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 BDA9AC433E0 for ; Thu, 18 Jun 2020 20:39:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A1551208C3 for ; Thu, 18 Jun 2020 20:39:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731238AbgFRUjl (ORCPT ); Thu, 18 Jun 2020 16:39:41 -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 S1731011AbgFRUjL (ORCPT ); Thu, 18 Jun 2020 16:39:11 -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 F069AB2656; 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 11/51] objtool: mcount: Use symbol structs to find mcount relocations Date: Thu, 18 Jun 2020 13:37:57 -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 open coding symbol name lookups in get_sym_and_*() we rename the structure and use objtool's lookup function to get the symbol name for a relocation. We also change the name of the function to better reflect its purpose. Signed-off-by: Matt Helsley --- tools/objtool/elf.c | 2 +- tools/objtool/elf.h | 1 + tools/objtool/recordmcount.h | 54 ++++++++++-------------------------- 3 files changed, 17 insertions(+), 40 deletions(-) diff --git a/tools/objtool/elf.c b/tools/objtool/elf.c index 17e39b3a1719..8dcdea8020a5 100644 --- a/tools/objtool/elf.c +++ b/tools/objtool/elf.c @@ -196,7 +196,7 @@ struct section *find_section_by_index(const struct elf *elf, unsigned int idx) return NULL; } -static struct symbol *find_symbol_by_index(struct elf *elf, unsigned int idx) +struct symbol *find_symbol_by_index(const struct elf *elf, unsigned int idx) { struct symbol *sym; diff --git a/tools/objtool/elf.h b/tools/objtool/elf.h index 60eb44661658..09fa0d085341 100644 --- a/tools/objtool/elf.h +++ b/tools/objtool/elf.h @@ -135,6 +135,7 @@ struct section *find_section_by_index(const struct elf *elf, unsigned int idx); struct symbol *find_func_by_offset(struct section *sec, unsigned long offset); struct symbol *find_symbol_by_offset(struct section *sec, unsigned long offset); struct symbol *find_symbol_by_name(const struct elf *elf, const char *name); +struct symbol *find_symbol_by_index(const struct elf *elf, unsigned int idx); struct symbol *find_symbol_containing(const struct section *sec, unsigned long offset); struct reloc *find_reloc_by_dest(const struct elf *elf, struct section *sec, unsigned long offset); struct reloc *find_reloc_by_dest_range(const struct elf *elf, struct section *sec, diff --git a/tools/objtool/recordmcount.h b/tools/objtool/recordmcount.h index b10f7fcd33c3..3dae878f11a8 100644 --- a/tools/objtool/recordmcount.h +++ b/tools/objtool/recordmcount.h @@ -31,7 +31,7 @@ #undef get_shnum #undef set_shnum #undef get_shstrndx -#undef get_sym_str_and_relp +#undef get_relp #undef do_func #undef Elf_Addr #undef Elf_Ehdr @@ -62,7 +62,7 @@ # define get_shnum get_shnum64 # define set_shnum set_shnum64 # define get_shstrndx get_shstrndx64 -# define get_sym_str_and_relp get_sym_str_and_relp_64 +# define get_relp get_relp_64 # define do_func do64 # define get_mcountsym get_mcountsym_64 # define is_fake_mcount is_fake_mcount64 @@ -97,7 +97,7 @@ # define get_shnum get_shnum32 # define set_shnum set_shnum32 # define get_shstrndx get_shstrndx32 -# define get_sym_str_and_relp get_sym_str_and_relp_32 +# define get_relp get_relp_32 # define do_func do32 # define get_mcountsym get_mcountsym_32 # define is_fake_mcount is_fake_mcount32 @@ -298,15 +298,10 @@ static int append_func(Elf_Ehdr *const ehdr, return elf_write(lf); } -static unsigned get_mcountsym(Elf_Sym const *const sym0, - Elf_Rel const *relp, - char const *const str0) +static unsigned get_mcountsym(Elf_Rel const *relp) { - unsigned mcountsym = 0; - - Elf_Sym const *const symp = - &sym0[Elf_r_sym(relp)]; - char const *symname = &str0[w(symp->st_name)]; + struct symbol *sym = find_symbol_by_index(lf, Elf_r_sym(relp)); + char const *symname = sym->name; char const *mcount = gpfx == '_' ? "_mcount" : "mcount"; char const *fentry = "__fentry__"; @@ -315,31 +310,16 @@ static unsigned get_mcountsym(Elf_Sym const *const sym0, if (strcmp(mcount, symname) == 0 || (altmcount && strcmp(altmcount, symname) == 0) || (strcmp(fentry, symname) == 0)) - mcountsym = Elf_r_sym(relp); - - return mcountsym; + return Elf_r_sym(relp); + return 0; } -static void get_sym_str_and_relp(const struct section * const rels, - Elf_Ehdr const *const ehdr, - Elf_Sym const **sym0, - char const **str0, - Elf_Rel const **relp) +static void get_relp(const struct section * const rels, + Elf_Ehdr const *const ehdr, + Elf_Rel const **relp) { - Elf_Shdr *const shdr0 = (Elf_Shdr *)(_w(ehdr->e_shoff) - + (void *)ehdr); - unsigned const symsec_sh_link = rels->sh.sh_link; - Elf_Shdr const *const symsec = &shdr0[symsec_sh_link]; - Elf_Shdr const *const strsec = &shdr0[w(symsec->sh_link)]; Elf_Rel const *const rel0 = (Elf_Rel const *)(rels->sh.sh_offset + (void *)ehdr); - - *sym0 = (Elf_Sym const *)(_w(symsec->sh_offset) - + (void *)ehdr); - - *str0 = (char const *)(_w(strsec->sh_offset) - + (void *)ehdr); - *relp = rel0; } @@ -359,19 +339,17 @@ static uint_t *sift_rel_mcount(uint_t *mlocp, { uint_t *const mloc0 = mlocp; Elf_Rel *mrelp = *mrelpp; - Elf_Sym const *sym0; - char const *str0; Elf_Rel const *relp; unsigned int rel_entsize = rels->sh.sh_entsize; unsigned const nrel = rels->sh.sh_size / rel_entsize; unsigned mcountsym = 0; unsigned t; - get_sym_str_and_relp(rels, ehdr, &sym0, &str0, &relp); + get_relp(rels, ehdr, &relp); for (t = nrel; t; --t) { if (!mcountsym) - mcountsym = get_mcountsym(sym0, relp, str0); + mcountsym = get_mcountsym(relp); if (mcountsym && mcountsym == Elf_r_sym(relp) && !is_fake_mcount(relp)) { @@ -405,8 +383,6 @@ static int nop_mcount(const struct section * const rels, { Elf_Shdr *const shdr0 = (Elf_Shdr *)(_w(ehdr->e_shoff) + (void *)ehdr); - Elf_Sym const *sym0; - char const *str0; Elf_Rel const *relp; Elf_Shdr const *const shdr = &shdr0[rels->sh.sh_info]; unsigned rel_entsize = rels->sh.sh_entsize; @@ -415,13 +391,13 @@ static int nop_mcount(const struct section * const rels, unsigned t; int once = 0; - get_sym_str_and_relp(rels, ehdr, &sym0, &str0, &relp); + get_relp(rels, ehdr, &relp); for (t = nrel; t; --t) { int ret = -1; if (!mcountsym) - mcountsym = get_mcountsym(sym0, relp, str0); + mcountsym = get_mcountsym(relp); if (mcountsym == Elf_r_sym(relp) && !is_fake_mcount(relp)) { if (make_nop) -- 2.20.1