diff options
Diffstat (limited to 'arch/x86_64/kernel/entry_64.S')
| -rw-r--r-- | arch/x86_64/kernel/entry_64.S | 1172 |
1 files changed, 0 insertions, 1172 deletions
diff --git a/arch/x86_64/kernel/entry_64.S b/arch/x86_64/kernel/entry_64.S deleted file mode 100644 index 1d232e5f565..00000000000 --- a/arch/x86_64/kernel/entry_64.S +++ /dev/null @@ -1,1172 +0,0 @@ -/* - * linux/arch/x86_64/entry.S - * - * Copyright (C) 1991, 1992 Linus Torvalds - * Copyright (C) 2000, 2001, 2002 Andi Kleen SuSE Labs - * Copyright (C) 2000 Pavel Machek <pavel@suse.cz> - */ - -/* - * entry.S contains the system-call and fault low-level handling routines. - * - * NOTE: This code handles signal-recognition, which happens every time - * after an interrupt and after each system call. - * - * Normal syscalls and interrupts don't save a full stack frame, this is - * only done for syscall tracing, signals or fork/exec et.al. - * - * A note on terminology: - * - top of stack: Architecture defined interrupt frame from SS to RIP - * at the top of the kernel process stack. - * - partial stack frame: partially saved registers upto R11. - * - full stack frame: Like partial stack frame, but all register saved. - * - * Some macro usage: - * - CFI macros are used to generate dwarf2 unwind information for better - * backtraces. They don't change any code. - * - SAVE_ALL/RESTORE_ALL - Save/restore all registers - * - SAVE_ARGS/RESTORE_ARGS - Save/restore registers that C functions modify. - * There are unfortunately lots of special cases where some registers - * not touched. The macro is a big mess that should be cleaned up. - * - SAVE_REST/RESTORE_REST - Handle the registers not saved by SAVE_ARGS. - * Gives a full stack frame. - * - ENTRY/END Define functions in the symbol table. - * - FIXUP_TOP_OF_STACK/RESTORE_TOP_OF_STACK - Fix up the hardware stack - * frame that is otherwise undefined after a SYSCALL - * - TRACE_IRQ_* - Trace hard interrupt state for lock debugging. - * - errorentry/paranoidentry/zeroentry - Define exception entry points. - */ - -#include <linux/linkage.h> -#include <asm/segment.h> -#include <asm/cache.h> -#include <asm/errno.h> -#include <asm/dwarf2.h> -#include <asm/calling.h> -#include <asm/asm-offsets.h> -#include <asm/msr.h> -#include <asm/unistd.h> -#include <asm/thread_info.h> -#include <asm/hw_irq.h> -#include <asm/page.h> -#include <asm/irqflags.h> - - .code64 - -#ifndef CONFIG_PREEMPT -#define retint_kernel retint_restore_args -#endif - - -.macro TRACE_IRQS_IRETQ offset=ARGOFFSET -#ifdef CONFIG_TRACE_IRQFLAGS - bt $9,EFLAGS-\offset(%rsp) /* interrupts off? */ - jnc 1f - TRACE_IRQS_ON -1: -#endif -.endm - -/* - * C code is not supposed to know about undefined top of stack. Every time - * a C function with an pt_regs argument is called from the SYSCALL based - * fast path FIXUP_TOP_OF_STACK is needed. - * RESTORE_TOP_OF_STACK syncs the syscall state after any possible ptregs - * manipulation. - */ - - /* %rsp:at FRAMEEND */ - .macro FIXUP_TOP_OF_STACK tmp - movq %gs:pda_oldrsp,\tmp - movq \tmp,RSP(%rsp) - movq $__USER_DS,SS(%rsp) - movq $__USER_CS,CS(%rsp) - movq $-1,RCX(%rsp) - movq R11(%rsp),\tmp /* get eflags */ - movq \tmp,EFLAGS(%rsp) - .endm - - .macro RESTORE_TOP_OF_STACK tmp,offset=0 - movq RSP-\offset(%rsp),\tmp - movq \tmp,%gs:pda_oldrsp - movq EFLAGS-\offset(%rsp),\tmp - movq \tmp,R11-\offset(%rsp) - .endm - - .macro FAKE_STACK_FRAME child_rip - /* push in order ss, rsp, eflags, cs, rip */ - xorl %eax, %eax - pushq %rax /* ss */ - CFI_ADJUST_CFA_OFFSET 8 - /*CFI_REL_OFFSET ss,0*/ - pushq %rax /* rsp */ - CFI_ADJUST_CFA_OFFSET 8 - CFI_REL_OFFSET rsp,0 - pushq $(1<<9) /* eflags - interrupts on */ - CFI_ADJUST_CFA_OFFSET 