38e20b07ef
Set the callback to receive evtchns from Xen, using the callback vector delivery mechanism. The traditional way for receiving event channel notifications from Xen is via the interrupts from the platform PCI device. The callback vector is a newer alternative that allow us to receive notifications on any vcpu and doesn't need any PCI support: we allocate a vector exclusively to receive events, in the vector handler we don't need to interact with the vlapic, therefore we avoid a VMEXIT. Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Signed-off-by: Sheng Yang <sheng@linux.intel.com> Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
1504 lines
33 KiB
ArmAsm
1504 lines
33 KiB
ArmAsm
/*
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*
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* Copyright (C) 1991, 1992 Linus Torvalds
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*/
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/*
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* entry.S contains the system-call and fault low-level handling routines.
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* This also contains the timer-interrupt handler, as well as all interrupts
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* and faults that can result in a task-switch.
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*
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* NOTE: This code handles signal-recognition, which happens every time
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* after a timer-interrupt and after each system call.
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*
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* I changed all the .align's to 4 (16 byte alignment), as that's faster
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* on a 486.
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*
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* Stack layout in 'syscall_exit':
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* ptrace needs to have all regs on the stack.
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* if the order here is changed, it needs to be
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* updated in fork.c:copy_process, signal.c:do_signal,
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* ptrace.c and ptrace.h
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*
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* 0(%esp) - %ebx
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* 4(%esp) - %ecx
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* 8(%esp) - %edx
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* C(%esp) - %esi
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* 10(%esp) - %edi
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* 14(%esp) - %ebp
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* 18(%esp) - %eax
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* 1C(%esp) - %ds
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* 20(%esp) - %es
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* 24(%esp) - %fs
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* 28(%esp) - %gs saved iff !CONFIG_X86_32_LAZY_GS
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* 2C(%esp) - orig_eax
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* 30(%esp) - %eip
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* 34(%esp) - %cs
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* 38(%esp) - %eflags
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* 3C(%esp) - %oldesp
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* 40(%esp) - %oldss
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*
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* "current" is in register %ebx during any slow entries.
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*/
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#include <linux/linkage.h>
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#include <asm/thread_info.h>
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#include <asm/irqflags.h>
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#include <asm/errno.h>
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#include <asm/segment.h>
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#include <asm/smp.h>
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#include <asm/page_types.h>
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#include <asm/percpu.h>
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#include <asm/dwarf2.h>
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#include <asm/processor-flags.h>
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#include <asm/ftrace.h>
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#include <asm/irq_vectors.h>
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#include <asm/cpufeature.h>
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/* Avoid __ASSEMBLER__'ifying <linux/audit.h> just for this. */
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#include <linux/elf-em.h>
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#define AUDIT_ARCH_I386 (EM_386|__AUDIT_ARCH_LE)
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#define __AUDIT_ARCH_LE 0x40000000
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#ifndef CONFIG_AUDITSYSCALL
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#define sysenter_audit syscall_trace_entry
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#define sysexit_audit syscall_exit_work
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#endif
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/*
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* We use macros for low-level operations which need to be overridden
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* for paravirtualization. The following will never clobber any registers:
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* INTERRUPT_RETURN (aka. "iret")
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* GET_CR0_INTO_EAX (aka. "movl %cr0, %eax")
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* ENABLE_INTERRUPTS_SYSEXIT (aka "sti; sysexit").
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*
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* For DISABLE_INTERRUPTS/ENABLE_INTERRUPTS (aka "cli"/"sti"), you must
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* specify what registers can be overwritten (CLBR_NONE, CLBR_EAX/EDX/ECX/ANY).
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* Allowing a register to be clobbered can shrink the paravirt replacement
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* enough to patch inline, increasing performance.
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*/
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#define nr_syscalls ((syscall_table_size)/4)
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#ifdef CONFIG_PREEMPT
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#define preempt_stop(clobbers) DISABLE_INTERRUPTS(clobbers); TRACE_IRQS_OFF
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#else
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#define preempt_stop(clobbers)
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#define resume_kernel restore_all
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#endif
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.macro TRACE_IRQS_IRET
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#ifdef CONFIG_TRACE_IRQFLAGS
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testl $X86_EFLAGS_IF,PT_EFLAGS(%esp) # interrupts off?
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jz 1f
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TRACE_IRQS_ON
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1:
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#endif
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.endm
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#ifdef CONFIG_VM86
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#define resume_userspace_sig check_userspace
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#else
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#define resume_userspace_sig resume_userspace
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#endif
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/*
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* User gs save/restore
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*
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* %gs is used for userland TLS and kernel only uses it for stack
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* canary which is required to be at %gs:20 by gcc. Read the comment
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* at the top of stackprotector.h for more info.
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*
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* Local labels 98 and 99 are used.
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*/
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#ifdef CONFIG_X86_32_LAZY_GS
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/* unfortunately push/pop can't be no-op */
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.macro PUSH_GS
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pushl $0
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CFI_ADJUST_CFA_OFFSET 4
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.endm
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.macro POP_GS pop=0
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addl $(4 + \pop), %esp
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CFI_ADJUST_CFA_OFFSET -(4 + \pop)
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.endm
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.macro POP_GS_EX
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.endm
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/* all the rest are no-op */
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.macro PTGS_TO_GS
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.endm
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.macro PTGS_TO_GS_EX
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.endm
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.macro GS_TO_REG reg
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.endm
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.macro REG_TO_PTGS reg
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.endm
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.macro SET_KERNEL_GS reg
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.endm
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#else /* CONFIG_X86_32_LAZY_GS */
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.macro PUSH_GS
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pushl %gs
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CFI_ADJUST_CFA_OFFSET 4
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/*CFI_REL_OFFSET gs, 0*/
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.endm
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.macro POP_GS pop=0
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98: popl %gs
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CFI_ADJUST_CFA_OFFSET -4
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/*CFI_RESTORE gs*/
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.if \pop <> 0
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add $\pop, %esp
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CFI_ADJUST_CFA_OFFSET -\pop
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.endif
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.endm
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.macro POP_GS_EX
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.pushsection .fixup, "ax"
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99: movl $0, (%esp)
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jmp 98b
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.section __ex_table, "a"
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.align 4
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.long 98b, 99b
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.popsection
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.endm
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.macro PTGS_TO_GS
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98: mov PT_GS(%esp), %gs
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.endm
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.macro PTGS_TO_GS_EX
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.pushsection .fixup, "ax"
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99: movl $0, PT_GS(%esp)
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jmp 98b
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.section __ex_table, "a"
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.align 4
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.long 98b, 99b
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.popsection
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.endm
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.macro GS_TO_REG reg
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movl %gs, \reg
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/*CFI_REGISTER gs, \reg*/
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.endm
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.macro REG_TO_PTGS reg
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movl \reg, PT_GS(%esp)
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/*CFI_REL_OFFSET gs, PT_GS*/
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.endm
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.macro SET_KERNEL_GS reg
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movl $(__KERNEL_STACK_CANARY), \reg
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movl \reg, %gs
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.endm
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#endif /* CONFIG_X86_32_LAZY_GS */
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.macro SAVE_ALL
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cld
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PUSH_GS
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pushl %fs
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CFI_ADJUST_CFA_OFFSET 4
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/*CFI_REL_OFFSET fs, 0;*/
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pushl %es
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CFI_ADJUST_CFA_OFFSET 4
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/*CFI_REL_OFFSET es, 0;*/
