1455 lines
34 KiB
ArmAsm
1455 lines
34 KiB
ArmAsm
/*
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* linux/arch/x86_64/entry.S
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*
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* Copyright (C) 1991, 1992 Linus Torvalds
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* Copyright (C) 2000, 2001, 2002 Andi Kleen SuSE Labs
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* Copyright (C) 2000 Pavel Machek <pavel@suse.cz>
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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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*
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* NOTE: This code handles signal-recognition, which happens every time
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* after an interrupt and after each system call.
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*
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* Normal syscalls and interrupts don't save a full stack frame, this is
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* only done for syscall tracing, signals or fork/exec et.al.
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*
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* A note on terminology:
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* - top of stack: Architecture defined interrupt frame from SS to RIP
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* at the top of the kernel process stack.
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* - partial stack frame: partially saved registers upto R11.
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* - full stack frame: Like partial stack frame, but all register saved.
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*
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* Some macro usage:
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* - CFI macros are used to generate dwarf2 unwind information for better
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* backtraces. They don't change any code.
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* - SAVE_ALL/RESTORE_ALL - Save/restore all registers
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* - SAVE_ARGS/RESTORE_ARGS - Save/restore registers that C functions modify.
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* There are unfortunately lots of special cases where some registers
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* not touched. The macro is a big mess that should be cleaned up.
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* - SAVE_REST/RESTORE_REST - Handle the registers not saved by SAVE_ARGS.
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* Gives a full stack frame.
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* - ENTRY/END Define functions in the symbol table.
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* - FIXUP_TOP_OF_STACK/RESTORE_TOP_OF_STACK - Fix up the hardware stack
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* frame that is otherwise undefined after a SYSCALL
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* - TRACE_IRQ_* - Trace hard interrupt state for lock debugging.
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* - errorentry/paranoidentry/zeroentry - Define exception entry points.
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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/cache.h>
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#include <asm/errno.h>
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#include <asm/dwarf2.h>
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#include <asm/calling.h>
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#include <asm/asm-offsets.h>
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#include <asm/msr.h>
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#include <asm/unistd.h>
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#include <asm/thread_info.h>
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#include <asm/hw_irq.h>
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#include <asm/page.h>
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#include <asm/irqflags.h>
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#include <asm/paravirt.h>
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#include <asm/ftrace.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_X86_64 (EM_X86_64|__AUDIT_ARCH_64BIT|__AUDIT_ARCH_LE)
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#define __AUDIT_ARCH_64BIT 0x80000000
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#define __AUDIT_ARCH_LE 0x40000000
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.code64
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#ifdef CONFIG_FTRACE
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#ifdef CONFIG_DYNAMIC_FTRACE
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ENTRY(mcount)
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retq
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END(mcount)
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ENTRY(ftrace_caller)
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/* taken from glibc */
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subq $0x38, %rsp
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movq %rax, (%rsp)
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movq %rcx, 8(%rsp)
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movq %rdx, 16(%rsp)
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movq %rsi, 24(%rsp)
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movq %rdi, 32(%rsp)
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movq %r8, 40(%rsp)
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movq %r9, 48(%rsp)
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movq 0x38(%rsp), %rdi
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movq 8(%rbp), %rsi
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subq $MCOUNT_INSN_SIZE, %rdi
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.globl ftrace_call
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ftrace_call:
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call ftrace_stub
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movq 48(%rsp), %r9
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movq 40(%rsp), %r8
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movq 32(%rsp), %rdi
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movq 24(%rsp), %rsi
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movq 16(%rsp), %rdx
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movq 8(%rsp), %rcx
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movq (%rsp), %rax
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addq $0x38, %rsp
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.globl ftrace_stub
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ftrace_stub:
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retq
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END(ftrace_caller)
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#else /* ! CONFIG_DYNAMIC_FTRACE */
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ENTRY(mcount)
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cmpq $ftrace_stub, ftrace_trace_function
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jnz trace
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.globl ftrace_stub
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ftrace_stub:
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retq
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trace:
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/* taken from glibc */
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subq $0x38, %rsp
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movq %rax, (%rsp)
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movq %rcx, 8(%rsp)
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movq %rdx, 16(%rsp)
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movq %rsi, 24(%rsp)
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movq %rdi, 32(%rsp)
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movq %r8, 40(%rsp)
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movq %r9, 48(%rsp)
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movq 0x38(%rsp), %rdi
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movq 8(%rbp), %rsi
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subq $MCOUNT_INSN_SIZE, %rdi
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call *ftrace_trace_function
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movq 48(%rsp), %r9
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movq 40(%rsp), %r8
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movq 32(%rsp), %rdi
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movq 24(%rsp), %rsi
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movq 16(%rsp), %rdx
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movq 8(%rsp), %rcx
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movq (%rsp), %rax
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addq $0x38, %rsp
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jmp ftrace_stub
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END(mcount)
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#endif /* CONFIG_DYNAMIC_FTRACE */
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#endif /* CONFIG_FTRACE */
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#ifndef CONFIG_PREEMPT
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#define retint_kernel retint_restore_args
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#endif
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#ifdef CONFIG_PARAVIRT
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ENTRY(native_usergs_sysret64)
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swapgs
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sysretq
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#endif /* CONFIG_PARAVIRT */
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.macro TRACE_IRQS_IRETQ offset=ARGOFFSET
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#ifdef CONFIG_TRACE_IRQFLAGS
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bt $9,EFLAGS-\offset(%rsp) /* interrupts off? */
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jnc 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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/*
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* C code is not supposed to know about undefined top of stack. Every time
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* a C function with an pt_regs argument is called from the SYSCALL based
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* fast path FIXUP_TOP_OF_STACK is needed.
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* RESTORE_TOP_OF_STACK syncs the syscall state after any possible ptregs
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* manipulation.
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*/
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/* %rsp:at FRAMEEND */
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.macro FIXUP_TOP_OF_STACK tmp
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movq %gs:pda_oldrsp,\tmp
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movq \tmp,RSP(%rsp)
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movq $__USER_DS,SS(%rsp)
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movq $__USER_CS,CS(%rsp)
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movq $-1,RCX(%rsp)
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movq R11(%rsp),\tmp /* get eflags */
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movq \tmp,EFLAGS(%rsp)
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.endm
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.macro RESTORE_TOP_OF_STACK tmp,offset=0
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movq RSP-\offset(%rsp),\tmp
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movq \tmp,%gs:pda_oldrsp
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movq EFLAGS-\offset(%rsp),\tmp
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movq \tmp,R11-\offset(%rsp)
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.endm
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.macro FAKE_STACK_FRAME child_rip
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/* push in order ss, rsp, eflags, cs, rip */
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xorl %eax, %eax
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pushq $__KERNEL_DS /* ss */
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CFI_ADJUST_CFA_OFFSET 8
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/*CFI_REL_OFFSET ss,0*/
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pushq %rax /* rsp */
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CFI_ADJUST_CFA_OFFSET 8
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CFI_REL_OFFSET rsp,0
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pushq $(1<<9) /* eflags - interrupts on */
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CFI_ADJUST_CFA_OFFSET 8
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/*CFI_REL_OFFSET rflags,0*/
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pushq $__KERNEL_CS /* cs */
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CFI_ADJUST_CFA_OFFSET 8
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/*CFI_REL_OFFSET cs,0*/
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pushq \child_rip /* rip */
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CFI_ADJUST_CFA_OFFSET 8
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CFI_REL_OFFSET rip,0
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pushq %rax /* orig rax */
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CFI_ADJUST_CFA_OFFSET 8
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.endm
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.macro UNFAKE_STACK_FRAME
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addq $8*6, %rsp
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CFI_ADJUST_CFA_OFFSET -(6*8)
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.endm
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.macro CFI_DEFAULT_STACK start=1
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.if \start
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CFI_STARTPROC simple
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CFI_SIGNAL_FRAME
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CFI_DEF_CFA rsp,SS+8
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.else
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CFI_DEF_CFA_OFFSET SS+8
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.endif
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CFI_REL_OFFSET r15,R15
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CFI_REL_OFFSET r14,R14
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CFI_REL_OFFSET r13,R13
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CFI_REL_OFFSET r12,R12
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CFI_REL_OFFSET rbp,RBP
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CFI_REL_OFFSET rbx,RBX
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CFI_REL_OFFSET r11,R11
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CFI_REL_OFFSET r10,R10
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CFI_REL_OFFSET r9,R9
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CFI_REL_OFFSET r8,R8
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CFI_REL_OFFSET rax,RAX
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CFI_REL_OFFSET rcx,RCX
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CFI_REL_OFFSET rdx,RDX
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CFI_REL_OFFSET rsi,RSI
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CFI_REL_OFFSET rdi,RDI
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CFI_REL_OFFSET rip,RIP
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/*CFI_REL_OFFSET cs,CS*/
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/*CFI_REL_OFFSET rflags,EFLAGS*/
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CFI_REL_OFFSET rsp,RSP
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/*CFI_REL_OFFSET ss,SS*/
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.endm
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/*
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* A newly forked process directly context switches into this.
