The git commite7a5cd063c7b4c58417f674821d63f5eb6747e37
("x86-64, gdt: Store/load GDT for ACPI S3 or hibernate/resume path
is not needed.") assumes that for the hibernate path the booting
kernel and the resuming kernel MUST be the same. That is certainly
the case for a 32-bit kernel (see check_image_kernel and
CONFIG_ARCH_HIBERNATION_HEADER config option).
However for 64-bit kernels it is OK to have a different kernel
version (and size of the image) of the booting and resuming kernels.
Hence the above mentioned git commit introduces an regression.
This patch fixes it by introducing a 'struct desc_ptr gdt_desc'
back in the 'struct saved_context'. However instead of having in the
'save_processor_state' and 'restore_processor_state' the
store/load_gdt calls, we are only saving the GDT in the
save_processor_state.
For the restore path the lgdt operation is done in
hibernate_asm_[32|64].S in the 'restore_registers' path.
The apt reader of this description will recognize that only 64-bit
kernels need this treatment, not 32-bit. This patch adds the logic
in the 32-bit path to be more similar to 64-bit so that in the future
the unification process can take advantage of this.
[ hpa: this also reverts an inadvertent on-disk format change ]
Suggested-by: "H. Peter Anvin" <hpa@zytor.com>
Acked-by: "Rafael J. Wysocki" <rjw@sisk.pl>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Link: http://lkml.kernel.org/r/1367459610-9656-2-git-send-email-konrad.wilk@oracle.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
		
	
			
		
			
				
	
	
		
			150 lines
		
	
	
	
		
			3.9 KiB
			
		
	
	
	
		
			ArmAsm
		
	
	
	
	
	
			
		
		
	
	
			150 lines
		
	
	
	
		
			3.9 KiB
			
		
	
	
	
		
			ArmAsm
		
	
	
	
	