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pushl %ds
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CFI_ADJUST_CFA_OFFSET 4
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/*CFI_REL_OFFSET ds, 0;*/
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pushl %eax
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CFI_ADJUST_CFA_OFFSET 4
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CFI_REL_OFFSET eax, 0
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pushl %ebp
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CFI_ADJUST_CFA_OFFSET 4
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CFI_REL_OFFSET ebp, 0
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pushl %edi
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CFI_ADJUST_CFA_OFFSET 4
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CFI_REL_OFFSET edi, 0
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pushl %esi
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CFI_ADJUST_CFA_OFFSET 4
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CFI_REL_OFFSET esi, 0
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pushl %edx
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CFI_ADJUST_CFA_OFFSET 4
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CFI_REL_OFFSET edx, 0
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pushl %ecx
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CFI_ADJUST_CFA_OFFSET 4
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CFI_REL_OFFSET ecx, 0
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pushl %ebx
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CFI_ADJUST_CFA_OFFSET 4
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CFI_REL_OFFSET ebx, 0
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movl $(__USER_DS), %edx
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movl %edx, %ds
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movl %edx, %es
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movl $(__KERNEL_PERCPU), %edx
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movl %edx, %fs
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SET_KERNEL_GS %edx
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.endm
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.macro RESTORE_INT_REGS
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popl %ebx
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CFI_ADJUST_CFA_OFFSET -4
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CFI_RESTORE ebx
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popl %ecx
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CFI_ADJUST_CFA_OFFSET -4
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CFI_RESTORE ecx
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popl %edx
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CFI_ADJUST_CFA_OFFSET -4
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CFI_RESTORE edx
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popl %esi
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CFI_ADJUST_CFA_OFFSET -4
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CFI_RESTORE esi
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popl %edi
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CFI_ADJUST_CFA_OFFSET -4
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CFI_RESTORE edi
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popl %ebp
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CFI_ADJUST_CFA_OFFSET -4
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CFI_RESTORE ebp
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popl %eax
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CFI_ADJUST_CFA_OFFSET -4
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CFI_RESTORE eax
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.endm
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.macro RESTORE_REGS pop=0
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RESTORE_INT_REGS
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1: popl %ds
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CFI_ADJUST_CFA_OFFSET -4
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/*CFI_RESTORE ds;*/
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2: popl %es
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CFI_ADJUST_CFA_OFFSET -4
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/*CFI_RESTORE es;*/
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3: popl %fs
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CFI_ADJUST_CFA_OFFSET -4
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/*CFI_RESTORE fs;*/
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POP_GS \pop
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.pushsection .fixup, "ax"
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4: movl $0, (%esp)
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jmp 1b
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5: movl $0, (%esp)
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jmp 2b
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6: movl $0, (%esp)
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jmp 3b
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.section __ex_table, "a"
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.align 4
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.long 1b, 4b
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.long 2b, 5b
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.long 3b, 6b
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.popsection
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POP_GS_EX
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.endm
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.macro RING0_INT_FRAME
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CFI_STARTPROC simple
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CFI_SIGNAL_FRAME
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CFI_DEF_CFA esp, 3*4
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/*CFI_OFFSET cs, -2*4;*/
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CFI_OFFSET eip, -3*4
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.endm
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.macro RING0_EC_FRAME
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CFI_STARTPROC simple
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CFI_SIGNAL_FRAME
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CFI_DEF_CFA esp, 4*4
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/*CFI_OFFSET cs, -2*4;*/
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CFI_OFFSET eip, -3*4
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.endm
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.macro RING0_PTREGS_FRAME
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CFI_STARTPROC simple
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CFI_SIGNAL_FRAME
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CFI_DEF_CFA esp, PT_OLDESP-PT_EBX
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/*CFI_OFFSET cs, PT_CS-PT_OLDESP;*/
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CFI_OFFSET eip, PT_EIP-PT_OLDESP
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/*CFI_OFFSET es, PT_ES-PT_OLDESP;*/
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/*CFI_OFFSET ds, PT_DS-PT_OLDESP;*/
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CFI_OFFSET eax, PT_EAX-PT_OLDESP
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CFI_OFFSET ebp, PT_EBP-PT_OLDESP
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CFI_OFFSET edi, PT_EDI-PT_OLDESP
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CFI_OFFSET esi, PT_ESI-PT_OLDESP
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CFI_OFFSET edx, PT_EDX-PT_OLDESP
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CFI_OFFSET ecx, PT_ECX-PT_OLDESP
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CFI_OFFSET ebx, PT_EBX-PT_OLDESP
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.endm
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ENTRY(ret_from_fork)
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CFI_STARTPROC
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pushl %eax
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CFI_ADJUST_CFA_OFFSET 4
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call schedule_tail
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GET_THREAD_INFO(%ebp)
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popl %eax
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CFI_ADJUST_CFA_OFFSET -4
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pushl $0x0202 # Reset kernel eflags
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CFI_ADJUST_CFA_OFFSET 4
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popfl
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CFI_ADJUST_CFA_OFFSET -4
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jmp syscall_exit
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CFI_ENDPROC
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END(ret_from_fork)
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/*
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* Interrupt exit functions should be protected against kprobes
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*/
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.pushsection .kprobes.text, "ax"
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/*
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* Return to user mode is not as complex as all this looks,
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* but we want the default path for a system call return to
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* go as quickly as possible which is why some of this is
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* less clear than it otherwise should be.
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*/
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# userspace resumption stub bypassing syscall exit tracing
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ALIGN
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RING0_PTREGS_FRAME
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ret_from_exception:
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preempt_stop(CLBR_ANY)
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ret_from_intr:
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GET_THREAD_INFO(%ebp)
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check_userspace:
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movl PT_EFLAGS(%esp), %eax # mix EFLAGS and CS
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movb PT_CS(%esp), %al
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andl $(X86_EFLAGS_VM | SEGMENT_RPL_MASK), %eax
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cmpl $USER_RPL, %eax
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jb resume_kernel # not returning to v8086 or userspace
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ENTRY(resume_userspace)
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LOCKDEP_SYS_EXIT
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DISABLE_INTERRUPTS(CLBR_ANY) # make sure we don't miss an interrupt
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# setting need_resched or sigpending
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# between sampling and the iret
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TRACE_IRQS_OFF
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movl TI_flags(%ebp), %ecx
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andl $_TIF_WORK_MASK, %ecx # is there any work to be done on
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# int/exception return?
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jne work_pending
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jmp restore_all
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END(ret_from_exception)
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#ifdef CONFIG_PREEMPT
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ENTRY(resume_kernel)
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DISABLE_INTERRUPTS(CLBR_ANY)
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cmpl $0,TI_preempt_count(%ebp) # non-zero preempt_count ?
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jnz restore_all
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need_resched:
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movl TI_flags(%ebp), %ecx # need_resched set ?
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testb $_TIF_NEED_RESCHED, %cl
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jz restore_all
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testl $X86_EFLAGS_IF,PT_EFLAGS(%esp) # interrupts off (exception path) ?
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jz restore_all
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call preempt_schedule_irq
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jmp need_resched
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END(resume_kernel)
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#endif
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CFI_ENDPROC
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/*
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* End of kprobes section
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*/
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.popsection
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/* SYSENTER_RETURN points to after the "sysenter" instruction in
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the vsyscall page. See vsyscall-sysentry.S, which defines the symbol. */
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# sysenter call handler stub
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ENTRY(ia32_sysenter_target)
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CFI_STARTPROC simple
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CFI_SIGNAL_FRAME
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CFI_DEF_CFA esp, 0
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CFI_REGISTER esp, ebp
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movl TSS_sysenter_sp0(%esp),%esp
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sysenter_past_esp:
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/*
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* Interrupts are disabled here, but we can't trace it until
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* enough kernel state to call TRACE_IRQS_OFF can be called - but
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* we immediately enable interrupts at that point anyway.