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*/
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/* rdi: prev */
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ENTRY(ret_from_fork)
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CFI_DEFAULT_STACK
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push kernel_eflags(%rip)
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CFI_ADJUST_CFA_OFFSET 8
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popf # reset kernel eflags
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CFI_ADJUST_CFA_OFFSET -8
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call schedule_tail
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GET_THREAD_INFO(%rcx)
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testl $(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT),TI_flags(%rcx)
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jnz rff_trace
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rff_action:
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RESTORE_REST
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testl $3,CS-ARGOFFSET(%rsp) # from kernel_thread?
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je int_ret_from_sys_call
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testl $_TIF_IA32,TI_flags(%rcx)
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jnz int_ret_from_sys_call
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RESTORE_TOP_OF_STACK %rdi,ARGOFFSET
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jmp ret_from_sys_call
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rff_trace:
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movq %rsp,%rdi
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call syscall_trace_leave
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GET_THREAD_INFO(%rcx)
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jmp rff_action
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CFI_ENDPROC
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END(ret_from_fork)
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/*
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* System call entry. Upto 6 arguments in registers are supported.
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*
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* SYSCALL does not save anything on the stack and does not change the
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* stack pointer.
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*/
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/*
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* Register setup:
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* rax system call number
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* rdi arg0
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* rcx return address for syscall/sysret, C arg3
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* rsi arg1
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* rdx arg2
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* r10 arg3 (--> moved to rcx for C)
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* r8 arg4
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* r9 arg5
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* r11 eflags for syscall/sysret, temporary for C
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* r12-r15,rbp,rbx saved by C code, not touched.
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*
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* Interrupts are off on entry.
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* Only called from user space.
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*
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* XXX if we had a free scratch register we could save the RSP into the stack frame
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* and report it properly in ps. Unfortunately we haven't.
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*
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* When user can change the frames always force IRET. That is because
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* it deals with uncanonical addresses better. SYSRET has trouble
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* with them due to bugs in both AMD and Intel CPUs.
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*/
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ENTRY(system_call)
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CFI_STARTPROC simple
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CFI_SIGNAL_FRAME
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CFI_DEF_CFA rsp,PDA_STACKOFFSET
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CFI_REGISTER rip,rcx
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/*CFI_REGISTER rflags,r11*/
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SWAPGS_UNSAFE_STACK
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/*
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* A hypervisor implementation might want to use a label
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* after the swapgs, so that it can do the swapgs
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* for the guest and jump here on syscall.
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*/
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ENTRY(system_call_after_swapgs)
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movq %rsp,%gs:pda_oldrsp
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movq %gs:pda_kernelstack,%rsp
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/*
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* No need to follow this irqs off/on section - it's straight
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* and short:
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*/
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ENABLE_INTERRUPTS(CLBR_NONE)
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SAVE_ARGS 8,1
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movq %rax,ORIG_RAX-ARGOFFSET(%rsp)
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movq %rcx,RIP-ARGOFFSET(%rsp)
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CFI_REL_OFFSET rip,RIP-ARGOFFSET
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GET_THREAD_INFO(%rcx)
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testl $_TIF_WORK_SYSCALL_ENTRY,TI_flags(%rcx)
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jnz tracesys
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system_call_fastpath:
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cmpq $__NR_syscall_max,%rax
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ja badsys
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movq %r10,%rcx
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call *sys_call_table(,%rax,8) # XXX: rip relative
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movq %rax,RAX-ARGOFFSET(%rsp)
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/*
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* Syscall return path ending with SYSRET (fast path)
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* Has incomplete stack frame and undefined top of stack.
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*/
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ret_from_sys_call:
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movl $_TIF_ALLWORK_MASK,%edi
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/* edi: flagmask */
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sysret_check:
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LOCKDEP_SYS_EXIT
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GET_THREAD_INFO(%rcx)
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DISABLE_INTERRUPTS(CLBR_NONE)
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TRACE_IRQS_OFF
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movl TI_flags(%rcx),%edx
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andl %edi,%edx
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jnz sysret_careful
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CFI_REMEMBER_STATE
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/*
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* sysretq will re-enable interrupts:
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*/
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TRACE_IRQS_ON
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movq RIP-ARGOFFSET(%rsp),%rcx
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CFI_REGISTER rip,rcx
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RESTORE_ARGS 0,-ARG_SKIP,1
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/*CFI_REGISTER rflags,r11*/
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movq %gs:pda_oldrsp, %rsp
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USERGS_SYSRET64
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CFI_RESTORE_STATE
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/* Handle reschedules */
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/* edx: work, edi: workmask */
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sysret_careful:
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bt $TIF_NEED_RESCHED,%edx
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jnc sysret_signal
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TRACE_IRQS_ON
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ENABLE_INTERRUPTS(CLBR_NONE)
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pushq %rdi
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CFI_ADJUST_CFA_OFFSET 8
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call schedule
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popq %rdi
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CFI_ADJUST_CFA_OFFSET -8
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jmp sysret_check
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/* Handle a signal */
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sysret_signal:
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TRACE_IRQS_ON
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ENABLE_INTERRUPTS(CLBR_NONE)
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#ifdef CONFIG_AUDITSYSCALL
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bt $TIF_SYSCALL_AUDIT,%edx
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jc sysret_audit
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#endif
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/* edx: work flags (arg3) */
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leaq do_notify_resume(%rip),%rax
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leaq -ARGOFFSET(%rsp),%rdi # &pt_regs -> arg1
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xorl %esi,%esi # oldset -> arg2
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call ptregscall_common
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movl $_TIF_WORK_MASK,%edi
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/* Use IRET because user could have changed frame. This
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works because ptregscall_common has called FIXUP_TOP_OF_STACK. */
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DISABLE_INTERRUPTS(CLBR_NONE)
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TRACE_IRQS_OFF
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jmp int_with_check
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badsys:
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movq $-ENOSYS,RAX-ARGOFFSET(%rsp)
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jmp ret_from_sys_call
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#ifdef CONFIG_AUDITSYSCALL
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/*
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* Fast path for syscall audit without full syscall trace.
