diff options
Diffstat (limited to 'scripts/recordmcount.h')
| -rw-r--r-- | scripts/recordmcount.h | 248 |
1 files changed, 195 insertions, 53 deletions
diff --git a/scripts/recordmcount.h b/scripts/recordmcount.h index 47fca2c69a73..1e9baa5c4fc6 100644 --- a/scripts/recordmcount.h +++ b/scripts/recordmcount.h @@ -29,6 +29,11 @@ #undef has_rel_mcount #undef tot_relsize #undef get_mcountsym +#undef find_symtab +#undef get_shnum +#undef set_shnum +#undef get_shstrndx +#undef get_symindex #undef get_sym_str_and_relp #undef do_func #undef Elf_Addr @@ -58,6 +63,11 @@ # define __has_rel_mcount __has64_rel_mcount # define has_rel_mcount has64_rel_mcount # define tot_relsize tot64_relsize +# define find_symtab find_symtab64 +# define get_shnum get_shnum64 +# define set_shnum set_shnum64 +# define get_shstrndx get_shstrndx64 +# define get_symindex get_symindex64 # define get_sym_str_and_relp get_sym_str_and_relp_64 # define do_func do64 # define get_mcountsym get_mcountsym_64 @@ -91,6 +101,11 @@ # define __has_rel_mcount __has32_rel_mcount # define has_rel_mcount has32_rel_mcount # define tot_relsize tot32_relsize +# define find_symtab find_symtab32 +# define get_shnum get_shnum32 +# define set_shnum set_shnum32 +# define get_shstrndx get_shstrndx32 +# define get_symindex get_symindex32 # define get_sym_str_and_relp get_sym_str_and_relp_32 # define do_func do32 # define get_mcountsym get_mcountsym_32 @@ -173,8 +188,74 @@ static int MIPS_is_fake_mcount(Elf_Rel const *rp) return is_fake; } +static unsigned int get_symindex(Elf_Sym const *sym, Elf32_Word const *symtab, + Elf32_Word const *symtab_shndx) +{ + unsigned long offset; + unsigned short shndx = w2(sym->st_shndx); + int index; + + if (shndx > SHN_UNDEF && shndx < SHN_LORESERVE) + return shndx; + + if (shndx == SHN_XINDEX) { + offset = (unsigned long)sym - (unsigned long)symtab; + index = offset / sizeof(*sym); + + return w(symtab_shndx[index]); + } + + return 0; +} + +static unsigned int get_shnum(Elf_Ehdr const *ehdr, Elf_Shdr const *shdr0) +{ + if (shdr0 && !ehdr->e_shnum) + return w(shdr0->sh_size); + + return w2(ehdr->e_shnum); +} + +static void set_shnum(Elf_Ehdr *ehdr, Elf_Shdr *shdr0, unsigned int new_shnum) +{ + if (new_shnum >= SHN_LORESERVE) { + ehdr->e_shnum = 0; + shdr0->sh_size = w(new_shnum); + } else + ehdr->e_shnum = w2(new_shnum); +} + +static int get_shstrndx(Elf_Ehdr const *ehdr, Elf_Shdr const *shdr0) +{ + if (ehdr->e_shstrndx != SHN_XINDEX) + return w2(ehdr->e_shstrndx); + + return w(shdr0->sh_link); +} + +static void find_symtab(Elf_Ehdr *const ehdr, Elf_Shdr const *shdr0, + unsigned const nhdr, Elf32_Word **symtab, + Elf32_Word **symtab_shndx) +{ + Elf_Shdr const *relhdr; + unsigned k; + + *symtab = NULL; + *symtab_shndx = NULL; + + for (relhdr = shdr0, k = nhdr; k; --k, ++relhdr) { + if (relhdr->sh_type == SHT_SYMTAB) + *symtab = (void *)ehdr + relhdr->sh_offset; + else if (relhdr->sh_type == SHT_SYMTAB_SHNDX) + *symtab_shndx = (void *)ehdr + relhdr->sh_offset; + + if (*symtab && *symtab_shndx) + break; + } +} + /* Append the new shstrtab, Elf_Shdr[], __mcount_loc and its relocations. */ -static void append_func(Elf_Ehdr *const ehdr, +static