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