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* We just call audit_syscall_entry() directly, and then
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* jump back to the normal fast path.
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*/
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auditsys:
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movq %r10,%r9 /* 6th arg: 4th syscall arg */
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movq %rdx,%r8 /* 5th arg: 3rd syscall arg */
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movq %rsi,%rcx /* 4th arg: 2nd syscall arg */
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movq %rdi,%rdx /* 3rd arg: 1st syscall arg */
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movq %rax,%rsi /* 2nd arg: syscall number */
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movl $AUDIT_ARCH_X86_64,%edi /* 1st arg: audit arch */
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call audit_syscall_entry
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LOAD_ARGS 0 /* reload call-clobbered registers */
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jmp system_call_fastpath
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/*
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* Return fast path for syscall audit. Call audit_syscall_exit()
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* directly and then jump back to the fast path with TIF_SYSCALL_AUDIT
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* masked off.
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*/
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sysret_audit:
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movq %rax,%rsi /* second arg, syscall return value */
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cmpq $0,%rax /* is it < 0? */
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setl %al /* 1 if so, 0 if not */
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movzbl %al,%edi /* zero-extend that into %edi */
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inc %edi /* first arg, 0->1(AUDITSC_SUCCESS), 1->2(AUDITSC_FAILURE) */
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call audit_syscall_exit
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movl $(_TIF_ALLWORK_MASK & ~_TIF_SYSCALL_AUDIT),%edi
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jmp sysret_check
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#endif /* CONFIG_AUDITSYSCALL */
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/* Do syscall tracing */
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tracesys:
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#ifdef CONFIG_AUDITSYSCALL
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testl $(_TIF_WORK_SYSCALL_ENTRY & ~_TIF_SYSCALL_AUDIT),TI_flags(%rcx)
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jz auditsys
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#endif
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SAVE_REST
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movq $-ENOSYS,RAX(%rsp) /* ptrace can change this for a bad syscall */
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FIXUP_TOP_OF_STACK %rdi
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movq %rsp,%rdi
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call syscall_trace_enter
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/*
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* Reload arg registers from stack in case ptrace changed them.
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* We don't reload %rax because syscall_trace_enter() returned
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* the value it wants us to use in the table lookup.
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*/
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LOAD_ARGS ARGOFFSET, 1
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RESTORE_REST
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cmpq $__NR_syscall_max,%rax
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ja int_ret_from_sys_call /* RAX(%rsp) set to -ENOSYS above */
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movq %r10,%rcx /* fixup for C */
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call *sys_call_table(,%rax,8)
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movq %rax,RAX-ARGOFFSET(%rsp)
|
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/* Use IRET because user could have changed frame */
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/*
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* Syscall return path ending with IRET.
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* Has correct top of stack, but partial stack frame.
|
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*/
|
|
.globl int_ret_from_sys_call
|
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.globl int_with_check
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int_ret_from_sys_call:
|
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DISABLE_INTERRUPTS(CLBR_NONE)
|
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TRACE_IRQS_OFF
|
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testl $3,CS-ARGOFFSET(%rsp)
|
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je retint_restore_args
|
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movl $_TIF_ALLWORK_MASK,%edi
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/* edi: mask to check */
|
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int_with_check:
|
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LOCKDEP_SYS_EXIT_IRQ
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GET_THREAD_INFO(%rcx)
|
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movl TI_flags(%rcx),%edx
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andl %edi,%edx
|
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jnz int_careful
|
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andl $~TS_COMPAT,TI_status(%rcx)
|
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jmp retint_swapgs
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|
|
/* Either reschedule or signal or syscall exit tracking needed. */
|
|
/* First do a reschedule test. */
|
|
/* edx: work, edi: workmask */
|
|
int_careful:
|
|
bt $TIF_NEED_RESCHED,%edx
|
|
jnc int_very_careful
|
|
TRACE_IRQS_ON
|
|
ENABLE_INTERRUPTS(CLBR_NONE)
|
|
pushq %rdi
|
|
CFI_ADJUST_CFA_OFFSET 8
|
|
call schedule
|
|
popq %rdi
|
|
CFI_ADJUST_CFA_OFFSET -8
|
|
DISABLE_INTERRUPTS(CLBR_NONE)
|
|
TRACE_IRQS_OFF
|
|
jmp int_with_check
|
|
|
|
/* handle signals and tracing -- both require a full stack frame */
|
|
int_very_careful:
|
|
TRACE_IRQS_ON
|
|
ENABLE_INTERRUPTS(CLBR_NONE)
|
|
SAVE_REST
|
|
/* Check for syscall exit trace */
|
|
testl $_TIF_WORK_SYSCALL_EXIT,%edx
|
|
jz int_signal
|
|
pushq %rdi
|
|
CFI_ADJUST_CFA_OFFSET 8
|
|
leaq 8(%rsp),%rdi # &ptregs -> arg1
|
|
call syscall_trace_leave
|
|
popq %rdi
|
|
CFI_ADJUST_CFA_OFFSET -8
|
|
andl $~(_TIF_WORK_SYSCALL_EXIT|_TIF_SYSCALL_EMU),%edi
|
|
jmp int_restore_rest
|
|
|
|
int_signal:
|
|
testl $_TIF_DO_NOTIFY_MASK,%edx
|
|
jz 1f
|
|
movq %rsp,%rdi # &ptregs -> arg1
|
|
xorl %esi,%esi # oldset -> arg2
|
|
call do_notify_resume
|
|
1: movl $_TIF_WORK_MASK,%edi
|
|
int_restore_rest:
|
|
RESTORE_REST
|
|
DISABLE_INTERRUPTS(CLBR_NONE)
|
|
TRACE_IRQS_OFF
|
|
jmp int_with_check
|
|
CFI_ENDPROC
|
|
END(system_call)
|
|
|
|
/*
|
|
* Certain special system calls that need to save a complete full stack frame.
|
|
*/
|
|
|
|
.macro PTREGSCALL label,func,arg
|
|
.globl \label
|
|
\label:
|
|
leaq \func(%rip),%rax
|
|
leaq -ARGOFFSET+8(%rsp),\arg /* 8 for return address */
|
|
jmp ptregscall_common
|
|
END(\label)
|
|
.endm
|
|
|
|
CFI_STARTPROC
|
|
|
|
PTREGSCALL stub_clone, sys_clone, %r8
|
|
PTREGSCALL stub_fork, sys_fork, %rdi
|
|
PTREGSCALL stub_vfork, sys_vfork, %rdi
|
|
PTREGSCALL stub_sigaltstack, sys_sigaltstack, %rdx
|
|
PTREGSCALL stub_iopl, sys_iopl, %rsi
|
|
|
|
ENTRY(ptregscall_common)
|
|
popq %r11
|
|
CFI_ADJUST_CFA_OFFSET -8
|
|
CFI_REGISTER rip, r11
|
|
SAVE_REST
|
|
movq %r11, %r15
|
|
CFI_REGISTER rip, r15
|
|
FIXUP_TOP_OF_STACK %r11
|
|
call *%rax
|
|
RESTORE_TOP_OF_STACK %r11
|
|
movq %r15, %r11
|
|
CFI_REGISTER rip, r11
|
|
RESTORE_REST
|
|
pushq %r11
|
|
CFI_ADJUST_CFA_OFFSET 8
|
|
CFI_REL_OFFSET rip, 0
|
|
ret
|
|
CFI_ENDPROC
|
|
END(ptregscall_common)
|
|
|
|
ENTRY(stub_execve)
|
|
CFI_STARTPROC
|
|
popq %r11
|
|
CFI_ADJUST_CFA_OFFSET -8
|
|
CFI_REGISTER rip, r11
|
|
SAVE_REST
|
|
FIXUP_TOP_OF_STACK %r11
|
|
movq %rsp, %rcx
|
|
call sys_execve
|
|
RESTORE_TOP_OF_STACK %r11
|
|
movq %rax,RAX(%rsp)
|
|
RESTORE_REST
|
|
jmp int_ret_from_sys_call
|
|
CFI_ENDPROC
|
|
END(stub_execve)
|
|
|
|
/*
|
|
* sigreturn is special because it needs to restore all registers on return.
