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Diffstat (limited to 'arch/i386/kernel/entry.S')
| -rw-r--r-- | arch/i386/kernel/entry.S | 663 |
1 files changed, 0 insertions, 663 deletions
diff --git a/arch/i386/kernel/entry.S b/arch/i386/kernel/entry.S deleted file mode 100644 index 9e24f7b207e..00000000000 --- a/arch/i386/kernel/entry.S +++ /dev/null @@ -1,663 +0,0 @@ -/* - * linux/arch/i386/entry.S - * - * Copyright (C) 1991, 1992 Linus Torvalds - */ - -/* - * entry.S contains the system-call and fault low-level handling routines. - * This also contains the timer-interrupt handler, as well as all interrupts - * and faults that can result in a task-switch. - * - * NOTE: This code handles signal-recognition, which happens every time - * after a timer-interrupt and after each system call. - * - * I changed all the .align's to 4 (16 byte alignment), as that's faster - * on a 486. - * - * Stack layout in 'ret_from_system_call': - * ptrace needs to have all regs on the stack. - * if the order here is changed, it needs to be - * updated in fork.c:copy_process, signal.c:do_signal, - * ptrace.c and ptrace.h - * - * 0(%esp) - %ebx - * 4(%esp) - %ecx - * 8(%esp) - %edx - * C(%esp) - %esi - * 10(%esp) - %edi - * 14(%esp) - %ebp - * 18(%esp) - %eax - * 1C(%esp) - %ds - * 20(%esp) - %es - * 24(%esp) - orig_eax - * 28(%esp) - %eip - * 2C(%esp) - %cs - * 30(%esp) - %eflags - * 34(%esp) - %oldesp - * 38(%esp) - %oldss - * - * "current" is in register %ebx during any slow entries. - */ - -#include <linux/config.h> -#include <linux/linkage.h> -#include <asm/thread_info.h> -#include <asm/errno.h> -#include <asm/segment.h> -#include <asm/smp.h> -#include <asm/page.h> -#include <asm/desc.h> -#include "irq_vectors.h" - -#define nr_syscalls ((syscall_table_size)/4) - -EBX = 0x00 -ECX = 0x04 -EDX = 0x08 -ESI = 0x0C -EDI = 0x10 -EBP = 0x14 -EAX = 0x18 -DS = 0x1C -ES = 0x20 -ORIG_EAX = 0x24 -EIP = 0x28 -CS = 0x2C -EFLAGS = 0x30 -OLDESP = 0x34 -OLDSS = 0x38 - -CF_MASK = 0x00000001 -TF_MASK = 0x00000100 -IF_MASK = 0x00000200 -DF_MASK = 0x00000400 -NT_MASK = 0x00004000 -VM_MASK = 0x00020000 - -#ifdef CONFIG_PREEMPT -#define preempt_stop cli -#else -#define preempt_stop -#define resume_kernel restore_nocheck -#endif - -#define SAVE_ALL \ - cld; \ - pushl %es; \ - pushl %ds; \ - pushl %eax; \ - pushl %ebp; \ - pushl %edi; \ - pushl %esi; \ - pushl %edx; \ - pushl %ecx; \ - pushl %ebx; \ - movl $(__USER_DS), %edx; \ - movl %edx, %ds; \ - movl %edx, %es; - -#define RESTORE_INT_REGS \ - popl %ebx; \ - popl %ecx; \ - popl %edx; \ - popl %esi; \ - popl %edi; \ - popl %ebp; \ - popl %eax - -#define RESTORE_REGS \ - RESTORE_INT_REGS; \ -1: popl %ds; \ -2: popl %es; \ -.section .fixup,"ax"; \ -3: movl $0,(%esp); \ - jmp 1b; \ -4: movl $0,(%esp); \ - jmp 2b; \ -.previous; \ -.section __ex_table,"a";\ - .align 4; \ - .long 1b,3b; \ - .long 2b,4b; \ -.previous - - -ENTRY(ret_from_fork) - pushl %eax - call schedule_tail - GET_THREAD_INFO(%ebp) - popl %eax - jmp syscall_exit - -/* - * Return to user mode is not as complex as all this looks, - * but we want the default path for a system call return to - * go as quickly as possible