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 if (argument->size == 8) { 86 intval = va_arg(vl, uint64_t); 87 } else { 88 intval = va_arg(vl, uint32_t); 89 } 90 argval = &intval; 91 arglen = argument->size; 92 break; 93 default: 94 assert(0 && "Invalid trace argument type"); 95 return; 96 } 97 98 /* Copy argument's data. For some argument types (strings) user is allowed to pass a 99 * value that is either larger or smaller than what's defined in the tracepoint's 100 * description. If the value is larger, we'll truncate it, while if it's smaller, 101 * we'll only fill portion of the buffer, without touching the rest. For instance, 102 * if the definition marks an argument as 40B and user passes 12B string, we'll only 103 * copy 13B (accounting for the NULL terminator). 104 */ 105 argoff = 0; 106 while (argoff < argument->size) { 107 /* Current buffer is full, we need to acquire another one */ 108 if (offset == sizeof(buffer->data)) { 109 buffer = (struct spdk_trace_entry_buffer *) get_trace_entry( 110 lcore_history, 111 lcore_history->next_entry + num_entries); 112 buffer->tpoint_id = SPDK_TRACE_MAX_TPOINT_ID; 113 buffer->tsc = tsc; 114 num_entries++; 115 offset = 0; 116 } 117 118 curlen = spdk_min(sizeof(buffer->data) - offset, argument->size - argoff); 119 if (argoff < arglen) { 120 assert(argval != NULL); 121 memcpy(&buffer->data[offset], (uint8_t *)argval + argoff, 122 spdk_min(curlen, arglen - argoff)); 123 } 124 125 offset += curlen; 126 argoff += curlen; 127 } 128 129 /* Make sure that truncated strings are NULL-terminated */ 130 if (argument->type == SPDK_TRACE_ARG_TYPE_STR) { 131 assert(offset > 0); 132 buffer->data[offset - 1] = '\0'; 133 } 134 } 135 va_end(vl); 136 137 /* Ensure all elements of the trace entry are visible to outside trace tools */ 138 spdk_smp_wmb(); 139 lcore_history->next_entry += num_entries; 140 } 141 142 int 143 spdk_trace_init(const char *shm_name, uint64_t num_entries) 144 { 145 int i = 0; 146 int histories_size; 147 uint64_t lcore_offsets[SPDK_TRACE_MAX_LCORE + 1]; 148 149 /* 0 entries requested - skip trace initialization */ 150 if (num_entries == 0) { 151 return 0; 152 } 153 154 lcore_offsets[0] = sizeof(struct spdk_trace_flags); 155 for (i = 1; i < (int)SPDK_COUNTOF(lcore_offsets); i++) { 156 lcore_offsets[i] = spdk_get_trace_history_size(num_entries) + lcore_offsets[i - 1]; 157 } 158 histories_size = lcore_offsets[SPDK_TRACE_MAX_LCORE]; 159 160 snprintf(g_shm_name, sizeof(g_shm_name), "%s", shm_name); 161 162 g_trace_fd = shm_open(shm_name, O_RDWR | O_CREAT, 0600); 163 if (g_trace_fd == -1) { 164 SPDK_ERRLOG("could not shm_open spdk_trace\n"); 165 SPDK_ERRLOG("errno=%d %s\n", errno, spdk_strerror(errno)); 166 return 1; 167 } 168 169 if (ftruncate(g_trace_fd, histories_size) != 0) { 170 SPDK_ERRLOG("could not truncate shm\n"); 171 goto trace_init_err; 172 } 173 174 g_trace_histories = mmap(NULL, histories_size, PROT_READ | PROT_WRITE, 175 MAP_SHARED, g_trace_fd, 0); 176 if (g_trace_histories == MAP_FAILED) { 177 SPDK_ERRLOG("could not mmap shm\n"); 178 goto trace_init_err; 179 } 180 181 /* TODO: On FreeBSD, mlock on shm_open'd memory doesn't seem to work. Docs say that kern.ipc.shm_use_phys=1 182 * should allow it, but forcing that doesn't seem to work either. So for now just skip mlock on FreeBSD 183 * altogether. 184 */ 185 #if defined(__linux__) 186 if (mlock(g_trace_histories, histories_size) != 0) { 187 SPDK_ERRLOG("Could not mlock shm for tracing - %s.\n", spdk_strerror(errno)); 188 if (errno == ENOMEM) { 189 SPDK_ERRLOG("Check /dev/shm for old tracing files that can be deleted.\n"); 190 } 191 goto trace_init_err; 192 } 193 #endif 194 195 memset(g_trace_histories, 0, histories_size); 196 197 g_trace_flags = &g_trace_histories->flags; 198 199 g_trace_flags->tsc_rate = spdk_get_ticks_hz(); 200 201 for (i = 0; i < SPDK_TRACE_MAX_LCORE; i++) { 202 struct spdk_trace_history *lcore_history; 203 204 g_trace_flags->lcore_history_offsets[i] = lcore_offsets[i]; 205 lcore_history = spdk_get_per_lcore_history(g_trace_histories, i); 206 lcore_history->lcore = i; 207 lcore_history->num_entries = num_entries; 208 } 209 g_trace_flags->lcore_history_offsets[SPDK_TRACE_MAX_LCORE] = lcore_offsets[SPDK_TRACE_MAX_LCORE]; 210 211 spdk_trace_flags_init(); 212 213 return 0; 214 215 trace_init_err: 216 if (g_trace_histories != MAP_FAILED) { 217 munmap(g_trace_histories, histories_size); 218 } 219 close(g_trace_fd); 220 g_trace_fd = -1; 221 shm_unlink(shm_name); 222 g_trace_histories = NULL; 223 224 return 1; 225 226 } 227 228 void 229 spdk_trace_cleanup(void) 230 { 231 bool unlink; 232 int i; 233 struct spdk_trace_history *lcore_history; 234 235 if (g_trace_histories == NULL) { 236 return; 237 } 238 239 /* 240 * Only unlink the shm if there were no trace_entry recorded. This ensures the file 241 * can be used after this process exits/crashes for debugging. 242 * Note that we have to calculate this value before g_trace_histories gets unmapped. 243 */ 244 for (i = 0; i < SPDK_TRACE_MAX_LCORE; i++) { 245 lcore_history = spdk_get_per_lcore_history(g_trace_histories, i); 246 unlink = lcore_history->entries[0].tsc == 0; 247 if (!unlink) { 248 break; 249 } 250 } 251 252 munmap(g_trace_histories, sizeof(struct spdk_trace_histories)); 253 g_trace_histories = NULL; 254 close(g_trace_fd); 255 256 if (unlink) { 257 shm_unlink(g_shm_name); 258 } 259 } 260