|
|
* This cannot be done with SYSRET, so use the IRET return path instead.
|
|
*/
|
|
ENTRY(stub_rt_sigreturn)
|
|
CFI_STARTPROC
|
|
addq $8, %rsp
|
|
CFI_ADJUST_CFA_OFFSET -8
|
|
SAVE_REST
|
|
movq %rsp,%rdi
|
|
FIXUP_TOP_OF_STACK %r11
|
|
call sys_rt_sigreturn
|
|
movq %rax,RAX(%rsp) # fixme, this could be done at the higher layer
|
|
RESTORE_REST
|
|
jmp int_ret_from_sys_call
|
|
CFI_ENDPROC
|
|
END(stub_rt_sigreturn)
|
|
|
|
/*
|
|
* initial frame state for interrupts and exceptions
|
|
*/
|
|
.macro _frame ref
|
|
CFI_STARTPROC simple
|
|
CFI_SIGNAL_FRAME
|
|
CFI_DEF_CFA rsp,SS+8-\ref
|
|
/*CFI_REL_OFFSET ss,SS-\ref*/
|
|
CFI_REL_OFFSET rsp,RSP-\ref
|
|
/*CFI_REL_OFFSET rflags,EFLAGS-\ref*/
|
|
/*CFI_REL_OFFSET cs,CS-\ref*/
|
|
CFI_REL_OFFSET rip,RIP-\ref
|
|
.endm
|
|
|
|
/* initial frame state for interrupts (and exceptions without error code) */
|
|
#define INTR_FRAME _frame RIP
|
|
/* initial frame state for exceptions with error code (and interrupts with
|
|
vector already pushed) */
|
|
#define XCPT_FRAME _frame ORIG_RAX
|
|
|
|
/*
|
|
* Interrupt entry/exit.
|
|
*
|
|
* Interrupt entry points save only callee clobbered registers in fast path.
|
|
*
|
|
* Entry runs with interrupts off.
|
|
*/
|
|
|
|
/* 0(%rsp): interrupt number */
|
|
.macro interrupt func
|
|
cld
|
|
SAVE_ARGS
|
|
leaq -ARGOFFSET(%rsp),%rdi # arg1 for handler
|
|
pushq %rbp
|
|
/*
|
|
* Save rbp twice: One is for marking the stack frame, as usual, and the
|
|
* other, to fill pt_regs properly. This is because bx comes right
|
|
* before the last saved register in that structure, and not bp. If the
|
|
* base pointer were in the place bx is today, this would not be needed.
|
|
*/
|
|
movq %rbp, -8(%rsp)
|
|
CFI_ADJUST_CFA_OFFSET 8
|
|
CFI_REL_OFFSET rbp, 0
|
|
movq %rsp,%rbp
|
|
CFI_DEF_CFA_REGISTER rbp
|
|
testl $3,CS(%rdi)
|
|
je 1f
|
|
SWAPGS
|
|
/* irqcount is used to check if a CPU is already on an interrupt
|
|
stack or not. While this is essentially redundant with preempt_count
|
|
it is a little cheaper to use a separate counter in the PDA
|
|
(short of moving irq_enter into assembly, which would be too
|
|
much work) */
|
|
1: incl %gs:pda_irqcount
|
|
cmoveq %gs:pda_irqstackptr,%rsp
|
|
push %rbp # backlink for old unwinder
|
|
/*
|
|
* We entered an interrupt context - irqs are off:
|
|
*/
|
|
TRACE_IRQS_OFF
|
|
call \func
|
|
.endm
|
|
|
|
ENTRY(common_interrupt)
|
|
XCPT_FRAME
|
|
interrupt do_IRQ
|
|
/* 0(%rsp): oldrsp-ARGOFFSET */
|
|
ret_from_intr:
|
|
DISABLE_INTERRUPTS(CLBR_NONE)
|
|
TRACE_IRQS_OFF
|
|
decl %gs:pda_irqcount
|
|
leaveq
|
|
CFI_DEF_CFA_REGISTER rsp
|
|
CFI_ADJUST_CFA_OFFSET -8
|
|
exit_intr:
|
|
GET_THREAD_INFO(%rcx)
|
|
testl $3,CS-ARGOFFSET(%rsp)
|
|
je retint_kernel
|
|
|
|
/* Interrupt came from user space */
|
|
/*
|
|
* Has a correct top of stack, but a partial stack frame
|
|
* %rcx: thread info. Interrupts off.
|
|
*/
|
|
retint_with_reschedule:
|
|
movl $_TIF_WORK_MASK,%edi
|
|
retint_check:
|
|
LOCKDEP_SYS_EXIT_IRQ
|
|
movl TI_flags(%rcx),%edx
|
|
andl %edi,%edx
|
|
CFI_REMEMBER_STATE
|
|
jnz retint_careful
|
|
|
|
retint_swapgs: /* return to user-space */
|
|
/*
|
|
* The iretq could re-enable interrupts:
|
|
*/
|
|
DISABLE_INTERRUPTS(CLBR_ANY)
|
|
TRACE_IRQS_IRETQ
|
|
SWAPGS
|
|
jmp restore_args
|
|
|
|
retint_restore_args: /* return to kernel space */
|
|
DISABLE_INTERRUPTS(CLBR_ANY)
|
|
/*
|
|
* The iretq could re-enable interrupts:
|
|
*/
|
|
TRACE_IRQS_IRETQ
|
|
restore_args:
|
|
RESTORE_ARGS 0,8,0
|
|
|
|
irq_return:
|
|
INTERRUPT_RETURN
|
|
|
|
.section __ex_table, "a"
|
|
.quad irq_return, bad_iret
|
|
.previous
|
|
|
|
#ifdef CONFIG_PARAVIRT
|
|
ENTRY(native_iret)
|
|
iretq
|
|
|
|
.section __ex_table,"a"
|
|
.quad native_iret, bad_iret
|
|
.previous
|
|
#endif
|
|
|
|
.section .fixup,"ax"
|
|
bad_iret:
|
|
/*
|
|
* The iret traps when the %cs or %ss being restored is bogus.
|
|
* We've lost the original trap vector and error code.
|
|
* #GPF is the most likely one to get for an invalid selector.
|
|
* So pretend we completed the iret and took the #GPF in user mode.
|
|
*
|
|
* We are now running with the kernel GS after exception recovery.
|
|
* But error_entry expects us to have user GS to match the user %cs,
|
|
* so swap back.