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*/
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pushl $(__USER_DS)
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CFI_ADJUST_CFA_OFFSET 4
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/*CFI_REL_OFFSET ss, 0*/
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pushl %ebp
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CFI_ADJUST_CFA_OFFSET 4
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CFI_REL_OFFSET esp, 0
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pushfl
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orl $X86_EFLAGS_IF, (%esp)
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CFI_ADJUST_CFA_OFFSET 4
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pushl $(__USER_CS)
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CFI_ADJUST_CFA_OFFSET 4
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/*CFI_REL_OFFSET cs, 0*/
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/*
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* Push current_thread_info()->sysenter_return to the stack.
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* A tiny bit of offset fixup is necessary - 4*4 means the 4 words
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* pushed above; +8 corresponds to copy_thread's esp0 setting.
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*/
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pushl (TI_sysenter_return-THREAD_SIZE+8+4*4)(%esp)
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CFI_ADJUST_CFA_OFFSET 4
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CFI_REL_OFFSET eip, 0
|
|
|
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pushl %eax
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CFI_ADJUST_CFA_OFFSET 4
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SAVE_ALL
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ENABLE_INTERRUPTS(CLBR_NONE)
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|
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/*
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* Load the potential sixth argument from user stack.
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* Careful about security.
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*/
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cmpl $__PAGE_OFFSET-3,%ebp
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jae syscall_fault
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1: movl (%ebp),%ebp
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movl %ebp,PT_EBP(%esp)
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.section __ex_table,"a"
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.align 4
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.long 1b,syscall_fault
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.previous
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|
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GET_THREAD_INFO(%ebp)
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|
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testl $_TIF_WORK_SYSCALL_ENTRY,TI_flags(%ebp)
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jnz sysenter_audit
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sysenter_do_call:
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cmpl $(nr_syscalls), %eax
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jae syscall_badsys
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call *sys_call_table(,%eax,4)
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movl %eax,PT_EAX(%esp)
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LOCKDEP_SYS_EXIT
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DISABLE_INTERRUPTS(CLBR_ANY)
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TRACE_IRQS_OFF
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movl TI_flags(%ebp), %ecx
|
|
testl $_TIF_ALLWORK_MASK, %ecx
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jne sysexit_audit
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|
sysenter_exit:
|
|
/* if something modifies registers it must also disable sysexit */
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movl PT_EIP(%esp), %edx
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movl PT_OLDESP(%esp), %ecx
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xorl %ebp,%ebp
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TRACE_IRQS_ON
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|
1: mov PT_FS(%esp), %fs
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PTGS_TO_GS
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ENABLE_INTERRUPTS_SYSEXIT
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|
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#ifdef CONFIG_AUDITSYSCALL
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sysenter_audit:
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testl $(_TIF_WORK_SYSCALL_ENTRY & ~_TIF_SYSCALL_AUDIT),TI_flags(%ebp)
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jnz syscall_trace_entry
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addl $4,%esp
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CFI_ADJUST_CFA_OFFSET -4
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/* %esi already in 8(%esp) 6th arg: 4th syscall arg */
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/* %edx already in 4(%esp) 5th arg: 3rd syscall arg */
|
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/* %ecx already in 0(%esp) 4th arg: 2nd syscall arg */
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movl %ebx,%ecx /* 3rd arg: 1st syscall arg */
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|
movl %eax,%edx /* 2nd arg: syscall number */
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|
movl $AUDIT_ARCH_I386,%eax /* 1st arg: audit arch */
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call audit_syscall_entry
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|
pushl %ebx
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|
CFI_ADJUST_CFA_OFFSET 4
|
|
movl PT_EAX(%esp),%eax /* reload syscall number */
|
|
jmp sysenter_do_call
|
|
|
|
sysexit_audit:
|
|
testl $(_TIF_ALLWORK_MASK & ~_TIF_SYSCALL_AUDIT), %ecx
|
|
jne syscall_exit_work
|
|
TRACE_IRQS_ON
|
|
ENABLE_INTERRUPTS(CLBR_ANY)
|
|
movl %eax,%edx /* second arg, syscall return value */
|
|
cmpl $0,%eax /* is it < 0? */
|
|
setl %al /* 1 if so, 0 if not */
|
|
movzbl %al,%eax /* zero-extend that */
|
|
inc %eax /* first arg, 0->1(AUDITSC_SUCCESS), 1->2(AUDITSC_FAILURE) */
|
|
call audit_syscall_exit
|
|
DISABLE_INTERRUPTS(CLBR_ANY)
|
|
TRACE_IRQS_OFF
|
|
movl TI_flags(%ebp), %ecx
|
|
testl $(_TIF_ALLWORK_MASK & ~_TIF_SYSCALL_AUDIT), %ecx
|
|
jne syscall_exit_work
|
|
movl PT_EAX(%esp),%eax /* reload syscall return value */
|
|
jmp sysenter_exit
|
|
#endif
|
|
|
|
CFI_ENDPROC
|
|
.pushsection .fixup,"ax"
|
|
2: movl $0,PT_FS(%esp)
|
|
jmp 1b
|
|
.section __ex_table,"a"
|
|
.align 4
|
|
.long 1b,2b
|
|
.popsection
|
|
PTGS_TO_GS_EX
|
|
ENDPROC(ia32_sysenter_target)
|
|
|
|
/*
|
|
* syscall stub including irq exit should be protected against kprobes
|
|
*/
|
|
.pushsection .kprobes.text, "ax"
|
|
# system call handler stub
|
|
ENTRY(system_call)
|
|
RING0_INT_FRAME # can't unwind into user space anyway
|
|
pushl %eax # save orig_eax
|
|
CFI_ADJUST_CFA_OFFSET 4
|
|
SAVE_ALL
|
|
GET_THREAD_INFO(%ebp)
|
|
# system call tracing in operation / emulation
|
|
testl $_TIF_WORK_SYSCALL_ENTRY,TI_flags(%ebp)
|
|
jnz syscall_trace_entry
|
|
cmpl $(nr_syscalls), %eax
|
|
jae syscall_badsys
|
|
syscall_call:
|
|
call *sys_call_table(,%eax,4)
|
|
movl %eax,PT_EAX(%esp) # store the return value
|
|
syscall_exit:
|
|
LOCKDEP_SYS_EXIT
|
|
DISABLE_INTERRUPTS(CLBR_ANY) # make sure we don't miss an interrupt
|
|
# setting need_resched or sigpending
|
|
# between sampling and the iret
|
|
TRACE_IRQS_OFF
|
|
movl TI_flags(%ebp), %ecx
|
|
testl $_TIF_ALLWORK_MASK, %ecx # current->work
|
|
jne syscall_exit_work
|
|
|
|
restore_all:
|
|
TRACE_IRQS_IRET
|
|
restore_all_notrace:
|
|
movl PT_EFLAGS(%esp), %eax # mix EFLAGS, SS and CS
|
|
# Warning: PT_OLDSS(%esp) contains the wrong/random values if we
|
|
# are returning to the kernel.
|
|
# See comments in process.c:copy_thread() for details.
|
|
movb PT_OLDSS(%esp), %ah
|
|
movb PT_CS(%esp), %al
|
|
andl $(X86_EFLAGS_VM | (SEGMENT_TI_MASK << 8) | SEGMENT_RPL_MASK), %eax
|
|
cmpl $((SEGMENT_LDT << 8) | USER_RPL), %eax
|
|
CFI_REMEMBER_STATE
|
|
je ldt_ss # returning to user-space with LDT SS
|
|
restore_nocheck:
|
|
RESTORE_REGS 4 # skip orig_eax/error_code
|
|
CFI_ADJUST_CFA_OFFSET -4
|
|
irq_return:
|
|
INTERRUPT_RETURN
|
|
.section .fixup,"ax"
|
|
ENTRY(iret_exc)
|
|
pushl $0 # no error code
|
|
pushl $do_iret_error
|
|
jmp error_code
|
|
.previous
|
|
.section __ex_table,"a"
|
|
.align 4
|
|
.long irq_return,iret_exc
|
|
.previous
|
|
|
|
CFI_RESTORE_STATE
|
|
ldt_ss:
|
|
larl PT_OLDSS(%esp), %eax
|
|
jnz restore_nocheck
|
|
testl $0x00400000, %eax # returning to 32bit stack?
