Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934506AbXIKUTs (ORCPT ); Tue, 11 Sep 2007 16:19:48 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S966387AbXIKULd (ORCPT ); Tue, 11 Sep 2007 16:11:33 -0400 Received: from nz-out-0506.google.com ([64.233.162.230]:13944 "EHLO nz-out-0506.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S966377AbXIKUL3 (ORCPT ); Tue, 11 Sep 2007 16:11:29 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=googlemail.com; s=beta; h=received:from:to:subject:date:user-agent:cc:references:in-reply-to:mime-version:content-type:message-id; b=NVkGDCUVSVU2YGNLJJk0/NB0nwk5Wc9SbqzpvJHoHJbFSlbuvacSDIl1f4++ubc+O0r3FzG4Qcxds8otMjTMfKbljE1liqvhd3AgivzMFaXxTwttsjiGce7hsf4GrduQ7RTHEn+WRVqYxiRSh12xcgApck1xonJ4k/7DTXd1B6I= From: Denys Vlasenko To: Sam Ravnborg Subject: [PATCH 3/4] build system: section garbage collection for vmlinux Date: Tue, 11 Sep 2007 21:11:21 +0100 User-Agent: KMail/1.9.1 Cc: linux-kernel@vger.kernel.org References: <200709112105.34301.vda.linux@googlemail.com> <200709112107.53155.vda.linux@googlemail.com> <200709112110.14270.vda.linux@googlemail.com> In-Reply-To: <200709112110.14270.vda.linux@googlemail.com> MIME-Version: 1.0 Content-Type: Multipart/Mixed; boundary="Boundary-00=_pZv5GoGs09SoG/q" Message-Id: <200709112111.21089.vda.linux@googlemail.com> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 9811 Lines: 296 --Boundary-00=_pZv5GoGs09SoG/q Content-Type: text/plain; charset="iso-8859-15" Content-Transfer-Encoding: 7bit Content-Disposition: inline This patch makes modpost able to process object files with more than 64k sections. Needed for huge kernel builds (allyesconfig, for example) with --gc-sections. This patch basically fixes modpost, it isn't specific for section garbage collection. Please apply. Signed-off-by: Denys Vlasenko -- vda --Boundary-00=_pZv5GoGs09SoG/q Content-Type: text/x-diff; charset="iso-8859-15"; name="linux-2.6.23-rc4.3.modpost_fix.patch" Content-Transfer-Encoding: 7bit Content-Disposition: attachment; filename="linux-2.6.23-rc4.3.modpost_fix.patch" --- linux-2.6.23-rc4.gc2/scripts/mod/file2alias.c Sun Sep 2 17:29:37 2007 +++ linux-2.6.23-rc4.gc3/scripts/mod/file2alias.c Sat Sep 8 22:07:54 2007 @@ -529,11 +529,11 @@ void *symval; /* We're looking for a section relative symbol */ - if (!sym->st_shndx || sym->st_shndx >= info->hdr->e_shnum) + if (!sym->st_shndx || get_secindex(info, sym) >= info->num_sections) return; symval = (void *)info->hdr - + info->sechdrs[sym->st_shndx].sh_offset + + info->sechdrs[get_secindex(info, sym)].sh_offset + sym->st_value; if (sym_is(symname, "__mod_pci_device_table")) --- linux-2.6.23-rc4.gc2/scripts/mod/modpost.c Sat Sep 8 22:06:52 2007 +++ linux-2.6.23-rc4.gc3/scripts/mod/modpost.c Sat Sep 8 22:07:54 2007 @@ -235,7 +235,7 @@ return export_unknown; } -static enum export export_from_sec(struct elf_info *elf, Elf_Section sec) +static enum export export_from_sec(struct elf_info *elf, unsigned sec) { if (sec == elf->export_sec) return export_plain; @@ -353,6 +353,8 @@ Elf_Ehdr *hdr; Elf_Shdr *sechdrs; Elf_Sym *sym; + const char *secstrings; + unsigned int symtab_idx = ~0U; hdr = grab_file(filename, &info->size); if (!hdr) { @@ -372,6 +374,7 @@ /* Not an ELF file - silently ignore it */ return 0; } + /* Fix endianness in ELF header */ hdr->e_shoff = TO_NATIVE(hdr->e_shoff); hdr->e_shstrndx = TO_NATIVE(hdr->e_shstrndx); @@ -381,8 +384,18 @@ sechdrs = (void *)hdr + hdr->e_shoff; info->sechdrs = sechdrs; + /* Fixups for more than 64k sections */ + info->num_sections = hdr->e_shnum; + if (info->num_sections == SHN_UNDEF) { /* more than 64k sections? */ + /* doesn't need shndx2secindex() */ + info->num_sections = TO_NATIVE(sechdrs[0].sh_size); + } + info->secindex_strings = hdr->e_shstrndx; + if (info->secindex_strings == SHN_XINDEX) + info->secindex_strings = shndx2secindex(TO_NATIVE(sechdrs[0].sh_link)); + /* Fix endianness in section headers */ - for (i = 0; i < hdr->e_shnum; i++) { + for (i = 0; i < info->num_sections; i++) { sechdrs[i].sh_type = TO_NATIVE(sechdrs[i].sh_type); sechdrs[i].sh_offset = TO_NATIVE(sechdrs[i].sh_offset); sechdrs[i].sh_size = TO_NATIVE(sechdrs[i].sh_size); @@ -392,9 +405,8 @@ sechdrs[i].sh_addr = TO_NATIVE(sechdrs[i].sh_addr); } /* Find symbol table. */ - for (i = 1; i < hdr->e_shnum; i++) { - const char *secstrings - = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset; + secstrings = (void *)hdr + sechdrs[info->secindex_strings].sh_offset; + for (i = 1; i < info->num_sections; i++) { const char *secname; if (sechdrs[i].sh_offset > info->size) { @@ -416,14 +428,29 @@ else if (strcmp(secname, "__ksymtab_gpl_future") == 0) info->export_gpl_future_sec = i; - if (sechdrs[i].sh_type != SHT_SYMTAB) - continue; + if (sechdrs[i].sh_type == SHT_SYMTAB) { + symtab_idx = i; + info->symtab_start = (void *)hdr + sechdrs[i].sh_offset; + info->symtab_stop = (void *)hdr + sechdrs[i].sh_offset + + sechdrs[i].sh_size; + info->strtab = (void *)hdr + + sechdrs[shndx2secindex(sechdrs[i].sh_link)].sh_offset; + } - info->symtab_start = (void *)hdr + sechdrs[i].sh_offset; - info->symtab_stop = (void *)hdr + sechdrs[i].sh_offset - + sechdrs[i].sh_size; - info->strtab = (void *)hdr + - sechdrs[sechdrs[i].sh_link].sh_offset; + /* 32bit section no. table? ("more than 64k sections") */ + if (sechdrs[i].sh_type == SHT_SYMTAB_SHNDX) { + uint32_t *p32; + info->symtab_shndx = (void *)hdr + sechdrs[i].sh_offset; + if (symtab_idx != shndx2secindex(sechdrs[i].sh_link)) + fatal("%s: SYMTAB_SHNDX has bad sh_link: %u!=%u\n", + filename, + shndx2secindex(sechdrs[i].sh_link), + symtab_idx); + /* Fix endianness */ + p32 = (void*)info->symtab_shndx + sechdrs[i].sh_size; + while (--p32 >= info->symtab_shndx) + *p32 = TO_NATIVE(*p32); + } } if (!info->symtab_start) { fatal("%s has no symtab?\n", filename); @@ -450,7 +477,7 @@ Elf_Sym *sym, const char *symname) { unsigned int crc; - enum export export = export_from_sec(info, sym->st_shndx); + enum export export = export_from_sec(info, get_secindex(info, sym)); switch (sym->st_shndx) { case SHN_COMMON: @@ -758,11 +785,14 @@ Elf_Sym *relsym) { Elf_Sym *sym; + unsigned relsym_secindex; if (relsym->st_name != 0) return relsym; + + relsym_secindex = get_secindex(elf, relsym); for (sym = elf->symtab_start; sym < elf->symtab_stop; sym++) { - if (sym->st_shndx != relsym->st_shndx) + if (get_secindex(elf, sym) != relsym_secindex) continue; if (ELF_ST_TYPE(sym->st_info) == STT_SECTION) continue; @@ -811,7 +841,7 @@ Elf_Addr beforediff = ~0; Elf_Addr afterdiff = ~0; const char *secstrings = (void *)hdr + - elf->sechdrs[hdr->e_shstrndx].sh_offset; + elf->sechdrs[elf->secindex_strings].sh_offset; *before = NULL; *after = NULL; @@ -819,9 +849,9 @@ for (sym = elf->symtab_start; sym < elf->symtab_stop; sym++) { const char *symsec; - if (sym->st_shndx >= SHN_LORESERVE) + if (is_shndx_special(sym->st_shndx)) continue; - symsec = secstrings + elf->sechdrs[sym->st_shndx].sh_name; + symsec = secstrings + elf->sechdrs[get_secindex(elf, sym)].sh_name; if (strcmp(symsec, sec) != 0) continue; if (!is_valid_name(elf, sym)) @@ -862,8 +892,8 @@ Elf_Ehdr *hdr = elf->hdr; Elf_Shdr *sechdrs = elf->sechdrs; const char *secstrings = (void *)hdr + - sechdrs[hdr->e_shstrndx].sh_offset; - const char *secname = secstrings + sechdrs[sym->st_shndx].sh_name; + sechdrs[elf->secindex_strings].sh_offset; + const char *secname = secstrings + sechdrs[get_secindex(elf, sym)].sh_name; find_symbols_between(elf, r.r_offset, fromsec, &before, &after); @@ -997,10 +1027,10 @@ Elf_Ehdr *hdr = elf->hdr; Elf_Shdr *sechdrs = elf->sechdrs; const char *secstrings = (void *)hdr + - sechdrs[hdr->e_shstrndx].sh_offset; + sechdrs[elf->secindex_strings].sh_offset; /* Walk through all sections */ - for (i = 0; i < hdr->e_shnum; i++) { + for (i = 0; i < elf->num_sections; i++) { const char *name = secstrings + sechdrs[i].sh_name; const char *secname; Elf_Rela r; @@ -1034,11 +1064,11 @@ r.r_addend = TO_NATIVE(rela->r_addend); sym = elf->symtab_start + r_sym; /* Skip special sections */ - if (sym->st_shndx >= SHN_LORESERVE) + if (is_shndx_special(sym->st_shndx)) continue; secname = secstrings + - sechdrs[sym->st_shndx].sh_name; + sechdrs[get_secindex(elf, sym)].sh_name; if (section(secname)) warn_sec_mismatch(modname, name, elf, sym, r); @@ -1085,11 +1115,11 @@ } sym = elf->symtab_start + r_sym; /* Skip special sections */ - if (sym->st_shndx >= SHN_LORESERVE) + if (is_shndx_special(sym->st_shndx)) continue; secname = secstrings + - sechdrs[sym->st_shndx].sh_name; + sechdrs[get_secindex(elf, sym)].sh_name; if (section(secname)) warn_sec_mismatch(modname, name, elf, sym, r); --- linux-2.6.23-rc4.gc2/scripts/mod/modpost.h Sun Sep 2 17:29:37 2007 +++ linux-2.6.23-rc4.gc3/scripts/mod/modpost.h Sat Sep 8 22:07:54 2007 @@ -127,7 +127,48 @@ const char *strtab; char *modinfo; unsigned int modinfo_len; + + /* support for 32bit section numbers */ + + unsigned int num_sections; /* max_secindex + 1 */ + unsigned int secindex_strings; + /* if Nth symbol table entry has .st_shndx = SHN_XINDEX, + * take shndx from symtab_shndx[N] instead */ + uint32_t *symtab_shndx; }; + +static inline int is_shndx_special(unsigned i) +{ + return i != SHN_XINDEX && i >= SHN_LORESERVE && i <= SHN_HIRESERVE; +} + +/* shndx is in [0..SHN_LORESERVE) U (SHN_HIRESERVE, 0xfffffff], thus: + * shndx == 0 <=> sechdrs[0] + * ...... + * shndx == SHN_LORESERVE-1 <=> sechdrs[SHN_LORESERVE-1] + * shndx == SHN_HIRESERVE+1 <=> sechdrs[SHN_LORESERVE] + * shndx == SHN_HIRESERVE+2 <=> sechdrs[SHN_LORESERVE+1] + * ...... + * fyi: sym->st_shndx is uint16, SHN_LORESERVE = ff00, SHN_HIRESERVE = ffff, + * so basically we map 0000..feff -> 0000..feff + * ff00..ffff -> (you are a bad boy, dont do it) + * 10000..xxxx -> ff00..(xxxx-0x100) + */ +static inline unsigned shndx2secindex(unsigned i) +{ + if (i <= SHN_HIRESERVE) + return i; + return i - (SHN_HIRESERVE + 1 - SHN_LORESERVE); +} + +/* Accessor for sym->st_shndx, hides ugliness of "64k sections" */ +static inline unsigned get_secindex(struct elf_info *info, Elf_Sym *sym) +{ + if (sym->st_shndx != SHN_XINDEX) + return sym->st_shndx; + return shndx2secindex(info->symtab_shndx[sym - info->symtab_start]); +} + /* file2alias.c */ void handle_moddevtable(struct module *mod, struct elf_info *info, --Boundary-00=_pZv5GoGs09SoG/q-- - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/