|
|
*/
|
|
pushq $0
|
|
|
|
SWAPGS
|
|
jmp general_protection
|
|
|
|
.previous
|
|
|
|
/* edi: workmask, edx: work */
|
|
retint_careful:
|
|
CFI_RESTORE_STATE
|
|
bt $TIF_NEED_RESCHED,%edx
|
|
jnc retint_signal
|
|
TRACE_IRQS_ON
|
|
ENABLE_INTERRUPTS(CLBR_NONE)
|
|
pushq %rdi
|
|
CFI_ADJUST_CFA_OFFSET 8
|
|
call schedule
|
|
popq %rdi
|
|
CFI_ADJUST_CFA_OFFSET -8
|
|
GET_THREAD_INFO(%rcx)
|
|
DISABLE_INTERRUPTS(CLBR_NONE)
|
|
TRACE_IRQS_OFF
|
|
jmp retint_check
|
|
|
|
retint_signal:
|
|
testl $_TIF_DO_NOTIFY_MASK,%edx
|
|
jz retint_swapgs
|
|
TRACE_IRQS_ON
|
|
ENABLE_INTERRUPTS(CLBR_NONE)
|
|
SAVE_REST
|
|
movq $-1,ORIG_RAX(%rsp)
|
|
xorl %esi,%esi # oldset
|
|
movq %rsp,%rdi # &pt_regs
|
|
call do_notify_resume
|
|
RESTORE_REST
|
|
DISABLE_INTERRUPTS(CLBR_NONE)
|
|
TRACE_IRQS_OFF
|
|
GET_THREAD_INFO(%rcx)
|
|
jmp retint_with_reschedule
|
|
|
|
#ifdef CONFIG_PREEMPT
|
|
/* Returning to kernel space. Check if we need preemption */
|
|
/* rcx: threadinfo. interrupts off. */
|
|
ENTRY(retint_kernel)
|
|
cmpl $0,TI_preempt_count(%rcx)
|
|
jnz retint_restore_args
|
|
bt $TIF_NEED_RESCHED,TI_flags(%rcx)
|
|
jnc retint_restore_args
|
|
bt $9,EFLAGS-ARGOFFSET(%rsp) /* interrupts off? */
|
|
jnc retint_restore_args
|
|
call preempt_schedule_irq
|
|
jmp exit_intr
|
|
#endif
|
|
|
|
CFI_ENDPROC
|
|
END(common_interrupt)
|
|
|
|
/*
|
|
* APIC interrupts.
|
|
*/
|
|
.macro apicinterrupt num,func
|
|
INTR_FRAME
|
|
pushq $~(\num)
|
|
CFI_ADJUST_CFA_OFFSET 8
|
|
interrupt \func
|
|
jmp ret_from_intr
|
|
CFI_ENDPROC
|
|
.endm
|
|
|
|
ENTRY(thermal_interrupt)
|
|
apicinterrupt THERMAL_APIC_VECTOR,smp_thermal_interrupt
|
|
END(thermal_interrupt)
|
|
|
|
ENTRY(threshold_interrupt)
|
|
apicinterrupt THRESHOLD_APIC_VECTOR,mce_threshold_interrupt
|
|
END(threshold_interrupt)
|
|
|
|
#ifdef CONFIG_SMP
|
|
ENTRY(reschedule_interrupt)
|
|
apicinterrupt RESCHEDULE_VECTOR,smp_reschedule_interrupt
|
|
END(reschedule_interrupt)
|
|
|
|
.macro INVALIDATE_ENTRY num
|
|
ENTRY(invalidate_interrupt\num)
|
|
apicinterrupt INVALIDATE_TLB_VECTOR_START+\num,smp_invalidate_interrupt
|
|
END(invalidate_interrupt\num)
|
|
.endm
|
|
|
|
INVALIDATE_ENTRY 0
|
|
INVALIDATE_ENTRY 1
|
|
INVALIDATE_ENTRY 2
|
|
INVALIDATE_ENTRY 3
|
|
INVALIDATE_ENTRY 4
|
|
INVALIDATE_ENTRY 5
|
|
INVALIDATE_ENTRY 6
|
|
INVALIDATE_ENTRY 7
|
|
|
|
ENTRY(call_function_interrupt)
|
|
apicinterrupt CALL_FUNCTION_VECTOR,smp_call_function_interrupt
|
|
END(call_function_interrupt)
|
|
ENTRY(call_function_single_interrupt)
|
|
apicinterrupt CALL_FUNCTION_SINGLE_VECTOR,smp_call_function_single_interrupt
|
|
END(call_function_single_interrupt)
|
|
ENTRY(irq_move_cleanup_interrupt)
|
|
apicinterrupt IRQ_MOVE_CLEANUP_VECTOR,smp_irq_move_cleanup_interrupt
|
|
END(irq_move_cleanup_interrupt)
|
|
#endif
|
|
|
|
ENTRY(apic_timer_interrupt)
|
|
apicinterrupt LOCAL_TIMER_VECTOR,smp_apic_timer_interrupt
|
|
END(apic_timer_interrupt)
|
|
|
|
ENTRY(uv_bau_message_intr1)
|
|
apicinterrupt 220,uv_bau_message_interrupt
|
|
END(uv_bau_message_intr1)
|
|
|
|
ENTRY(error_interrupt)
|
|
apicinterrupt ERROR_APIC_VECTOR,smp_error_interrupt
|
|
END(error_interrupt)
|
|
|
|
ENTRY(spurious_interrupt)
|
|
apicinterrupt SPURIOUS_APIC_VECTOR,smp_spurious_interrupt
|
|
END(spurious_interrupt)
|
|
|
|
/*
|
|
* Exception entry points.
|
|
*/
|
|
.macro zeroentry sym
|
|
INTR_FRAME
|
|
PARAVIRT_ADJUST_EXCEPTION_FRAME
|
|
pushq $0 /* push error code/oldrax */
|
|
CFI_ADJUST_CFA_OFFSET 8
|
|
pushq %rax /* push real oldrax to the rdi slot */
|
|
CFI_ADJUST_CFA_OFFSET 8
|
|
CFI_REL_OFFSET rax,0
|
|
leaq \sym(%rip),%rax
|
|
jmp error_entry
|
|
CFI_ENDPROC
|
|
.endm
|
|
|
|
.macro errorentry sym
|
|
XCPT_FRAME
|
|
PARAVIRT_ADJUST_EXCEPTION_FRAME
|
|
pushq %rax
|
|
CFI_ADJUST_CFA_OFFSET 8
|
|
CFI_REL_OFFSET rax,0
|
|
leaq \sym(%rip),%rax
|
|
jmp error_entry
|
|
CFI_ENDPROC
|
|
.endm
|
|
|
|
/* error code is on the stack already */
|
|
/* handle NMI like exceptions that can happen everywhere */
|
|
.macro paranoidentry sym, ist=0, irqtrace=1
|
|
SAVE_ALL
|
|
cld
|
|
movl $1,%ebx
|
|
movl $MSR_GS_BASE,%ecx
|
|
rdmsr
|
|
testl %edx,%edx
|
|
js 1f
|
|
SWAPGS
|
|
xorl %ebx,%ebx
|
|
1:
|
|
.if \ist
|
|
movq %gs:pda_data_offset, %rbp
|
|
.endif
|
|
.if \irqtrace
|
|
TRACE_IRQS_OFF
|
|
.endif
|
|
movq %rsp,%rdi
|
|
movq ORIG_RAX(%rsp),%rsi
|
|
movq $-1,ORIG_RAX(%rsp)
|
|
.if \ist
|
|
subq $EXCEPTION_STKSZ, per_cpu__init_tss + TSS_ist + (\ist - 1) * 8(%rbp)
|
|
.endif
|
|
call \sym
|
|
.if \ist
|
|
addq $EXCEPTION_STKSZ, per_cpu__init_tss + TSS_ist + (\ist - 1) * 8(%rbp)
|
|
.endif
|
|
DISABLE_INTERRUPTS(CLBR_NONE)
|
|
.if \irqtrace
|
|
TRACE_IRQS_OFF
|
|
.endif
|
|
.endm
|
|
|
|
/*
|
|
* "Paranoid" exit path from exception stack.