which is why some of this is - * less clear than it otherwise should be. - */ - - # userspace resumption stub bypassing syscall exit tracing - ALIGN -ret_from_exception: - preempt_stop -ret_from_intr: - GET_THREAD_INFO(%ebp) - movl EFLAGS(%esp), %eax # mix EFLAGS and CS - movb CS(%esp), %al - testl $(VM_MASK | 3), %eax - jz resume_kernel -ENTRY(resume_userspace) - cli # make sure we don't miss an interrupt - # setting need_resched or sigpending - # between sampling and the iret - movl TI_flags(%ebp), %ecx - andl $_TIF_WORK_MASK, %ecx # is there any work to be done on - # int/exception return? - jne work_pending - jmp restore_all - -#ifdef CONFIG_PREEMPT -ENTRY(resume_kernel) - cli - cmpl $0,TI_preempt_count(%ebp) # non-zero preempt_count ? - jnz restore_nocheck -need_resched: - movl TI_flags(%ebp), %ecx # need_resched set ? - testb $_TIF_NEED_RESCHED, %cl - jz restore_all - testl $IF_MASK,EFLAGS(%esp) # interrupts off (exception path) ? - jz restore_all - call preempt_schedule_irq - jmp need_resched -#endif - -/* SYSENTER_RETURN points to after the "sysenter" instruction in - the vsyscall page. See vsyscall-sysentry.S, which defines the symbol. */ - - # sysenter call handler stub -ENTRY(sysenter_entry) - movl TSS_sysenter_esp0(%esp),%esp -sysenter_past_esp: - sti - pushl $(__USER_DS) - pushl %ebp - pushfl - pushl $(__USER_CS) - pushl $SYSENTER_RETURN - -/* - * Load the potential sixth argument from user stack. - * Careful about security. - */ - cmpl $__PAGE_OFFSET-3,%ebp - jae syscall_fault -1: movl (%ebp),%ebp -.section __ex_table,"a" - .align 4 - .long 1b,syscall_fault -.previous - - pushl %eax - SAVE_ALL - GET_THREAD_INFO(%ebp) - - /* Note, _TIF_SECCOMP is bit number 8, and so it needs testw and not testb */ - testw $(_TIF_SYSCALL_EMU|_TIF_SYSCALL_TRACE|_TIF_SECCOMP|_TIF_SYSCALL_AUDIT),TI_flags(%ebp) - jnz syscall_trace_entry - cmpl $(nr_syscalls), %eax - jae syscall_badsys - call *sys_call_table(,%eax,4) - movl %eax,EAX(%esp) - cli - movl TI_flags(%ebp), %ecx - testw $_TIF_ALLWORK_MASK, %cx - jne syscall_exit_work -/* if something modifies registers it must also disable sysexit */ - movl EIP(%esp), %edx - movl OLDESP(%esp), %ecx - xorl %ebp,%ebp - sti - sysexit - - - # system call handler stub -ENTRY(system_call) - pushl %eax # save orig_eax - SAVE_ALL - GET_THREAD_INFO(%ebp) - # system call tracing in operation / emulation - /* Note, _TIF_SECCOMP is bit number 8, and so it needs testw and not testb */ - testw $(_TIF_SYSCALL_EMU|_TIF_SYSCALL_TRACE|_TIF_SECCOMP|_TIF_SYSCALL_AUDIT),TI_flags(%ebp) - jnz syscall_trace_entry - cmpl $(nr_syscalls), %eax - jae syscall_badsys -syscall_call: - call *sys_call_table(,%eax,4) - movl %eax,EAX(%esp) # store the return value -syscall_exit: - cli # make sure we don't miss an interrupt - # setting need_resched or sigpending - # between sampling and the iret - movl TI_flags(%ebp), %ecx - testw $_TIF_ALLWORK_MASK, %cx # current->work - jne syscall_exit_work - -restore_all: - movl EFLAGS(%esp), %eax # mix EFLAGS, SS and CS - # Warning: OLDSS(%esp) contains the wrong/random values if we - # are returning to the kernel. - # See comments in process.c:copy_thread() for