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 1BC27C43334 for ; Wed, 20 Jul 2022 01:21:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241643AbiGTBVR (ORCPT ); Tue, 19 Jul 2022 21:21:17 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48514 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241362AbiGTBT5 (ORCPT ); Tue, 19 Jul 2022 21:19:57 -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 32B7769F03; Tue, 19 Jul 2022 18:16:02 -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 E940B617EC; Wed, 20 Jul 2022 01:16:00 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id AEAA9C341C6; Wed, 20 Jul 2022 01:15:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1658279760; bh=1U3MoXaHg97XVksfWF7PC+ecrd9t1aS1+YbqjhckeKk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=U50hLjrW6bppgmzK3AAzW2sp96fqkK5rCfLsBfzQUA4dICJjdf0XzgnnT+lu/95Q7 FsSg9Kp2VLtzjKnmhAeB8GvDRCnbC6OuBlf4dDRC5BnwbXziDZ0avGz4bn48IqYcAB g2CYN3h52sQ+6NDLsJprJVlC9TALK+SdU4jAYUoJ7hRqvXR5nSiBdv0n9p2G06QNxe ZzwzMzeL/4EacNJLDD3BgBFCxrzqItiOS9LDrgIQBjr5JwXvsthw23ZB8NdR1PT8ED VCvkpYJv/EAeR/uo28lS91Pv7lPcvGTTluf3S6F8rOHFNRnyFX1CwGjhsuKHw1Jzob A+I02Th8Y69gA== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Konrad Rzeszutek Wilk , Edward Tran , Awais Tanveer , Ankur Arora , Alexandre Chartre , Borislav Petkov , Sasha Levin , tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, x86@kernel.org, peterz@infradead.org, jpoimboe@kernel.org, thomas.lendacky@amd.com Subject: [PATCH AUTOSEL 5.15 35/42] x86/kexec: Disable RET on kexec Date: Tue, 19 Jul 2022 21:13:43 -0400 Message-Id: <20220720011350.1024134-35-sashal@kernel.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220720011350.1024134-1-sashal@kernel.org> References: <20220720011350.1024134-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Konrad Rzeszutek Wilk [ Upstream commit 697977d8415d61f3acbc4ee6d564c9dcf0309507 ] 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: Sasha Levin --- arch/x86/kernel/relocate_kernel_32.S | 25 +++++++++++++++++++------ arch/x86/kernel/relocate_kernel_64.S | 23 +++++++++++++++++------ 2 files changed, 36 insertions(+), 12 deletions(-) diff --git a/arch/x86/kernel/relocate_kernel_32.S b/arch/x86/kernel/relocate_kernel_32.S index fcc8a7699103..c7c4b1917336 100644 --- 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_mapped) 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_mapped) 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_mapped) 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 diff --git a/arch/x86/kernel/relocate_kernel_64.S b/arch/x86/kernel/relocate_kernel_64.S index 5019091af059..8a9cea950e39 100644 --- 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_mapped) 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_mapped) 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_mapped) 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 -- 2.35.1