diff options
Diffstat (limited to 'arch/x86/kernel/relocate_kernel_32.S')
| -rw-r--r-- | arch/x86/kernel/relocate_kernel_32.S | 48 |
1 files changed, 31 insertions, 17 deletions
diff --git a/arch/x86/kernel/relocate_kernel_32.S b/arch/x86/kernel/relocate_kernel_32.S index e13f8e7c22a6..57276f134d12 100644 --- a/arch/x86/kernel/relocate_kernel_32.S +++ b/arch/x86/kernel/relocate_kernel_32.S @@ -1,18 +1,18 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ /* * relocate_kernel.S - put the kernel image in place to boot * Copyright (C) 2002-2004 Eric Biederman <ebiederm@xmission.com> - * - * This source code is licensed under the GNU General Public License, - * Version 2. See the file COPYING for more details. */ #include <linux/linkage.h> #include <asm/page_types.h> #include <asm/kexec.h> +#include <asm/nospec-branch.h> #include <asm/processor-flags.h> /* - * 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) @@ -37,8 +37,7 @@ #define CP_PA_BACKUP_PAGES_MAP DATA(0x1c) .text - .globl relocate_kernel -relocate_kernel: +SYM_CODE_START_NOALIGN(relocate_kernel) /* Save the CPU context, used for jumping back */ pushl %ebx @@ -94,9 +93,12 @@ relocate_kernel: movl %edi, %eax addl $(identity_mapped - relocate_kernel), %eax pushl %eax + ANNOTATE_UNRET_SAFE ret + int3 +SYM_CODE_END(relocate_kernel) -identity_mapped: +SYM_CODE_START_LOCAL_NOALIGN(identity_mapped) /* set return address to 0 if not preserving context */ pushl $0 /* store the start address on the stack */ @@ -109,7 +111,7 @@ identity_mapped: * - Write protect disabled * - No task switch * - Don't do FP software emulation. - * - Proctected mode enabled + * - Protected mode enabled */ movl %cr0, %eax andl $~(X86_CR0_PG | X86_CR0_AM | X86_CR0_WP | X86_CR0_TS | X86_CR0_EM), %eax @@ -161,12 +163,15 @@ identity_mapped: xorl %edx, %edx xorl %esi, %esi xorl %ebp, %ebp + 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 */ @@ -192,9 +197,12 @@ identity_mapped: movl %edi, %eax addl $(virtual_mapped - relocate_kernel), %eax pushl %eax + ANNOTATE_UNRET_SAFE ret + int3 +SYM_CODE_END(identity_mapped) -virtual_mapped: +SYM_CODE_START_LOCAL_NOALIGN(virtual_mapped) movl CR4(%edi), %eax movl %eax, %cr4 movl CR3(%edi), %eax @@ -209,10 +217,13 @@ virtual_mapped: popl %edi popl %esi popl %ebx + ANNOTATE_UNRET_SAFE ret + int3 +SYM_CODE_END(virtual_mapped) /* Do the copies */ -swap_pages: +SYM_CODE_START_LOCAL_NOALIGN(swap_pages) movl 8(%esp), %edx movl 4(%esp), %ecx pushl %ebp @@ -226,23 +237,23 @@ swap_pages: movl (%ebx), %ecx addl $4, %ebx 1: - testl $0x1, %ecx /* is it a destination page */ + testb $0x1, %cl /* is it a destination page */ jz 2f movl %ecx, %edi andl $0xfffff000, %edi jmp 0b 2: - testl $0x2, %ecx /* is it an indirection page */ + testb $0x2, %cl /* is it an indirection page */ jz 2f movl %ecx, %ebx andl $0xfffff000, %ebx jmp 0b 2: - testl $0x4, %ecx /* is it the done indicator */ + testb $0x4, %cl /* is it the done indicator */ jz 2f jmp 3f 2: - testl $0x8, %ecx /* is it the source indicator */ + testb $0x8, %cl /* is it the source indicator */ jz 0b /* Ignore it otherwise */ movl %ecx, %esi /* For every source page do a copy */ andl $0xfffff000, %esi @@ -252,17 +263,17 @@ swap_pages: movl %edx, %edi movl $1024, %ecx - rep ; movsl + rep movsl movl %ebp, %edi movl %eax, %esi movl $1024, %ecx - rep ; movsl + rep movsl movl %eax, %edi movl %edx, %esi movl $1024, %ecx - rep ; movsl + rep movsl lea PAGE_SIZE(%ebp), %esi jmp 0b @@ -271,7 +282,10 @@ swap_pages: popl %edi popl %ebx popl %ebp + ANNOTATE_UNRET_SAFE ret + int3 +SYM_CODE_END(swap_pages) .globl kexec_control_code_size .set kexec_control_code_size, . - relocate_kernel |