ffa64eff95
Srinivas Pandruvada reported a problem with system resume from suspend-to-RAM on 32-bit x86 systems where the DS register of the CPU is set to __KERNEL_DS instead of __USER_DS on return to user space which cases a General Protection Fault to occur. The issue is that DS is set to __KERNEL_DS by the ACPI resume code path while the SYSEXIT path never reloads DS/ES. It assumes they are still __USER_DS set at the SYSENTER time (Brian Gerst), so if the return to user space happens to be through SYSEXIT, it will lead to the reported GPF. Fix the problem by setting the DS and ES registers to __USER_DS as expected by the SYSEXIT path. Link: https://bugzilla.kernel.org/show_bug.cgi?id=61781 Link: http://marc.info/?l=linux-pm&m=143406648920385&w=2 Acked-by: Pavel Machek <pavel@ucw.cz> Tested-by: Pavel Machek <pavel@ucw.cz> Acked-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
100 lines
1.7 KiB
ArmAsm
100 lines
1.7 KiB
ArmAsm
.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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# Copyright 2003, 2008 Pavel Machek <pavel@suse.cz>, distribute under GPLv2
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.code32
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ALIGN
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ENTRY(wakeup_pmode_return)
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wakeup_pmode_return:
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movw $__KERNEL_DS, %ax
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movw %ax, %ss
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movw %ax, %fs
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movw %ax, %gs
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movw $__USER_DS, %ax
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movw %ax, %ds
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movw %ax, %es
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# reload the gdt, as we need the full 32 bit address
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lidt saved_idt
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lldt saved_ldt
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ljmp $(__KERNEL_CS), $1f
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1:
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movl %cr3, %eax
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movl %eax, %cr3
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wbinvd
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# and restore the stack ... but you need gdt for this to work
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movl saved_context_esp, %esp
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movl %cs:saved_magic, %eax
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cmpl $0x12345678, %eax
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jne bogus_magic
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# jump to place where we left off
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movl saved_eip, %eax
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jmp *%eax
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bogus_magic:
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jmp bogus_magic
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save_registers:
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sidt saved_idt
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sldt saved_ldt
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str saved_tss
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leal 4(%esp), %eax
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movl %eax, 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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movl $ret_point, saved_eip
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ret
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restore_registers:
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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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ret
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ENTRY(do_suspend_lowlevel)
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call save_processor_state
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call save_registers
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pushl $3
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call x86_acpi_enter_sleep_state
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addl $4, %esp
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# In case of S3 failure, we'll emerge here. Jump
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# to ret_point to recover
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jmp ret_point
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.p2align 4,,7
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ret_point:
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call restore_registers
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call restore_processor_state
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ret
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.data
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ALIGN
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ENTRY(saved_magic) .long 0
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ENTRY(saved_eip) .long 0
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# saved registers
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saved_idt: .long 0,0
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saved_ldt: .long 0
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saved_tss: .long 0
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