|
|
jnz restore_nocheck # allright, normal return
|
|
|
|
#ifdef CONFIG_PARAVIRT
|
|
/*
|
|
* The kernel can't run on a non-flat stack if paravirt mode
|
|
* is active. Rather than try to fixup the high bits of
|
|
* ESP, bypass this code entirely. This may break DOSemu
|
|
* and/or Wine support in a paravirt VM, although the option
|
|
* is still available to implement the setting of the high
|
|
* 16-bits in the INTERRUPT_RETURN paravirt-op.
|
|
*/
|
|
cmpl $0, pv_info+PARAVIRT_enabled
|
|
jne restore_nocheck
|
|
#endif
|
|
|
|
/*
|
|
* Setup and switch to ESPFIX stack
|
|
*
|
|
* We're returning to userspace with a 16 bit stack. The CPU will not
|
|
* restore the high word of ESP for us on executing iret... This is an
|
|
* "official" bug of all the x86-compatible CPUs, which we can work
|
|
* around to make dosemu and wine happy. We do this by preloading the
|
|
* high word of ESP with the high word of the userspace ESP while
|
|
* compensating for the offset by changing to the ESPFIX segment with
|
|
* a base address that matches for the difference.
|
|
*/
|
|
mov %esp, %edx /* load kernel esp */
|
|
mov PT_OLDESP(%esp), %eax /* load userspace esp */
|
|
mov %dx, %ax /* eax: new kernel esp */
|
|
sub %eax, %edx /* offset (low word is 0) */
|
|
PER_CPU(gdt_page, %ebx)
|
|
shr $16, %edx
|
|
mov %dl, GDT_ENTRY_ESPFIX_SS * 8 + 4(%ebx) /* bits 16..23 */
|
|
mov %dh, GDT_ENTRY_ESPFIX_SS * 8 + 7(%ebx) /* bits 24..31 */
|
|
pushl $__ESPFIX_SS
|
|
CFI_ADJUST_CFA_OFFSET 4
|
|
push %eax /* new kernel esp */
|
|
CFI_ADJUST_CFA_OFFSET 4
|
|
/* Disable interrupts, but do not irqtrace this section: we
|
|
* will soon execute iret and the tracer was already set to
|
|
* the irqstate after the iret */
|
|
DISABLE_INTERRUPTS(CLBR_EAX)
|
|
lss (%esp), %esp /* switch to espfix segment */
|
|
CFI_ADJUST_CFA_OFFSET -8
|
|
jmp restore_nocheck
|
|
CFI_ENDPROC
|
|
ENDPROC(system_call)
|
|
|
|
# perform work that needs to be done immediately before resumption
|
|
ALIGN
|
|
RING0_PTREGS_FRAME # can't unwind into user space anyway
|
|
work_pending:
|
|
testb $_TIF_NEED_RESCHED, %cl
|
|
jz work_notifysig
|
|
work_resched:
|
|
call schedule
|
|
LOCKDEP_SYS_EXIT
|
|
DISABLE_INTERRUPTS(CLBR_ANY) # make sure we don't miss an interrupt
|
|
# setting need_resched or sigpending
|
|
# between sampling and the iret
|
|
TRACE_IRQS_OFF
|
|
movl TI_flags(%ebp), %ecx
|
|
andl $_TIF_WORK_MASK, %ecx # is there any work to be done other
|
|
# than syscall tracing?
|
|
jz restore_all
|
|
testb $_TIF_NEED_RESCHED, %cl
|
|
jnz work_resched
|
|
|
|
work_notifysig: # deal with pending signals and
|
|
# notify-resume requests
|
|
#ifdef CONFIG_VM86
|
|
testl $X86_EFLAGS_VM, PT_EFLAGS(%esp)
|
|
movl %esp, %eax
|
|
jne work_notifysig_v86 # returning to kernel-space or
|
|
# vm86-space
|
|
xorl %edx, %edx
|
|
call do_notify_resume
|
|
jmp resume_userspace_sig
|
|
|
|
ALIGN
|
|
work_notifysig_v86:
|
|
pushl %ecx # save ti_flags for do_notify_resume
|
|
CFI_ADJUST_CFA_OFFSET 4
|
|
call save_v86_state # %eax contains pt_regs pointer
|
|
popl %ecx
|
|
CFI_ADJUST_CFA_OFFSET -4
|
|
movl %eax, %esp
|
|
#else
|
|
movl %esp, %eax
|
|
#endif
|
|
xorl %edx, %edx
|
|
call do_notify_resume
|
|
jmp resume_userspace_sig
|
|
END(work_pending)
|
|
|
|
# perform syscall exit tracing
|
|
ALIGN
|
|
syscall_trace_entry:
|
|
movl $-ENOSYS,PT_EAX(%esp)
|
|
movl %esp, %eax
|
|
call syscall_trace_enter
|
|
/* What it returned is what we'll actually use. */
|
|
cmpl $(nr_syscalls), %eax
|
|
jnae syscall_call
|
|
jmp syscall_exit
|
|
END(syscall_trace_entry)
|
|
|
|
# perform syscall exit tracing
|
|
ALIGN
|
|
syscall_exit_work:
|
|
testl $_TIF_WORK_SYSCALL_EXIT, %ecx
|
|
jz work_pending
|
|
TRACE_IRQS_ON
|
|
ENABLE_INTERRUPTS(CLBR_ANY) # could let syscall_trace_leave() call
|
|
# schedule() instead
|
|
movl %esp, %eax
|
|
call syscall_trace_leave
|
|
jmp resume_userspace
|
|
END(syscall_exit_work)
|
|
CFI_ENDPROC
|
|
|
|
RING0_INT_FRAME # can't unwind into user space anyway
|
|
syscall_fault:
|
|
GET_THREAD_INFO(%ebp)
|
|
movl $-EFAULT,PT_EAX(%esp)
|
|
jmp resume_userspace
|
|
END(syscall_fault)
|
|
|
|
syscall_badsys:
|
|
movl $-ENOSYS,PT_EAX(%esp)
|
|
jmp resume_userspace
|
|
END(syscall_badsys)
|
|
CFI_ENDPROC
|
|
/*
|
|
* End of kprobes section
|
|
*/
|
|
.popsection
|
|
|
|
/*
|
|
* System calls that need a pt_regs pointer.
