From patchwork Wed Oct 27 08:52:57 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Peter Zijlstra X-Patchwork-Id: 12586723 X-Patchwork-Delegate: bpf@iogearbox.net 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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4C193C4167B for ; Wed, 27 Oct 2021 08:58:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3190561040 for ; Wed, 27 Oct 2021 08:58:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241129AbhJ0JBF (ORCPT ); Wed, 27 Oct 2021 05:01:05 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52500 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241127AbhJ0JA6 (ORCPT ); Wed, 27 Oct 2021 05:00:58 -0400 Received: from desiato.infradead.org (desiato.infradead.org [IPv6:2001:8b0:10b:1:d65d:64ff:fe57:4e05]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0BA87C061220 for ; Wed, 27 Oct 2021 01:58:33 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=desiato.20200630; h=Content-Type:MIME-Version:References: Subject:To:From:Date:Message-ID:Sender:Reply-To:Cc:Content-Transfer-Encoding: Content-ID:Content-Description:In-Reply-To; bh=eYPAZo+0FtCg9b7QXUoJ4s5MyxJv/uR6aBOezIPDLiE=; b=L+qFuQSO8I+0+PNsjiX+Mrvzxt uiLkbJHSVRbQnGuRl60jOuquh0IEptlZS9oKjmfPsOTT4GrT9HsugnLNHtW0LCcvTXAH1QHvqeHp2 5mvmIgUzyHRs7EZ5+4KrWk3x3GIIDW6cenbv/yDxlmi9frUp+X8X9axrOSqtJzJG12V6tBK0LfX/a 84NuctHxoYq8PJa1orrRpgb/fCrOzdCvED3DooJK+oK/aQfzJqa1Sc4fpVLUpdFDqCD5GJqb/f+BP WZgx+iY1uQcW1ZLoOa30f9209mBGjLfS1UWm4bNbvelXBhlWZqeoGW4dGFhYQCc9k8LD5XzBXRzFL jSeJZaIA==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by desiato.infradead.org with esmtpsa (Exim 4.94.2 #2 (Red Hat Linux)) id 1mfelT-00CWWK-5N for bpf@vger.kernel.org; Wed, 27 Oct 2021 08:58:31 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id B79B9301998 for ; Wed, 27 Oct 2021 10:58:20 +0200 (CEST) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 0) id A7BA3236E43D9; Wed, 27 Oct 2021 10:58:20 +0200 (CEST) Message-ID: <20211027085520.992974471@infradead.org> User-Agent: quilt/0.66 Date: Wed, 27 Oct 2021 10:52:57 +0200 From: Peter Zijlstra To: bpf@vger.kernel.org Subject: [PATCH bpf-next 14/17] x86/alternative: Add debug prints to apply_retpolines() References: <20211027085243.008677168@infradead.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org X-Patchwork-Delegate: bpf@iogearbox.net Make sure we can see the text changes when booting with 'debug-alternative'. Example output: [ ] SMP alternatives: retpoline at: __traceiter_initcall_level+0x1f/0x30 (ffffffff8100066f) len: 5 to: __x86_indirect_thunk_rax+0x0/0x20 [ ] SMP alternatives: ffffffff82603e58: [2:5) optimized NOPs: ff d0 0f 1f 00 [ ] SMP alternatives: ffffffff8100066f: orig: e8 cc 30 00 01 [ ] SMP alternatives: ffffffff8100066f: repl: ff d0 0f 1f 00 Signed-off-by: Peter Zijlstra (Intel) --- arch/x86/kernel/alternative.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) --- a/arch/x86/kernel/alternative.c +++ b/arch/x86/kernel/alternative.c @@ -492,9 +492,15 @@ void __init_or_module noinline apply_ret continue; } + DPRINTK("retpoline at: %pS (%px) len: %d to: %pS", + addr, addr, insn.length, + addr + insn.length + insn.immediate.value); + len = patch_retpoline(addr, &insn, bytes); if (len == insn.length) { optimize_nops(bytes, len); + DUMP_BYTES(((u8*)addr), len, "%px: orig: ", addr); + DUMP_BYTES(((u8*)bytes), len, "%px: repl: ", addr); text_poke_early(addr, bytes, len); } }