1460 lines
33 KiB
ArmAsm
1460 lines
33 KiB
ArmAsm
/*
|
|
*
|
|
* 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 'syscall_exit':
|
|
* 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) - %fs
|
|
* 28(%esp) - %gs saved iff !CONFIG_X86_32_LAZY_GS
|
|
* 2C(%esp) - orig_eax
|
|
* 30(%esp) - %eip
|
|
* 34(%esp) - %cs
|
|
* 38(%esp) - %eflags
|
|
* 3C(%esp) - %oldesp
|
|
* 40(%esp) - %oldss
|
|
*
|
|
* "current" is in register %ebx during any slow entries.
|
|
*/
|
|
|
|
#include <linux/linkage.h>
|
|
#include <linux/err.h>
|
|
#include <asm/thread_info.h>
|
|
#include <asm/irqflags.h>
|
|
#include <asm/errno.h>
|
|
#include <asm/segment.h>
|
|
#include <asm/smp.h>
|
|
#include <asm/page_types.h>
|
|
#include <asm/percpu.h>
|
|
#include <asm/dwarf2.h>
|
|
#include <asm/processor-flags.h>
|
|
#include <asm/ftrace.h>
|
|
#include <asm/irq_vectors.h>
|
|
#include <asm/cpufeature.h>
|
|
#include <asm/alternative-asm.h>
|
|
#include <asm/asm.h>
|
|
#include <asm/smap.h>
|
|
|
|
/* Avoid __ASSEMBLER__'ifying <linux/audit.h> just for this. */
|
|
#include <linux/elf-em.h>
|
|
#define AUDIT_ARCH_I386 (EM_386|__AUDIT_ARCH_LE)
|
|
#define __AUDIT_ARCH_LE 0x40000000
|
|
|
|
#ifndef CONFIG_AUDITSYSCALL
|
|
#define sysenter_audit syscall_trace_entry
|
|
#define sysexit_audit syscall_exit_work
|
|
#endif
|
|
|
|
.section .entry.text, "ax"
|
|
|
|
/*
|
|
* We use macros for low-level operations which need to be overridden
|
|
* for paravirtualization. The following will never clobber any registers:
|
|
* INTERRUPT_RETURN (aka. "iret")
|
|
* GET_CR0_INTO_EAX (aka. "movl %cr0, %eax")
|
|
* ENABLE_INTERRUPTS_SYSEXIT (aka "sti; sysexit").
|
|
*
|
|
* For DISABLE_INTERRUPTS/ENABLE_INTERRUPTS (aka "cli"/"sti"), you must
|
|
* specify what registers can be overwritten (CLBR_NONE, CLBR_EAX/EDX/ECX/ANY).
|
|
* Allowing a register to be clobbered can shrink the paravirt replacement
|
|
* enough to patch inline, increasing performance.
|
|
*/
|
|
|
|
#ifdef CONFIG_PREEMPT
|
|
#define preempt_stop(clobbers) DISABLE_INTERRUPTS(clobbers); TRACE_IRQS_OFF
|
|
#else
|
|
#define preempt_stop(clobbers)
|
|
#define resume_kernel restore_all
|
|
#endif
|
|
|
|
.macro TRACE_IRQS_IRET
|
|
#ifdef CONFIG_TRACE_IRQFLAGS
|
|
testl $X86_EFLAGS_IF,PT_EFLAGS(%esp) # interrupts off?
|
|
jz 1f
|
|
TRACE_IRQS_ON
|
|
1:
|
|
#endif
|
|
.endm
|
|
|
|
/*
|
|
* User gs save/restore
|
|
*
|
|
* %gs is used for userland TLS and kernel only uses it for stack
|
|
* canary which is required to be at %gs:20 by gcc. Read the comment
|
|
* at the top of stackprotector.h for more info.
|
|
*
|
|
* Local labels 98 and 99 are used.