8 - /*CFI_REL_OFFSET rflags,0*/ - pushq $__KERNEL_CS /* cs */ - CFI_ADJUST_CFA_OFFSET 8 - /*CFI_REL_OFFSET cs,0*/ - pushq \child_rip /* rip */ - CFI_ADJUST_CFA_OFFSET 8 - CFI_REL_OFFSET rip,0 - pushq %rax /* orig rax */ - CFI_ADJUST_CFA_OFFSET 8 - .endm - - .macro UNFAKE_STACK_FRAME - addq $8*6, %rsp - CFI_ADJUST_CFA_OFFSET -(6*8) - .endm - - .macro CFI_DEFAULT_STACK start=1 - .if \start - CFI_STARTPROC simple - CFI_SIGNAL_FRAME - CFI_DEF_CFA rsp,SS+8 - .else - CFI_DEF_CFA_OFFSET SS+8 - .endif - CFI_REL_OFFSET r15,R15 - CFI_REL_OFFSET r14,R14 - CFI_REL_OFFSET r13,R13 - CFI_REL_OFFSET r12,R12 - CFI_REL_OFFSET rbp,RBP - CFI_REL_OFFSET rbx,RBX - CFI_REL_OFFSET r11,R11 - CFI_REL_OFFSET r10,R10 - CFI_REL_OFFSET r9,R9 - CFI_REL_OFFSET r8,R8 - CFI_REL_OFFSET rax,RAX - CFI_REL_OFFSET rcx,RCX - CFI_REL_OFFSET rdx,RDX - CFI_REL_OFFSET rsi,RSI - CFI_REL_OFFSET rdi,RDI - CFI_REL_OFFSET rip,RIP - /*CFI_REL_OFFSET cs,CS*/ - /*CFI_REL_OFFSET rflags,EFLAGS*/ - CFI_REL_OFFSET rsp,RSP - /*CFI_REL_OFFSET ss,SS*/ - .endm -/* - * A newly forked process directly context switches into this. - */ -/* rdi: prev */ -ENTRY(ret_from_fork) - CFI_DEFAULT_STACK - push kernel_eflags(%rip) - CFI_ADJUST_CFA_OFFSET 4 - popf # reset kernel eflags - CFI_ADJUST_CFA_OFFSET -4 - call schedule_tail - GET_THREAD_INFO(%rcx) - testl $(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT),threadinfo_flags(%rcx) - jnz rff_trace -rff_action: - RESTORE_REST - testl $3,CS-ARGOFFSET(%rsp) # from kernel_thread? - je int_ret_from_sys_call - testl $_TIF_IA32,threadinfo_flags(%rcx) - jnz int_ret_from_sys_call - RESTORE_TOP_OF_STACK %rdi,ARGOFFSET - jmp ret_from_sys_call -rff_trace: - movq %rsp,%rdi - call syscall_trace_leave - GET_THREAD_INFO(%rcx) - jmp rff_action - CFI_ENDPROC -END(ret_from_fork) - -/* - * System call entry. Upto 6 arguments in registers are supported. - * - * SYSCALL does not save anything on the stack and does not change the - * stack pointer. - */ - -/* - * Register setup: - * rax system call number - * rdi arg0 - * rcx return address for syscall/sysret, C arg3 - * rsi arg1 - * rdx arg2 - * r10 arg3 (--> moved to rcx for C) - * r8 arg4 - * r9 arg5 - * r11 eflags for syscall/sysret, temporary for C - * r12-r15,rbp,rbx saved by C code, not touched. - * - * Interrupts are off on entry. - * Only called from user space. - * - * XXX if we had a free scratch register we could save the RSP into the stack frame - * and report it properly in ps. Unfortunately we haven't. - * - * When user can change the frames always force IRET. That is because - * it deals with uncanonical addresses better. SYSRET has trouble - * with them due to bugs in both AMD and Intel CPUs. - */ - -ENTRY(system_call) - CFI_STARTPROC simple - CFI_SIGNAL_FRAME - CFI_DEF_CFA rsp,PDA_STACKOFFSET - CFI_REGISTER rip,rcx - /*CFI_REGISTER rflags,r11*/ - swapgs - movq %rsp,%gs:pda_oldrsp - movq %gs:pda_kernelstack,%rsp - /* - * No need to follow this irqs off/on section - it's straight - * and short: - */ - sti - SAVE_ARGS 8,1 - movq %rax,ORIG_RAX-ARGOFFSET(%rsp) - movq %rcx,RIP-ARGOFFSET(%rsp) - CFI_REL_OFFSET rip,RIP-ARGOFFSET - GET_THREAD_INFO(%rcx) - testl $(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT|_TIF_SECCOMP),threadinfo_flags(%rcx) - jnz tracesys - cmpq $__NR_syscall_max,%rax - ja badsys - movq %r10,%rcx - call *sys_call_table(,%rax,8) # XXX: rip relative - movq %rax,RAX-ARGOFFSET(%rsp) -/* - * Syscall return path ending with SYSRET (fast path) - * Has incomplete stack frame and undefined top of stack. - */ -ret_from_sys_call: - movl $_TIF_ALLWORK_MASK,%edi - /* edi: flagmask */ -sysret_check: - GET_THREAD_INFO(%rcx) - cli - TRACE_IRQS_OFF - movl threadinfo_flags(%rcx),%edx - andl %edi,%edx - jnz sysret_careful - CFI_REMEMBER_STATE - /* - * sysretq will re-enable interrupts: - */ - TRACE_IRQS_ON - movq RIP-ARGOFFSET(%rsp),%rcx - CFI_REGISTER rip,rcx - RESTORE_ARGS 0,-ARG_SKIP,1 - /*CFI_REGISTER rflags,r11*/ - movq %gs:pda_oldrsp,%rsp - swapgs - sysretq - - CFI_RESTORE_STATE - /* Handle reschedules */ - /* edx: work, edi: workmask */ -sysret_careful: - bt $TIF_NEED_RESCHED,%edx - jnc sysret_signal - TRACE_IRQS_ON - sti - pushq %rdi - CFI_ADJUST_CFA_OFFSET 8 - call schedule - popq %rdi - CFI_ADJUST_CFA_OFFSET -8 - jmp sysret_check - - /* Handle a signal */ -sysret_signal: - TRACE_IRQS_ON - sti - testl $(_TIF_SIGPENDING|_TIF_SINGLESTEP|_TIF_MCE_NOTIFY),%edx - jz 1f - - /* Really a signal */ - /* edx: work flags (arg3) */ - leaq do_notify_resume(%rip),%rax - leaq -ARGOFFSET(%rsp),%rdi # &pt_regs -> arg1 - xorl %esi,%esi # oldset -> arg2 - call ptregscall_common -1: movl $_TIF_NEED_RESCHED,%edi - /* Use IRET because user could have changed frame. This - works because ptregscall_common has called FIXUP_TOP_OF_STACK. */ - cli - TRACE_IRQS_OFF - jmp int_with_check - -badsys: - movq $-ENOSYS,RAX-ARGOFFSET(%rsp) - jmp ret_from_sys_call - - /* Do syscall tracing */ -tracesys: - SAVE_REST - movq $-ENOSYS,RAX(%rsp) - FIXUP_TOP_OF_STACK %rdi - movq %rsp,%rdi - call syscall_trace_enter - LOAD_ARGS ARGOFFSET /* reload args from stack in case ptrace changed it */ - RESTORE_REST - cmpq $__NR_syscall_max,%rax - movq $-ENOSYS,%rcx - cmova %rcx,%rax - ja 1f - movq %r10,%rcx /* fixup for C */ - call *sys_call_table(,%rax,8) -1: movq %rax,RAX-ARGOFFSET(%rsp) - /* Use IRET because user could have changed frame */ - -/* - * Syscall return path ending with IRET. - * Has correct top of stack, but partial stack frame. - */ - .globl int_ret_from_sys_call -int_ret_from_sys_call: - cli - TRACE_IRQS_OFF - testl $3,CS-ARGOFFSET(%rsp) - je retint_restore_args - movl $_TIF_ALLWORK_MASK,%edi - /* edi: mask to check */ -int_with_check: - GET_THREAD_INFO(%rcx) - movl threadinfo_flags(%rcx),%edx - andl %edi,%edx - jnz int_careful - andl $~TS_COMPAT,threadinfo_status(%rcx) - jmp retint_swapgs - - /* 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 - sti - pushq %rdi - CFI_ADJUST_CFA_OFFSET 8 - call schedule - popq %rdi - CFI_ADJUST_CFA_OFFSET -8 - cli - TRACE_IRQS_OFF - jmp int_with_check - - /* handle signals and tracing -- both require a full stack frame */ -int_very_careful: - TRACE_IRQS_ON - sti - SAVE_REST - /* Check for syscall exit trace */ - testl $(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT|_TIF_SINGLESTEP),%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_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT|_TIF_SINGLESTEP),%edi - jmp int_restore_rest - -int_signal: - testl $(_TIF_SIGPENDING|_TIF_SINGLESTEP|_TIF_MCE_NOTIFY),%edx - jz 1f - movq %rsp,%rdi # &ptregs -> arg1 - xorl %esi,%esi # oldset -> arg2 - call do_notify_resume -1: movl $_TIF_NEED_RESCHED,%edi -int_restore_rest: - RESTORE_REST - cli - 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_rt_sigsuspend, sys_rt_sigsuspend, %rdx - 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 - 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 - 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: - cli - 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: - movl threadinfo_flags(%rcx),%edx - andl %edi,%edx - CFI_REMEMBER_STATE - jnz retint_careful -retint_swapgs: - /* - * The iretq could re-enable interrupts: - */ - cli - TRACE_IRQS_IRETQ - swapgs - jmp restore_args - -retint_restore_args: - cli - /* - * The iretq could re-enable interrupts: - */ - TRACE_IRQS_IRETQ -restore_args: - RESTORE_ARGS 0,8,0 -iret_label: - iretq - - .section __ex_table,"a" - .quad iret_label,bad_iret - .previous - .section .fixup,"ax" - /* force a signal here? this matches i386 behaviour */ - /* running with kernel gs */ -bad_iret: - movq $11,%rdi /* SIGSEGV */ - TRACE_IRQS_ON - sti - jmp do_exit - .previous - - /* edi: workmask, edx: work */ -retint_careful: - CFI_RESTORE_STATE - bt $TIF_NEED_RESCHED,%edx - jnc retint_signal - TRACE_IRQS_ON - sti - pushq %rdi - CFI_ADJUST_CFA_OFFSET 8 - call schedule - popq %rdi - CFI_ADJUST_CFA_OFFSET -8 - GET_THREAD_INFO(%rcx) - cli - TRACE_IRQS_OFF - jmp retint_check - -retint_signal: - testl $(_TIF_SIGPENDING|_TIF_SINGLESTEP|_TIF_MCE_NOTIFY),%edx - jz retint_swapgs - TRACE_IRQS_ON - sti - SAVE_REST - movq $-1,ORIG_RAX(%rsp) - xorl %esi,%esi # oldset - movq %rsp,%rdi # &pt_regs - call do_notify_resume - RESTORE_REST - cli - TRACE_IRQS_OFF - movl $_TIF_NEED_RESCHED,%edi - GET_THREAD_INFO(%rcx) - jmp retint_check - -#ifdef CONFIG_PREEMPT - /* Returning to kernel space. Check if we need preemption */ - /* rcx: threadinfo. interrupts off. */ -ENTRY(retint_kernel) - cmpl $0,threadinfo_preempt_count(%rcx) - jnz retint_restore_args - bt $TIF_NEED_RESCHED,threadinfo_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(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(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 - 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 - 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 - 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 - cli - .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 -paranoid_restore\trace: - RESTORE_ALL 8 - iretq -paranoid_userspace\trace: - GET_THREAD_INFO(%rcx) - movl threadinfo_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 - sti - xorl %esi,%esi /* arg2: oldset */ - movq %rsp,%rdi /* arg1: &pt_regs */ - call do_notify_resume - cli - .if \trace - TRACE_IRQS_OFF - .endif - jmp paranoid_userspace\trace -paranoid_schedule\trace: - .if \trace - TRACE_IRQS_ON - .endif - sti - call schedule - cli - .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: - 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 - cli - TRACE_IRQS_OFF - GET_THREAD_INFO(%rcx) - testl %eax,%eax - jne retint_kernel - movl threadinfo_flags(%rcx),%edx - movl $_TIF_WORK_MASK,%edi - andl %edi,%edx - jnz retint_careful - /* - * The iret might restore flags: - */ - TRACE_IRQS_IRETQ - swapgs - RESTORE_ARGS 0,8,0 - jmp iret_label - 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 iret_label(%rip),%rbp - cmpq %rbp,RIP(%rsp) - je error_swapgs - movl %ebp,%ebp /* zero extend */ - cmpq %rbp,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(load_gs_index) - CFI_STARTPROC - pushf - CFI_ADJUST_CFA_OFFSET 8 - cli - swapgs -gs_change: - movl %edi,%gs -2: mfence /* workaround */ - swapgs - popf - CFI_ADJUST_CFA_OFFSET -8 - ret - CFI_ENDPROC -ENDPROC(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 - xorl %edi, %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, fake frame on the stack - */ -ENTRY(kernel_execve) - CFI_STARTPROC - FAKE_STACK_FRAME $0 - SAVE_ALL - 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 math_state_restore -END(device_not_available) - - /* runs on exception stack */ -KPROBE_ENTRY(debug) - INTR_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 - 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 - 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) - -ENTRY(reserved) - zeroentry do_reserved -END(reserved) - - /* runs on exception stack */ -ENTRY(double_fault) - XCPT_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 - 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 - 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) |