kernel.git - Linux vanilla kernels for Fedora – https://fedoraproject.org/wiki/Kernel_Vanilla

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Diffstat (limited to 'kernel-aarch64-debug-fedora.config')

0 files changed, 0 insertions, 0 deletions

/* * 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> #include <asm/paravirt.h> #include <asm/ftrace.h> /* Avoid __ASSEMBLER__'ifying <linux/audit.h> just for this. */ #include <linux/elf-em.h> #define AUDIT_ARCH_X86_64 (EM_X86_64|__AUDIT_ARCH_64BIT|__AUDIT_ARCH_LE) #define __AUDIT_ARCH_64BIT 0x80000000 #define __AUDIT_ARCH_LE 0x40000000 .code64 #ifdef CONFIG_FTRACE #ifdef CONFIG_DYNAMIC_FTRACE ENTRY(mcount) retq END(mcount) ENTRY(ftrace_caller) /* taken from glibc */ subq $0x38, %rsp movq %rax, (%rsp) movq %rcx, 8(%rsp) movq %rdx, 16(%rsp) movq %rsi, 24(%rsp) movq %rdi, 32(%rsp) movq %r8, 40(%rsp) movq %r9, 48(%rsp) movq 0x38(%rsp), %rdi movq 8(%rbp), %rsi subq $MCOUNT_INSN_SIZE, %rdi .globl ftrace_call ftrace_call: call ftrace_stub movq 48(%rsp), %r9 movq 40(%rsp), %r8 movq 32(%rsp), %rdi movq 24(%rsp), %rsi movq 16(%rsp), %rdx movq 8(%rsp), %rcx movq (%rsp), %rax addq $0x38, %rsp .globl ftrace_stub ftrace_stub: retq END(ftrace_caller) #else /* ! CONFIG_DYNAMIC_FTRACE */ ENTRY(mcount) cmpq $ftrace_stub, ftrace_trace_function jnz trace .globl ftrace_stub ftrace_stub: retq trace: /* taken from glibc */ subq $0x38, %rsp movq %rax, (%rsp) movq %rcx, 8(%rsp) movq %rdx, 16(%rsp) movq %rsi, 24(%rsp) movq %rdi, 32(%rsp) movq %r8, 40(%rsp) movq %r9, 48(%rsp) movq 0x38(%rsp), %rdi movq 8(%rbp), %rsi subq $MCOUNT_INSN_SIZE, %rdi call *ftrace_trace_function movq 48(%rsp), %r9 movq 40(%rsp), %r8 movq 32(%rsp), %rdi movq 24(%rsp), %rsi movq 16(%rsp), %rdx movq 8(%rsp), %rcx movq (%rsp), %rax addq $0x38, %rsp jmp ftrace_stub END(mcount) #endif /* CONFIG_DYNAMIC_FTRACE */ #endif /* CONFIG_FTRACE */ #ifndef CONFIG_PREEMPT #define retint_kernel retint_restore_args #endif #ifdef CONFIG_PARAVIRT ENTRY(native_usergs_sysret64) swapgs sysretq #endif /* CONFIG_PARAVIRT */ .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 $__KERNEL_DS /* 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 8 popf # reset kernel eflags CFI_ADJUST_CFA_OFFSET -8 call schedule_tail GET_THREAD_INFO(%rcx) testl $(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT),TI_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,TI_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_UNSAFE_STACK /* * A hypervisor implementation might want to use a label * after the swapgs, so that it can do the swapgs * for the guest and jump here on syscall. */ ENTRY(system_call_after_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: */ ENABLE_INTERRUPTS(CLBR_NONE) 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_WORK_SYSCALL_ENTRY,TI_flags(%rcx) jnz tracesys system_call_fastpath: 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: LOCKDEP_SYS_EXIT GET_THREAD_INFO(%rcx) DISABLE_INTERRUPTS(CLBR_NONE) TRACE_IRQS_OFF movl TI_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 