|
|
*/
|
|
#define PTREGSCALL0(name) \
|
|
ALIGN; \
|
|
ptregs_##name: \
|
|
leal 4(%esp),%eax; \
|
|
jmp sys_##name;
|
|
|
|
#define PTREGSCALL1(name) \
|
|
ALIGN; \
|
|
ptregs_##name: \
|
|
leal 4(%esp),%edx; \
|
|
movl (PT_EBX+4)(%esp),%eax; \
|
|
jmp sys_##name;
|
|
|
|
#define PTREGSCALL2(name) \
|
|
ALIGN; \
|
|
ptregs_##name: \
|
|
leal 4(%esp),%ecx; \
|
|
movl (PT_ECX+4)(%esp),%edx; \
|
|
movl (PT_EBX+4)(%esp),%eax; \
|
|
jmp sys_##name;
|
|
|
|
#define PTREGSCALL3(name) \
|
|
ALIGN; \
|
|
ptregs_##name: \
|
|
leal 4(%esp),%eax; \
|
|
pushl %eax; \
|
|
movl PT_EDX(%eax),%ecx; \
|
|
movl PT_ECX(%eax),%edx; \
|
|
movl PT_EBX(%eax),%eax; \
|
|
call sys_##name; \
|
|
addl $4,%esp; \
|
|
ret
|
|
|
|
PTREGSCALL1(iopl)
|
|
PTREGSCALL0(fork)
|
|
PTREGSCALL0(vfork)
|
|
PTREGSCALL3(execve)
|
|
PTREGSCALL2(sigaltstack)
|
|
PTREGSCALL0(sigreturn)
|
|
PTREGSCALL0(rt_sigreturn)
|
|
PTREGSCALL2(vm86)
|
|
PTREGSCALL1(vm86old)
|
|
|
|
/* Clone is an oddball. The 4th arg is in %edi */
|
|
ALIGN;
|
|
ptregs_clone:
|
|
leal 4(%esp),%eax
|
|
pushl %eax
|
|
pushl PT_EDI(%eax)
|
|
movl PT_EDX(%eax),%ecx
|
|
movl PT_ECX(%eax),%edx
|
|
movl PT_EBX(%eax),%eax
|
|
call sys_clone
|
|
addl $8,%esp
|
|
ret
|
|
|
|
.macro FIXUP_ESPFIX_STACK
|
|
/*
|
|
* Switch back for ESPFIX stack to the normal zerobased stack
|
|
*
|
|
* We can't call C functions using the ESPFIX stack. This code reads
|
|
* the high word of the segment base from the GDT and swiches to the
|
|
* normal stack and adjusts ESP with the matching offset.
|
|
*/
|
|
/* fixup the stack */
|
|
PER_CPU(gdt_page, %ebx)
|
|
mov GDT_ENTRY_ESPFIX_SS * 8 + 4(%ebx), %al /* bits 16..23 */
|
|
mov GDT_ENTRY_ESPFIX_SS * 8 + 7(%ebx), %ah /* bits 24..31 */
|
|
shl $16, %eax
|
|
addl %esp, %eax /* the adjusted stack pointer */
|
|
pushl $__KERNEL_DS
|
|
CFI_ADJUST_CFA_OFFSET 4
|
|
pushl %eax
|
|
CFI_ADJUST_CFA_OFFSET 4
|
|
lss (%esp), %esp /* switch to the normal stack segment */
|
|
CFI_ADJUST_CFA_OFFSET -8
|
|
.endm
|
|
.macro UNWIND_ESPFIX_STACK
|
|
movl %ss, %eax
|
|
/* see if on espfix stack */
|
|
cmpw $__ESPFIX_SS, %ax
|
|
jne 27f
|
|
movl $__KERNEL_DS, %eax
|
|
movl %eax, %ds
|
|
movl %eax, %es
|
|
/* switch to normal stack */
|
|
FIXUP_ESPFIX_STACK
|
|
27:
|
|
.endm
|
|
|
|
/*
|
|
* Build the entry stubs and pointer table with some assembler magic.
|
|
* We pack 7 stubs into a single 32-byte chunk, which will fit in a
|
|
* single cache line on all modern x86 implementations.
|
|
*/
|
|
.section .init.rodata,"a"
|
|
ENTRY(interrupt)
|
|
.text
|
|
.p2align 5
|
|
.p2align CONFIG_X86_L1_CACHE_SHIFT
|
|
ENTRY(irq_entries_start)
|
|
RING0_INT_FRAME
|
|
vector=FIRST_EXTERNAL_VECTOR
|
|
.rept (NR_VECTORS-FIRST_EXTERNAL_VECTOR+6)/7
|
|
.balign 32
|
|
.rept 7
|
|
.if vector < NR_VECTORS
|
|
.if vector <> FIRST_EXTERNAL_VECTOR
|
|
CFI_ADJUST_CFA_OFFSET -4
|
|
.endif
|
|
1: pushl $(~vector+0x80) /* Note: always in signed byte range */
|
|
CFI_ADJUST_CFA_OFFSET 4
|
|
.if ((vector-FIRST_EXTERNAL_VECTOR)%7) <> 6
|
|
jmp 2f
|
|
.endif
|
|
.previous
|
|
.long 1b
|
|
.text
|
|
vector=vector+1
|
|
.endif
|
|
.endr
|
|
2: jmp common_interrupt
|
|
.endr
|
|
END(irq_entries_start)
|
|
|
|
.previous
|
|
END(interrupt)
|
|
.previous
|
|
|
|
/*
|
|
* the CPU automatically disables interrupts when executing an IRQ vector,
|
|
* so IRQ-flags tracing has to follow that:
|
|
*/
|
|
.p2align CONFIG_X86_L1_CACHE_SHIFT
|
|
common_interrupt:
|
|
addl $-0x80,(%esp) /* Adjust vector into the [-256,-1] range */
|
|
SAVE_ALL
|
|
TRACE_IRQS_OFF
|
|
movl %esp,%eax
|
|
call do_IRQ
|
|
jmp ret_from_intr
|
|
ENDPROC(common_interrupt)
|
|
CFI_ENDPROC
|
|
|
|
/*
|
|
* Irq entries should be protected against kprobes
|
|
*/
|
|
.pushsection .kprobes.text, "ax"
|
|
#define BUILD_INTERRUPT3(name, nr, fn) \
|
|
ENTRY(name) \
|
|
RING0_INT_FRAME; \
|
|
pushl $~(nr); \
|
|
CFI_ADJUST_CFA_OFFSET 4; \
|
|
SAVE_ALL; \
|
|
TRACE_IRQS_OFF \
|
|
movl %esp,%eax; \
|
|
call fn; \
|
|
jmp ret_from_intr; \
|
|
CFI_ENDPROC; \
|
|
ENDPROC(name)
|
|
|
|
#define BUILD_INTERRUPT(name, nr) BUILD_INTERRUPT3(name, nr, smp_##name)
|
|
|
|
/* The include is where all of the SMP etc. interrupts come from */
|
|
#include <asm/entry_arch.h>
|
|
|
|
ENTRY(coprocessor_error)
|
|
RING0_INT_FRAME
|
|
pushl $0
|
|
CFI_ADJUST_CFA_OFFSET 4
|
|
pushl $do_coprocessor_error
|
|
CFI_ADJUST_CFA_OFFSET 4
|
|
jmp error_code
|
|
CFI_ENDPROC
|
|
END(coprocessor_error)
|
|
|
|
ENTRY(simd_coprocessor_error)
|
|
RING0_INT_FRAME
|
|
pushl $0
|
|
CFI_ADJUST_CFA_OFFSET 4
|
|
#ifdef CONFIG_X86_INVD_BUG
|
|