|
|
*/
|
|
#ifdef CONFIG_X86_32_LAZY_GS
|
|
|
|
/* unfortunately push/pop can't be no-op */
|
|
.macro PUSH_GS
|
|
pushl_cfi $0
|
|
.endm
|
|
.macro POP_GS pop=0
|
|
addl $(4 + \pop), %esp
|
|
CFI_ADJUST_CFA_OFFSET -(4 + \pop)
|
|
.endm
|
|
.macro POP_GS_EX
|
|
.endm
|
|
|
|
/* all the rest are no-op */
|
|
.macro PTGS_TO_GS
|
|
.endm
|
|
.macro PTGS_TO_GS_EX
|
|
.endm
|
|
.macro GS_TO_REG reg
|
|
.endm
|
|
.macro REG_TO_PTGS reg
|
|
.endm
|
|
.macro SET_KERNEL_GS reg
|
|
.endm
|
|
|
|
#else /* CONFIG_X86_32_LAZY_GS */
|
|
|
|
.macro PUSH_GS
|
|
pushl_cfi %gs
|
|
/*CFI_REL_OFFSET gs, 0*/
|
|
.endm
|
|
|
|
.macro POP_GS pop=0
|
|
98: popl_cfi %gs
|
|
/*CFI_RESTORE gs*/
|
|
.if \pop <> 0
|
|
add $\pop, %esp
|
|
CFI_ADJUST_CFA_OFFSET -\pop
|
|
.endif
|
|
.endm
|
|
.macro POP_GS_EX
|
|
.pushsection .fixup, "ax"
|
|
99: movl $0, (%esp)
|
|
jmp 98b
|
|
.popsection
|
|
_ASM_EXTABLE(98b,99b)
|
|
.endm
|
|
|
|
.macro PTGS_TO_GS
|
|
98: mov PT_GS(%esp), %gs
|
|
.endm
|
|
.macro PTGS_TO_GS_EX
|
|
.pushsection .fixup, "ax"
|
|
99: movl $0, PT_GS(%esp)
|
|
jmp 98b
|
|
.popsection
|
|
_ASM_EXTABLE(98b,99b)
|
|
.endm
|
|
|
|
.macro GS_TO_REG reg
|
|
movl %gs, \reg
|
|
/*CFI_REGISTER gs, \reg*/
|
|
.endm
|
|
.macro REG_TO_PTGS reg
|
|
movl \reg, PT_GS(%esp)
|
|
/*CFI_REL_OFFSET gs, PT_GS*/
|
|
.endm
|
|
.macro SET_KERNEL_GS reg
|
|
movl $(__KERNEL_STACK_CANARY), \reg
|
|
movl \reg, %gs
|
|
.endm
|
|
|
|
#endif /* CONFIG_X86_32_LAZY_GS */
|
|
|
|
.macro SAVE_ALL
|
|
cld
|
|
PUSH_GS
|
|
pushl_cfi %fs
|
|
/*CFI_REL_OFFSET fs, 0;*/
|
|
pushl_cfi %es
|
|
/*CFI_REL_OFFSET es, 0;*/
|
|
pushl_cfi %ds
|
|
/*CFI_REL_OFFSET ds, 0;*/
|
|
pushl_cfi %eax
|
|
CFI_REL_OFFSET eax, 0
|
|
pushl_cfi %ebp
|
|
CFI_REL_OFFSET ebp, 0
|
|
pushl_cfi %edi
|
|
CFI_REL_OFFSET edi, 0
|
|
pushl_cfi %esi
|
|
CFI_REL_OFFSET esi, 0
|
|
pushl_cfi %edx
|
|
CFI_REL_OFFSET edx, 0
|
|
pushl_cfi %ecx
|
|
CFI_REL_OFFSET ecx, 0
|
|
pushl_cfi %ebx
|
|
CFI_REL_OFFSET ebx, 0
|
|
movl $(__USER_DS), %edx
|
|
movl %edx, %ds
|
|
movl %edx, %es
|
|
movl $(__KERNEL_PERCPU), %edx
|
|
movl %edx, %fs
|
|
SET_KERNEL_GS %edx
|
|
.endm
|
|
|
|
.macro RESTORE_INT_REGS
|
|
popl_cfi %ebx
|
|
CFI_RESTORE ebx
|
|
popl_cfi %ecx
|
|