|
|
* Paranoid because this is used by NMIs and cannot take
|
|
* any kernel state for granted.
|
|
* We don't do kernel preemption checks here, because only
|
|
* NMI should be common and it does not enable IRQs and
|
|
* cannot get reschedule ticks.
|
|
*
|
|
* "trace" is 0 for the NMI handler only, because irq-tracing
|
|
* is fundamentally NMI-unsafe. (we cannot change the soft and
|
|
* hard flags at once, atomically)
|
|
*/
|
|
.macro paranoidexit trace=1
|
|
/* ebx: no swapgs flag */
|
|
paranoid_exit\trace:
|
|
testl %ebx,%ebx /* swapgs needed? */
|
|
jnz paranoid_restore\trace
|
|
testl $3,CS(%rsp)
|
|
jnz paranoid_userspace\trace
|
|
paranoid_swapgs\trace:
|
|
.if \trace
|
|
TRACE_IRQS_IRETQ 0
|
|
.endif
|
|
SWAPGS_UNSAFE_STACK
|
|
paranoid_restore\trace:
|
|
RESTORE_ALL 8
|
|
jmp irq_return
|
|
paranoid_userspace\trace:
|
|
GET_THREAD_INFO(%rcx)
|
|
movl TI_flags(%rcx),%ebx
|
|
andl $_TIF_WORK_MASK,%ebx
|
|
jz paranoid_swapgs\trace
|
|
movq %rsp,%rdi /* &pt_regs */
|
|
call sync_regs
|
|
movq %rax,%rsp /* switch stack for scheduling */
|
|
testl $_TIF_NEED_RESCHED,%ebx
|
|
jnz paranoid_schedule\trace
|
|
movl %ebx,%edx /* arg3: thread flags */
|
|
.if \trace
|
|
TRACE_IRQS_ON
|
|
.endif
|
|
ENABLE_INTERRUPTS(CLBR_NONE)
|
|
xorl %esi,%esi /* arg2: oldset */
|
|
movq %rsp,%rdi /* arg1: &pt_regs */
|
|
call do_notify_resume
|
|
DISABLE_INTERRUPTS(CLBR_NONE)
|
|
.if \trace
|
|
TRACE_IRQS_OFF
|
|
.endif
|
|
jmp paranoid_userspace\trace
|
|
paranoid_schedule\trace:
|
|
.if \trace
|
|
TRACE_IRQS_ON
|
|
.endif
|
|
ENABLE_INTERRUPTS(CLBR_ANY)
|
|
call schedule
|
|
DISABLE_INTERRUPTS(CLBR_ANY)
|
|
.if \trace
|
|
TRACE_IRQS_OFF
|
|
.endif
|
|
jmp paranoid_userspace\trace
|
|
CFI_ENDPROC
|
|
.endm
|
|
|
|
/*
|
|
* Exception entry point. This expects an error code/orig_rax on the stack
|
|
* and the exception handler in %rax.
|
|
*/
|
|
KPROBE_ENTRY(error_entry)
|
|
_frame RDI
|
|
CFI_REL_OFFSET rax,0
|
|
/* rdi slot contains rax, oldrax contains error code */
|
|
cld
|
|
subq $14*8,%rsp
|
|
CFI_ADJUST_CFA_OFFSET (14*8)
|
|
movq %rsi,13*8(%rsp)
|
|
CFI_REL_OFFSET rsi,RSI
|
|
movq 14*8(%rsp),%rsi /* load rax from rdi slot */
|
|
CFI_REGISTER rax,rsi
|
|
movq %rdx,12*8(%rsp)
|
|
CFI_REL_OFFSET rdx,RDX
|
|
movq %rcx,11*8(%rsp)
|
|
CFI_REL_OFFSET rcx,RCX
|
|
movq %rsi,10*8(%rsp) /* store rax */
|
|
CFI_REL_OFFSET rax,RAX
|
|
movq %r8, 9*8(%rsp)
|
|
CFI_REL_OFFSET r8,R8
|
|
movq %r9, 8*8(%rsp)
|
|
CFI_REL_OFFSET r9,R9
|
|
movq %r10,7*8(%rsp)
|
|
CFI_REL_OFFSET r10,R10
|
|
movq %r11,6*8(%rsp)
|
|
CFI_REL_OFFSET r11,R11
|
|
movq %rbx,5*8(%rsp)
|
|
CFI_REL_OFFSET rbx,RBX
|
|
movq %rbp,4*8(%rsp)
|
|
CFI_REL_OFFSET rbp,RBP
|
|
movq %r12,3*8(%rsp)
|
|
CFI_REL_OFFSET r12,R12
|
|
movq %r13,2*8(%rsp)
|
|
CFI_REL_OFFSET r13,R13
|
|
movq %r14,1*8(%rsp)
|
|
CFI_REL_OFFSET r14,R14
|
|
movq %r15,(%rsp)
|
|
CFI_REL_OFFSET r15,R15
|
|
xorl %ebx,%ebx
|
|
testl $3,CS(%rsp)
|
|
je error_kernelspace
|
|
error_swapgs:
|
|
SWAPGS
|
|
error_sti:
|
|
TRACE_IRQS_OFF
|
|
movq %rdi,RDI(%rsp)
|
|
CFI_REL_OFFSET rdi,RDI
|
|
movq %rsp,%rdi
|
|
movq ORIG_RAX(%rsp),%rsi /* get error code */
|
|
movq $-1,ORIG_RAX(%rsp)
|
|
call *%rax
|
|
/* ebx: no swapgs flag (1: don't need swapgs, 0: need it) */
|
|
error_exit:
|
|
movl %ebx,%eax
|
|
RESTORE_REST
|
|
DISABLE_INTERRUPTS(CLBR_NONE)
|
|
TRACE_IRQS_OFF
|
|
GET_THREAD_INFO(%rcx)
|
|
testl %eax,%eax
|
|
jne retint_kernel
|
|
LOCKDEP_SYS_EXIT_IRQ
|
|
movl TI_flags(%rcx),%edx
|
|
movl $_TIF_WORK_MASK,%edi
|
|
andl %edi,%edx
|
|
jnz retint_careful
|
|
jmp retint_swapgs
|
|
CFI_ENDPROC
|
|
|
|
error_kernelspace:
|
|
incl %ebx
|
|
/* There are two places in the kernel that can potentially fault with
|
|
usergs. Handle them here. The exception handlers after
|
|
iret run with kernel gs again, so don't set the user space flag.
