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=-3.8 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS 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 0B915C43381 for ; Mon, 18 Mar 2019 15:52:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D12362087E for ; Mon, 18 Mar 2019 15:52:57 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="NvWSMmpv" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727586AbfCRPw4 (ORCPT ); Mon, 18 Mar 2019 11:52:56 -0400 Received: from bombadil.infradead.org ([198.137.202.133]:45616 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727426AbfCRPwz (ORCPT ); Mon, 18 Mar 2019 11:52:55 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; h=Content-Type:MIME-Version:References: Subject:Cc:To:From:Date:Message-Id:Sender:Reply-To:Content-Transfer-Encoding: Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:List-Id:List-Help: List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=pnQ+YnUj1ZIwlTJ9q0qmAJneQVZi9pnabkm2uQjoiPU=; b=NvWSMmpviGwYXxwG0i3miTPTSM Chpn/xM+kOzhEcUVU6KEW16SRenSqPy3wc8WyENLF+URJ7dkCqdAu1HX/joILi0iBDblRw2ZCcbWN PCKhwDT5Uo03i9a9wJ+fiGILKNto3P91Zi8AWb7lQ2i1ErwmDpgwzSNtNqwmw8k9f7mACXucfN7f+ JsAlprCdNnMQrpeAwhXUcjGsImz/xzREzelHziLsmZ+qISKyngDWfw65xoNn5apU5KcZV8pcAGRkL Hb6yTfO6R/0VD3wMmlfr6z8lke8D6D8Lu9yMq8bKYGtJ/37+SNCLMf9xbcUz06DrOONdC4aMByU+s qizeEKYQ==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=hirez.programming.kicks-ass.net) by bombadil.infradead.org with esmtpsa (Exim 4.90_1 #2 (Red Hat Linux)) id 1h5uZ9-0006n5-EJ; Mon, 18 Mar 2019 15:52:43 +0000 Received: by hirez.programming.kicks-ass.net (Postfix, from userid 0) id DA4DF25E45D7E; Mon, 18 Mar 2019 16:52:38 +0100 (CET) Message-Id: <20190318155141.558827084@infradead.org> User-Agent: quilt/0.65 Date: Mon, 18 Mar 2019 16:38:58 +0100 From: Peter Zijlstra To: torvalds@linux-foundation.org, tglx@linutronix.de, hpa@zytor.com, julien.thierry@arm.com, will.deacon@arm.com, luto@amacapital.net, mingo@kernel.org, catalin.marinas@arm.com, james.morse@arm.com, valentin.schneider@arm.com, brgerst@gmail.com, jpoimboe@redhat.com, luto@kernel.org, bp@alien8.de, dvlasenk@redhat.com Cc: linux-kernel@vger.kernel.org, peterz@infradead.org, dvyukov@google.com, rostedt@goodmis.org Subject: [PATCH 18/25] objtool: Handle function aliases References: <20190318153840.906404905@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Function aliases result in different symbols for the same set of instructions; track a canonical symbol so there is a unique point of access. This again prepares the way for function attributes. And in particular the need for aliases comes from how KASAN uses them. Signed-off-by: Peter Zijlstra (Intel) --- tools/objtool/elf.c | 15 +++++++++++---- tools/objtool/elf.h | 2 +- 2 files changed, 12 insertions(+), 5 deletions(-) --- a/tools/objtool/elf.c +++ b/tools/objtool/elf.c @@ -219,7 +219,7 @@ static int read_sections(struct elf *elf static int read_symbols(struct elf *elf) { struct section *symtab, *sec; - struct symbol *sym, *pfunc; + struct symbol *sym, *pfunc, *alias; struct list_head *entry, *tmp; int symbols_nr, i; char *coldstr; @@ -239,6 +239,7 @@ static int read_symbols(struct elf *elf) return -1; } memset(sym, 0, sizeof(*sym)); + alias = sym; sym->idx = i; @@ -288,11 +289,17 @@ static int read_symbols(struct elf *elf) break; } - if (sym->offset == s->offset && sym->len >= s->len) { - entry = tmp; - break; + if (sym->offset == s->offset) { + if (sym->len == s->len && alias == sym) + alias = s; + + if (sym->len >= s->len) { + entry = tmp; + break; + } } } + sym->alias = alias; list_add(&sym->list, entry); hash_add(sym->sec->symbol_hash, &sym->hash, sym->idx); } --- a/tools/objtool/elf.h +++ b/tools/objtool/elf.h @@ -61,7 +61,7 @@ struct symbol { unsigned char bind, type; unsigned long offset; unsigned int len; - struct symbol *pfunc, *cfunc; + struct symbol *pfunc, *cfunc, *alias; }; struct rela {