1 // SPDX-License-Identifier: GPL-2.0 1 // SPDX-License-Identifier: GPL-2.0 2 #include <linux/compiler.h> 2 #include <linux/compiler.h> 3 #include <elfutils/libdw.h> 3 #include <elfutils/libdw.h> 4 #include <elfutils/libdwfl.h> 4 #include <elfutils/libdwfl.h> 5 #include <inttypes.h> 5 #include <inttypes.h> 6 #include <errno.h> 6 #include <errno.h> 7 #include "debug.h" 7 #include "debug.h" 8 #include "dso.h" 8 #include "dso.h" 9 #include "unwind.h" 9 #include "unwind.h" 10 #include "unwind-libdw.h" 10 #include "unwind-libdw.h" 11 #include "machine.h" 11 #include "machine.h" 12 #include "map.h" 12 #include "map.h" 13 #include "symbol.h" 13 #include "symbol.h" 14 #include "thread.h" 14 #include "thread.h" 15 #include <linux/types.h> 15 #include <linux/types.h> 16 #include <linux/zalloc.h> 16 #include <linux/zalloc.h> 17 #include "event.h" 17 #include "event.h" 18 #include "perf_regs.h" 18 #include "perf_regs.h" 19 #include "callchain.h" 19 #include "callchain.h" 20 #include "util/env.h" << 21 20 22 static char *debuginfo_path; 21 static char *debuginfo_path; 23 22 24 static int __find_debuginfo(Dwfl_Module *mod _ 23 static int __find_debuginfo(Dwfl_Module *mod __maybe_unused, void **userdata, 25 const char *modnam 24 const char *modname __maybe_unused, Dwarf_Addr base __maybe_unused, 26 const char *file_n 25 const char *file_name, const char *debuglink_file __maybe_unused, 27 GElf_Word debuglin 26 GElf_Word debuglink_crc __maybe_unused, char **debuginfo_file_name) 28 { 27 { 29 const struct dso *dso = *userdata; 28 const struct dso *dso = *userdata; 30 29 31 assert(dso); 30 assert(dso); 32 if (dso__symsrc_filename(dso) && strcm !! 31 if (dso->symsrc_filename && strcmp (file_name, dso->symsrc_filename)) 33 *debuginfo_file_name = strdup( !! 32 *debuginfo_file_name = strdup(dso->symsrc_filename); 34 return -1; 33 return -1; 35 } 34 } 36 35 37 static const Dwfl_Callbacks offline_callbacks 36 static const Dwfl_Callbacks offline_callbacks = { 38 .find_debuginfo = __find_debug 37 .find_debuginfo = __find_debuginfo, 39 .debuginfo_path = &debuginfo_p 38 .debuginfo_path = &debuginfo_path, 40 .section_address = dwfl_offline 39 .section_address = dwfl_offline_section_address, 41 // .find_elf is not set as we use dwfl 40 // .find_elf is not set as we use dwfl_report_elf() instead. 42 }; 41 }; 43 42 44 static int __report_module(struct addr_locatio 43 static int __report_module(struct addr_location *al, u64 ip, 45 struct unwind_info 44 struct unwind_info *ui) 46 { 45 { 47 Dwfl_Module *mod; 46 Dwfl_Module *mod; 48 struct dso *dso = NULL; 47 struct dso *dso = NULL; 49 Dwarf_Addr base; << 50 /* 48 /* 51 * Some callers will use al->sym, so w 49 * Some callers will use al->sym, so we can't just use the 52 * cheaper thread__find_map() here. 50 * cheaper thread__find_map() here. 53 */ 51 */ 54 thread__find_symbol(ui->thread, PERF_R 52 thread__find_symbol(ui->thread, PERF_RECORD_MISC_USER, ip, al); 55 53 56 if (al->map) 54 if (al->map) 57 dso = map__dso(al->map); !! 55 dso = al->map->dso; 58 56 59 if (!dso) 57 if (!dso) 60 return 0; 58 return 0; 61 59 62 /* << 63 * The generated JIT DSO files only ma << 64 * ELF headers. Since JIT codes used << 65 * segment, calculating the base addre << 66 * a different code in another DSO. S << 67 * directly to pick the correct one. << 68 */ << 69 if (!strncmp(dso__long_name(dso), "/tm << 70 base = map__start(al->map); << 71 else << 72 base = map__start(al->map) - m << 73 << 74 mod = dwfl_addrmodule(ui->dwfl, ip); 60 mod = dwfl_addrmodule(ui->dwfl, ip); 75 if (mod) { 61 if (mod) { 76 Dwarf_Addr s; 62 Dwarf_Addr s; 77 63 78 dwfl_module_info(mod, NULL, &s 64 dwfl_module_info(mod, NULL, &s, NULL, NULL, NULL, NULL, NULL); 79 if (s != base) !! 