linux/arch/x86/power/hibernate_asm_64.S
Josh Poimboeuf 9077c016a3 x86/power: Support objtool validation in hibernate_asm_64.S
The OBJECT_FILES_NON_STANDARD annotation is used to tell objtool to
ignore a file.  File-level ignores won't work when validating vmlinux.o.

Instead, convert restore_image() and core_restore_code() to be ELF
functions.  Their code is conventional enough for objtool to be able to
understand them.

Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Link: https://lore.kernel.org/r/974f8ceb5385e470f72e93974c70ab5c894bb0dc.1611263462.git.jpoimboe@redhat.com
2021-01-26 11:33:04 -06:00

151 lines
3.7 KiB
ArmAsm

/* SPDX-License-Identifier: GPL-2.0-only */
/*
* Hibernation support for x86-64
*
* Copyright 2007 Rafael J. Wysocki <rjw@sisk.pl>
* Copyright 2005 Andi Kleen <ak@suse.de>
* Copyright 2004 Pavel Machek <pavel@suse.cz>
*
* swsusp_arch_resume must not use any stack or any nonlocal variables while
* copying pages:
*
* Its rewriting one kernel image with another. What is stack in "old"
* image could very well be data page in "new" image, and overwriting
* your own stack under you is bad idea.
*/
.text
#include <linux/linkage.h>
#include <asm/segment.h>
#include <asm/page_types.h>
#include <asm/asm-offsets.h>
#include <asm/processor-flags.h>
#include <asm/frame.h>
#include <asm/nospec-branch.h>
/* code below belongs to the image kernel */
.align PAGE_SIZE
SYM_FUNC_START(restore_registers)
/* go back to the original page tables */
movq %r9, %cr3
/* Flush TLB, including "global" things (vmalloc) */
movq mmu_cr4_features(%rip), %rax
movq %rax, %rdx
andq $~(X86_CR4_PGE), %rdx
movq %rdx, %cr4; # turn off PGE
movq %cr3, %rcx; # flush TLB
movq %rcx, %cr3
movq %rax, %cr4; # turn PGE back on
/* We don't restore %rax, it must be 0 anyway */
movq $saved_context, %rax
movq pt_regs_sp(%rax), %rsp
movq pt_regs_bp(%rax), %rbp
movq pt_regs_si(%rax), %rsi
movq pt_regs_di(%rax), %rdi
movq pt_regs_bx(%rax), %rbx
movq pt_regs_cx(%rax), %rcx
movq pt_regs_dx(%rax), %rdx
movq pt_regs_r8(%rax), %r8
movq pt_regs_r9(%rax), %r9
movq pt_regs_r10(%rax), %r10
movq pt_regs_r11(%rax), %r11
movq pt_regs_r12(%rax), %r12
movq pt_regs_r13(%rax), %r13
movq pt_regs_r14(%rax), %r14
movq pt_regs_r15(%rax), %r15
pushq pt_regs_flags(%rax)
popfq
/* Saved in save_processor_state. */
lgdt saved_context_gdt_desc(%rax)
xorl %eax, %eax
/* tell the hibernation core that we've just restored the memory */
movq %rax, in_suspend(%rip)
ret
SYM_FUNC_END(restore_registers)
SYM_FUNC_START(swsusp_arch_suspend)
movq $saved_context, %rax
movq %rsp, pt_regs_sp(%rax)
movq %rbp, pt_regs_bp(%rax)
movq %rsi, pt_regs_si(%rax)
movq %rdi, pt_regs_di(%rax)
movq %rbx, pt_regs_bx(%rax)
movq %rcx, pt_regs_cx(%rax)
movq %rdx, pt_regs_dx(%rax)
movq %r8, pt_regs_r8(%rax)
movq %r9, pt_regs_r9(%rax)
movq %r10, pt_regs_r10(%rax)
movq %r11, pt_regs_r11(%rax)
movq %r12, pt_regs_r12(%rax)
movq %r13, pt_regs_r13(%rax)
movq %r14, pt_regs_r14(%rax)
movq %r15, pt_regs_r15(%rax)
pushfq
popq pt_regs_flags(%rax)
/* save cr3 */
movq %cr3, %rax
movq %rax, restore_cr3(%rip)
FRAME_BEGIN
call swsusp_save
FRAME_END
ret
SYM_FUNC_END(swsusp_arch_suspend)
SYM_FUNC_START(restore_image)
/* prepare to jump to the image kernel */
movq restore_jump_address(%rip), %r8
movq restore_cr3(%rip), %r9
/* prepare to switch to temporary page tables */
movq temp_pgt(%rip), %rax
movq mmu_cr4_features(%rip), %rbx
/* prepare to copy image data to their original locations */
movq restore_pblist(%rip), %rdx
/* jump to relocated restore code */
movq relocated_restore_code(%rip), %rcx
ANNOTATE_RETPOLINE_SAFE
jmpq *%rcx
SYM_FUNC_END(restore_image)
/* code below has been relocated to a safe page */
SYM_FUNC_START(core_restore_code)
/* switch to temporary page tables */
movq %rax, %cr3
/* flush TLB */
movq %rbx, %rcx
andq $~(X86_CR4_PGE), %rcx
movq %rcx, %cr4; # turn off PGE
movq %cr3, %rcx; # flush TLB
movq %rcx, %cr3;
movq %rbx, %cr4; # turn PGE back on
.Lloop:
testq %rdx, %rdx
jz .Ldone
/* get addresses from the pbe and copy the page */
movq pbe_address(%rdx), %rsi
movq pbe_orig_address(%rdx), %rdi
movq $(PAGE_SIZE >> 3), %rcx
rep
movsq
/* progress to the next pbe */
movq pbe_next(%rdx), %rdx
jmp .Lloop
.Ldone:
/* jump to the restore_registers address from the image header */
ANNOTATE_RETPOLINE_SAFE
jmpq *%r8
SYM_FUNC_END(core_restore_code)