64_t); 88 break; 89 default: 90 assert(0 && "Invalid trace argument type"); 91 return; 92 } 93 94 /* Copy argument's data. For some argument types (strings) user is allowed to pass a 95 * value that is either larger or smaller than what's defined in the tracepoint's 96 * description. If the value is larger, we'll truncate it, while if it's smaller, 97 * we'll only fill portion of the buffer, without touching the rest. For instance, 98 * if the definition marks an argument as 40B and user passes 12B string, we'll only 99 * copy 13B (accounting for the NULL terminator). 100 */ 101 argoff = 0; 102 while (argoff < argument->size) { 103 /* Current buffer is full, we need to acquire another one */ 104 if (offset == sizeof(buffer->data)) { 105 buffer = (struct spdk_trace_entry_buffer *) get_trace_entry( 106 lcore_history, 107 lcore_history->next_entry + num_entries); 108 buffer->tpoint_id = SPDK_TRACE_MAX_TPOINT_ID; 109 buffer->tsc = tsc; 110 num_entries++; 111 offset = 0; 112 } 113 114 curlen = spdk_min(sizeof(buffer->data) - offset, argument->size - argoff); 115 if (argoff < arglen) { 116 assert(argval != NULL); 117 memcpy(&buffer->data[offset], (uint8_t *)argval + argoff, 118 spdk_min(curlen, arglen - argoff)); 119 } 120 121 offset += curlen; 122 argoff += curlen; 123 } 124 125 /* Make sure that truncated strings are NULL-terminated */ 126 if (argument->type == SPDK_TRACE_ARG_TYPE_STR) { 127 assert(offset > 0); 128 buffer->data[offset - 1] = '\0'; 129 } 130 } 131 va_end(vl); 132 133 /* Ensure all elements of the trace entry are visible to outside trace tools */ 134 spdk_smp_wmb(); 135 lcore_history->next_entry += num_entries; 136 } 137 138 int 139 spdk_trace_init(const char *shm_name, uint64_t num_entries) 140 { 141 int i = 0; 142 int histories_size; 143 uint64_t lcore_offsets[SPDK_TRACE_MAX_LCORE + 1]; 144 145 /* 0 entries requested - skip trace initialization */ 146 if (num_entries == 0) { 147 return 0; 148 } 149 150 lcore_offsets[0] = sizeof(struct spdk_trace_flags); 151 for (i = 1; i < (int)SPDK_COUNTOF(lcore_offsets); i++) { 152 lcore_offsets[i] = spdk_get_trace_history_size(num_entries) + lcore_offsets[i - 1]; 153 } 154 histories_size = lcore_offsets[SPDK_TRACE_MAX_LCORE]; 155 156 snprintf(g_shm_name, sizeof(g_shm_name), "%s", shm_name); 157 158 g_trace_fd = shm_open(shm_name, O_RDWR | O_CREAT, 0600); 159 if (g_trace_fd == -1) { 160 SPDK_ERRLOG("could not shm_open spdk_trace\n"); 161 SPDK_ERRLOG("errno=%d %s\n", errno, spdk_strerror(errno)); 162 return 1; 163 } 164 165 if (ftruncate(g_trace_fd, histories_size) != 0) { 166 SPDK_ERRLOG("could not truncate shm\n"); 167 goto trace_init_err; 168 } 169 170 g_trace_histories = mmap(NULL, histories_size, PROT_READ | PROT_WRITE, 171 MAP_SHARED, g_trace_fd, 0); 172 if (g_trace_histories == MAP_FAILED) { 173 SPDK_ERRLOG("could not mmap shm\n"); 174 goto trace_init_err; 175 } 176 177 /* TODO: On FreeBSD, mlock on shm_open'd memory doesn't seem to work. Docs say that kern.ipc.shm_use_phys=1 178 * should allow it, but forcing that doesn't seem to work either. So for now just skip mlock on FreeBSD 179 * altogether. 180 */ 181 #if defined(__linux__) 182 if (mlock(g_trace_histories, histories_size) != 0) { 183 SPDK_ERRLOG("Could not mlock shm for tracing - %s.\n", spdk_strerror(errno)); 184 if (errno == ENOMEM) { 185 SPDK_ERRLOG("Check /dev/shm for old tracing files that can be deleted.\n"); 186 } 187 goto trace_init_err; 188 } 189 #endif 190 191 memset(g_trace_histories, 0, histories_size); 192 193 g_trace_flags = &g_trace_histories->flags; 194 195 g_trace_flags->tsc_rate = spdk_get_ticks_hz(); 196 197 for (i = 0; i < SPDK_TRACE_MAX_LCORE; i++) { 198 struct spdk_trace_history *lcore_history; 199 200 g_trace_flags->lcore_history_offsets[i] = lcore_offsets[i]; 201 lcore_history = spdk_get_per_lcore_history(g_trace_histories, i); 202 lcore_history->lcore = i; 203 lcore_history->num_entries = num_entries; 204 } 205 g_trace_flags->lcore_history_offsets[SPDK_TRACE_MAX_LCORE] = lcore_offsets[SPDK_TRACE_MAX_LCORE]; 206 207 spdk_trace_flags_init(); 208 209 return 0; 210 211 trace_init_err: 212 if (g_trace_histories != MAP_FAILED) { 213 munmap(g_trace_histories, histories_size); 214 } 215 close(g_trace_fd); 216 g_trace_fd = -1; 217 shm_unlink(shm_name); 218 g_trace_histories = NULL; 219 220 return 1; 221 222 } 223 224 void 225 spdk_trace_cleanup(void) 226 { 227 bool unlink; 228 int i; 229 struct spdk_trace_history *lcore_history; 230 231 if (g_trace_histories == NULL) { 232 return; 233 } 234 235 /* 236 * Only unlink the shm if there were no trace_entry recorded. This ensures the file 237 * can be used after this process exits/crashes for debugging. 238 * Note that we have to calculate this value before g_trace_histories gets unmapped. 239 */ 240 for (i = 0; i < SPDK_TRACE_MAX_LCORE; i++) { 241 lcore_history = spdk_get_per_lcore_history(g_trace_histories, i); 242 unlink = lcore_history->entries[0].tsc == 0; 243 if (!unlink) { 244 break; 245 } 246 } 247 248 munmap(g_trace_histories, sizeof(struct spdk_trace_histories)); 249 g_trace_histories = NULL; 250 close(g_trace_fd); 251 252 if (unlink) { 253 shm_unlink(g_shm_name); 254 } 255 } 256