65 if (s != al->map->start - al->map->pgoff) 80 mod = NULL; !! 66 mod = 0; 81 } 67 } 82 68 83 if (!mod) { !! 69 if (!mod) 84 char filename[PATH_MAX]; !! 70 mod = dwfl_report_elf(ui->dwfl, dso->short_name, dso->long_name, -1, 85 !! 71 al->map->start - al->map->pgoff, false); 86 __symbol__join_symfs(filename, << 87 mod = dwfl_report_elf(ui->dwfl << 88 base, fa << 89 } << 90 if (!mod) { 72 if (!mod) { 91 char filename[PATH_MAX]; 73 char filename[PATH_MAX]; 92 74 93 if (dso__build_id_filename(dso 75 if (dso__build_id_filename(dso, filename, sizeof(filename), false)) 94 mod = dwfl_report_elf( !! 76 mod = dwfl_report_elf(ui->dwfl, dso->short_name, filename, -1, 95 !! 77 al->map->start - al->map->pgoff, false); 96 } 78 } 97 79 98 if (mod) { 80 if (mod) { 99 void **userdatap; 81 void **userdatap; 100 82 101 dwfl_module_info(mod, &userdat 83 dwfl_module_info(mod, &userdatap, NULL, NULL, NULL, NULL, NULL, NULL); 102 *userdatap = dso; 84 *userdatap = dso; 103 } 85 } 104 86 105 return mod && dwfl_addrmodule(ui->dwfl 87 return mod && dwfl_addrmodule(ui->dwfl, ip) == mod ? 0 : -1; 106 } 88 } 107 89 108 static int report_module(u64 ip, struct unwind 90 static int report_module(u64 ip, struct unwind_info *ui) 109 { 91 { 110 struct addr_location al; 92 struct addr_location al; 111 int res; << 112 93 113 addr_location__init(&al); !! 94 return __report_module(&al, ip, ui); 114 res = __report_module(&al, ip, ui); << 115 addr_location__exit(&al); << 116 return res; << 117 } 95 } 118 96 119 /* 97 /* 120 * Store all entries within entries array, 98 * Store all entries within entries array, 121 * we will process it after we finish unwind. 99 * we will process it after we finish unwind. 122 */ 100 */ 123 static int entry(u64 ip, struct unwind_info *u 101 static int entry(u64 ip, struct unwind_info *ui) 124 102 125 { 103 { 126 struct unwind_entry *e = &ui->entries[ 104 struct unwind_entry *e = &ui->entries[ui->idx++]; 127 struct addr_location al; 105 struct addr_location al; 128 106 129 addr_location__init(&al); !! 107 if (__report_module(&al, ip, ui)) 130 if (__report_module(&al, ip, ui)) { << 131 addr_location__exit(&al); << 132 return -1; 108 return -1; 133 } << 134 109 135 e->ip = ip; 110 e->ip = ip; 136 e->ms.maps = al.maps; 111 e->ms.maps = al.maps; 137 e->ms.map = al.map; 112 e->ms.map = al.map; 138 e->ms.sym = al.sym; 113 e->ms.sym = al.sym; 139 114 140 pr_debug("unwind: %s:ip = 0x%" PRIx64 115 pr_debug("unwind: %s:ip = 0x%" PRIx64 " (0x%" PRIx64 ")\n", 141 al.sym ? al.sym->name : "''", 116 al.sym ? al.sym->name : "''", 142 ip, 117 ip, 143 al.map ? map__map_ip(al.map, !! 118 al.map ? al.map->map_ip(al.map, ip) : (u64) 0); 144 addr_location__exit(&al); << 145 return 0; 119 return 0; 146 } 120 } 147 121 148 static pid_t next_thread(Dwfl *dwfl, void *arg 122 static pid_t next_thread(Dwfl *dwfl, void *arg, void **thread_argp) 149 { 123 { 150 /* We want only single thread to be pr 124 /* We want only single thread to be processed. */ 151 if (*thread_argp != NULL) 125 if (*thread_argp != NULL) 152 return 0; 126 return 0; 153 127 154 *thread_argp = arg; 128 *thread_argp = arg; 155 return dwfl_pid(dwfl); 129 return dwfl_pid(dwfl); 156 } 130 } 157 131 158 static int access_dso_mem(struct unwind_info * 132 static int access_dso_mem(struct unwind_info *ui, Dwarf_Addr addr, 159 Dwarf_Word *data) 133 Dwarf_Word *data) 160 { 134 { 161 struct addr_location al; 135 struct addr_location al; 162 ssize_t size; 136 ssize_t size; 163 struct dso *dso; << 164 137 165 addr_location__init(&al); << 166 if (!thread__find_map(ui->thread, PERF 138 if (!thread__find_map(ui->thread, PERF_RECORD_MISC_USER, addr, &al)) { 167 pr_debug("unwind: no map for % 139 pr_debug("unwind: no map for %lx\n", (unsigned long)addr); 168 goto out_fail; !! 