int append_func(Elf_Ehdr *const ehdr, Elf_Shdr *const shstr, uint_t const *const mloc0, uint_t const *const mlocp, @@ -188,10 +269,12 @@ static void append_func(Elf_Ehdr *const ehdr, char const *mc_name = (sizeof(Elf_Rela) == rel_entsize) ? ".rela__mcount_loc" : ".rel__mcount_loc"; - unsigned const old_shnum = w2(ehdr->e_shnum); uint_t const old_shoff = _w(ehdr->e_shoff); uint_t const old_shstr_sh_size = _w(shstr->sh_size); uint_t const old_shstr_sh_offset = _w(shstr->sh_offset); + Elf_Shdr *const shdr0 = (Elf_Shdr *)(old_shoff + (void *)ehdr); + unsigned int const old_shnum = get_shnum(ehdr, shdr0); + unsigned int const new_shnum = 2 + old_shnum; /* {.rel,}__mcount_loc */ uint_t t = 1 + strlen(mc_name) + _w(shstr->sh_size); uint_t new_e_shoff; @@ -201,16 +284,23 @@ static void append_func(Elf_Ehdr *const ehdr, t += (_align & -t); /* word-byte align */ new_e_shoff = t; + set_shnum(ehdr, shdr0, new_shnum); + /* body for new shstrtab */ - ulseek(fd_map, sb.st_size, SEEK_SET); - uwrite(fd_map, old_shstr_sh_offset + (void *)ehdr, old_shstr_sh_size); - uwrite(fd_map, mc_name, 1 + strlen(mc_name)); + if (ulseek(sb.st_size, SEEK_SET) < 0) + return -1; + if (uwrite(old_shstr_sh_offset + (void *)ehdr, old_shstr_sh_size) < 0) + return -1; + if (uwrite(mc_name, 1 + strlen(mc_name)) < 0) + return -1; /* old(modified) Elf_Shdr table, word-byte aligned */ - ulseek(fd_map, t, SEEK_SET); + if (ulseek(t, SEEK_SET) < 0) + return -1; t += sizeof(Elf_Shdr) * old_shnum; - uwrite(fd_map, old_shoff + (void *)ehdr, - sizeof(Elf_Shdr) * old_shnum); + if (uwrite(old_shoff + (void *)ehdr, + sizeof(Elf_Shdr) * old_shnum) < 0) + return -1; /* new sections __mcount_loc and .rel__mcount_loc */ t += 2*sizeof(mcsec); @@ -225,7 +315,8 @@ static void append_func(Elf_Ehdr *const ehdr, mcsec.sh_info = 0; mcsec.sh_addralign = _w(_size); mcsec.sh_entsize = _w(_size); - uwrite(fd_map, &mcsec, sizeof(mcsec)); + if (uwrite(&mcsec, sizeof(mcsec)) < 0) + return -1; mcsec.sh_name = w(old_shstr_sh_size); mcsec.sh_type = (sizeof(Elf_Rela) == rel_entsize) @@ -239,15 +330,21 @@ static void append_func(Elf_Ehdr *const ehdr, mcsec.sh_info = w(old_shnum); mcsec.sh_addralign = _w(_size); mcsec.sh_entsize = _w(rel_entsize); - uwrite(fd_map, &mcsec, sizeof(mcsec)); - uwrite(fd_map, mloc0, (void *)mlocp - (void *)mloc0); - uwrite(fd_map, mrel0, (void *)mrelp - (void *)mrel0); + if (uwrite(&mcsec, sizeof(mcsec)) < 0) + return -1; + + if (uwrite(mloc0, (void *)mlocp - (void *)mloc0) < 0) + return -1; + if (uwrite(mrel0, (void *)mrelp - (void *)mrel0) < 0) + return -1; ehdr->e_shoff = _w(new_e_shoff); - ehdr->e_shnum = w2(2 + w2(ehdr->e_shnum)); /* {.rel,}__mcount_loc */ - ulseek(fd_map, 0, SEEK_SET); - uwrite(fd_map, ehdr, sizeof(*ehdr)); + if (ulseek(0, SEEK_SET) < 0) + return -1; + if (uwrite(ehdr, sizeof(*ehdr)) < 0) + return -1; + return 0; } static unsigned get_mcountsym(Elf_Sym const *const sym0, @@ -351,9 +448,9 @@ static uint_t *sift_rel_mcount(uint_t *mlocp, * that are not going to be traced. The mcount calls here will be converted * into nops. */ -static void nop_mcount(Elf_Shdr const *const relhdr, - Elf_Ehdr const *const ehdr, - const char *const