From nobody Tue Apr 7 14:22:06 2026 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id A2C14C4332F for ; Mon, 17 Oct 2022 14:56:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231401AbiJQO43 (ORCPT ); Mon, 17 Oct 2022 10:56:29 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59688 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231182AbiJQOyP (ORCPT ); Mon, 17 Oct 2022 10:54:15 -0400 Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 44762691A5; Mon, 17 Oct 2022 07:54:05 -0700 (PDT) Date: Mon, 17 Oct 2022 14:54:02 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1666018443; h=from:from:sender:sender:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=DuN0mXwWkXkPpbB55PqFQ+7RoejEE6nRQT+hjzfltP4=; b=zkZwcE9gGOX7PbT3GwSVVM4TN2w/tFLQDSrelW/eujv4kbNICfCOcVG8D/5Om1Q71YoYbJ aSPJt71sbft9YQ+niFXaMloW9rmWRuzqSruJlZ/akjV4rDquj4ZOZHK3URPlGA+EKn75vF XDaX6cieJqvgzsD778nXzZWs9x0+k+rP9QWz49iLTa86HXefZ/CNF0zoGGMGWseAyocpLb NoiM4VnCRb5MxbxFPE/NNfJm8tKem4cKSVW25hjFPbPurJrRb2GnIwwnYeOc4+HyiVmPUR UnHaufphB+vA0DvkjMOwmydYZ3SBqC9uATy3M/jHkKI08sql8j9D7OyEa0RsGQ== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1666018443; h=from:from:sender:sender:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=DuN0mXwWkXkPpbB55PqFQ+7RoejEE6nRQT+hjzfltP4=; b=kQ5jW4dgw3aVNMAbukPFjwwLHGGY3znm4eokzM34s/wKjUfnhI3dAcARgkR1/Izhyfcu4o DbUOZK3dQx1fNEBA== From: "tip-bot2 for Peter Zijlstra" Sender: tip-bot2@linutronix.de Reply-to: linux-kernel@vger.kernel.org To: linux-tip-commits@vger.kernel.org Subject: [tip: x86/core] objtool: Allow !PC relative relocations Cc: "Peter Zijlstra (Intel)" , Thomas Gleixner , x86@kernel.org, linux-kernel@vger.kernel.org In-Reply-To: <20220915111145.806607235@infradead.org> References: <20220915111145.806607235@infradead.org> MIME-Version: 1.0 Message-ID: <166601844226.401.9535379202269375669.tip-bot2@tip-bot2> Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The following commit has been merged into the x86/core branch of tip: Commit-ID: 61c6065ef7ec0447a280179d04b2d81c80c2f479 Gitweb: https://git.kernel.org/tip/61c6065ef7ec0447a280179d04b2d81c8= 0c2f479 Author: Peter Zijlstra AuthorDate: Thu, 15 Sep 2022 13:11:07 +02:00 Committer: Peter Zijlstra CommitterDate: Mon, 17 Oct 2022 16:41:06 +02:00 objtool: Allow !PC relative relocations Objtool doesn't currently much like per-cpu usage in alternatives: arch/x86/entry/entry_64.o: warning: objtool: .altinstr_replacement+0xf: uns= upported relocation in alternatives section f: 65 c7 04 25 00 00 00 00 00 00 00 80 movl $0x80000000,%gs:0x0 = 13: R_X86_64_32S __x86_call_depth Since the R_X86_64_32S relocation is location invariant (it's computation doesn't include P - the address of the location itself), it can be trivially allowed. Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Thomas Gleixner Signed-off-by: Peter Zijlstra (Intel) Link: https://lore.kernel.org/r/20220915111145.806607235@infradead.org --- tools/objtool/arch/x86/decode.c | 24 ++++++++++++++++++++++++ tools/objtool/check.c | 2 +- tools/objtool/include/objtool/arch.h | 2 ++ 3 files changed, 27 insertions(+), 1 deletion(-) diff --git a/tools/objtool/arch/x86/decode.c b/tools/objtool/arch/x86/decod= e.c index 1c253b4..f094383 100644 --- a/tools/objtool/arch/x86/decode.c +++ b/tools/objtool/arch/x86/decode.c @@ -73,6 +73,30 @@ unsigned long arch_jump_destination(struct instruction *= insn) return insn->offset + insn->len + insn->immediate; } =20 +bool arch_pc_relative_reloc(struct reloc *reloc) +{ + /* + * All relocation types where P (the address of the target) + * is included in the computation. + */ + switch (reloc->type) { + case R_X86_64_PC8: + case R_X86_64_PC16: + case R_X86_64_PC32: + case R_X86_64_PC64: + + case R_X86_64_PLT32: + case R_X86_64_GOTPC32: + case R_X86_64_GOTPCREL: + return true; + + default: + break; + } + + return false; +} + #define ADD_OP(op) \ if (!(op =3D calloc(1, sizeof(*op)))) \ return -1; \ diff --git a/tools/objtool/check.c b/tools/objtool/check.c index 43ec14c..7174bba 100644 --- a/tools/objtool/check.c +++ b/tools/objtool/check.c @@ -1645,7 +1645,7 @@ static int handle_group_alt(struct objtool_file *file, * accordingly. */ alt_reloc =3D insn_reloc(file, insn); - if (alt_reloc && + if (alt_reloc && arch_pc_relative_reloc(alt_reloc) && !arch_support_alt_relocation(special_alt, insn, alt_reloc)) { =20 WARN_FUNC("unsupported relocation in alternatives section", diff --git a/tools/objtool/include/objtool/arch.h b/tools/objtool/include/o= bjtool/arch.h index beb2f3a..fe2ea4b 100644 --- a/tools/objtool/include/objtool/arch.h +++ b/tools/objtool/include/objtool/arch.h @@ -93,4 +93,6 @@ bool arch_is_rethunk(struct symbol *sym); =20 int arch_rewrite_retpolines(struct objtool_file *file); =20 +bool arch_pc_relative_reloc(struct reloc *reloc); + #endif /* _ARCH_H */