CFI_RESTORE ecx
|
|
popl_cfi %edx
|
|
CFI_RESTORE edx
|
|
popl_cfi %esi
|
|
CFI_RESTORE esi
|
|
popl_cfi %edi
|
|
CFI_RESTORE edi
|
|
popl_cfi %ebp
|
|
CFI_RESTORE ebp
|
|
popl_cfi %eax
|
|
CFI_RESTORE eax
|
|
.endm
|
|
|
|
.macro RESTORE_REGS pop=0
|
|
RESTORE_INT_REGS
|
|
1: popl_cfi %ds
|
|
/*CFI_RESTORE ds;*/
|
|
2: popl_cfi %es
|
|
/*CFI_RESTORE es;*/
|
|
3: popl_cfi %fs
|
|
/*CFI_RESTORE fs;*/
|
|
POP_GS \pop
|
|
.pushsection .fixup, "ax"
|
|
4: movl $0, (%esp)
|
|
jmp 1b
|
|
5: movl $0, (%esp)
|
|
jmp 2b
|
|
6: movl $0, (%esp)
|
|
jmp 3b
|
|
.popsection
|
|
_ASM_EXTABLE(1b,4b)
|
|
_ASM_EXTABLE(2b,5b)
|
|
_ASM_EXTABLE(3b,6b)
|
|
POP_GS_EX
|
|
.endm
|
|
|
|
.macro RING0_INT_FRAME
|
|
CFI_STARTPROC simple
|
|
CFI_SIGNAL_FRAME
|
|
CFI_DEF_CFA esp, 3*4
|
|
/*CFI_OFFSET cs, -2*4;*/
|
|
CFI_OFFSET eip, -3*4
|
|
.endm
|
|
|
|
.macro RING0_EC_FRAME
|
|
CFI_STARTPROC simple
|
|
CFI_SIGNAL_FRAME
|
|
CFI_DEF_CFA esp, 4*4
|
|
/*CFI_OFFSET cs, -2*4;*/
|
|
CFI_OFFSET eip, -3*4
|
|
.endm
|
|
|
|
.macro RING0_PTREGS_FRAME
|
|
CFI_STARTPROC simple
|
|
CFI_SIGNAL_FRAME
|
|
CFI_DEF_CFA esp, PT_OLDESP-PT_EBX
|
|
/*CFI_OFFSET cs, PT_CS-PT_OLDESP;*/
|
|
CFI_OFFSET eip, PT_EIP-PT_OLDESP
|
|
/*CFI_OFFSET es, PT_ES-PT_OLDESP;*/
|
|
/*CFI_OFFSET ds, PT_DS-PT_OLDESP;*/
|
|
CFI_OFFSET eax, PT_EAX-PT_OLDESP
|
|
CFI_OFFSET ebp, PT_EBP-PT_OLDESP
|
|
CFI_OFFSET edi, PT_EDI-PT_OLDESP
|
|
CFI_OFFSET esi, PT_ESI-PT_OLDESP
|
|
CFI_OFFSET edx, PT_EDX-PT_OLDESP
|
|
CFI_OFFSET ecx, PT_ECX-PT_OLDESP
|
|
CFI_OFFSET ebx, PT_EBX-PT_OLDESP
|
|
.endm
|
|
|
|
ENTRY(ret_from_fork)
|
|
CFI_STARTPROC
|
|
pushl_cfi %eax
|
|
call schedule_tail
|
|
GET_THREAD_INFO(%ebp)
|
|
popl_cfi %eax
|
|
pushl_cfi $0x0202 # Reset kernel eflags
|
|
popfl_cfi
|
|
jmp syscall_exit
|
|
CFI_ENDPROC
|
|
END(ret_from_fork)
|
|
|
|
ENTRY(ret_from_kernel_thread)
|
|
CFI_STARTPROC
|
|
pushl_cfi %eax
|
|
call schedule_tail
|
|
GET_THREAD_INFO(%ebp)
|
|
popl_cfi %eax
|
|
pushl_cfi $0x0202 # Reset kernel eflags
|
|
popfl_cfi
|
|
movl PT_EBP(%esp),%eax
|
|
call *PT_EBX(%esp)
|
|
movl $0,PT_EAX(%esp)
|
|
jmp syscall_exit
|
|
CFI_ENDPROC
|
|
ENDPROC(ret_from_kernel_thread)
|
|
|
|
/*
|
|
* Interrupt exit functions should be protected against kprobes