/* AMD 486 bug: invd from userspace calls exception 19 instead of #GP */
|
|
661: pushl $do_general_protection
|
|
662:
|
|
.section .altinstructions,"a"
|
|
.balign 4
|
|
.long 661b
|
|
.long 663f
|
|
.byte X86_FEATURE_XMM
|
|
.byte 662b-661b
|
|
.byte 664f-663f
|
|
.previous
|
|
.section .altinstr_replacement,"ax"
|
|
663: pushl $do_simd_coprocessor_error
|
|
664:
|
|
.previous
|
|
#else
|
|
pushl $do_simd_coprocessor_error
|
|
#endif
|
|
CFI_ADJUST_CFA_OFFSET 4
|
|
jmp error_code
|
|
CFI_ENDPROC
|
|
END(simd_coprocessor_error)
|
|
|
|
ENTRY(device_not_available)
|
|
RING0_INT_FRAME
|
|
pushl $-1 # mark this as an int
|
|
CFI_ADJUST_CFA_OFFSET 4
|
|
pushl $do_device_not_available
|
|
CFI_ADJUST_CFA_OFFSET 4
|
|
jmp error_code
|
|
CFI_ENDPROC
|
|
END(device_not_available)
|
|
|
|
#ifdef CONFIG_PARAVIRT
|
|
ENTRY(native_iret)
|
|
iret
|
|
.section __ex_table,"a"
|
|
.align 4
|
|
.long native_iret, iret_exc
|
|
.previous
|
|
END(native_iret)
|
|
|
|
ENTRY(native_irq_enable_sysexit)
|
|
sti
|
|
sysexit
|
|
END(native_irq_enable_sysexit)
|
|
#endif
|
|
|
|
ENTRY(overflow)
|
|
RING0_INT_FRAME
|
|
pushl $0
|
|
CFI_ADJUST_CFA_OFFSET 4
|
|
pushl $do_overflow
|
|
CFI_ADJUST_CFA_OFFSET 4
|
|
jmp error_code
|
|
CFI_ENDPROC
|
|
END(overflow)
|
|
|
|
ENTRY(bounds)
|
|
RING0_INT_FRAME
|
|
pushl $0
|
|
CFI_ADJUST_CFA_OFFSET 4
|
|
pushl $do_bounds
|
|
CFI_ADJUST_CFA_OFFSET 4
|
|
jmp error_code
|
|
CFI_ENDPROC
|
|
END(bounds)
|
|
|
|
ENTRY(invalid_op)
|
|
RING0_INT_FRAME
|
|
pushl $0
|
|
CFI_ADJUST_CFA_OFFSET 4
|
|
pushl $do_invalid_op
|
|
CFI_ADJUST_CFA_OFFSET 4
|
|
jmp error_code
|
|
CFI_ENDPROC
|
|
END(invalid_op)
|
|
|
|
ENTRY(coprocessor_segment_overrun)
|
|
RING0_INT_FRAME
|
|
pushl $0
|
|
CFI_ADJUST_CFA_OFFSET 4
|
|
pushl $do_coprocessor_segment_overrun
|
|
CFI_ADJUST_CFA_OFFSET 4
|
|
jmp error_code
|
|
CFI_ENDPROC
|
|
END(coprocessor_segment_overrun)
|
|
|
|
ENTRY(invalid_TSS)
|
|
RING0_EC_FRAME
|
|
pushl $do_invalid_TSS
|
|
CFI_ADJUST_CFA_OFFSET 4
|
|
jmp error_code
|
|
CFI_ENDPROC
|
|
END(invalid_TSS)
|
|
|
|
ENTRY(segment_not_present)
|
|
RING0_EC_FRAME
|
|
pushl $do_segment_not_present
|
|
CFI_ADJUST_CFA_OFFSET 4
|
|
jmp error_code
|
|
CFI_ENDPROC
|
|
END(segment_not_present)
|
|
|
|
ENTRY(stack_segment)
|
|
RING0_EC_FRAME
|
|
pushl $do_stack_segment
|
|
CFI_ADJUST_CFA_OFFSET 4
|
|
jmp error_code
|
|
CFI_ENDPROC
|
|
END(stack_segment)
|
|
|
|
ENTRY(alignment_check)
|
|
RING0_EC_FRAME
|
|
pushl $do_alignment_check
|
|
CFI_ADJUST_CFA_OFFSET 4
|
|
jmp error_code
|
|
CFI_ENDPROC
|
|
END(alignment_check)
|
|
|
|
ENTRY(divide_error)
|
|
RING0_INT_FRAME
|
|
pushl $0 # no error code
|
|
CFI_ADJUST_CFA_OFFSET 4
|
|
pushl $do_divide_error
|
|
CFI_ADJUST_CFA_OFFSET 4
|
|
jmp error_code
|
|
CFI_ENDPROC
|
|
END(divide_error)
|
|
|
|
#ifdef CONFIG_X86_MCE
|
|
ENTRY(machine_check)
|
|
RING0_INT_FRAME
|
|
pushl $0
|
|
CFI_ADJUST_CFA_OFFSET 4
|
|
pushl machine_check_vector
|
|
CFI_ADJUST_CFA_OFFSET 4
|
|
jmp error_code
|
|
CFI_ENDPROC
|
|
END(machine_check)
|
|
#endif
|
|
|
|
ENTRY(spurious_interrupt_bug)
|
|
RING0_INT_FRAME
|
|
pushl $0
|
|
CFI_ADJUST_CFA_OFFSET 4
|
|
pushl $do_spurious_interrupt_bug
|
|
CFI_ADJUST_CFA_OFFSET 4
|
|
jmp error_code
|
|
CFI_ENDPROC
|
|
END(spurious_interrupt_bug)
|
|
/*
|
|
* End of kprobes section
|
|
*/
|
|
.popsection
|
|
|
|
ENTRY(kernel_thread_helper)
|
|
pushl $0 # fake return address for unwinder
|
|
CFI_STARTPROC
|
|
movl %edi,%eax
|
|
call *%esi
|
|
call do_exit
|
|
ud2 # padding for call trace
|
|
CFI_ENDPROC
|
|
ENDPROC(kernel_thread_helper)
|
|
|
|
#ifdef CONFIG_XEN
|
|
/* Xen doesn't set %esp to be precisely what the normal sysenter
|
|
entrypoint expects, so fix it up before using the normal path. */
|
|
ENTRY(xen_sysenter_target)
|
|
RING0_INT_FRAME
|
|
addl $5*4, %esp /* remove xen-provided frame */
|
|
CFI_ADJUST_CFA_OFFSET -5*4
|
|
jmp sysenter_past_esp
|
|
CFI_ENDPROC
|
|
|
|
ENTRY(xen_hypervisor_callback)
|
|
CFI_STARTPROC
|
|
pushl $0
|
|
CFI_ADJUST_CFA_OFFSET 4
|
|
SAVE_ALL
|
|
TRACE_IRQS_OFF
|
|
|
|
/* Check to see if we got the event in the critical
|
|
region in xen_iret_direct, after we've reenabled
|
|
events and checked for pending events. This simulates
|
|
iret instruction's behaviour where it delivers a
|
|
pending interrupt when enabling interrupts. */
|
|
movl PT_EIP(%esp),%eax
|
|
cmpl $xen_iret_start_crit,%eax
|
|
jb 1f
|
|
cmpl $xen_iret_end_crit,%eax
|
|
jae 1f
|
|
|
|
jmp xen_iret_crit_fixup
|
|
|
|
ENTRY(xen_do_upcall)
|
|
1: mov %esp, %eax
|
|
call xen_evtchn_do_upcall
|
|
jmp ret_from_intr
|
|
CFI_ENDPROC
|
|
ENDPROC(xen_hypervisor_callback)
