From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.7 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id BB4DEC433E0 for ; Thu, 18 Jun 2020 20:43:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9D6E520890 for ; Thu, 18 Jun 2020 20:43:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728399AbgFRUnQ (ORCPT ); Thu, 18 Jun 2020 16:43:16 -0400 Received: from ex13-edg-ou-002.vmware.com ([208.91.0.190]:48844 "EHLO EX13-EDG-OU-002.vmware.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730971AbgFRUjI (ORCPT ); Thu, 18 Jun 2020 16:39:08 -0400 Received: from sc9-mailhost2.vmware.com (10.113.161.72) by EX13-EDG-OU-002.vmware.com (10.113.208.156) with Microsoft SMTP Server id 15.0.1156.6; Thu, 18 Jun 2020 13:39:03 -0700 Received: from sc9-mailhost2.vmware.com (unknown [10.129.221.29]) by sc9-mailhost2.vmware.com (Postfix) with ESMTP id 2DCEDB2656; Thu, 18 Jun 2020 16:39:06 -0400 (EDT) From: Matt Helsley To: CC: Josh Poimboeuf , Peter Zijlstra , Steven Rostedt , Julien Thierry , Kamalesh Babulal , Matt Helsley Subject: [RFC][PATCH v5 10/51] objtool: mcount: Walk objtool Elf structs in find_secsym_ndx Date: Thu, 18 Jun 2020 13:37:56 -0700 Message-ID: X-Mailer: git-send-email 2.25.4 In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: 7BIT Content-Type: text/plain; charset=US-ASCII Received-SPF: None (EX13-EDG-OU-002.vmware.com: mhelsley@vmware.com does not designate permitted sender hosts) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Rather than using indices into raw ELF32/64 tables mapped for the wrapper, use the objtool functions to find the suitable symbol in the given text section. This also removes all callers to find_symtab() and get_symindex() so we can remove them as well. Also take advantage of this commit to rename the function to something that reads more easily. Signed-off-by: Matt Helsley --- tools/objtool/recordmcount.c | 2 + tools/objtool/recordmcount.h | 94 ++++++++---------------------------- 2 files changed, 22 insertions(+), 74 deletions(-) diff --git a/tools/objtool/recordmcount.c b/tools/objtool/recordmcount.c index f20582ac99e2..843027a46e1b 100644 --- a/tools/objtool/recordmcount.c +++ b/tools/objtool/recordmcount.c @@ -422,6 +422,8 @@ static int is_mcounted_section_name(char const *const txtname) strcmp(".cpuidle.text", txtname) == 0; } +static const unsigned int missing_sym = (unsigned int)-1; + /* 32 bit and 64 bit are very similar */ #include "recordmcount.h" #define RECORD_MCOUNT_64 diff --git a/tools/objtool/recordmcount.h b/tools/objtool/recordmcount.h index 30f8913aa841..b10f7fcd33c3 100644 --- a/tools/objtool/recordmcount.h +++ b/tools/objtool/recordmcount.h @@ -24,15 +24,13 @@ #undef mcount_adjust #undef sift_rel_mcount #undef nop_mcount -#undef find_secsym_ndx +#undef find_section_sym_index #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 @@ -58,14 +56,12 @@ # define append_func append64 # define sift_rel_mcount sift64_rel_mcount # define nop_mcount nop_mcount_64 -# define find_secsym_ndx find64_secsym_ndx +# define find_section_sym_index find64_section_sym_index # 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 @@ -95,14 +91,12 @@ # define append_func append32 # define sift_rel_mcount sift32_rel_mcount # define nop_mcount nop_mcount_32 -# define find_secsym_ndx find32_secsym_ndx +# define find_section_sym_index find32_section_sym_index # 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 @@ -185,21 +179,6 @@ 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; - int index; - - if (sym->st_shndx != SHN_XINDEX) - return w2(sym->st_shndx); - - offset = (unsigned long)sym - (unsigned long)symtab; - index = offset / sizeof(*sym); - - return w(symtab_shndx[index]); -} - static unsigned int get_shnum(Elf_Ehdr const *ehdr, Elf_Shdr const *shdr0) { if (shdr0 && !ehdr->e_shnum) @@ -225,28 +204,6 @@ static int get_shstrndx(Elf_Ehdr const *ehdr, Elf_Shdr const *shdr0) return w(shdr0->sh_link); } -static void find_symtab(Elf_Ehdr *const ehdr, Elf_Shdr const *shdr0, - Elf32_Word **symtab, - Elf32_Word **symtab_shndx) -{ - unsigned const nhdr = get_shnum(ehdr, shdr0); - 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 int append_func(Elf_Ehdr *const ehdr, Elf_Shdr *const shstr, @@ -507,40 +464,37 @@ static int nop_mcount(const struct section * const rels, * Num: Value Size Type Bind Vis Ndx Name * 2: 00000000 0 SECTION LOCAL DEFAULT 1 */ -static int find_secsym_ndx(unsigned const txtndx, +static int find_section_sym_index(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) - + (void *)ehdr); - unsigned const nsym = _w(symhdr->sh_size) / _w(symhdr->sh_entsize); - Elf_Sym const *symp; - unsigned t; + struct symbol *sym; + struct section *txts = find_section_by_index(lf, txtndx); - for (symp = sym0, t = nsym; t; --t, ++symp) { - unsigned int const st_bind = ELF_ST_BIND(symp->st_info); + if (!txts) { + fprintf(stderr, "Cannot find section %u: %s.\n", + txtndx, txtname); + return missing_sym; + } - if (txtndx == get_symindex(symp, symtab, symtab_shndx) - /* avoid STB_WEAK */ - && (STB_LOCAL == st_bind || STB_GLOBAL == st_bind)) { + list_for_each_entry(sym, &txts->symbol_list, list) { + /* avoid symbols with weak binding */ + if ((sym->bind == STB_LOCAL) || (sym->bind == STB_GLOBAL)) { /* function symbols on ARM have quirks, avoid them */ if (w2(ehdr->e_machine) == EM_ARM - && ELF_ST_TYPE(symp->st_info) == STT_FUNC) + && sym->type == STT_FUNC) continue; - *recvalp = _w(symp->st_value); - *sym_index = symp - sym0; + *recvalp = sym->sym.st_value; + *sym_index = sym->idx; return 0; } } fprintf(stderr, "Cannot find symbol for section %u: %s.\n", txtndx, txtname); - return -1; + return missing_sym; } static char const *has_rel_mcount(const struct section * const rels) @@ -577,9 +531,6 @@ static int do_func(Elf_Ehdr *const ehdr, Elf_Shdr *const shdr0 = (Elf_Shdr *)(_w(ehdr->e_shoff) + (void *)ehdr); - Elf32_Word *symtab; - Elf32_Word *symtab_shndx; - /* Upper bound on space: assume all relevant relocs are for mcount. */ unsigned totrelsz; @@ -615,8 +566,6 @@ static int do_func(Elf_Ehdr *const ehdr, return -1; } - find_symtab(ehdr, shdr0, &symtab, &symtab_shndx); - list_for_each_entry(sec, &lf->sections, list) { char const *txtname; @@ -626,11 +575,8 @@ static int do_func(Elf_Ehdr *const ehdr, uint_t recval = 0; symsec_sh_link = sec->sh.sh_link; - result = find_secsym_ndx(sec->sh.sh_info, txtname, - &recval, &recsym, - &shdr0[symsec_sh_link], - symtab, symtab_shndx, - ehdr); + result = find_section_sym_index(sec->sh.sh_info, + txtname, &recval, &recsym, ehdr); if (result) goto out; -- 2.20.1