|
|
*/
|
|
.pushsection .kprobes.text, "ax"
|
|
/*
|
|
* 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
|
|
RING0_PTREGS_FRAME
|
|
ret_from_exception:
|
|
preempt_stop(CLBR_ANY)
|
|
ret_from_intr:
|
|
GET_THREAD_INFO(%ebp)
|
|
#ifdef CONFIG_VM86
|
|
movl PT_EFLAGS(%esp), %eax # mix EFLAGS and CS
|
|
movb PT_CS(%esp), %al
|
|
andl $(X86_EFLAGS_VM | SEGMENT_RPL_MASK), %eax
|
|
#else
|
|
/*
|
|
* We can be coming here from child spawned by kernel_thread().
|
|
*/
|
|
movl PT_CS(%esp), %eax
|
|
andl $SEGMENT_RPL_MASK, %eax
|
|
#endif
|
|
cmpl $USER_RPL, %eax
|
|
jb resume_kernel # not returning to v8086 or userspace
|
|
|
|
ENTRY(resume_userspace)
|
|
LOCKDEP_SYS_EXIT
|
|
DISABLE_INTERRUPTS(CLBR_ANY) # make sure we don't miss an interrupt
|
|
# setting need_resched or sigpending
|
|
# between sampling and the iret
|
|
TRACE_IRQS_OFF
|
|
movl TI_flags(%ebp), %ecx
|
|
andl $_TIF_WORK_MASK, %ecx # is there any work to be done on
|
|
# int/exception return?
|
|
jne work_pending
|
|
jmp restore_all
|
|
END(ret_from_exception)
|
|
|
|
#ifdef CONFIG_PREEMPT
|
|
ENTRY(resume_kernel)
|
|
DISABLE_INTERRUPTS(CLBR_ANY)
|
|
need_resched:
|
|
cmpl $0,PER_CPU_VAR(__preempt_count)
|
|
jnz restore_all
|
|
testl $X86_EFLAGS_IF,PT_EFLAGS(%esp) # interrupts off (exception path) ?
|
|
jz restore_all
|
|
call preempt_schedule_irq
|
|
jmp need_resched
|
|
END(resume_kernel)
|
|
#endif
|
|
CFI_ENDPROC
|
|
/*
|
|
* End of kprobes section
|
|
*/
|
|
.popsection
|
|
|
|
/* 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(ia32_sysenter_target)
|
|
CFI_STARTPROC simple
|
|
CFI_SIGNAL_FRAME
|
|
CFI_DEF_CFA esp, 0
|
|
CFI_REGISTER esp, ebp
|
|
movl TSS_sysenter_sp0(%esp),%esp
|
|
sysenter_past_esp:
|
|
/*
|
|
* Interrupts are disabled here, but we can't trace it until
|
|
* enough kernel state to call TRACE_IRQS_OFF can be called - but
|
|
* we immediately enable interrupts at that point anyway.
|
|
*/
|
|
pushl_cfi $__USER_DS
|
|
/*CFI_REL_OFFSET ss, 0*/
|
|
pushl_cfi %ebp
|
|
CFI_REL_OFFSET esp, 0
|
|
pushfl_cfi
|
|
orl $X86_EFLAGS_IF, (%esp)
|
|
pushl_cfi $__USER_CS
|
|
/*CFI_REL_OFFSET cs, 0*/
|
|
/*
|
|
* Push current_thread_info()->sysenter_return to the stack.
