X-Git-Url: https://git.libre-soc.org/?a=blobdiff_plain;f=libiberty%2Fsimple-object-elf.c;h=a421177f0c2077b809680c7d8168a9a208b59f30;hb=f1cee837665a932d3d747597d8512cd0d3650478;hp=22c9ae7ed2df01dfe221e9627b82e6d56f225824;hpb=827041555ac443bd57340060f3e034fd7b199dd8;p=binutils-gdb.git diff --git a/libiberty/simple-object-elf.c b/libiberty/simple-object-elf.c index 22c9ae7ed2d..a421177f0c2 100644 --- a/libiberty/simple-object-elf.c +++ b/libiberty/simple-object-elf.c @@ -1,5 +1,5 @@ /* simple-object-elf.c -- routines to manipulate ELF object files. - Copyright (C) 2010-2019 Free Software Foundation, Inc. + Copyright (C) 2010-2021 Free Software Foundation, Inc. Written by Ian Lance Taylor, Google. This program is free software; you can redistribute it and/or modify it @@ -548,7 +548,15 @@ simple_object_elf_match (unsigned char header[SIMPLE_OBJECT_MATCH_HEADER_LEN], XDELETE (eor); return NULL; } - + + if (eor->shstrndx == 0) + { + *errmsg = "invalid ELF shstrndx == 0"; + *err = 0; + XDELETE (eor); + return NULL; + } + return (void *) eor; } @@ -1183,7 +1191,7 @@ simple_object_elf_copy_lto_debug_sections (simple_object_read *sobj, unsigned int sh_link; sh_link = ELF_FETCH_FIELD (type_functions, ei_class, Shdr, shdr, sh_link, Elf_Word); - symtab_indices_shndx[sh_link - 1] = i; + symtab_indices_shndx[sh_link - 1] = i - 1; /* Always discard the extended index sections, after copying it will not be needed. This way we don't need to update it and deal with the ordering constraints of @@ -1358,50 +1366,73 @@ simple_object_elf_copy_lto_debug_sections (simple_object_read *sobj, return errmsg; } - /* If we are processing .symtab purge __gnu_lto_v1 and - __gnu_lto_slim symbols from it and any symbols in discarded - sections. */ + /* If we are processing .symtab purge any symbols + in discarded sections. */ if (sh_type == SHT_SYMTAB) { unsigned entsize = ELF_FETCH_FIELD (type_functions, ei_class, Shdr, shdr, sh_entsize, Elf_Addr); - unsigned strtab = ELF_FETCH_FIELD (type_functions, ei_class, Shdr, - shdr, sh_link, Elf_Word); - unsigned char *strshdr = shdrs + (strtab - 1) * shdr_size; - off_t stroff = ELF_FETCH_FIELD (type_functions, ei_class, Shdr, - strshdr, sh_offset, Elf_Addr); - size_t strsz = ELF_FETCH_FIELD (type_functions, ei_class, Shdr, - strshdr, sh_size, Elf_Addr); - char *strings = XNEWVEC (char, strsz); - char *gnu_lto = strings; + size_t prevailing_name_idx = 0; unsigned char *ent; unsigned *shndx_table = NULL; - simple_object_internal_read (sobj->descriptor, - sobj->offset + stroff, - (unsigned char *)strings, - strsz, &errmsg, err); - /* Find gnu_lto_ in strings. */ - while ((gnu_lto = (char *) memchr (gnu_lto, 'g', - strings + strsz - gnu_lto))) - if (strncmp (gnu_lto, "gnu_lto_v1", - strings + strsz - gnu_lto) == 0) - break; - else - gnu_lto++; /* Read the section index table if present. */ if (symtab_indices_shndx[i - 1] != 0) { - unsigned char *sidxhdr = shdrs + (strtab - 1) * shdr_size; + unsigned char *sidxhdr = shdrs + symtab_indices_shndx[i - 1] * shdr_size; off_t sidxoff = ELF_FETCH_FIELD (type_functions, ei_class, Shdr, sidxhdr, sh_offset, Elf_Addr); size_t sidxsz = ELF_FETCH_FIELD (type_functions, ei_class, Shdr, sidxhdr, sh_size, Elf_Addr); + unsigned int shndx_type + = ELF_FETCH_FIELD (type_functions, ei_class, Shdr, + sidxhdr, sh_type, Elf_Word); + if (shndx_type != SHT_SYMTAB_SHNDX) + return "Wrong section type of a SYMTAB SECTION INDICES section"; shndx_table = (unsigned *)XNEWVEC (char, sidxsz); simple_object_internal_read (sobj->descriptor, sobj->offset + sidxoff, (unsigned char *)shndx_table, sidxsz, &errmsg, err); } + + /* Find a WEAK HIDDEN symbol which name we will use for removed + symbols. We know there's a prevailing weak hidden symbol + at the start of the .debug_info section. */ + for (ent = buf; ent < buf + length; ent += entsize) + { + unsigned st_shndx = ELF_FETCH_FIELD (type_functions, ei_class, + Sym, ent, + st_shndx, Elf_Half); + unsigned char *st_info; + unsigned char *st_other; + if (ei_class == ELFCLASS32) + { + st_info = &((Elf32_External_Sym *)ent)->st_info; + st_other = &((Elf32_External_Sym *)ent)->st_other; + } + else + { + st_info = &((Elf64_External_Sym *)ent)->st_info; + st_other = &((Elf64_External_Sym *)ent)->st_other; + } + if (st_shndx == SHN_XINDEX) + st_shndx = type_functions->fetch_Elf_Word + ((unsigned char *)(shndx_table + (ent - buf) / entsize)); + + if (st_shndx != SHN_COMMON + && !(st_shndx != SHN_UNDEF + && st_shndx < shnum + && pfnret[st_shndx - 1] == -1) + && ELF_ST_BIND (*st_info) == STB_WEAK + && *st_other == STV_HIDDEN) + { + prevailing_name_idx = ELF_FETCH_FIELD (type_functions, + ei_class, Sym, ent, + st_name, Elf_Word); + break; + } + } + for (ent = buf; ent < buf + length; ent += entsize) { unsigned st_shndx = ELF_FETCH_FIELD (type_functions, ei_class, @@ -1424,9 +1455,10 @@ simple_object_elf_copy_lto_debug_sections (simple_object_read *sobj, if (st_shndx == SHN_XINDEX) st_shndx = type_functions->fetch_Elf_Word ((unsigned char *)(shndx_table + (ent - buf) / entsize)); - /* Eliminate all COMMONs - this includes __gnu_lto_v1 - and __gnu_lto_slim which otherwise cause endless - LTO plugin invocation. */ + /* Eliminate all COMMONs - this includes __gnu_lto_slim + which otherwise cause endless LTO plugin invocation. + FIXME: remove the condition once we remove emission + of __gnu_lto_slim symbol. */ if (st_shndx == SHN_COMMON) discard = 1; /* We also need to remove symbols refering to sections @@ -1438,6 +1470,11 @@ simple_object_elf_copy_lto_debug_sections (simple_object_read *sobj, && st_shndx < shnum && pfnret[st_shndx - 1] == -1) discard = 1; + /* We also need to remove global UNDEFs which can + cause link fails later. */ + else if (st_shndx == SHN_UNDEF + && ELF_ST_BIND (*st_info) == STB_GLOBAL) + discard = 1; if (discard) { @@ -1458,13 +1495,13 @@ simple_object_elf_copy_lto_debug_sections (simple_object_read *sobj, else { /* Make discarded global symbols hidden weak - undefined and sharing the gnu_lto_ name. */ + undefined and sharing a name of a prevailing + symbol. */ bind = STB_WEAK; other = STV_HIDDEN; - if (gnu_lto) - ELF_SET_FIELD (type_functions, ei_class, Sym, - ent, st_name, Elf_Word, - gnu_lto - strings); + ELF_SET_FIELD (type_functions, ei_class, Sym, + ent, st_name, Elf_Word, + prevailing_name_idx); ELF_SET_FIELD (type_functions, ei_class, Sym, ent, st_shndx, Elf_Half, SHN_UNDEF); } @@ -1481,7 +1518,6 @@ simple_object_elf_copy_lto_debug_sections (simple_object_read *sobj, ELF_SET_FIELD (type_functions, ei_class, Sym, ent, st_shndx, Elf_Half, sh_map[st_shndx]); } - XDELETEVEC (strings); XDELETEVEC (shndx_table); } else if (sh_type == SHT_GROUP)