txtname) +static int nop_mcount(Elf_Shdr const *const relhdr, + Elf_Ehdr const *const ehdr, + const char *const txtname) { Elf_Shdr *const shdr0 = (Elf_Shdr *)(_w(ehdr->e_shoff) + (void *)ehdr); @@ -384,7 +481,7 @@ static void nop_mcount(Elf_Shdr const *const relhdr, once = 1; /* just warn? */ if (!make_nop) - return; + return 0; } } @@ -396,14 +493,16 @@ static void nop_mcount(Elf_Shdr const *const relhdr, Elf_Rel rel; rel = *(Elf_Rel *)relp; Elf_r_info(&rel, Elf_r_sym(relp), rel_type_nop); - ulseek(fd_map, (void *)relp - (void *)ehdr, SEEK_SET); - uwrite(fd_map, &rel, sizeof(rel)); + if (ulseek((void *)relp - (void *)ehdr, SEEK_SET) < 0) + return -1; + if (uwrite(&rel, sizeof(rel)) < 0) + return -1; } relp = (Elf_Rel const *)(rel_entsize + (void *)relp); } + return 0; } - /* * Find a symbol in the given section, to be used as the base for relocating * the table of offsets of calls to mcount. A local or global symbol suffices, @@ -414,10 +513,13 @@ static void nop_mcount(Elf_Shdr const *const relhdr, * Num: Value Size Type Bind Vis Ndx Name * 2: 00000000 0 SECTION LOCAL DEFAULT 1 */ -static unsigned find_secsym_ndx(unsigned const txtndx, +static int find_secsym_ndx(unsigned const txtndx, char const *const txtname, uint_t *const recvalp, + unsigned int *sym_index, Elf_Shdr const *const symhdr, + Elf32_Word const *symtab, + Elf32_Word const *symtab_shndx, Elf_Ehdr const *const ehdr) { Elf_Sym const *const sym0 = (Elf_Sym const *)(_w(symhdr->sh_offset) @@ -429,7 +531,7 @@ static unsigned find_secsym_ndx(unsigned const txtndx, for (symp = sym0, t = nsym; t; --t, ++symp) { unsigned int const st_bind = ELF_ST_BIND(symp->st_info); - if (txtndx == w2(symp->st_shndx) + if (txtndx == get_symindex(symp, symtab, symtab_shndx) /* avoid STB_WEAK */ && (STB_LOCAL == st_bind || STB_GLOBAL == st_bind)) { /* function symbols on ARM have quirks, avoid them */ @@ -438,21 +540,20 @@ static unsigned find_secsym_ndx(unsigned const txtndx, continue; *recvalp = _w(symp->st_value); - return symp - sym0; + *sym_index = symp - sym0; + return 0; } } fprintf(stderr, "Cannot find symbol for section %u: %s.\n", txtndx, txtname); - fail_file(); + return -1; } - /* Evade ISO C restriction: no declaration after statement in has_rel_mcount. */ -static char const * -__has_rel_mcount(Elf_Shdr const *const relhdr, /* is SHT_REL or SHT_RELA */ - Elf_Shdr const *const shdr0, - char const *const shstrtab, - char const *const fname) +static char const * __has_rel_mcount(Elf_Shdr const *const relhdr, /* reltype */ + Elf_Shdr const *const shdr0, + char const *const shstrtab, + char const *const fname) { /* .sh_info depends on .sh_type == SHT_REL[,A] */ Elf_Shdr const *const txthdr = &shdr0[w(relhdr->sh_info)]; @@ -461,7 +562,7 @@ __has_rel_mcount(Elf_Shdr const *const relhdr, /* is SHT_REL or SHT_RELA */ if (strcmp("__mcount_loc", txtname) == 0) { fprintf(stderr, "warning: __mcount_loc already exists: %s\n", fname); - succeed_file(); + return already_has_rel_mcount; } if (w(txthdr->sh_type) != SHT_PROGBITS || !