1 #include <stdlib.h> 2 #include <stdio.h> 3 #include <unistd.h> 4 #include <string.h> 5 #include <sys/ioctl.h> 6 #include <linux/perf_event.h> 7 #include <asm/unistd.h> 8 #include <sys/mman.h> 9 #include <sys/stat.h> 10 #include <poll.h> 11 #include <signal.h> 12 #include <fcntl.h> 13 #include <elf.h> 14 #include <string.h> 15 16 #include <vector> 17 #include <string> 18 #include <map> 19 #include <unordered_map> 20 #include <algorithm> 21 using namespace std; 22 23 24 #define MAXN 128 25 #define MAXCPU 1024 26 #define error(msg) do { perror(msg); exit(1); } while(0) 27 //--------------------------------Tree for call chain and report------------------------------- 28 // 29 struct TNode { 30 int c=0; 31 unordered_map<string, TNode*> s; 32 struct TNode *add(string n) { 33 c++; 34 if (s[n]==nullptr) s[n] = new TNode(); 35 return s[n]; 36 } 37 int printit(FILE *fp, int k) { 38 if (s.size()) { 39 using tt = tuple<int, string, TNode*>; 40 vector<tt> xx; 41 for (auto x: s) xx.push_back(make_tuple(x.second->c, x.first, x.second)); 42 sort(begin(xx), end(xx), greater<tt>()); 43 for (auto x: xx) { 44 auto count = get<0>(x); 45 if (100.0*count/c<1) continue; 46 auto name = get<1>(x); 47 auto nx = get<2>(x); 48 fprintf(fp, "<li>\n"); 49 fprintf(fp, "<input type=\"checkbox\" id=\"c%d\" />\n", k); 50 fprintf(fp, "<label class=\"tree_label\" for=\"c%d\">%s(%.3f%% %d/%d)</label>\n", k, name.c_str(), 100.0*count/c, count, c); 51 fprintf(fp, "<ul>\n"); 52 // printf("%s(%.3f%% %d/%d)\n", name.c_str(), 100.0*count/c, count, c); 53 k = nx->printit(fp, k+1); 54 fprintf(fp, "</ul>\n"); 55 fprintf(fp, "</li>\n"); 56 } 57 } 58 return k; 59 } 60 }; 61 62 //--------------------------------symbols------------------------------------------- 63 using STORE_T = map<unsigned long long, pair<string, unsigned long long>>; 64 using K_STORE_T = map<unsigned long long, string>; 65 66 /* 67 * load FUNC symbols refering to the section indicated by the offset, relocate the virtual address 68 */ 69 void parse_elf64(FILE *fp, unsigned long long v_addr, unsigned long long v_size, unsigned long long v_offset, STORE_T& store) { 70 // printf("read elf with offset 0x%llx, addr 0x%llx\n", v_offset, v_addr); 71 Elf64_Ehdr ehdr; 72 int rc = fread(&ehdr, sizeof(ehdr), 1, fp); 73 if (rc != 1) return; 74 int n, s, i; 75 unsigned long long offset; 76 77 // load program headers 78 unsigned long long p_vaddr, p_size; 79 n = ehdr.e_phnum; 80 s = ehdr.e_phentsize; 81 offset = ehdr.e_phoff; 82 Elf64_Phdr phdr; 83 for (i=0; i<n; i++) { 84 rc = fseek(fp, offset, SEEK_SET); 85 if (rc<0) { perror("fail to seek"); return; } 86 rc = fread(&phdr, sizeof(phdr), 1, fp); 87 if (rc != 1) { perror("fail to read program header"); return; } 88 if (phdr.p_flags&PF_X) { 89 if (phdr.p_offset == v_offset) { 90 p_vaddr = phdr.p_vaddr; 91 p_size = phdr.p_memsz; if (p_size==0) p_size = 0xffffffff; 92 break; 93 } 94 } 95 offset+=s; 96 } 97 if (i>=n) { printf("No program header match offset found, fail to load\n"); return; } 98 99 // load section headers 100 n = ehdr.e_shnum; 101 s = ehdr.e_shentsize; 102 offset = ehdr.e_shoff; 103 Elf64_Shdr shdr; 104 vector<Elf64_Shdr> headers; 105 for (int i=0; i<n; i++) { 106 rc = fseek(fp, offset, SEEK_SET); 107 if (rc<0) { perror("fail to seek"); return; } 108 rc = fread(&shdr, sizeof(shdr), 1, fp); 109 if (rc != 1) { perror("fail to read sec header"); return; } 110 headers.push_back(shdr); 111 offset+=s; 112 } 113 Elf64_Sym symb; 114 unsigned long long faddr, fsize; 115 unsigned long long size, item_size; 116 int link, ix, flink, k; 