1 #ifndef lint 2 static const char rcsid[] = 3 "$FreeBSD$"; 4 #endif /* not lint */ 5 6 #include <sys/types.h> 7 #include <sys/mman.h> 8 #include <sys/stat.h> 9 #include <machine/elf.h> 10 11 #include <err.h> 12 #include <fcntl.h> 13 #include <string.h> 14 #include <unistd.h> 15 16 #include "gprof.h" 17 18 static bool wantsym(const Elf_Sym *, const char *); 19 20 /* Things which get -E excluded by default. */ 21 static char *excludes[] = { ".mcount", "_mcleanup", NULL }; 22 23 int 24 elf_getnfile(const char *filename, char ***defaultEs) 25 { 26 int fd; 27 Elf_Ehdr h; 28 struct stat s; 29 void *mapbase; 30 const char *base; 31 const Elf_Shdr *shdrs; 32 const Elf_Shdr *sh_symtab; 33 const Elf_Shdr *sh_strtab; 34 const char *strtab; 35 const Elf_Sym *symtab; 36 int symtabct; 37 int i; 38 39 if ((fd = open(filename, O_RDONLY)) == -1) 40 err(1, "%s", filename); 41 if (read(fd, &h, sizeof h) != sizeof h || !IS_ELF(h)) { 42 close(fd); 43 return -1; 44 } 45 if (fstat(fd, &s) == -1) 46 err(1, "Cannot fstat %s", filename); 47 if ((mapbase = mmap(0, s.st_size, PROT_READ, MAP_SHARED, fd, 0)) == 48 MAP_FAILED) 49 err(1, "Cannot mmap %s", filename); 50 close(fd); 51 52 base = (const char *)mapbase; 53 shdrs = (const Elf_Shdr *)(base + h.e_shoff); 54 55 /* Find the symbol table and associated string table section. */ 56 for (i = 1; i < h.e_shnum; i++) 57 if (shdrs[i].sh_type == SHT_SYMTAB) 58 break; 59 if (i == h.e_shnum) 60 errx(1, "%s has no symbol table", filename); 61 sh_symtab = &shdrs[i]; 62 sh_strtab = &shdrs[sh_symtab->sh_link]; 63 64 symtab = (const Elf_Sym *)(base + sh_symtab->sh_offset); 65 symtabct = sh_symtab->sh_size / sh_symtab->sh_entsize; 66 strtab = (const char *)(base + sh_strtab->sh_offset); 67 68 /* Count the symbols that we're interested in. */ 69 nname = 0; 70 for (i = 1; i < symtabct; i++) 71 if (wantsym(&symtab[i], strtab)) 72 nname++; 73 74 /* Allocate memory for them, plus a terminating entry. */ 75 if ((nl = (nltype *)calloc(nname + 1, sizeof(nltype))) == NULL) 76 errx(1, "Insufficient memory for symbol table"); 77 78 /* Read them in. */ 79 npe = nl; 80 for (i = 1; i < symtabct; i++) { 81 const Elf_Sym *sym = &symtab[i]; 82 83 if (wantsym(sym, strtab)) { 84 npe->value = sym->st_value; 85 npe->name = strtab + sym->st_name; 86 npe++; 87 } 88 } 89 npe->value = -1; 90 91 *defaultEs = excludes; 92 return 0; 93 } 94 95 static bool 96 wantsym(const Elf_Sym *sym, const char *strtab) 97 { 98 int type; 99 int bind; 100 101 type = ELF_ST_TYPE(sym->st_info); 102 bind = ELF_ST_BIND(sym->st_info); 103 104 if (type != STT_FUNC || 105 (aflag && bind == STB_LOCAL) || 106 (uflag && strchr(strtab + sym->st_name, '.') != NULL)) 107 return 0; 108 109 return 1; 110 } 111