|
|
B stepping K8s sometimes report an truncated RIP for IRET
|
|
exceptions returning to compat mode. Check for these here too. */
|
|
leaq irq_return(%rip),%rcx
|
|
cmpq %rcx,RIP(%rsp)
|
|
je error_swapgs
|
|
movl %ecx,%ecx /* zero extend */
|
|
cmpq %rcx,RIP(%rsp)
|
|
je error_swapgs
|
|
cmpq $gs_change,RIP(%rsp)
|
|
je error_swapgs
|
|
jmp error_sti
|
|
KPROBE_END(error_entry)
|
|
|
|
/* Reload gs selector with exception handling */
|
|
/* edi: new selector */
|
|
ENTRY(native_load_gs_index)
|
|
CFI_STARTPROC
|
|
pushf
|
|
CFI_ADJUST_CFA_OFFSET 8
|
|
DISABLE_INTERRUPTS(CLBR_ANY | ~(CLBR_RDI))
|
|
SWAPGS
|
|
gs_change:
|
|
movl %edi,%gs
|
|
2: mfence /* workaround */
|
|
SWAPGS
|
|
popf
|
|
CFI_ADJUST_CFA_OFFSET -8
|
|
ret
|
|
CFI_ENDPROC
|
|
ENDPROC(native_load_gs_index)
|
|
|
|
.section __ex_table,"a"
|
|
.align 8
|
|
.quad gs_change,bad_gs
|
|
.previous
|
|
.section .fixup,"ax"
|
|
/* running with kernelgs */
|
|
bad_gs:
|
|
SWAPGS /* switch back to user gs */
|
|
xorl %eax,%eax
|
|
movl %eax,%gs
|
|
jmp 2b
|
|
.previous
|
|
|
|
/*
|
|
* Create a kernel thread.
|
|
*
|
|
* C extern interface:
|
|
* extern long kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
|
|
*
|
|
* asm input arguments:
|
|
* rdi: fn, rsi: arg, rdx: flags
|
|
*/
|
|
ENTRY(kernel_thread)
|
|
CFI_STARTPROC
|
|
FAKE_STACK_FRAME $child_rip
|
|
SAVE_ALL
|
|
|
|
# rdi: flags, rsi: usp, rdx: will be &pt_regs
|
|
movq %rdx,%rdi
|
|
orq kernel_thread_flags(%rip),%rdi
|
|
movq $-1, %rsi
|
|
movq %rsp, %rdx
|
|
|
|
xorl %r8d,%r8d
|
|
xorl %r9d,%r9d
|
|
|
|
# clone now
|
|
call do_fork
|
|
movq %rax,RAX(%rsp)
|
|
xorl %edi,%edi
|
|
|
|
/*
|
|
* It isn't worth to check for reschedule here,
|
|
* so internally to the x86_64 port you can rely on kernel_thread()
|
|
* not to reschedule the child before returning, this avoids the need
|
|
* of hacks for example to fork off the per-CPU idle tasks.
|
|
* [Hopefully no generic code relies on the reschedule -AK]
|
|
*/
|
|
RESTORE_ALL
|
|
UNFAKE_STACK_FRAME
|
|
ret
|
|
CFI_ENDPROC
|
|
ENDPROC(kernel_thread)
|
|
|
|
child_rip:
|
|
pushq $0 # fake return address
|
|
CFI_STARTPROC
|
|
/*
|
|
* Here we are in the child and the registers are set as they were
|
|
* at kernel_thread() invocation in the parent.
|
|
*/
|
|
movq %rdi, %rax
|
|
movq %rsi, %rdi
|
|
call *%rax
|
|
# exit
|
|
mov %eax, %edi
|
|
call do_exit
|
|
CFI_ENDPROC
|
|
ENDPROC(child_rip)
|
|
|
|
/*
|
|
* execve(). This function needs to use IRET, not SYSRET, to set up all state properly.
|
|
*
|
|
* C extern interface:
|
|
* extern long execve(char *name, char **argv, char **envp)
|
|
*
|
|
* asm input arguments:
|
|
* rdi: name, rsi: argv, rdx: envp
|
|
*
|
|
* We want to fallback into:
|
|
* extern long sys_execve(char *name, char **argv,char **envp, struct pt_regs *regs)
|
|
*
|
|
* do_sys_execve asm fallback arguments:
|
|
* rdi: name, rsi: argv, rdx: envp, rcx: fake frame on the stack
|
|
*/
|
|
ENTRY(kernel_execve)
|
|
CFI_STARTPROC
|
|
FAKE_STACK_FRAME $0
|
|
SAVE_ALL
|
|
movq %rsp,%rcx
|
|
call sys_execve
|
|
movq %rax, RAX(%rsp)
|
|
RESTORE_REST
|
|
testq %rax,%rax
|
|
je int_ret_from_sys_call
|
|
RESTORE_ARGS
|
|
UNFAKE_STACK_FRAME
|
|
ret
|
|
CFI_ENDPROC
|
|
ENDPROC(kernel_execve)
|
|
|
|
KPROBE_ENTRY(page_fault)
|
|
errorentry do_page_fault
|
|
KPROBE_END(page_fault)
|
|
|
|
ENTRY(coprocessor_error)
|
|
zeroentry do_coprocessor_error
|
|
END(coprocessor_error)
|
|
|
|
ENTRY(simd_coprocessor_error)
|
|
zeroentry do_simd_coprocessor_error
|
|
END(simd_coprocessor_error)
|
|
|
|
ENTRY(device_not_available)
|
|
zeroentry do_device_not_available
|
|
END(device_not_available)
|
|
|
|
/* runs on exception stack */
|
|
KPROBE_ENTRY(debug)
|
|
INTR_FRAME
|
|
PARAVIRT_ADJUST_EXCEPTION_FRAME
|
|
pushq $0
|
|
CFI_ADJUST_CFA_OFFSET 8
|
|
paranoidentry do_debug, DEBUG_STACK
|
|
paranoidexit
|
|
KPROBE_END(debug)
|
|
|
|
/* runs on exception stack */
|
|
KPROBE_ENTRY(nmi)
|
|
INTR_FRAME
|
|
PARAVIRT_ADJUST_EXCEPTION_FRAME
|
|
pushq $-1
|
|
CFI_ADJUST_CFA_OFFSET 8
|
|
paranoidentry do_nmi, 0, 0
|
|
#ifdef CONFIG_TRACE_IRQFLAGS
|
|
paranoidexit 0
|
|
#else
|
|
jmp paranoid_exit1
|
|
CFI_ENDPROC
|
|
#endif
|
|
KPROBE_END(nmi)
|
|
|
|
KPROBE_ENTRY(int3)
|
|
INTR_FRAME
|
|
PARAVIRT_ADJUST_EXCEPTION_FRAME
|
|
pushq $0
|
|
CFI_ADJUST_CFA_OFFSET 8
|
|
paranoidentry do_int3, DEBUG_STACK
|
|
jmp paranoid_exit1
|
|
CFI_ENDPROC
|
|
KPROBE_END(int3)
|
|
|
|
ENTRY(overflow)
|
|
zeroentry do_overflow
|
|
END(overflow)
|
|
|
|
ENTRY(bounds)
|
|
zeroentry do_bounds
|
|
END(bounds)
|
|
|
|
ENTRY(invalid_op)
|
|
zeroentry do_invalid_op
|
|
END(invalid_op)
|
|
|
|
ENTRY(coprocessor_segment_overrun)
|
|
zeroentry do_coprocessor_segment_overrun
|
|
END(coprocessor_segment_overrun)
|
|
|
|
/* runs on exception stack */
|
|
ENTRY(double_fault)
|
|
XCPT_FRAME
|
|
PARAVIRT_ADJUST_EXCEPTION_FRAME
|
|
paranoidentry do_double_fault
