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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1CBDFC43334 for ; Fri, 22 Jul 2022 09:19:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235862AbiGVJT4 (ORCPT ); Fri, 22 Jul 2022 05:19:56 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50874 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235937AbiGVJTG (ORCPT ); Fri, 22 Jul 2022 05:19:06 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B5841BA4C0; Fri, 22 Jul 2022 02:13:14 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id E3F0761F63; Fri, 22 Jul 2022 09:13:13 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id E9F32C341C6; Fri, 22 Jul 2022 09:13:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1658481193; bh=PGRmaAe/AdS2PihBF4QvoD0vhgDljbzkBc5aceuTT1M=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=RuHleC/U06FQVXUsZOoV0XTvttA5wa1uyX+DvVrHqifhHonY0AaUk4m3HLciyiQ3H iBIAi7CTmZohxTlWqZh1wTLpk21imP+n8K0bI/urGzhrGBgclg+IgHeqC7Wes0pRm0 DuYUmBu9z9xYaRdi2ueCyB3UcwmhTu42YsuuqBxo= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, "Peter Zijlstra (Intel)" , Borislav Petkov , Josh Poimboeuf , Thadeu Lima de Souza Cascardo Subject: [PATCH 5.15 27/89] x86/retpoline: Swizzle retpoline thunk Date: Fri, 22 Jul 2022 11:11:01 +0200 Message-Id: <20220722091134.887305367@linuxfoundation.org> X-Mailer: git-send-email 2.37.1 In-Reply-To: <20220722091133.320803732@linuxfoundation.org> References: <20220722091133.320803732@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Peter Zijlstra commit 00e1533325fd1fb5459229fe37f235462649f668 upstream. Put the actual retpoline thunk as the original code so that it can become more complicated. Specifically, it allows RET to be a JMP, which can't be .altinstr_replacement since that doesn't do relocations (except for the very first instruction). Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Borislav Petkov Reviewed-by: Borislav Petkov Reviewed-by: Josh Poimboeuf Signed-off-by: Borislav Petkov Signed-off-by: Thadeu Lima de Souza Cascardo Signed-off-by: Greg Kroah-Hartman --- arch/x86/lib/retpoline.S | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) --- a/arch/x86/lib/retpoline.S +++ b/arch/x86/lib/retpoline.S @@ -32,9 +32,9 @@ SYM_INNER_LABEL(__x86_indirect_thunk_\reg, SYM_L_GLOBAL) UNWIND_HINT_EMPTY - ALTERNATIVE_2 __stringify(ANNOTATE_RETPOLINE_SAFE; jmp *%\reg), \ - __stringify(RETPOLINE \reg), X86_FEATURE_RETPOLINE, \ - __stringify(lfence; ANNOTATE_RETPOLINE_SAFE; jmp *%\reg; int3), X86_FEATURE_RETPOLINE_LFENCE + ALTERNATIVE_2 __stringify(RETPOLINE \reg), \ + __stringify(lfence; ANNOTATE_RETPOLINE_SAFE; jmp *%\reg; int3), X86_FEATURE_RETPOLINE_LFENCE, \ + __stringify(ANNOTATE_RETPOLINE_SAFE; jmp *%\reg), ALT_NOT(X86_FEATURE_RETPOLINE) .endm