|
|
* A tiny bit of offset fixup is necessary - 4*4 means the 4 words
|
|
* pushed above; +8 corresponds to copy_thread's esp0 setting.
|
|
*/
|
|
pushl_cfi ((TI_sysenter_return)-THREAD_SIZE+8+4*4)(%esp)
|
|
CFI_REL_OFFSET eip, 0
|
|
|
|
pushl_cfi %eax
|
|
SAVE_ALL
|
|
ENABLE_INTERRUPTS(CLBR_NONE)
|
|
|
|
/*
|
|
* Load the potential sixth argument from user stack.
|
|
* Careful about security.
|
|
*/
|
|
cmpl $__PAGE_OFFSET-3,%ebp
|
|
jae syscall_fault
|
|
ASM_STAC
|
|
1: movl (%ebp),%ebp
|
|
ASM_CLAC
|
|
movl %ebp,PT_EBP(%esp)
|
|
_ASM_EXTABLE(1b,syscall_fault)
|
|
|
|
GET_THREAD_INFO(%ebp)
|
|
|
|
testl $_TIF_WORK_SYSCALL_ENTRY,TI_flags(%ebp)
|
|
jnz sysenter_audit
|
|
sysenter_do_call:
|
|
cmpl $(NR_syscalls), %eax
|
|
jae syscall_badsys
|
|
call *sys_call_table(,%eax,4)
|
|
movl %eax,PT_EAX(%esp)
|
|
LOCKDEP_SYS_EXIT
|
|
DISABLE_INTERRUPTS(CLBR_ANY)
|
|
TRACE_IRQS_OFF
|
|
movl TI_flags(%ebp), %ecx
|
|
testl $_TIF_ALLWORK_MASK, %ecx
|
|
jne sysexit_audit
|
|
sysenter_exit:
|
|
/* if something modifies registers it must also disable sysexit */
|
|
movl PT_EIP(%esp), %edx
|
|
movl PT_OLDESP(%esp), %ecx
|
|
xorl %ebp,%ebp
|
|
TRACE_IRQS_ON
|
|
1: mov PT_FS(%esp), %fs
|
|
PTGS_TO_GS
|
|
ENABLE_INTERRUPTS_SYSEXIT
|
|
|
|
#ifdef CONFIG_AUDITSYSCALL
|
|
sysenter_audit:
|
|
testl $(_TIF_WORK_SYSCALL_ENTRY & ~_TIF_SYSCALL_AUDIT),TI_flags(%ebp)
|
|
jnz syscall_trace_entry
|
|
addl $4,%esp
|
|
CFI_ADJUST_CFA_OFFSET -4
|
|
/* %esi already in 8(%esp) 6th arg: 4th syscall arg */
|
|
/* %edx already in 4(%esp) 5th arg: 3rd syscall arg */
|
|
/* %ecx already in 0(%esp) 4th arg: 2nd syscall arg */
|
|
movl %ebx,%ecx /* 3rd arg: 1st syscall arg */
|
|
movl %eax,%edx /* 2nd arg: syscall number */
|
|
movl $AUDIT_ARCH_I386,%eax /* 1st arg: audit arch */
|
|
call __audit_syscall_entry
|
|
pushl_cfi %ebx
|
|
movl PT_EAX(%esp),%eax /* reload syscall number */
|
|
jmp sysenter_do_call
|
|
|
|
sysexit_audit:
|
|
testl $(_TIF_ALLWORK_MASK & ~_TIF_SYSCALL_AUDIT), %ecx
|
|
jne syscall_exit_work
|
|
TRACE_IRQS_ON
|
|
ENABLE_INTERRUPTS(CLBR_ANY)
|
|
movl %eax,%edx /* second arg, syscall return value */
|
|
cmpl $-MAX_ERRNO,%eax /* is it an error ? */
|
|
setbe %al /* 1 if so, 0 if not */
|
|
movzbl %al,%eax /* zero-extend that */
|
|
call __audit_syscall_exit
|
|
DISABLE_INTERRUPTS(CLBR_ANY)
|
|
TRACE_IRQS_OFF
