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https://github.com/FEX-Emu/linux.git
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cc456c4e7c
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>
85 lines
1.7 KiB
ArmAsm
85 lines
1.7 KiB
ArmAsm
/*
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* This may not use any stack, nor any variable that is not "NoSave":
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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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#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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.text
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ENTRY(swsusp_arch_suspend)
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movl %esp, saved_context_esp
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movl %ebx, saved_context_ebx
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movl %ebp, saved_context_ebp
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movl %esi, saved_context_esi
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movl %edi, saved_context_edi
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pushfl
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popl saved_context_eflags
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call swsusp_save
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ret
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ENTRY(restore_image)
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movl mmu_cr4_features, %ecx
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movl resume_pg_dir, %eax
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subl $__PAGE_OFFSET, %eax
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movl %eax, %cr3
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jecxz 1f # cr4 Pentium and higher, skip if zero
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andl $~(X86_CR4_PGE), %ecx
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movl %ecx, %cr4; # turn off PGE
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movl %cr3, %eax; # flush TLB
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movl %eax, %cr3
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1:
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movl restore_pblist, %edx
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.p2align 4,,7
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copy_loop:
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testl %edx, %edx
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jz done
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movl pbe_address(%edx), %esi
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movl pbe_orig_address(%edx), %edi
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movl $1024, %ecx
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rep
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movsl
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movl pbe_next(%edx), %edx
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jmp copy_loop
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.p2align 4,,7
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done:
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/* go back to the original page tables */
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movl $swapper_pg_dir, %eax
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subl $__PAGE_OFFSET, %eax
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movl %eax, %cr3
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movl mmu_cr4_features, %ecx
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jecxz 1f # cr4 Pentium and higher, skip if zero
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movl %ecx, %cr4; # turn PGE back on
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1:
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movl saved_context_esp, %esp
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movl saved_context_ebp, %ebp
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movl saved_context_ebx, %ebx
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movl saved_context_esi, %esi
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movl saved_context_edi, %edi
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pushl saved_context_eflags
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popfl
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/* Saved in save_processor_state. */
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movl $saved_context, %eax
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lgdt saved_context_gdt_desc(%eax)
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xorl %eax, %eax
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ret
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