140 return -1; 169 } 141 } 170 dso = map__dso(al.map); << 171 if (!dso) << 172 goto out_fail; << 173 142 174 size = dso__data_read_addr(dso, al.map !! 143 if (!al.map->dso) >> 144 return -1; >> 145 >> 146 size = dso__data_read_addr(al.map->dso, al.map, ui->machine, >> 147 addr, (u8 *) data, sizeof(*data)); 175 148 176 addr_location__exit(&al); << 177 return !(size == sizeof(*data)); 149 return !(size == sizeof(*data)); 178 out_fail: << 179 addr_location__exit(&al); << 180 return -1; << 181 } 150 } 182 151 183 static bool memory_read(Dwfl *dwfl __maybe_unu 152 static bool memory_read(Dwfl *dwfl __maybe_unused, Dwarf_Addr addr, Dwarf_Word *result, 184 void *arg) 153 void *arg) 185 { 154 { 186 struct unwind_info *ui = arg; 155 struct unwind_info *ui = arg; 187 const char *arch = perf_env__arch(ui-> << 188 struct stack_dump *stack = &ui->sample 156 struct stack_dump *stack = &ui->sample->user_stack; 189 u64 start, end; 157 u64 start, end; 190 int offset; 158 int offset; 191 int ret; 159 int ret; 192 160 193 ret = perf_reg_value(&start, &ui->samp !! 161 ret = perf_reg_value(&start, &ui->sample->user_regs, PERF_REG_SP); 194 perf_arch_reg_sp( << 195 if (ret) 162 if (ret) 196 return false; 163 return false; 197 164 198 end = start + stack->size; 165 end = start + stack->size; 199 166 200 /* Check overflow. */ 167 /* Check overflow. */ 201 if (addr + sizeof(Dwarf_Word) < addr) 168 if (addr + sizeof(Dwarf_Word) < addr) 202 return false; 169 return false; 203 170 204 if (addr < start || addr + sizeof(Dwar 171 if (addr < start || addr + sizeof(Dwarf_Word) > end) { 205 ret = access_dso_mem(ui, addr, 172 ret = access_dso_mem(ui, addr, result); 206 if (ret) { 173 if (ret) { 207 pr_debug("unwind: acce 174 pr_debug("unwind: access_mem 0x%" PRIx64 " not inside range" 208 " 0x%" PRIx64 175 " 0x%" PRIx64 "-0x%" PRIx64 "\n", 209 addr, start, e 176 addr, start, end); 210 return false; 177 return false; 211 } 178 } 212 return true; 179 return true; 213 } 180 } 214 181 215 offset = addr - start; 182 offset = addr - start; 216 *result = *(Dwarf_Word *)&stack->data[ 183 *result = *(Dwarf_Word *)&stack->data[offset]; 217 pr_debug("unwind: access_mem addr 0x%" 184 pr_debug("unwind: access_mem addr 0x%" PRIx64 ", val %lx, offset %d\n", 218 addr, (unsigned long)*result, 185 addr, (unsigned long)*result, offset); 219 return true; 186 return true; 220 } 187 } 221 188 222 static const Dwfl_Thread_Callbacks callbacks = 189 static const Dwfl_Thread_Callbacks callbacks = { 223 .next_thread = next_thread, 190 .next_thread = next_thread, 224 .memory_read = memory_read, 191 .memory_read = memory_read, 225 .set_initial_registers = libdw__arch_ 192 .set_initial_registers = libdw__arch_set_initial_registers, 226 }; 193 }; 227 194 228 static int 195 static int 229 frame_callback(Dwfl_Frame *state, void *arg) 196 frame_callback(Dwfl_Frame *state, void *arg) 230 { 197 { 231 struct unwind_info *ui = arg; 198 struct unwind_info *ui = arg; 232 Dwarf_Addr pc; 199 Dwarf_Addr pc; 233 bool isactivation; 200 bool isactivation; 234 201 235 if (!dwfl_frame_pc(state, &pc, NULL)) 202 if (!dwfl_frame_pc(state, &pc, NULL)) { 236 if (!ui->best_effort) 203 if (!ui->best_effort) 237 pr_err("%s", dwfl_errm 204 pr_err("%s", dwfl_errmsg(-1)); 238 return DWARF_CB_ABORT; 205 return DWARF_CB_ABORT; 239 } 206 } 240 207 241 // report the module before we query f 208 // report the module before we query for isactivation 242 report_module(pc, ui); 209 report_module(pc, ui); 243 210 244 if (!dwfl_frame_pc(state, &pc, &isacti 211 if (!dwfl_frame_pc(state, &pc, &isactivation)) { 245 if (!ui->best_effort) 212 if (!ui->best_effort) 246 pr_err("%s", dwfl_errm 213 pr_err("%s", dwfl_errmsg(-1)); 247 return DWARF_CB_ABORT; 214 return DWARF_CB_ABORT; 248 } 215 } 249 216 250 if (!isactivation) 217 if (!isactivation) 251 --pc; 218 --pc; 252 219 253 return entry(pc, ui) || !