Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934642AbXEVOzg (ORCPT ); Tue, 22 May 2007 10:55:36 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1758139AbXEVOz2 (ORCPT ); Tue, 22 May 2007 10:55:28 -0400 Received: from fregatti-new.mermit.fi ([194.100.131.2]:51754 "HELO fregatti.mermit.fi" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with SMTP id S1754958AbXEVOz2 (ORCPT ); Tue, 22 May 2007 10:55:28 -0400 X-Greylist: delayed 438 seconds by postgrey-1.27 at vger.kernel.org; Tue, 22 May 2007 10:55:27 EDT X-fsav-clean: Database version: 2007-05-22_06 Message-ID: <465302A9.8080701@kolumbus.fi> Date: Tue, 22 May 2007 17:48:09 +0300 From: =?ISO-8859-1?Q?Mika_Penttil=E4?= User-Agent: Thunderbird 1.5.0.10 (Windows/20070221) MIME-Version: 1.0 To: Atsushi Nemoto CC: torvalds@linux-foundation.org, ben.collins@ubuntu.com, linux-kernel@vger.kernel.org, akpm@linux-foundation.org, sam@ravnborg.org, dwmw2@infradead.org, adobriyan@gmail.com Subject: Re: [RFC] Crash on modpost, addend_386_rel() References: <20070522.134015.65004318.nemoto@toshiba-tops.co.jp> <20070522.142929.05161433.nemoto@toshiba-tops.co.jp> <20070522.182739.48825006.nemoto@toshiba-tops.co.jp> In-Reply-To: <20070522.182739.48825006.nemoto@toshiba-tops.co.jp> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 6614 Lines: 190 Atsushi Nemoto kirjoitti: > On Tue, 22 May 2007 14:29:29 +0900 (JST), Atsushi Nemoto wrote: > >> Subject: [PATCH] kbuild: make better section mismatch reports on i386, arm and mips (take 3) >> > > Updated again to get a little bit better report on i386 relocatable > vmlinux. > > > Subject: [PATCH] kbuild: make better section mismatch reports on i386, arm and mips (take 4) > > On i386, ARM and MIPS, warn_sec_mismatch() sometimes fails to show > usefull symbol name. This is because empty 'refsym' due to 0 r_addend > value. This patch is to adjust r_addend value, consulting with > apply_relocate() routine in kernel code. > > Signed-off-by: Atsushi Nemoto > --- > diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c > index 8e5610d..760b2b3 100644 > --- a/scripts/mod/modpost.c > +++ b/scripts/mod/modpost.c > @@ -374,6 +374,7 @@ static int parse_elf(struct elf_info *info, const char *filename) > hdr->e_shstrndx = TO_NATIVE(hdr->e_shstrndx); > hdr->e_shnum = TO_NATIVE(hdr->e_shnum); > hdr->e_machine = TO_NATIVE(hdr->e_machine); > + hdr->e_type = TO_NATIVE(hdr->e_type); > sechdrs = (void *)hdr + hdr->e_shoff; > info->sechdrs = sechdrs; > > @@ -384,6 +385,8 @@ static int parse_elf(struct elf_info *info, const char *filename) > sechdrs[i].sh_size = TO_NATIVE(sechdrs[i].sh_size); > sechdrs[i].sh_link = TO_NATIVE(sechdrs[i].sh_link); > sechdrs[i].sh_name = TO_NATIVE(sechdrs[i].sh_name); > + sechdrs[i].sh_info = TO_NATIVE(sechdrs[i].sh_info); > + sechdrs[i].sh_addr = TO_NATIVE(sechdrs[i].sh_addr); > } > /* Find symbol table. */ > for (i = 1; i < hdr->e_shnum; i++) { > @@ -753,6 +756,8 @@ static Elf_Sym *find_elf_symbol(struct elf_info *elf, Elf_Addr addr, > for (sym = elf->symtab_start; sym < elf->symtab_stop; sym++) { > if (sym->st_shndx != relsym->st_shndx) > continue; > + if (ELF_ST_TYPE(sym->st_info) == STT_SECTION) > + continue; > if (sym->st_value == addr) > return sym; > } > @@ -895,6 +900,72 @@ static void warn_sec_mismatch(const char *modname, const char *fromsec, > } > } > > +static inline unsigned int *reloc_location(struct elf_info *elf, > + int rsection, Elf_Rela *r) > +{ > + Elf_Shdr *sechdrs = elf->sechdrs; > + int section = sechdrs[rsection].sh_info; > + > + return (void *)elf->hdr + sechdrs[section].sh_offset + > + (r->r_offset - sechdrs[section].sh_addr); > +} > + > +static void addend_386_rel(struct elf_info *elf, int rsection, Elf_Rela *r) > +{ > + unsigned int r_typ = ELF_R_TYPE(r->r_info); > + unsigned int *location = reloc_location(elf, rsection, r); > + > + switch (r_typ) { > + case R_386_32: > + r->r_addend = TO_NATIVE(*location); > + break; > + case R_386_PC32: > + r->r_addend = TO_NATIVE(*location) + 4; > + /* For CONFIG_RELOCATABLE=y */ > + if (elf->hdr->e_type == ET_EXEC) > + r->r_addend += r->r_offset; > + break; > + } > +} > + > +static void addend_arm_rel(struct elf_info *elf, int rsection, Elf_Rela *r) > +{ > + unsigned int r_typ = ELF_R_TYPE(r->r_info); > + unsigned int *location = reloc_location(elf, rsection, r); > + > + switch (r_typ) { > + case R_ARM_ABS32: > + r->r_addend = TO_NATIVE(*location); > + break; > + case R_ARM_PC24: > + r->r_addend = ((TO_NATIVE(*location) & 0x00ffffff) << 2) + 8; > + break; > + } > +} > + > +static int addend_mips_rel(struct elf_info *elf, int rsection, Elf_Rela *r) > +{ > + unsigned int r_typ = ELF_R_TYPE(r->r_info); > + unsigned int *location = reloc_location(elf, rsection, r); > + unsigned int inst; > + > + if (r_typ == R_MIPS_HI16) > + return 1; /* skip this */ > + inst = TO_NATIVE(*location); > + switch (r_typ) { > + case R_MIPS_LO16: > + r->r_addend = inst & 0xffff; > + break; > + case R_MIPS_26: > + r->r_addend = (inst & 0x03ffffff) << 2; > + break; > + case R_MIPS_32: > + r->r_addend = inst; > + break; > + } > + return 0; > +} > + > /** > * A module includes a number of sections that are discarded > * either when loaded or when used as built-in. > @@ -938,8 +1009,11 @@ static void check_sec_ref(struct module *mod, const char *modname, > r.r_offset = TO_NATIVE(rela->r_offset); > #if KERNEL_ELFCLASS == ELFCLASS64 > if (hdr->e_machine == EM_MIPS) { > + unsigned int r_typ; > r_sym = ELF64_MIPS_R_SYM(rela->r_info); > r_sym = TO_NATIVE(r_sym); > + r_typ = ELF64_MIPS_R_TYPE(rela->r_info); > + r.r_info = ELF64_R_INFO(r_sym, r_typ); > } else { > r.r_info = TO_NATIVE(rela->r_info); > r_sym = ELF_R_SYM(r.r_info); > @@ -972,8 +1046,11 @@ static void check_sec_ref(struct module *mod, const char *modname, > r.r_offset = TO_NATIVE(rel->r_offset); > #if KERNEL_ELFCLASS == ELFCLASS64 > if (hdr->e_machine == EM_MIPS) { > + unsigned int r_typ; > r_sym = ELF64_MIPS_R_SYM(rel->r_info); > r_sym = TO_NATIVE(r_sym); > + r_typ = ELF64_MIPS_R_TYPE(rel->r_info); > + r.r_info = ELF64_R_INFO(r_sym, r_typ); > } else { > r.r_info = TO_NATIVE(rel->r_info); > r_sym = ELF_R_SYM(r.r_info); > @@ -983,6 +1060,14 @@ static void check_sec_ref(struct module *mod, const char *modname, > r_sym = ELF_R_SYM(r.r_info); > #endif > r.r_addend = 0; > + if (hdr->e_machine == EM_386) > + addend_386_rel(elf, i, &r); > + else if (hdr->e_machine == EM_ARM) > + addend_arm_rel(elf, i, &r); > + else if (hdr->e_machine == EM_MIPS) { > + if (addend_mips_rel(elf, i, &r)) > + continue; > + } > sym = elf->symtab_start + r_sym; > /* Skip special sections */ > if (sym->st_shndx >= SHN_LORESERVE) > diff --git a/scripts/mod/modpost.h b/scripts/mod/modpost.h > index 0858caa..4156dd3 100644 > --- a/scripts/mod/modpost.h > +++ b/scripts/mod/modpost.h > @@ -60,6 +60,9 @@ typedef union > #define ELF64_MIPS_R_SYM(i) \ > ((__extension__ (_Elf64_Mips_R_Info_union)(i)).r_info_fields.r_sym) > > +#define ELF64_MIPS_R_TYPE(i) \ > + ((__extension__ (_Elf64_Mips_R_Info_union)(i)).r_info_fields.r_type1) > + > #if KERNEL_ELFDATA != HOST_ELFDATA > > static inline void __endian(const void *src, void *dest, unsigned int size) > - > > I can't see how this use of r_attend is going to work. find_elf_symbol compares relsym->st_value to Elf_Rela->r_attend. I think it doesn't work for RELA archs and even with this patch for REL. --Mika - 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/