From patchwork Thu May 16 10:36:46 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Raphael Gault X-Patchwork-Id: 10946331 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 66B90924 for ; Thu, 16 May 2019 10:39:17 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 543312854F for ; Thu, 16 May 2019 10:39:17 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 45D3428842; Thu, 16 May 2019 10:39:17 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.2 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,MAILING_LIST_MULTI,RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id AF73C2854F for ; Thu, 16 May 2019 10:39:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:MIME-Version:Cc:List-Subscribe: List-Help:List-Post:List-Archive:List-Unsubscribe:List-Id:References: In-Reply-To:Message-Id:Date:Subject:To:From:Reply-To:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Owner; bh=p6wT/l/1JAGWjp/WJzUWZd2kFG8RpC+wTMymmAotyOM=; b=OaU3VT1hClJ6/GBADJgBCmd6mL pBKBU0o2WMtj4jIaqy+dcOWA0VIw1VDKbJyKeI5Ulq4F0r3pDd1L65X11EvTD8Ft/EJ67Y6jRFqQh /D7QANMyEQ/Nh2cg8tFPJhIWRljXPaEWcaebR3PW5gLLRHYNEsG65q+Kz2HG53/zpsosJG6POVfif Z9yAIo/7MejgQdyvQtGCcB2P/dmR2NevkPVkG0Gh9dG81le9S22RDNhpVxpd/aUMihvaZY/mn6R7n zliu2rzKQ/K1TkaW7joxl8v91dXknUBjm1ITRuEFGk3rkYAzkocSUCS4qKq6FnjGh7PULYiodBR54 dNHvkLjw==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1hRDn4-0006uj-Gf; Thu, 16 May 2019 10:39:10 +0000 Received: from usa-sjc-mx-foss1.foss.arm.com ([217.140.101.70] helo=foss.arm.com) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1hRDm9-0005jk-Jg for linux-arm-kernel@lists.infradead.org; Thu, 16 May 2019 10:38:21 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 313251A25; Thu, 16 May 2019 03:38:13 -0700 (PDT) Received: from e121650-lin.cambridge.arm.com (e121650-lin.cambridge.arm.com [10.1.196.108]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id AA3BE3F703; Thu, 16 May 2019 03:38:11 -0700 (PDT) From: Raphael Gault To: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: [RFC 07/16] objtool: special: Adapt special section handling Date: Thu, 16 May 2019 11:36:46 +0100 Message-Id: <20190516103655.5509-8-raphael.gault@arm.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20190516103655.5509-1-raphael.gault@arm.com> References: <20190516103655.5509-1-raphael.gault@arm.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190516_033813_938670_20C5608D X-CRM114-Status: GOOD ( 18.26 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: julien.thierry@arm.com, peterz@infradead.org, catalin.marinas@arm.com, will.deacon@arm.com, Raphael Gault , jpoimboe@redhat.com MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP This patch abstracts the few architecture dependent tests that are perform when handling special section and switch tables. It enables any architecture to ignore a particular CPU feature or not to handle switch tables. Signed-off-by: Raphael Gault --- tools/objtool/arch/arm64/Build | 1 + tools/objtool/arch/arm64/include/arch_special.h | 10 ++++++++-- tools/objtool/arch/x86/Build | 1 + tools/objtool/arch/x86/include/arch_special.h | 9 +++++++++ tools/objtool/check.c | 15 +++++++++++++-- tools/objtool/special.c | 9 ++------- tools/objtool/special.h | 3 +++ 7 files changed, 37 insertions(+), 11 deletions(-) diff --git a/tools/objtool/arch/arm64/Build b/tools/objtool/arch/arm64/Build index bf7a32c2b9e9..3d09be745a84 100644 --- a/tools/objtool/arch/arm64/Build +++ b/tools/objtool/arch/arm64/Build @@ -1,3 +1,4 @@ +objtool-y += arch_special.o objtool-y += decode.o objtool-y += orc_dump.o objtool-y += orc_gen.o diff --git a/tools/objtool/arch/arm64/include/arch_special.h b/tools/objtool/arch/arm64/include/arch_special.h index 63da775d0581..185103be8a51 100644 --- a/tools/objtool/arch/arm64/include/arch_special.h +++ b/tools/objtool/arch/arm64/include/arch_special.h @@ -30,7 +30,13 @@ #define ALT_ORIG_LEN_OFFSET 10 #define ALT_NEW_LEN_OFFSET 11 -#define X86_FEATURE_POPCNT (4 * 32 + 23) -#define X86_FEATURE_SMAP (9 * 32 + 20) +static inline bool arch_should_ignore_feature(unsigned short feature) +{ + return false; +} +static inline bool arch_support_switch_table(void) +{ + return false; +} #endif /* _ARM64_ARCH_SPECIAL_H */ diff --git a/tools/objtool/arch/x86/Build b/tools/objtool/arch/x86/Build index 1f11b45999d0..63e167775bc8 100644 --- a/tools/objtool/arch/x86/Build +++ b/tools/objtool/arch/x86/Build @@ -1,3 +1,4 @@ +objtool-y += arch_special.o objtool-y += decode.o objtool-y += orc_dump.o objtool-y += orc_gen.o diff --git a/tools/objtool/arch/x86/include/arch_special.h b/tools/objtool/arch/x86/include/arch_special.h index 424ce47013e3..fce2b1193194 100644 --- a/tools/objtool/arch/x86/include/arch_special.h +++ b/tools/objtool/arch/x86/include/arch_special.h @@ -33,4 +33,13 @@ #define X86_FEATURE_POPCNT (4 * 32 + 23) #define X86_FEATURE_SMAP (9 * 32 + 20) +static inline bool arch_should_ignore_feature(unsigned short feature) +{ + return feature == X86_FEATURE_POPCNT; +} + +static inline bool arch_support_switch_table(void) +{ + return true; +} #endif /* _X86_ARCH_SPECIAL_H */ diff --git a/tools/objtool/check.c b/tools/objtool/check.c index cd9cd26206d1..0ee3b781ddd8 100644 --- a/tools/objtool/check.c +++ b/tools/objtool/check.c @@ -738,7 +738,7 @@ static int handle_group_alt(struct objtool_file *file, last_orig_insn = insn; } - if (next_insn_same_sec(file, last_orig_insn)) { + if (last_orig_insn && next_insn_same_sec(file, last_orig_insn)) { fake_jump = malloc(sizeof(*fake_jump)); if (!fake_jump) { WARN("malloc failed"); @@ -1054,6 +1054,17 @@ static struct rela *find_switch_table(struct objtool_file *file, if (find_symbol_containing(rodata_sec, table_offset)) continue; + /* + * If we are on arm64 architecture, we now that we + * are in presence of a switch table thanks to + * the `br ` insn. but we can't retrieve it yet. + * So we just ignore unreachable for this file. + */ + if (!arch_support_switch_table()) { + file->ignore_unreachables = true; + return NULL; + } + rodata_rela = find_rela_by_dest(rodata_sec, table_offset); if (rodata_rela) { /* @@ -1853,7 +1864,7 @@ static int validate_branch(struct objtool_file *file, struct instruction *first, insn = first; sec = insn->sec; - if (insn->alt_group && list_empty(&insn->alts)) { + if (!insn->visited && insn->alt_group && list_empty(&insn->alts)) { WARN_FUNC("don't know how to handle branch to middle of alternative instruction group", sec, insn->offset); return 1; diff --git a/tools/objtool/special.c b/tools/objtool/special.c index fd7c928fa1d6..e33321637932 100644 --- a/tools/objtool/special.c +++ b/tools/objtool/special.c @@ -93,7 +93,7 @@ static int get_alt_entry(struct elf *elf, struct special_entry *entry, * feature path which is a "very very small percentage of * machines". */ - if (feature == X86_FEATURE_POPCNT) + if (arch_should_ignore_feature(feature)) alt->skip_orig = true; /* @@ -105,12 +105,7 @@ static int get_alt_entry(struct elf *elf, struct special_entry *entry, * find paths that see the STAC but take the NOP instead of * CLAC and the other way around. */ - if (feature == X86_FEATURE_SMAP) { - if (uaccess) - alt->skip_orig = true; - else - alt->skip_alt = true; - } + arch_force_alt_path(feature, uaccess, alt); } orig_rela = find_rela_by_dest(sec, offset + entry->orig); diff --git a/tools/objtool/special.h b/tools/objtool/special.h index d5c062e718ef..05f1e496bf7c 100644 --- a/tools/objtool/special.h +++ b/tools/objtool/special.h @@ -39,5 +39,8 @@ struct special_alt { }; int special_get_alts(struct elf *elf, struct list_head *alts); +void arch_force_alt_path(unsigned short feature, + bool uaccess, + struct special_alt *alt); #endif /* _SPECIAL_H */