	
/*
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 * Hibernation support for x86-64
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 *
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 * Distribute under GPLv2.
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 *
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 * Copyright 2007 Rafael J. Wysocki <rjw@sisk.pl>
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 * Copyright 2005 Andi Kleen <ak@suse.de>
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 * Copyright 2004 Pavel Machek <pavel@suse.cz>
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 *
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 * swsusp_arch_resume must not use any stack or any nonlocal variables while
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 * copying pages:
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 *
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 * Its rewriting one kernel image with another. What is stack in "old"
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 * image could very well be data page in "new" image, and overwriting
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 * your own stack under you is bad idea.
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 */
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	.text
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#include <linux/linkage.h>
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#include <asm/segment.h>
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#include <asm/page_types.h>
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#include <asm/asm-offsets.h>
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#include <asm/processor-flags.h>
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ENTRY(swsusp_arch_suspend)
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	movq	$saved_context, %rax
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	movq	%rsp, pt_regs_sp(%rax)
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	movq	%rbp, pt_regs_bp(%rax)
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	movq	%rsi, pt_regs_si(%rax)
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	movq	%rdi, pt_regs_di(%rax)
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	movq	%rbx, pt_regs_bx(%rax)
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	movq	%rcx, pt_regs_cx(%rax)
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	movq	%rdx, pt_regs_dx(%rax)
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	movq	%r8, pt_regs_r8(%rax)
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	movq	%r9, pt_regs_r9(%rax)
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	movq	%r10, pt_regs_r10(%rax)
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	movq	%r11, pt_regs_r11(%rax)
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	movq	%r12, pt_regs_r12(%rax)
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	movq	%r13, pt_regs_r13(%rax)
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	movq	%r14, pt_regs_r14(%rax)
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	movq	%r15, pt_regs_r15(%rax)
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	pushfq
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	popq	pt_regs_flags(%rax)
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	/* save the address of restore_registers */
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	movq	$restore_registers, %rax
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	movq	%rax, restore_jump_address(%rip)
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	/* save cr3 */
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	movq	%cr3, %rax
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	movq	%rax, restore_cr3(%rip)
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	call swsusp_save
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	ret
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ENTRY(restore_image)
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	/* switch to temporary page tables */
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	movq	$__PAGE_OFFSET, %rdx
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	movq	temp_level4_pgt(%rip), %rax
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	subq	%rdx, %rax
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	movq	%rax, %cr3
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	/* Flush TLB */
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	movq	mmu_cr4_features(%rip), %rax
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	movq	%rax, %rdx
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	andq	$~(X86_CR4_PGE), %rdx
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	movq	%rdx, %cr4;  # turn off PGE
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	movq	%cr3, %rcx;  # flush TLB
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	movq	%rcx, %cr3;
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	movq	%rax, %cr4;  # turn PGE back on
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	/* prepare to jump to the image kernel */
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	movq	restore_jump_address(%rip), %rax
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	movq	restore_cr3(%rip), %rbx
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	/* prepare to copy image data to their original locations */
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	movq	restore_pblist(%rip), %rdx
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	movq	relocated_restore_code(%rip), %rcx
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	jmpq	*%rcx
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	/* code below has been relocated to a safe page */
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ENTRY(core_restore_code)
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loop:
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	testq	%rdx, %rdx
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	jz	done
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	/* get addresses from the pbe and copy the page */
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	movq	pbe_address(%rdx), %rsi
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	movq	pbe_orig_address(%rdx), %rdi
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	movq	$(PAGE_SIZE >> 3), %rcx
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	rep
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	movsq
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	/* progress to the next pbe */
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	movq	pbe_next(%rdx), %rdx
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	jmp	loop
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done:
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	/* jump to the restore_registers address from the image header */
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	jmpq	*%rax
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	/*
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	 * NOTE: This assumes that the boot kernel's text mapping covers the
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	 * image kernel's page containing restore_registers and the address of
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	 * this page is the same as in the image kernel's text mapping (it
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	 * should always be true, because the text mapping is linear, starting
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	 * from 0, and is supposed to cover the entire kernel text for every
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	 * kernel).
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	 *
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	 * code below belongs to the image kernel
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	 */
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ENTRY(restore_registers)
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	/* go back to the original page tables */
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	movq    %rbx, %cr3
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	/* Flush TLB, including "global" things (vmalloc) */
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	movq	mmu_cr4_features(%rip), %rax
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	movq	%rax, %rdx
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	andq	$~(X86_CR4_PGE), %rdx
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	movq	%rdx, %cr4;  # turn off PGE
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	movq	%cr3, %rcx;  # flush TLB
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	movq	%rcx, %cr3
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	movq	%rax, %cr4;  # turn PGE back on
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	/* We don't restore %rax, it must be 0 anyway */
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	movq	$saved_context, %rax
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	movq	pt_regs_sp(%rax), %rsp
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	movq	pt_regs_bp(%rax), %rbp
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	movq	pt_regs_si(%rax), %rsi
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	movq	pt_regs_di(%rax), %rdi
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	movq	pt_regs_bx(%rax), %rbx
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	movq	pt_regs_cx(%rax), %rcx
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	movq	pt_regs_dx(%rax), %rdx
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	movq	pt_regs_r8(%rax), %r8
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	movq	pt_regs_r9(%rax), %r9
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	movq	pt_regs_r10(%rax), %r10
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	movq	pt_regs_r11(%rax), %r11
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	movq	pt_regs_r12(%rax), %r12
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	movq	pt_regs_r13(%rax), %r13
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	movq	pt_regs_r14(%rax), %r14
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	movq	pt_regs_r15(%rax), %r15
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	pushq	pt_regs_flags(%rax)
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	popfq
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	/* Saved in save_processor_state. */
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	lgdt	saved_context_gdt_desc(%rax)
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	xorq	%rax, %rax
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	/* tell the hibernation core that we've just restored the memory */
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	movq	%rax, in_suspend(%rip)
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	ret
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