|
|
jmp paranoid_exit1
|
|
CFI_ENDPROC
|
|
END(double_fault)
|
|
|
|
ENTRY(invalid_TSS)
|
|
errorentry do_invalid_TSS
|
|
END(invalid_TSS)
|
|
|
|
ENTRY(segment_not_present)
|
|
errorentry do_segment_not_present
|
|
END(segment_not_present)
|
|
|
|
/* runs on exception stack */
|
|
ENTRY(stack_segment)
|
|
XCPT_FRAME
|
|
PARAVIRT_ADJUST_EXCEPTION_FRAME
|
|
paranoidentry do_stack_segment
|
|
jmp paranoid_exit1
|
|
CFI_ENDPROC
|
|
END(stack_segment)
|
|
|
|
KPROBE_ENTRY(general_protection)
|
|
errorentry do_general_protection
|
|
KPROBE_END(general_protection)
|
|
|
|
ENTRY(alignment_check)
|
|
errorentry do_alignment_check
|
|
END(alignment_check)
|
|
|
|
ENTRY(divide_error)
|
|
zeroentry do_divide_error
|
|
END(divide_error)
|
|
|
|
ENTRY(spurious_interrupt_bug)
|
|
zeroentry do_spurious_interrupt_bug
|
|
END(spurious_interrupt_bug)
|
|
|
|
#ifdef CONFIG_X86_MCE
|
|
/* runs on exception stack */
|
|
ENTRY(machine_check)
|
|
INTR_FRAME
|
|
PARAVIRT_ADJUST_EXCEPTION_FRAME
|
|
pushq $0
|
|
CFI_ADJUST_CFA_OFFSET 8
|
|
paranoidentry do_machine_check
|
|
jmp paranoid_exit1
|
|
CFI_ENDPROC
|
|
END(machine_check)
|
|
#endif
|
|
|
|
/* Call softirq on interrupt stack. Interrupts are off. */
|
|
ENTRY(call_softirq)
|
|
CFI_STARTPROC
|
|
push %rbp
|
|
CFI_ADJUST_CFA_OFFSET 8
|
|
CFI_REL_OFFSET rbp,0
|
|
mov %rsp,%rbp
|
|
CFI_DEF_CFA_REGISTER rbp
|
|
incl %gs:pda_irqcount
|
|
cmove %gs:pda_irqstackptr,%rsp
|
|
push %rbp # backlink for old unwinder
|
|
call __do_softirq
|
|
leaveq
|
|
CFI_DEF_CFA_REGISTER rsp
|
|
CFI_ADJUST_CFA_OFFSET -8
|
|
decl %gs:pda_irqcount
|
|
ret
|
|
CFI_ENDPROC
|
|
ENDPROC(call_softirq)
|
|
|
|
KPROBE_ENTRY(ignore_sysret)
|
|
CFI_STARTPROC
|
|
mov $-ENOSYS,%eax
|
|
sysret
|
|
CFI_ENDPROC
|
|
ENDPROC(ignore_sysret)
|
|
|
|
#ifdef CONFIG_XEN
|
|
ENTRY(xen_hypervisor_callback)
|
|
zeroentry xen_do_hypervisor_callback
|
|
END(xen_hypervisor_callback)
|
|
|
|
/*
|
|
# A note on the "critical region" in our callback handler.
|
|
# We want to avoid stacking callback handlers due to events occurring
|
|
# during handling of the last event. To do this, we keep events disabled
|
|
# until we've done all processing. HOWEVER, we must enable events before
|
|
# popping the stack frame (can't be done atomically) and so it would still
|
|
# be possible to get enough handler activations to overflow the stack.
|
|
# Although unlikely, bugs of that kind are hard to track down, so we'd
|
|
# like to avoid the possibility.
|
|
# So, on entry to the handler we detect whether we interrupted an
|
|
# existing activation in its critical region -- if so, we pop the current
|
|
# activation and restart the handler using the previous one.
|
|
*/
|
|
ENTRY(xen_do_hypervisor_callback) # do_hypervisor_callback(struct *pt_regs)
|
|
CFI_STARTPROC
|
|
/* Since we don't modify %rdi, evtchn_do_upall(struct *pt_regs) will
|
|
see the correct pointer to the pt_regs */
|
|
movq %rdi, %rsp # we don't return, adjust the stack frame
|
|
CFI_ENDPROC
|
|
CFI_DEFAULT_STACK
|
|
11: incl %gs:pda_irqcount
|
|
movq %rsp,%rbp
|
|
CFI_DEF_CFA_REGISTER rbp
|
|
cmovzq %gs:pda_irqstackptr,%rsp
|
|
pushq %rbp # backlink for old unwinder
|
|
call xen_evtchn_do_upcall
|
|
popq %rsp
|
|
CFI_DEF_CFA_REGISTER rsp
|
|
decl %gs:pda_irqcount
|
|
jmp error_exit
|
|
CFI_ENDPROC
|
|
END(do_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 do not need to fix up as Xen has already reloaded all segment
|
|
# registers that could be reloaded and zeroed the others.
|
|
# Category 2 we fix up by killing the current process. 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 comparing each saved segment register
|
|
# with its current contents: any discrepancy means we in category 1.
|
|
*/
|
|
ENTRY(xen_failsafe_callback)
|
|
framesz = (RIP-0x30) /* workaround buggy gas */
|
|
_frame framesz
|
|
CFI_REL_OFFSET rcx, 0
|
|
CFI_REL_OFFSET r11, 8
|
|
movw %ds,%cx
|
|
cmpw %cx,0x10(%rsp)
|
|
CFI_REMEMBER_STATE
|
|
jne 1f
|
|
movw %es,%cx
|
|
cmpw %cx,0x18(%rsp)
|
|
jne 1f
|
|
movw %fs,%cx
|
|
cmpw %cx,0x20(%rsp)
|
|
jne 1f
|
|
movw %gs,%cx
|
|
cmpw %cx,0x28(%rsp)
|
|
jne 1f
|
|
/* All segments match their saved values => Category 2 (Bad IRET). */
|
|
movq (%rsp),%rcx
|
|
CFI_RESTORE rcx
|
|
movq 8(%rsp),%r11
|
|
CFI_RESTORE r11
|
|
addq $0x30,%rsp
|
|
CFI_ADJUST_CFA_OFFSET -0x30
|
|
pushq $0
|
|
CFI_ADJUST_CFA_OFFSET 8
|
|
pushq %r11
|
|
CFI_ADJUST_CFA_OFFSET 8
|
|
pushq %rcx
|
|
CFI_ADJUST_CFA_OFFSET 8
|
|
jmp general_protection
|
|
CFI_RESTORE_STATE
|
|
1: /* Segment mismatch => Category 1 (Bad segment). Retry the IRET. */
|
|
movq (%rsp),%rcx
|
|
CFI_RESTORE rcx
|
|
movq 8(%rsp),%r11
|
|
CFI_RESTORE r11
|
|
addq $0x30,%rsp
|
|
CFI_ADJUST_CFA_OFFSET -0x30
|
|
pushq $0
|
|
CFI_ADJUST_CFA_OFFSET 8
|
|
SAVE_ALL
|
|
jmp error_exit
|
|
CFI_ENDPROC
|
|
END(xen_failsafe_callback)
|
|
|
|
#endif /* CONFIG_XEN */
|