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=-9.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, 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 0A997C04AAF for ; Thu, 16 May 2019 10:38:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D13B020881 for ; Thu, 16 May 2019 10:38:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727287AbfEPKiP (ORCPT ); Thu, 16 May 2019 06:38:15 -0400 Received: from foss.arm.com ([217.140.101.70]:40892 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727263AbfEPKiN (ORCPT ); Thu, 16 May 2019 06:38:13 -0400 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 Cc: jpoimboe@redhat.com, peterz@infradead.org, catalin.marinas@arm.com, will.deacon@arm.com, julien.thierry@arm.com, Raphael Gault 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> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 */ -- 2.17.1