details. - movb OLDSS(%esp), %ah - movb CS(%esp), %al - andl $(VM_MASK | (4 << 8) | 3), %eax - cmpl $((4 << 8) | 3), %eax - je ldt_ss # returning to user-space with LDT SS -restore_nocheck: - RESTORE_REGS - addl $4, %esp -1: iret -.section .fixup,"ax" -iret_exc: - sti - pushl $0 # no error code - pushl $do_iret_error - jmp error_code -.previous -.section __ex_table,"a" - .align 4 - .long 1b,iret_exc -.previous - -ldt_ss: - larl OLDSS(%esp), %eax - jnz restore_nocheck - testl $0x00400000, %eax # returning to 32bit stack? - jnz restore_nocheck # allright, normal return - /* If returning to userspace with 16bit stack, - * try to fix the higher word of ESP, as the CPU - * won't restore it. - * This is an "official" bug of all the x86-compatible - * CPUs, which we can try to work around to make - * dosemu and wine happy. */ - subl $8, %esp # reserve space for switch16 pointer - cli - movl %esp, %eax - /* Set up the 16bit stack frame with switch32 pointer on top, - * and a switch16 pointer on top of the current frame. */ - call setup_x86_bogus_stack - RESTORE_REGS - lss 20+4(%esp), %esp # switch to 16bit stack -1: iret -.section __ex_table,"a" - .align 4 - .long 1b,iret_exc -.previous - - # perform work that needs to be done immediately before resumption - ALIGN -work_pending: - testb $_TIF_NEED_RESCHED, %cl - jz work_notifysig -work_resched: - call schedule - cli # make sure we don't miss an interrupt - # setting need_resched or sigpending - # between sampling and the iret - movl TI_flags(%ebp), %ecx - andl $_TIF_WORK_MASK, %ecx # is there any work to be done other - # than syscall tracing? - jz restore_all - testb $_TIF_NEED_RESCHED, %cl - jnz work_resched - -work_notifysig: # deal with pending signals and - # notify-resume requests - testl $VM_MASK, EFLAGS(%esp) - movl %esp, %eax - jne work_notifysig_v86 # returning to kernel-space or - # vm86-space - xorl %edx, %edx - call do_notify_resume - jmp resume_userspace - - ALIGN -work_notifysig_v86: - pushl %ecx # save ti_flags for do_notify_resume - call save_v86_state # %eax contains pt_regs pointer - popl %ecx - movl %eax, %esp - xorl %edx, %edx - call do_notify_resume - jmp resume_userspace - - # perform syscall exit tracing - ALIGN -syscall_trace_entry: - movl $-ENOSYS,EAX(%esp) - movl %esp, %eax - xorl %edx,%edx - call do_syscall_trace - cmpl $0, %eax - jne resume_userspace # ret != 0 -> running under PTRACE_SYSEMU, - # so must skip actual syscall - movl ORIG_EAX(%esp), %eax - cmpl $(nr_syscalls), %eax - jnae syscall_call - jmp syscall_exit - - # perform syscall exit tracing - ALIGN -syscall_exit_work: - testb $(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT|_TIF_SINGLESTEP), %cl - jz work_pending - sti # could let do_syscall_trace() call - # schedule() instead - movl %esp, %eax - movl $1, %edx - call do_syscall_trace - jmp resume_userspace - - ALIGN -syscall_fault: - pushl %eax # save orig_eax - SAVE_ALL - GET_THREAD_INFO(%ebp) - movl $-EFAULT,EAX(%esp) - jmp resume_userspace - - ALIGN -syscall_badsys: - movl $-ENOSYS,EAX(%esp) - jmp resume_userspace - -#define FIXUP_ESPFIX_STACK \ - movl %esp, %eax; \ - /* switch to 32bit stack using