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 CC9C8C433EF for ; Sat, 23 Jul 2022 10:12:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238656AbiGWKMa (ORCPT ); Sat, 23 Jul 2022 06:12:30 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43202 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239373AbiGWKJf (ORCPT ); Sat, 23 Jul 2022 06:09:35 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 954C58149C; Sat, 23 Jul 2022 03:02:43 -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 ams.source.kernel.org (Postfix) with ESMTPS id B0BE2B82C1A; Sat, 23 Jul 2022 10:02:40 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 23109C341C7; Sat, 23 Jul 2022 10:02:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1658570559; bh=6ZJiZorj7WVCzB1nyaRhoBZ6f67OnAAunAmOUTsjtKA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=EFNio/uUjUMiCyS+KCVhcEHeYEoE84p7CMbRtl7qkYkwWS60lHpcwLsOlMNb+PmQ5 8VH3ADEUXtI7Zq96YvDPYGe4pqlbQJ0nbPN+e/Dd5eCfI2nuNaim4RA3nMSIUPkKYC 1C9d7fL5GsXhUEYxpbVN6D1Q+sBDRK14FuDg35x8= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Edward Tran , Awais Tanveer , Ankur Arora , Konrad Rzeszutek Wilk , Alexandre Chartre , Borislav Petkov , Ben Hutchings Subject: [PATCH 5.10 128/148] x86/kexec: Disable RET on kexec Date: Sat, 23 Jul 2022 11:55:40 +0200 Message-Id: <20220723095300.164230742@linuxfoundation.org> X-Mailer: git-send-email 2.37.1 In-Reply-To: <20220723095224.302504400@linuxfoundation.org> References: <20220723095224.302504400@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: Konrad Rzeszutek Wilk commit 697977d8415d61f3acbc4ee6d564c9dcf0309507 upstream. All the invocations unroll to __x86_return_thunk and this file must be PIC independent. This fixes kexec on 64-bit AMD boxes. [ bp: Fix 32-bit build. ] Reported-by: Edward Tran Reported-by: Awais Tanveer Suggested-by: Ankur Arora Signed-off-by: Konrad Rzeszutek Wilk Signed-off-by: Alexandre Chartre Signed-off-by: Borislav Petkov Signed-off-by: Ben Hutchings Signed-off-by: Greg Kroah-Hartman --- arch/x86/kernel/relocate_kernel_32.S | 25 +++++++++++++++++++------ arch/x86/kernel/relocate_kernel_64.S | 23 +++++++++++++++++------ 2 files changed, 36 insertions(+), 12 deletions(-) --- a/arch/x86/kernel/relocate_kernel_32.S +++ b/arch/x86/kernel/relocate_kernel_32.S @@ -7,10 +7,12 @@ #include #include #include +#include #include /* - * Must be relocatable PIC code callable as a C function + * Must be relocatable PIC code callable as a C function, in particular + * there must be a plain RET and not jump to return thunk. */ #define PTR(x) (x << 2) @@ -91,7 +93,9 @@ SYM_CODE_START_NOALIGN(relocate_kernel) movl %edi, %eax addl $(identity_mapped - relocate_kernel), %eax pushl %eax - RET + ANNOTATE_UNRET_SAFE + ret + int3 SYM_CODE_END(relocate_kernel) SYM_CODE_START_LOCAL_NOALIGN(identity_mapped) @@ -159,12 +163,15 @@ SYM_CODE_START_LOCAL_NOALIGN(identity_ma xorl %edx, %edx xorl %esi, %esi xorl %ebp, %ebp - RET + ANNOTATE_UNRET_SAFE + ret + int3 1: popl %edx movl CP_PA_SWAP_PAGE(%edi), %esp addl $PAGE_SIZE, %esp 2: + ANNOTATE_RETPOLINE_SAFE call *%edx /* get the re-entry point of the peer system */ @@ -190,7 +197,9 @@ SYM_CODE_START_LOCAL_NOALIGN(identity_ma movl %edi, %eax addl $(virtual_mapped - relocate_kernel), %eax pushl %eax - RET + ANNOTATE_UNRET_SAFE + ret + int3 SYM_CODE_END(identity_mapped) SYM_CODE_START_LOCAL_NOALIGN(virtual_mapped) @@ -208,7 +217,9 @@ SYM_CODE_START_LOCAL_NOALIGN(virtual_map popl %edi popl %esi popl %ebx - RET + ANNOTATE_UNRET_SAFE + ret + int3 SYM_CODE_END(virtual_mapped) /* Do the copies */ @@ -271,7 +282,9 @@ SYM_CODE_START_LOCAL_NOALIGN(swap_pages) popl %edi popl %ebx popl %ebp - RET + ANNOTATE_UNRET_SAFE + ret + int3 SYM_CODE_END(swap_pages) .globl kexec_control_code_size --- a/arch/x86/kernel/relocate_kernel_64.S +++ b/arch/x86/kernel/relocate_kernel_64.S @@ -13,7 +13,8 @@ #include /* - * Must be relocatable PIC code callable as a C function + * Must be relocatable PIC code callable as a C function, in particular + * there must be a plain RET and not jump to return thunk. */ #define PTR(x) (x << 3) @@ -104,7 +105,9 @@ SYM_CODE_START_NOALIGN(relocate_kernel) /* jump to identity mapped page */ addq $(identity_mapped - relocate_kernel), %r8 pushq %r8 - RET + ANNOTATE_UNRET_SAFE + ret + int3 SYM_CODE_END(relocate_kernel) SYM_CODE_START_LOCAL_NOALIGN(identity_mapped) @@ -191,7 +194,9 @@ SYM_CODE_START_LOCAL_NOALIGN(identity_ma xorl %r14d, %r14d xorl %r15d, %r15d - RET + ANNOTATE_UNRET_SAFE + ret + int3 1: popq %rdx @@ -210,7 +215,9 @@ SYM_CODE_START_LOCAL_NOALIGN(identity_ma call swap_pages movq $virtual_mapped, %rax pushq %rax - RET + ANNOTATE_UNRET_SAFE + ret + int3 SYM_CODE_END(identity_mapped) SYM_CODE_START_LOCAL_NOALIGN(virtual_mapped) @@ -231,7 +238,9 @@ SYM_CODE_START_LOCAL_NOALIGN(virtual_map popq %r12 popq %rbp popq %rbx - RET + ANNOTATE_UNRET_SAFE + ret + int3 SYM_CODE_END(virtual_mapped) /* Do the copies */ @@ -288,7 +297,9 @@ SYM_CODE_START_LOCAL_NOALIGN(swap_pages) lea PAGE_SIZE(%rax), %rsi jmp 0b 3: - RET + ANNOTATE_UNRET_SAFE + ret + int3 SYM_CODE_END(swap_pages) .globl kexec_control_code_size