|
|
|
|
# Hypervisor uses this for application faults while it executes.
|
|
# We get here for two reasons:
|
|
# 1. Fault while reloading DS, ES, FS or GS
|
|
# 2. Fault while executing IRET
|
|
# Category 1 we fix up by reattempting the load, and zeroing the segment
|
|
# register if the load fails.
|
|
# Category 2 we fix up by jumping to do_iret_error. We cannot use the
|
|
# normal Linux return path in this case because if we use the IRET hypercall
|
|
# to pop the stack frame we end up in an infinite loop of failsafe callbacks.
|
|
# We distinguish between categories by maintaining a status value in EAX.
|
|
ENTRY(xen_failsafe_callback)
|
|
CFI_STARTPROC
|
|
pushl %eax
|
|
CFI_ADJUST_CFA_OFFSET 4
|
|
movl $1,%eax
|
|
1: mov 4(%esp),%ds
|
|
2: mov 8(%esp),%es
|
|
3: mov 12(%esp),%fs
|
|
4: mov 16(%esp),%gs
|
|
testl %eax,%eax
|
|
popl %eax
|
|
CFI_ADJUST_CFA_OFFSET -4
|
|
lea 16(%esp),%esp
|
|
CFI_ADJUST_CFA_OFFSET -16
|
|
jz 5f
|
|
addl $16,%esp
|
|
jmp iret_exc # EAX != 0 => Category 2 (Bad IRET)
|
|
5: pushl $0 # EAX == 0 => Category 1 (Bad segment)
|
|
CFI_ADJUST_CFA_OFFSET 4
|
|
SAVE_ALL
|
|
jmp ret_from_exception
|
|
CFI_ENDPROC
|
|
|
|
.section .fixup,"ax"
|
|
6: xorl %eax,%eax
|
|
movl %eax,4(%esp)
|
|
jmp 1b
|
|
7: xorl %eax,%eax
|
|
movl %eax,8(%esp)
|
|
jmp 2b
|
|
8: xorl %eax,%eax
|
|
movl %eax,12(%esp)
|
|
jmp 3b
|
|
9: xorl %eax,%eax
|
|
movl %eax,16(%esp)
|
|
jmp 4b
|
|
.previous
|
|
.section __ex_table,"a"
|
|
.align 4
|
|
.long 1b,6b
|
|
.long 2b,7b
|
|
.long 3b,8b
|
|
.long 4b,9b
|
|
.previous
|
|
ENDPROC(xen_failsafe_callback)
|
|
|
|
BUILD_INTERRUPT3(xen_hvm_callback_vector, XEN_HVM_EVTCHN_CALLBACK,
|
|
xen_evtchn_do_upcall)
|
|
|
|
#endif /* CONFIG_XEN */
|
|
|
|
#ifdef CONFIG_FUNCTION_TRACER
|
|
#ifdef CONFIG_DYNAMIC_FTRACE
|
|
|
|
ENTRY(mcount)
|
|
ret
|
|
END(mcount)
|
|
|
|
ENTRY(ftrace_caller)
|
|
cmpl $0, function_trace_stop
|
|
jne ftrace_stub
|
|
|
|
pushl %eax
|
|
pushl %ecx
|
|
pushl %edx
|
|
movl 0xc(%esp), %eax
|
|
movl 0x4(%ebp), %edx
|
|
subl $MCOUNT_INSN_SIZE, %eax
|
|
|
|
.globl ftrace_call
|
|
ftrace_call:
|
|
call ftrace_stub
|
|
|
|
popl %edx
|
|
popl %ecx
|
|
popl %eax
|
|
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
|
|
.globl ftrace_graph_call
|
|
ftrace_graph_call:
|
|
jmp ftrace_stub
|
|
#endif
|
|
|
|
.globl ftrace_stub
|
|
ftrace_stub:
|
|
ret
|
|
END(ftrace_caller)
|
|
|
|
#else /* ! CONFIG_DYNAMIC_FTRACE */
|
|
|
|
ENTRY(mcount)
|
|
cmpl $0, function_trace_stop
|
|
jne ftrace_stub
|
|
|
|
cmpl $ftrace_stub, ftrace_trace_function
|
|
jnz trace
|
|
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
|
|
cmpl $ftrace_stub, ftrace_graph_return
|
|
jnz ftrace_graph_caller
|
|
|
|
cmpl $ftrace_graph_entry_stub, ftrace_graph_entry
|
|
jnz ftrace_graph_caller
|
|
#endif
|
|
.globl ftrace_stub
|
|
ftrace_stub:
|
|
ret
|
|
|
|
/* taken from glibc */
|
|
trace:
|
|
pushl %eax
|
|
pushl %ecx
|
|
pushl %edx
|
|
movl 0xc(%esp), %eax
|
|
movl 0x4(%ebp), %edx
|
|
subl $MCOUNT_INSN_SIZE, %eax
|
|
|
|
call *ftrace_trace_function
|
|
|
|
popl %edx
|
|
popl %ecx
|
|
popl %eax
|
|
jmp ftrace_stub
|
|
END(mcount)
|
|
#endif /* CONFIG_DYNAMIC_FTRACE */
|
|
#endif /* CONFIG_FUNCTION_TRACER */
|
|
|
|
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
|
|
ENTRY(ftrace_graph_caller)
|
|
cmpl $0, function_trace_stop
|
|
jne ftrace_stub
|
|
|
|
pushl %eax
|
|
pushl %ecx
|
|
pushl %edx
|
|
movl 0xc(%esp), %edx
|
|
lea 0x4(%ebp), %eax
|
|
movl (%ebp), %ecx
|
|
subl $MCOUNT_INSN_SIZE, %edx
|
|
call prepare_ftrace_return
|
|
popl %edx
|
|
popl %ecx
|
|
popl %eax
|
|
ret
|
|
END(ftrace_graph_caller)
|
|
|
|
.globl return_to_handler
|
|
return_to_handler:
|
|
pushl %eax
|
|
pushl %edx
|
|
movl %ebp, %eax
|
|
call ftrace_return_to_handler
|
|
movl %eax, %ecx
|
|
popl %edx
|
|
popl %eax
|
|
jmp *%ecx
|
|
#endif
|
|
|
|
.section .rodata,"a"
|
|
#include "syscall_table_32.S"
|
|
|
|
syscall_table_size=(.-sys_call_table)
|
|
|
|
/*
|
|
* Some functions should be protected against kprobes
|
|
*/
|
|
.pushsection .kprobes.text, "ax"
|
|
|
|
ENTRY(page_fault)
|
|
RING0_EC_FRAME
|
|
pushl $do_page_fault
|
|
CFI_ADJUST_CFA_OFFSET 4
|
|
ALIGN
|
|
error_code:
|
|
/* the function address is in %gs's slot on the stack */
|
|
pushl %fs
|
|
CFI_ADJUST_CFA_OFFSET 4
|
|
/*CFI_REL_OFFSET fs, 0*/
|
|
pushl %es
|
|
CFI_ADJUST_CFA_OFFSET 4
|
|
/*CFI_REL_OFFSET es, 0*/
|
|
pushl %ds
|
|
CFI_ADJUST_CFA_OFFSET 4
|
|
/*CFI_REL_OFFSET ds, 0*/
|
|
pushl %eax
|
|
CFI_ADJUST_CFA_OFFSET 4
|
|
CFI_REL_OFFSET eax, 0
|
|
pushl %ebp
|
|
CFI_ADJUST_CFA_OFFSET 4
|
|
CFI_REL_OFFSET ebp, 0
|
|
pushl %edi
|
|
CFI_ADJUST_CFA_OFFSET 4
|
|
CFI_REL_OFFSET edi, 0
|
|
pushl %esi
|
|
CFI_ADJUST_CFA_OFFSET 4
|
|
CFI_REL_OFFSET esi, 0
|
|
pushl %edx
|
|
CFI_ADJUST_CFA_OFFSET 4
|
|
CFI_REL_OFFSET edx, 0
|
|
pushl %ecx
|
|
CFI_ADJUST_CFA_OFFSET 4
|
|
CFI_REL_OFFSET ecx, 0
|
|
pushl %ebx
|
|
CFI_ADJUST_CFA_OFFSET 4
|
|
CFI_REL_OFFSET ebx, 0
|
|
cld
|
|
movl $(__KERNEL_PERCPU), %ecx
|
|
movl %ecx, %fs
|
|
UNWIND_ESPFIX_STACK
|
|
GS_TO_REG %ecx
|
|
movl PT_GS(%esp), %edi # get the function address
|
|
movl PT_ORIG_EAX(%esp), %edx # get the error code
|
|
movl $-1, PT_ORIG_EAX(%esp) # no syscall to restart
|
|
REG_TO_PTGS %ecx
|
|
SET_KERNEL_GS %ecx
|
|
movl $(__USER_DS), %ecx
|
|
movl %ecx, %ds
|
|
movl %ecx, %es
|
|
TRACE_IRQS_OFF
|
|
movl %esp,%eax # pt_regs pointer
|
|
call *%edi
|
|
jmp ret_from_exception
|
|
CFI_ENDPROC
|
|
END(page_fault)
|
|
|
|
/*
|
|
* Debug traps and NMI can happen at the one SYSENTER instruction
|
|
* that sets up the real kernel stack. Check here, since we can't
|
|
* allow the wrong stack to be used.