the pointer on top of 16bit stack */ \ - lss %ss:CPU_16BIT_STACK_SIZE-8, %esp; \ - /* copy data from 16bit stack to 32bit stack */ \ - call fixup_x86_bogus_stack; \ - /* put ESP to the proper location */ \ - movl %eax, %esp; -#define UNWIND_ESPFIX_STACK \ - pushl %eax; \ - movl %ss, %eax; \ - /* see if on 16bit stack */ \ - cmpw $__ESPFIX_SS, %ax; \ - jne 28f; \ - movl $__KERNEL_DS, %edx; \ - movl %edx, %ds; \ - movl %edx, %es; \ - /* switch to 32bit stack */ \ - FIXUP_ESPFIX_STACK \ -28: popl %eax; - -/* - * Build the entry stubs and pointer table with - * some assembler magic. - */ -.data -ENTRY(interrupt) -.text - -vector=0 -ENTRY(irq_entries_start) -.rept NR_IRQS - ALIGN -1: pushl $vector-256 - jmp common_interrupt -.data - .long 1b -.text -vector=vector+1 -.endr - - ALIGN -common_interrupt: - SAVE_ALL - movl %esp,%eax - call do_IRQ - jmp ret_from_intr - -#define BUILD_INTERRUPT(name, nr) \ -ENTRY(name) \ - pushl $nr-256; \ - SAVE_ALL \ - movl %esp,%eax; \ - call smp_/**/name; \ - jmp ret_from_intr; - -/* The include is where all of the SMP etc. interrupts come from */ -#include "entry_arch.h" - -ENTRY(divide_error) - pushl $0 # no error code - pushl $do_divide_error - ALIGN -error_code: - pushl %ds - pushl %eax - xorl %eax, %eax - pushl %ebp - pushl %edi - pushl %esi - pushl %edx - decl %eax # eax = -1 - pushl %ecx - pushl %ebx - cld - pushl %es - UNWIND_ESPFIX_STACK - popl %ecx - movl ES(%esp), %edi # get the function address - movl ORIG_EAX(%esp), %edx # get the error code - movl %eax, ORIG_EAX(%esp) - movl %ecx, ES(%esp) - movl $(__USER_DS), %ecx - movl %ecx, %ds - movl %ecx, %es - movl %esp,%eax # pt_regs pointer - call *%edi - jmp ret_from_exception - -ENTRY(coprocessor_error) - pushl $0 - pushl $do_coprocessor_error - jmp error_code - -ENTRY(simd_coprocessor_error) - pushl $0 - pushl $do_simd_coprocessor_error - jmp error_code - -ENTRY(device_not_available) - pushl $-1 # mark this as an int - SAVE_ALL - movl %cr0, %eax - testl $0x4, %eax # EM (math emulation bit) - jne device_not_available_emulate - preempt_stop - call math_state_restore - jmp ret_from_exception -device_not_available_emulate: - pushl $0 # temporary storage for ORIG_EIP - call math_emulate - addl $4, %esp - jmp ret_from_exception - -/* - * Debug traps and NMI can happen at the one SYSENTER instruction - * that sets up the real kernel stack. Check here, since we can't - * allow the wrong stack to be used. - * - * "TSS_sysenter_esp0+12" is because the NMI/debug handler will have - * already pushed 3 words if it hits on the sysenter instruction: - * eflags, cs and eip. - * - * We just load the right stack, and push the three (known) values - * by hand onto the new stack - while updating the return eip past - * the instruction that would have done it for sysenter. - */ -#define FIX_STACK(offset, ok, label) \ - cmpw $__KERNEL_CS,4(%esp); \ - jne ok; \ -label: \ - movl TSS_sysenter_esp0+offset(%esp),%esp; \ - pushfl; \ - pushl $__KERNEL_CS; \ - pushl $sysenter_past_esp - -KPROBE_ENTRY(debug) - cmpl $sysenter_entry,(%esp) - jne debug_stack_correct - FIX_STACK(12, debug_stack_correct, debug_esp_fix_insn) -debug_stack_correct: - pushl $-1 # mark this as an int - SAVE_ALL - xorl %edx,%edx # error code 0 - movl %esp,%eax # pt_regs pointer - call do_debug - jmp ret_from_exception - .previous .text -/* - * NMI is doubly nasty. It can happen _while_ we're handling - * a debug fault, and the debug fault hasn't yet been able to - * clear up the stack. So we first check whether we got an - * NMI on the sysenter entry path, but after that we need to - * check whether we got an NMI on the debug path where the debug - * fault happened on the sysenter path. - */ -ENTRY(nmi) - pushl %eax - movl %ss, %eax - cmpw $__ESPFIX_SS, %ax - popl %eax - je nmi_16bit_stack - cmpl $sysenter_entry,(%esp) - je nmi_stack_fixup - pushl %eax - movl %esp,%eax - /* Do not access memory above the end of our stack page, - * it might not exist. - */ - andl $(THREAD_SIZE-1),%eax - cmpl $(THREAD_SIZE-20),%eax - popl %eax - jae nmi_stack_correct - cmpl $sysenter_entry,12(%esp) - je nmi_debug_stack_check -nmi_stack_correct: - pushl %eax - SAVE_ALL - xorl %edx,%edx # zero error code - movl %esp,%eax # pt_regs pointer - call do_nmi - jmp restore_all - -nmi_stack_fixup: - FIX_STACK(12,nmi_stack_correct, 1) - jmp nmi_stack_correct -nmi_debug_stack_check: - cmpw $__KERNEL_CS,16(%esp) - jne nmi_stack_correct - cmpl $debug - 1,(%esp) - jle nmi_stack_correct - cmpl $debug_esp_fix_insn,(%esp) - jle nmi_debug_stack_fixup -nmi_debug_stack_fixup: - FIX_STACK(24,nmi_stack_correct, 1) - jmp nmi_stack_correct - -nmi_16bit_stack: - /* create the pointer to lss back */ - pushl %ss - pushl %esp - movzwl %sp, %esp - addw $4, (%esp) - /* copy the iret frame of 12 bytes */ - .rept 3 - pushl 16(%esp) - .endr - pushl %eax - SAVE_ALL - FIXUP_ESPFIX_STACK # %eax == %esp - xorl %edx,%edx # zero error code - call do_nmi - RESTORE_REGS - lss 12+4(%esp), %esp # back to 16bit stack -1: iret -.section __ex_table,"a" - .align 4 - .long 1b,iret_exc -.previous - -KPROBE_ENTRY(int3) - pushl $-1 # mark this as an int - SAVE_ALL - xorl %edx,%edx # zero error code - movl %esp,%eax # pt_regs pointer - call do_int3 - jmp ret_from_exception - .previous .text - -ENTRY(overflow) - pushl $0 - pushl $do_overflow - jmp error_code - -ENTRY(bounds) - pushl $0 - pushl $do_bounds - jmp error_code - -ENTRY(invalid_op) - pushl $0 - pushl $do_invalid_op - jmp error_code - -ENTRY(coprocessor_segment_overrun) - pushl $0 - pushl $do_coprocessor_segment_overrun - jmp error_code - -ENTRY(invalid_TSS) - pushl $do_invalid_TSS - jmp error_code - -ENTRY(segment_not_present) - pushl $do_segment_not_present - jmp error_code - -ENTRY(stack_segment) - pushl $do_stack_segment - jmp error_code - -KPROBE_ENTRY(general_protection) - pushl $do_general_protection - jmp error_code - .previous .text - -ENTRY(alignment_check) - pushl $do_alignment_check - jmp error_code - -KPROBE_ENTRY(page_fault) - pushl $do_page_fault - jmp error_code - .previous .text - -#ifdef CONFIG_X86_MCE -ENTRY(machine_check) - pushl $0 - pushl machine_check_vector - jmp error_code -#endif - -ENTRY(spurious_interrupt_bug) - pushl $0 - pushl $do_spurious_interrupt_bug - jmp error_code - -#include "syscall_table.S" - -syscall_table_size=(.-sys_call_table) |