117 char fname[128]; 118 for (int i=0; i<n; i++) { 119 switch(headers[i].sh_type) { 120 case SHT_SYMTAB: 121 case SHT_DYNSYM: 122 offset = headers[i].sh_offset; 123 size = headers[i].sh_size; 124 item_size = headers[i].sh_entsize; 125 link = headers[i].sh_link; 126 if (link<=0) break; 127 for (k=0; k+item_size<=size; k+=item_size) { 128 rc = fseek(fp, offset+k, SEEK_SET); if (rc<0) continue; 129 rc = fread(&symb, sizeof(symb), 1, fp); if (rc != 1) continue; 130 if (ELF64_ST_TYPE(symb.st_info) != STT_FUNC ) continue; 131 flink = symb.st_shndx; if (flink==0) continue; 132 fsize = symb.st_size; if (fsize==0) continue; 133 faddr = symb.st_value; if (faddr>p_vaddr+p_size) continue; 134 ix = symb.st_name; if (ix==0) continue; 135 rc = fseek(fp, headers[link].sh_offset+ix, SEEK_SET); if (rc<0) continue; 136 if (fgets(fname, sizeof(fname), fp)==NULL) continue; 137 faddr = faddr-p_vaddr+v_addr; 138 // printf("0x%llx +%lld > %s\n", faddr, fsize, fname); 139 store[faddr] = make_pair(string(fname), fsize); 140 } 141 break; 142 default: 143 break; 144 } 145 } 146 } 147 148 int load_symbol_from_file(const char *path, unsigned long long addr, unsigned long long size, unsigned long long offset, STORE_T& store) { 149 printf("loading symble from %s\n", path); 150 FILE *fp = fopen(path, "rb"); 151 if (fp==NULL) { perror("fail to open file"); return -1; } 152 char ident[EI_NIDENT], c; 153 int err=0; 154 int rc = fread(ident, sizeof(ident), 1, fp); 155 if (rc != 1) { perror("fail to read ident"); err=-1; goto end; } 156 if (ident[0]!=0x7f) { printf("not a elf file\n"); err=-1; goto end; } 157 c=ident[4]; 158 rc = fseek(fp, 0, SEEK_SET); if (rc<0) { perror("fail to rewind"); goto end; } 159 if (c == ELFCLASS32) { 160 printf("32bit elf not supported yet\n"); err=-2; goto end; 161 } else if (c == ELFCLASS64) { 162 parse_elf64(fp, addr, size, offset, store); 163 } else { 164 printf("unknown elf type %d\n", c); 165 } 166 167 end: 168 fclose(fp); 169 return err; 170 } 171 172 static unsigned long long parse_hex(char *p, int *n) { 173 unsigned long long r=0; 174 int i=0; 175 *n = 0; 176 while(p[i]==' '||p[i]=='\t') i++; 177 if (p[i]==0) return 0; 178 if (p[i+1]=='x') i+=2; 179 int v; 180 while(p[i]) { 181 if (p[i]>='0'&&p[i]<='9') v=p[i]-'0'; 182 else if (p[i]>='a'&&p[i]<='f') v=10+p[i]-'a'; 183 else if (p[i]>='A'&&p[i]<='F') v=10+p[i]-'A'; 184 else break; 185 r=(r<<4)+v; 186 i++; 187 } 188 *n = i; 189 return r; 190 } 191 192 STORE_T* load_symbol_pid(int pid, STORE_T* in) { 193 printf("loading symbols for %d\n", pid); 194 char bb[128]; 195 sprintf(bb, "/proc/%d/maps", pid); 196 FILE* fp = fopen(bb, "r"); 197 if (fp==NULL) return NULL; 198 STORE_T *store = in; 199 unsigned long long start, end, offset=0; 200 if (store==NULL) store=new STORE_T(); 201 char *p; 202 int i, c, j; 203 while(1) { 204 p=fgets(bb, sizeof(bb), fp); if (p==NULL) break; 205 i=0; c=0; 206 start = parse_hex(p, &c); if (start==0) continue; i+=c; if (p[i]!='-') continue; i++; 207 end = parse_hex(p+i, &c); if (end==0) continue; i+=c; 208 // parse type 209 for (j=0; j<8; j++) { if (p[i]=='x') break; i++; } if (j>=8) continue; 210 while(p[i]!=' '&&p[i]!='\t'&&p[i]!=0) i++; if (p[i]==0) continue; 211 offset = parse_hex(p+i, &c); if (c==0) continue; 212 // remaining should contains '/' indicating this mmap is refering to a file 213 while(p[i]&&p[i]!