linux/arch/x86/power/hibernate_asm_32.S
Zhimin Gu 8e5b2a3c5a x86-32/asm/power: Create stack frames in hibernate_asm_32.S
swsusp_arch_suspend() is callable non-leaf function which doesn't
honor CONFIG_FRAME_POINTER, which can result in bad stack traces.
Also it's not annotated as ELF callable function which can confuse tooling.

Create a stack frame for it when CONFIG_FRAME_POINTER is enabled and
give it proper ELF function annotation.

Also in this patch introduces the restore_registers() symbol and
gives it ELF function annotation, thus to prepare for later register
restore.

Analogous changes were made for 64bit before in commit ef0f3ed5a4
(x86/asm/power: Create stack frames in hibernate_asm_64.S) and
commit 4ce827b4cc (x86/power/64: Fix hibernation return address
corruption).

Signed-off-by: Zhimin Gu <kookoo.gu@intel.com>
Signed-off-by: Chen Yu <yu.c.chen@intel.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2018-10-03 11:56:33 +02:00

95 lines
1.9 KiB
ArmAsm

/* SPDX-License-Identifier: GPL-2.0 */
/*
* This may not use any stack, nor any variable that is not "NoSave":
*
* 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.
*/
#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>
.text
ENTRY(swsusp_arch_suspend)
movl %esp, saved_context_esp
movl %ebx, saved_context_ebx
movl %ebp, saved_context_ebp
movl %esi, saved_context_esi
movl %edi, saved_context_edi
pushfl
popl saved_context_eflags
FRAME_BEGIN
call swsusp_save
FRAME_END
ret
ENDPROC(swsusp_arch_suspend)
ENTRY(restore_image)
movl mmu_cr4_features, %ecx
movl resume_pg_dir, %eax
subl $__PAGE_OFFSET, %eax
movl %eax, %cr3
jecxz 1f # cr4 Pentium and higher, skip if zero
andl $~(X86_CR4_PGE), %ecx
movl %ecx, %cr4; # turn off PGE
movl %cr3, %eax; # flush TLB
movl %eax, %cr3
1:
movl restore_pblist, %edx
.p2align 4,,7
copy_loop:
testl %edx, %edx
jz done
movl pbe_address(%edx), %esi
movl pbe_orig_address(%edx), %edi
movl $1024, %ecx
rep
movsl
movl pbe_next(%edx), %edx
jmp copy_loop
.p2align 4,,7
done:
/* code below belongs to the image kernel */
.align PAGE_SIZE
ENTRY(restore_registers)
/* go back to the original page tables */
movl $swapper_pg_dir, %eax
subl $__PAGE_OFFSET, %eax
movl %eax, %cr3
movl mmu_cr4_features, %ecx
jecxz 1f # cr4 Pentium and higher, skip if zero
movl %ecx, %cr4; # turn PGE back on
1:
movl saved_context_esp, %esp
movl saved_context_ebp, %ebp
movl saved_context_ebx, %ebx
movl saved_context_esi, %esi
movl saved_context_edi, %edi
pushl saved_context_eflags
popfl
/* Saved in save_processor_state. */
movl $saved_context, %eax
lgdt saved_context_gdt_desc(%eax)
xorl %eax, %eax
ret
ENDPROC(restore_registers)