From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751645AbdI1Ffv (ORCPT ); Thu, 28 Sep 2017 01:35:51 -0400 Received: from terminus.zytor.com ([65.50.211.136]:59185 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751490AbdI1Fft (ORCPT ); Thu, 28 Sep 2017 01:35:49 -0400 Date: Wed, 27 Sep 2017 22:31:27 -0700 From: tip-bot for Josh Poimboeuf Message-ID: Cc: mingo@kernel.org, linux-kernel@vger.kernel.org, hpa@zytor.com, jpoimboe@redhat.com, torvalds@linux-foundation.org, peterz@infradead.org, arnd@arndb.de, tglx@linutronix.de Reply-To: linux-kernel@vger.kernel.org, hpa@zytor.com, mingo@kernel.org, arnd@arndb.de, tglx@linutronix.de, torvalds@linux-foundation.org, peterz@infradead.org, jpoimboe@redhat.com In-Reply-To: References: To: linux-tip-commits@vger.kernel.org Subject: [tip:core/urgent] objtool: Support unoptimized frame pointer setup Git-Commit-ID: 607a4029d439cdfa258aff5da32bb9cd6ed1a66d X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: 607a4029d439cdfa258aff5da32bb9cd6ed1a66d Gitweb: https://git.kernel.org/tip/607a4029d439cdfa258aff5da32bb9cd6ed1a66d Author: Josh Poimboeuf AuthorDate: Wed, 27 Sep 2017 10:36:38 -0500 Committer: Ingo Molnar CommitDate: Thu, 28 Sep 2017 07:25:54 +0200 objtool: Support unoptimized frame pointer setup Arnd Bergmann reported a bunch of warnings like: crypto/jitterentropy.o: warning: objtool: jent_fold_time()+0x3b: call without frame pointer save/setup crypto/jitterentropy.o: warning: objtool: jent_stuck()+0x1d: call without frame pointer save/setup crypto/jitterentropy.o: warning: objtool: jent_unbiased_bit()+0x15: call without frame pointer save/setup crypto/jitterentropy.o: warning: objtool: jent_read_entropy()+0x32: call without frame pointer save/setup crypto/jitterentropy.o: warning: objtool: jent_entropy_collector_free()+0x19: call without frame pointer save/setup and arch/x86/events/core.o: warning: objtool: collect_events uses BP as a scratch register arch/x86/events/core.o: warning: objtool: events_ht_sysfs_show()+0x22: call without frame pointer save/setup With certain rare configurations, GCC sometimes sets up the frame pointer with: lea (%rsp),%rbp instead of: mov %rsp,%rbp The instructions are equivalent, so treat the former like the latter. Reported-by: Arnd Bergmann Signed-off-by: Josh Poimboeuf Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/a468af8b28a69b83fffc6d7668be9b6fcc873699.1506526584.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar --- tools/objtool/arch/x86/decode.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) diff --git a/tools/objtool/arch/x86/decode.c b/tools/objtool/arch/x86/decode.c index 0f22768..34a579f 100644 --- a/tools/objtool/arch/x86/decode.c +++ b/tools/objtool/arch/x86/decode.c @@ -284,11 +284,16 @@ int arch_decode_instruction(struct elf *elf, struct section *sec, case 0x8d: if (sib == 0x24 && rex_w && !rex_b && !rex_x) { - /* lea disp(%rsp), reg */ *type = INSN_STACK; - op->src.type = OP_SRC_ADD; + if (!insn.displacement.value) { + /* lea (%rsp), reg */ + op->src.type = OP_SRC_REG; + } else { + /* lea disp(%rsp), reg */ + op->src.type = OP_SRC_ADD; + op->src.offset = insn.displacement.value; + } op->src.reg = CFI_SP; - op->src.offset = insn.displacement.value; op->dest.type = OP_DEST_REG; op->dest.reg = op_to_cfi_reg[modrm_reg][rex_r];