='/') i++; if (p[i]==0) continue; 214 sprintf(bb, "/proc/%d/map_files/%llx-%llx", pid, start, end); 215 load_symbol_from_file(bb, start, end-start, offset, *store); 216 } 217 fclose(fp); 218 return store; 219 } 220 221 /* parse kernel func symbols from /proc/kallsyms */ 222 K_STORE_T* load_kernel() { 223 FILE* fp = fopen("/proc/kallsyms", "r"); 224 if (fp == NULL) return NULL; 225 char *p; 226 unsigned long long addr; 227 int c; 228 K_STORE_T* store = new K_STORE_T(); 229 char bb[128], adr[128], type[8], name[128]; 230 while(1) { 231 p = fgets(bb, sizeof(bb), fp); if (p==NULL) break; 232 if (sscanf(p, "%s %s %s", adr, type, name)!=3) continue;; 233 if (type[0]!='t'&&type[0]!='T') continue; 234 addr=parse_hex(adr, &c); if (c==0) continue; 235 (*store)[addr] = string(name); 236 } 237 return store; 238 fclose(fp); 239 } 240 241 //------------------------------perf profiler------------------------- 242 static long perf_event_open(struct perf_event_attr *perf_event, pid_t pid, int cpu, int group_fd, unsigned long flags) { 243 return syscall(__NR_perf_event_open, perf_event, pid, cpu, group_fd, flags); 244 } 245 unordered_map<int, STORE_T*> pid_symbols; 246 unordered_map<int, pair<string,string>> pid_infos; 247 K_STORE_T* kernel_symbols = NULL; 248 249 struct pollfd polls[MAXCPU]; 250 // res for cleanup 251 static long long psize; 252 map<int, pair<void*, long long>> res; 253 TNode* gnode = NULL; 254 int exiting = 0; 255 256 void int_exit(int x) { 257 exiting = 1; 258 for (auto x: res) { 259 auto y = x.second; 260 void* addr = y.first; 261 munmap(addr, (1+MAXN)*psize); 262 close(x.first); 263 } 264 res.clear(); 265 if (gnode!=NULL) { 266 FILE* fp = fopen("./report.html", "w"); 267 if (fp) { 268 fprintf(fp, "<head> <link rel=\"stylesheet\" href=\"report.css\"> <script src=\"report.js\"> </script> </head>\n"); 269 fprintf(fp, "<ul class=\"tree\">\n"); 270 gnode->printit(fp, 0); 271 fprintf(fp, "</ul>\n"); 272 fclose(fp); 273 printf("report done\n"); 274 } 275 gnode = NULL; 276 } 277 exit(x); 278 } 279 /* 280 perf call chain process 281 For now, if a address would not be located to some function, the address would be skipped. 282 */ 283 int process_event(char *base, unsigned long long size, unsigned long long offset) { 284 struct perf_event_header* p = NULL; 285 int pid, xpid; 286 unsigned long long time; 287 offset%=size; 288 // assuming the header would fit within size 289 p = (struct perf_event_header*) (base+offset); 290 offset+=sizeof(*p); if (offset>=size) offset-=size; 291 if (p->type != PERF_RECORD_SAMPLE) return p->size; 292 // pid, tip; 293 pid = *((int *)(base+offset)); offset+=8; if (offset>=size) offset-=size; 294 unsigned long long nr = *((unsigned long long*)(base+offset)); offset+=8; if (offset>=size) offset-=size; 295 unsigned long long addr, o, addr0; 296 if (nr) { 297 if (gnode==NULL) gnode=new TNode(); 298 char bb[64]; 299 TNode* r = gnode; 300 if (pid_symbols.count(pid)==0) { 301 pid_symbols[pid] = load_symbol_pid(pid, NULL); 302 // load command 303 char b[128]; 304 char comm[128]="NA"; 305 char host[128]="NA"; 306 sprintf(b, "/proc/%d/comm", pid); 307 FILE* fp = fopen(b, "r"); 308 if (fp) { 309 fscanf(fp, "%s", comm); 310 fclose(fp); 311 } 312 sprintf(b, "/proc/%d/root/etc/hostname", pid); 313 fp = fopen(b, "r"); 314 if (fp) { 315 fscanf(fp, "%s", host); 316 fclose(fp); 317 } 318 pid_infos[pid]=make_pair(string(comm), string(host)); 319 } 320 STORE_T* px = pid_symbols[pid]; 321 addr0 = *((unsigned long long *)(base+offset)); 322 char user_mark = 0; 323 char need_reload= 0; 324 auto pinfo = pid_infos[pid]; 325 for (int i=nr-1; i>=0; i--) { 326 o = i*8+offset; if (o>=size) o-=size; 327 addr = *((unsigned long long*)(base+o)); 328 if ((addr>>56)==(addr0>>56) && (p->misc&PERF_RECORD_MISC_KERNEL)) { 329 // skip the cross line command, no idear how to correctly resolve it now. 330 if (user_mark) { user_mark=0; continue; } 331 // check in kernel 332 if (kernel_symbols&&!kernel_symbols->empty()) { 333 auto x = kernel_symbols->upper_bound(addr); 334 if (x==kernel_symbols->begin()) { 335 // sprintf(bb, "0x%llx", addr); r = r->add(string(bb)); 336 } else { 337 x--; 338 r = r->add((*x).second); 339 } 340 } else { 341 // sprintf(bb, "0x%llx", addr); r = r->add(string(bb)); 342 } 343 } else { 344 if (px) { 345 auto x = px->upper_bound(addr); 346 if (x==px->begin()) { 347 // sprintf(bb, "0x%llx", addr); r = r->add(string(bb)); 348 r = r->add(string("unknwon[")+pinfo.first+'@'+pinfo.second+"]"); 349 } else { 350 x--; 351 auto y = (*x).second; 352 if (addr>(*x).first+y.second) { 353 // r = r->add(y.first); 354 // sprintf(bb, "0x%llx", addr); r = r->add(string(bb)); 355 r = r->add(string("unknwon[")+pinfo.first+'@'+pinfo.second+"]"); 356 } else { 357 r = r->add(y.first+"["+pinfo.first+'@'+pinfo.second+"]"); 358 } 359 } 360 } else { 361 // sprintf(bb, "0x%llx", addr); r = r->add(string(bb)); 362 } 363 user_mark=1; 364 } 365 } 366 } 367 return p->size; 368 } 369 370 int main(int argc, char *argv[]) { 371 kernel_symbols = load_kernel(); 372 if (argc<2) { printf("Need kprobe function name, e.g. %s <some rarely called kernel function>\n", argv[0]); return 1; } 373 int type; 374 char *func = argv[1]; 375 FILE *fp = fopen("/sys/bus/event_source/devices/kprobe/type", "r"); 376 if (fp == NULL) { printf("fail to find type for kprobe\n"); return 1; } 377 type = 0; 378 fscanf(fp, "%d", &type); 379 fclose(fp); 380 if (type <= 0) { printf("unexpected type %d\n", type); return 1; } 381 // start perf event 382 psize = sysconf(_SC_PAGE_SIZE); // getpagesize(); 383 int cpu_num = sysconf(_SC_NPROCESSORS_ONLN); 384 struct perf_event_attr attr; 385 memset(&attr, 0, sizeof(attr)); 386 attr.type = type; 387 attr.size = sizeof(attr); 388 attr.config = 0; // (1<<0) for kreprobe 389 attr.sample_period = 2; 390 attr.wakeup_events = 2; 391 attr.sample_type = PERF_SAMPLE_TID|PERF_SAMPLE_CALLCHAIN; 392 attr.kprobe_func = (__u64)func; // "do_sys_open"; // "bprm_execve"; 393 attr.probe_offset = 0; 394 int fd, i, k; 395 void* addr; 396 for (i=0, k=0; i<cpu_num&&i<MAXCPU; i++) { 397 printf("attaching cpu %d\n", i); 398 fd = perf_event_open(&attr, -1, i, -1, PERF_FLAG_FD_CLOEXEC); 399 if (fd<0) { perror("fail to open perf event"); continue; } 400 addr = mmap(NULL, (1+MAXN)*psize, PROT_READ, MAP_SHARED, fd, 0); 401 if (addr == MAP_FAILED) { perror("mmap failed"); close(fd); continue; } 402 res[fd] = make_pair(addr, 0); 403 polls[k].fd = fd; 404 polls[k].events = POLLIN; 405 polls[k].revents = 0; 406 k++; 407 } 408 if (k==0) { printf("no cpu event attached at all\n"); return 1; } 409 410 signal(SIGINT, int_exit); 411 signal(SIGTERM, int_exit); 412 413 unsigned long long head; 414 struct perf_event_mmap_page *mp; 415 while (poll(polls, k, -1)>0) { 416 for (i=0; i<k; i++) { 417 if (exiting) break; 418 if ((polls[i].revents&POLLIN)==0) continue; 419 fd = polls[i].fd; 420 addr = res[fd].first; 421 mp = (struct perf_event_mmap_page *)addr; 422 head = res[fd].second; 423 if (head==mp->data_head) continue; 424 ioctl(fd, PERF_EVENT_IOC_PAUSE_OUTPUT, 1); 425 head = mp->data_head-((mp->data_head-head)%mp->data_size); 426 while(head<mp->data_head) head+=process_event((char*)addr+mp->data_offset, mp->data_size, head); 427 ioctl(fd, PERF_EVENT_IOC_PAUSE_OUTPUT, 0); 428 res[fd].second = mp->data_head; 429 } 430 } 431 432 int_exit(0); 433 return 0; 434 } 435