(_w(txthdr->sh_flags) & SHF_EXECINSTR)) @@ -491,48 +592,85 @@ static unsigned tot_relsize(Elf_Shdr const *const shdr0, for (; nhdr; --nhdr, ++shdrp) { txtname = has_rel_mcount(shdrp, shdr0, shstrtab, fname); + if (txtname == already_has_rel_mcount) { + totrelsz = 0; + break; + } if (txtname && is_mcounted_section_name(txtname)) totrelsz += _w(shdrp->sh_size); } return totrelsz; } - /* Overall supervision for Elf32 ET_REL file. */ -static void -do_func(Elf_Ehdr *const ehdr, char const *const fname, unsigned const reltype) +static int do_func(Elf_Ehdr *const ehdr, char const *const fname, + unsigned const reltype) { Elf_Shdr *const shdr0 = (Elf_Shdr *)(_w(ehdr->e_shoff) + (void *)ehdr); - unsigned const nhdr = w2(ehdr->e_shnum); - Elf_Shdr *const shstr = &shdr0[w2(ehdr->e_shstrndx)]; + unsigned const nhdr = get_shnum(ehdr, shdr0); + Elf_Shdr *const shstr = &shdr0[get_shstrndx(ehdr, shdr0)]; char const *const shstrtab = (char const *)(_w(shstr->sh_offset) + (void *)ehdr); Elf_Shdr const *relhdr; unsigned k; + Elf32_Word *symtab; + Elf32_Word *symtab_shndx; + /* Upper bound on space: assume all relevant relocs are for mcount. */ - unsigned const totrelsz = tot_relsize(shdr0, nhdr, shstrtab, fname); - Elf_Rel *const mrel0 = umalloc(totrelsz); - Elf_Rel * mrelp = mrel0; + unsigned totrelsz; - /* 2*sizeof(address) <= sizeof(Elf_Rel) */ - uint_t *const mloc0 = umalloc(totrelsz>>1); - uint_t * mlocp = mloc0; + Elf_Rel * mrel0; + Elf_Rel * mrelp; + + uint_t * mloc0; + uint_t * mlocp; unsigned rel_entsize = 0; unsigned symsec_sh_link = 0; + int result = 0; + + totrelsz = tot_relsize(shdr0, nhdr, shstrtab, fname); + if (totrelsz == 0) + return 0; + mrel0 = umalloc(totrelsz); + mrelp = mrel0; + if (!mrel0) + return -1; + + /* 2*sizeof(address) <= sizeof(Elf_Rel) */ + mloc0 = umalloc(totrelsz>>1); + mlocp = mloc0; + if (!mloc0) { + free(mrel0); + return -1; + } + + find_symtab(ehdr, shdr0, nhdr, &symtab, &symtab_shndx); + for (relhdr = shdr0, k = nhdr; k; --k, ++relhdr) { char const *const txtname = has_rel_mcount(relhdr, shdr0, shstrtab, fname); + if (txtname == already_has_rel_mcount) { + result = 0; + file_updated = 0; + goto out; /* Nothing to be done; don't append! */ + } if (txtname && is_mcounted_section_name(txtname)) { + unsigned int recsym; uint_t recval = 0; - unsigned const recsym = find_secsym_ndx( - w(relhdr->sh_info), txtname, &recval, - &shdr0[symsec_sh_link = w(relhdr->sh_link)], - ehdr); + + symsec_sh_link = w(relhdr->sh_link); + result = find_secsym_ndx(w(relhdr->sh_info), txtname, + &recval, &recsym, + &shdr0[symsec_sh_link], + symtab, symtab_shndx, + ehdr); + if (result) + goto out; rel_entsize = _w(relhdr->sh_entsize); mlocp = sift_rel_mcount(mlocp, @@ -543,13 +681,17 @@ do_func(Elf_Ehdr *const ehdr, char const *const fname, unsigned const reltype) * This section is ignored by ftrace, but still * has mcount calls. Convert them to nops now. */ - nop_mcount(relhdr, ehdr, txtname); + if (nop_mcount(relhdr, ehdr, txtname) < 0) { + result = -1; + goto out; + } } } - if (mloc0 != mlocp) { - append_func(ehdr, shstr, mloc0, mlocp, mrel0, mrelp, - rel_entsize, symsec_sh_link); - } + if (!result && mloc0 != mlocp) + result = append_func(ehdr, shstr, mloc0, mlocp, mrel0, mrelp, + rel_entsize, symsec_sh_link); +out: free(mrel0); free(mloc0); + return result; } |