|
|
*
|
|
* "TSS_sysenter_sp0+12" is because the NMI/debug handler will have
|
|
* already pushed 3 words if it hits on the sysenter instruction:
|
|
* eflags, cs and eip.
|
|
*
|
|
* We just load the right stack, and push the three (known) values
|
|
* by hand onto the new stack - while updating the return eip past
|
|
* the instruction that would have done it for sysenter.
|
|
*/
|
|
.macro FIX_STACK offset ok label
|
|
cmpw $__KERNEL_CS, 4(%esp)
|
|
jne \ok
|
|
\label:
|
|
movl TSS_sysenter_sp0 + \offset(%esp), %esp
|
|
CFI_DEF_CFA esp, 0
|
|
CFI_UNDEFINED eip
|
|
pushfl
|
|
CFI_ADJUST_CFA_OFFSET 4
|
|
pushl $__KERNEL_CS
|
|
CFI_ADJUST_CFA_OFFSET 4
|
|
pushl $sysenter_past_esp
|
|
CFI_ADJUST_CFA_OFFSET 4
|
|
CFI_REL_OFFSET eip, 0
|
|
.endm
|
|
|
|
ENTRY(debug)
|
|
RING0_INT_FRAME
|
|
cmpl $ia32_sysenter_target,(%esp)
|
|
jne debug_stack_correct
|
|
FIX_STACK 12, debug_stack_correct, debug_esp_fix_insn
|
|
debug_stack_correct:
|
|
pushl $-1 # mark this as an int
|
|
CFI_ADJUST_CFA_OFFSET 4
|
|
SAVE_ALL
|
|
TRACE_IRQS_OFF
|
|
xorl %edx,%edx # error code 0
|
|
movl %esp,%eax # pt_regs pointer
|
|
call do_debug
|
|
jmp ret_from_exception
|
|
CFI_ENDPROC
|
|
END(debug)
|
|
|
|
/*
|
|
* NMI is doubly nasty. It can happen _while_ we're handling
|
|
* a debug fault, and the debug fault hasn't yet been able to
|
|
* clear up the stack. So we first check whether we got an
|
|
* NMI on the sysenter entry path, but after that we need to
|
|
* check whether we got an NMI on the debug path where the debug
|
|
* fault happened on the sysenter path.
|
|
*/
|
|
ENTRY(nmi)
|
|
RING0_INT_FRAME
|
|
pushl %eax
|
|
CFI_ADJUST_CFA_OFFSET 4
|
|
movl %ss, %eax
|
|
cmpw $__ESPFIX_SS, %ax
|
|
popl %eax
|
|
CFI_ADJUST_CFA_OFFSET -4
|
|
je nmi_espfix_stack
|
|
cmpl $ia32_sysenter_target,(%esp)
|
|
je nmi_stack_fixup
|
|
pushl %eax
|
|
CFI_ADJUST_CFA_OFFSET 4
|
|
movl %esp,%eax
|
|
/* Do not access memory above the end of our stack page,
|
|
* it might not exist.
|
|
*/
|
|
andl $(THREAD_SIZE-1),%eax
|
|
cmpl $(THREAD_SIZE-20),%eax
|
|
popl %eax
|
|
CFI_ADJUST_CFA_OFFSET -4
|
|
jae nmi_stack_correct
|
|
cmpl $ia32_sysenter_target,12(%esp)
|
|
je nmi_debug_stack_check
|
|
nmi_stack_correct:
|
|
/* We have a RING0_INT_FRAME here */
|
|
pushl %eax
|
|
CFI_ADJUST_CFA_OFFSET 4
|
|
SAVE_ALL
|
|
xorl %edx,%edx # zero error code
|
|
movl %esp,%eax # pt_regs pointer
|
|
call do_nmi
|
|
jmp restore_all_notrace
|
|
CFI_ENDPROC
|
|
|
|
nmi_stack_fixup:
|
|
RING0_INT_FRAME
|
|
FIX_STACK 12, nmi_stack_correct, 1
|
|
jmp nmi_stack_correct
|
|
|
|
nmi_debug_stack_check:
|
|
/* We have a RING0_INT_FRAME here */
|
|
cmpw $__KERNEL_CS,16(%esp)
|
|
jne nmi_stack_correct
|
|
cmpl $debug,(%esp)
|
|
jb nmi_stack_correct
|
|
cmpl $debug_esp_fix_insn,(%esp)
|
|
ja nmi_stack_correct
|
|
FIX_STACK 24, nmi_stack_correct, 1
|
|
jmp nmi_stack_correct
|
|
|
|
nmi_espfix_stack:
|
|
/* We have a RING0_INT_FRAME here.
|
|
*
|
|
* create the pointer to lss back
|
|
*/
|
|
pushl %ss
|
|
CFI_ADJUST_CFA_OFFSET 4
|
|
pushl %esp
|
|
CFI_ADJUST_CFA_OFFSET 4
|
|
addl $4, (%esp)
|
|
/* copy the iret frame of 12 bytes */
|
|
.rept 3
|
|
pushl 16(%esp)
|
|
CFI_ADJUST_CFA_OFFSET 4
|
|
.endr
|
|
pushl %eax
|
|
CFI_ADJUST_CFA_OFFSET 4
|
|
SAVE_ALL
|
|
FIXUP_ESPFIX_STACK # %eax == %esp
|
|
xorl %edx,%edx # zero error code
|
|
call do_nmi
|
|
RESTORE_REGS
|
|
lss 12+4(%esp), %esp # back to espfix stack
|
|
CFI_ADJUST_CFA_OFFSET -24
|
|
jmp irq_return
|
|
CFI_ENDPROC
|
|
END(nmi)
|
|
|
|
ENTRY(int3)
|
|
RING0_INT_FRAME
|
|
pushl $-1 # mark this as an int
|
|
CFI_ADJUST_CFA_OFFSET 4
|
|
SAVE_ALL
|
|
TRACE_IRQS_OFF
|
|
xorl %edx,%edx # zero error code
|
|
movl %esp,%eax # pt_regs pointer
|
|
call do_int3
|
|
jmp ret_from_exception
|
|
CFI_ENDPROC
|
|
END(int3)
|
|
|
|
ENTRY(general_protection)
|
|
RING0_EC_FRAME
|
|
pushl $do_general_protection
|
|
CFI_ADJUST_CFA_OFFSET 4
|
|
jmp error_code
|
|
CFI_ENDPROC
|
|
END(general_protection)
|
|
|
|
/*
|
|
* End of kprobes section
|
|
*/
|
|
.popsection
|