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