USERGS_SYSRET64 CFI_RESTORE_STATE /* Handle reschedules */ /* edx: work, edi: workmask */ sysret_careful: bt $TIF_NEED_RESCHED,%edx jnc sysret_signal TRACE_IRQS_ON ENABLE_INTERRUPTS(CLBR_NONE) 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 ENABLE_INTERRUPTS(CLBR_NONE) #ifdef CONFIG_AUDITSYSCALL bt $TIF_SYSCALL_AUDIT,%edx jc sysret_audit #endif /* 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 movl $_TIF_WORK_MASK,%edi /* Use IRET because user could have changed frame. This works because ptregscall_common has called FIXUP_TOP_OF_STACK. */ DISABLE_INTERRUPTS(CLBR_NONE) TRACE_IRQS_OFF jmp int_with_check badsys: movq $-ENOSYS,RAX-ARGOFFSET(%rsp) jmp ret_from_sys_call #ifdef CONFIG_AUDITSYSCALL /* * Fast path for syscall audit without full syscall trace. * We just call audit_syscall_entry() directly, and then * jump back to the normal fast path. */ auditsys: movq %r10,%r9 /* 6th arg: 4th syscall arg */ movq %rdx,%r8 /* 5th arg: 3rd syscall arg */ movq %rsi,%rcx /* 4th arg: 2nd syscall arg */ movq %rdi,%rdx /* 3rd arg: 1st syscall arg */ movq %rax,%rsi /* 2nd arg: syscall number */ movl $AUDIT_ARCH_X86_64,%edi /* 1st arg: audit arch */ call audit_syscall_entry LOAD_ARGS 0 /* reload call-clobbered registers */ jmp system_call_fastpath /* * Return fast path for syscall audit. Call audit_syscall_exit() * directly and then jump back to the fast path with TIF_SYSCALL_AUDIT * masked off. */ sysret_audit: movq %rax,%rsi /* second arg, syscall return value */ cmpq $0,%rax /* is it < 0? */ setl %al /* 1 if so, 0 if not */ movzbl %al,%edi /* zero-extend that into %edi */ inc %edi /* first arg, 0->1(AUDITSC_SUCCESS), 1->2(AUDITSC_FAILURE) */ call audit_syscall_exit movl $(_TIF_ALLWORK_MASK & ~_TIF_SYSCALL_AUDIT),%edi jmp sysret_check #endif /* CONFIG_AUDITSYSCALL */ /* Do syscall tracing */ tracesys: #ifdef CONFIG_AUDITSYSCALL testl $(_TIF_WORK_SYSCALL_ENTRY & ~_TIF_SYSCALL_AUDIT),TI_flags(%rcx) jz auditsys #endif SAVE_REST movq $-ENOSYS,RAX(%rsp) /* ptrace can change this for a bad syscall */ FIXUP_TOP_OF_STACK %rdi movq %rsp,%rdi call syscall_trace_enter /* * Reload arg registers from stack in case ptrace changed them. * We don't reload %rax because syscall_trace_enter() returned * the value it wants us to use in the table lookup. */ LOAD_ARGS ARGOFFSET, 1 RESTORE_REST cmpq $__NR_syscall_max,%rax ja int_ret_from_sys_call /* RAX(%rsp) set to -ENOSYS above */ movq %r10,%rcx /* fixup for C */ call *sys_call_table(,%rax,8) 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 .globl int_with_check int_ret_from_sys_call: DISABLE_INTERRUPTS(CLBR_NONE) TRACE_IRQS_OFF testl $3,CS-ARGOFFSET(%rsp) je retint_restore_args movl $_TIF_ALLWORK_MASK,%edi /* edi: mask to check */ int_with_check: LOCKDEP_SYS_EXIT_IRQ GET_THREAD_INFO(%rcx) movl TI_flags(%rcx),%edx andl %edi,%edx jnz int_careful andl $~TS_COMPAT,TI_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 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


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