(--ui->max_st 220 return entry(pc, ui) || !(--ui->max_stack) ? 254 DWARF_CB_ABORT : DWARF_CB_OK; 221 DWARF_CB_ABORT : DWARF_CB_OK; 255 } 222 } 256 223 257 int unwind__get_entries(unwind_entry_cb_t cb, 224 int unwind__get_entries(unwind_entry_cb_t cb, void *arg, 258 struct thread *thread, 225 struct thread *thread, 259 struct perf_sample *da 226 struct perf_sample *data, 260 int max_stack, 227 int max_stack, 261 bool best_effort) 228 bool best_effort) 262 { 229 { 263 struct unwind_info *ui, ui_buf = { 230 struct unwind_info *ui, ui_buf = { 264 .sample = data, 231 .sample = data, 265 .thread = thread, 232 .thread = thread, 266 .machine = maps__machin !! 233 .machine = thread->maps->machine, 267 .cb = cb, 234 .cb = cb, 268 .arg = arg, 235 .arg = arg, 269 .max_stack = max_stack, 236 .max_stack = max_stack, 270 .best_effort = best_effort 237 .best_effort = best_effort 271 }; 238 }; 272 const char *arch = perf_env__arch(ui_b << 273 Dwarf_Word ip; 239 Dwarf_Word ip; 274 int err = -EINVAL, i; 240 int err = -EINVAL, i; 275 241 276 if (!data->user_regs.regs) 242 if (!data->user_regs.regs) 277 return -EINVAL; 243 return -EINVAL; 278 244 279 ui = zalloc(sizeof(ui_buf) + sizeof(ui 245 ui = zalloc(sizeof(ui_buf) + sizeof(ui_buf.entries[0]) * max_stack); 280 if (!ui) 246 if (!ui) 281 return -ENOMEM; 247 return -ENOMEM; 282 248 283 *ui = ui_buf; 249 *ui = ui_buf; 284 250 285 ui->dwfl = dwfl_begin(&offline_callbac 251 ui->dwfl = dwfl_begin(&offline_callbacks); 286 if (!ui->dwfl) 252 if (!ui->dwfl) 287 goto out; 253 goto out; 288 254 289 err = perf_reg_value(&ip, &data->user_ !! 255 err = perf_reg_value(&ip, &data->user_regs, PERF_REG_IP); 290 if (err) 256 if (err) 291 goto out; 257 goto out; 292 258 293 err = report_module(ip, ui); 259 err = report_module(ip, ui); 294 if (err) 260 if (err) 295 goto out; 261 goto out; 296 262 297 err = !dwfl_attach_state(ui->dwfl, EM_ !! 263 err = !dwfl_attach_state(ui->dwfl, EM_NONE, thread->tid, &callbacks, ui); 298 if (err) 264 if (err) 299 goto out; 265 goto out; 300 266 301 err = dwfl_getthread_frames(ui->dwfl, !! 267 err = dwfl_getthread_frames(ui->dwfl, thread->tid, frame_callback, ui); 302 268 303 if (err && ui->max_stack != max_stack) 269 if (err && ui->max_stack != max_stack) 304 err = 0; 270 err = 0; 305 271 306 /* 272 /* 307 * Display what we got based on the or 273 * Display what we got based on the order setup. 308 */ 274 */ 309 for (i = 0; i < ui->idx && !err; i++) 275 for (i = 0; i < ui->idx && !err; i++) { 310 int j = i; 276 int j = i; 311 277 312 if (callchain_param.order == O 278 if (callchain_param.order == ORDER_CALLER) 313 j = ui->idx - i - 1; 279 j = ui->idx - i - 1; 314 280 315 err = ui->entries[j].ip ? ui-> 281 err = ui->entries[j].ip ? ui->cb(&ui->entries[j], ui->arg) : 0; 316 } 282 } 317 283 318 out: 284 out: 319 if (err) 285 if (err) 320 pr_debug("unwind: failed with 286 pr_debug("unwind: failed with '%s'\n", dwfl_errmsg(-1)); 321 287 322 dwfl_end(ui->dwfl); 288 dwfl_end(ui->dwfl); 323 free(ui); 289 free(ui); 324 return 0; 290 return 0; 325 } 291 } 326 292
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