|
|
movl TI_flags(%ebp), %ecx
|
|
testl $(_TIF_ALLWORK_MASK & ~_TIF_SYSCALL_AUDIT), %ecx
|
|
jne syscall_exit_work
|
|
movl PT_EAX(%esp),%eax /* reload syscall return value */
|
|
jmp sysenter_exit
|
|
#endif
|
|
|
|
CFI_ENDPROC
|
|
.pushsection .fixup,"ax"
|
|
2: movl $0,PT_FS(%esp)
|
|
jmp 1b
|
|
.popsection
|
|
_ASM_EXTABLE(1b,2b)
|
|
PTGS_TO_GS_EX
|
|
ENDPROC(ia32_sysenter_target)
|
|
|
|
/*
|
|
* syscall stub including irq exit should be protected against kprobes
|
|
*/
|
|
.pushsection .kprobes.text, "ax"
|
|
# system call handler stub
|
|
ENTRY(system_call)
|
|
RING0_INT_FRAME # can't unwind into user space anyway
|
|
ASM_CLAC
|
|
pushl_cfi %eax # save orig_eax
|
|
SAVE_ALL
|
|
GET_THREAD_INFO(%ebp)
|
|
# system call tracing in operation / emulation
|
|
testl $_TIF_WORK_SYSCALL_ENTRY,TI_flags(%ebp)
|
|
jnz syscall_trace_entry
|
|
cmpl $(NR_syscalls), %eax
|
|
jae syscall_badsys
|
|
syscall_call:
|
|
call *sys_call_table(,%eax,4)
|
|
movl %eax,PT_EAX(%esp) # store the return value
|
|
syscall_exit:
|
|
LOCKDEP_SYS_EXIT
|
|
DISABLE_INTERRUPTS(CLBR_ANY) # make sure we don't miss an interrupt
|
|
# setting need_resched or sigpending
|
|
# between sampling and the iret
|
|
TRACE_IRQS_OFF
|
|
movl TI_flags(%ebp), %ecx
|
|
testl $_TIF_ALLWORK_MASK, %ecx # current->work
|
|
jne syscall_exit_work
|
|
|
|
restore_all:
|
|
TRACE_IRQS_IRET
|
|
restore_all_notrace:
|
|
movl PT_EFLAGS(%esp), %eax # mix EFLAGS, SS and CS
|
|
# Warning: PT_OLDSS(%esp) contains the wrong/random values if we
|
|
# are returning to the kernel.
|
|
# See comments in process.c:copy_thread() for details.
|
|
movb PT_OLDSS(%esp), %ah
|
|
movb PT_CS(%esp), %al
|
|
andl $(X86_EFLAGS_VM | (SEGMENT_TI_MASK << 8) | SEGMENT_RPL_MASK), %eax
|
|
cmpl $((SEGMENT_LDT << 8) | USER_RPL), %eax
|
|
CFI_REMEMBER_STATE
|
|
je ldt_ss # returning to user-space with LDT SS
|
|
restore_nocheck:
|
|
RESTORE_REGS 4 # skip orig_eax/error_code
|
|
irq_return:
|
|
INTERRUPT_RETURN
|
|
.section .fixup,"ax"
|
|
ENTRY(iret_exc)
|
|
pushl $0 # no error code
|
|
pushl $do_iret_error
|
|
jmp error_code
|
|
.previous
|
|
_ASM_EXTABLE(irq_return,iret_exc)
|
|
|
|
CFI_RESTORE_STATE
|
|
ldt_ss:
|
|
larl PT_OLDSS(%esp), %eax
|
|
jnz restore_nocheck
|
|
testl $0x00400000, %eax # returning to 32bit stack?
|
|
jnz restore_nocheck # allright, normal return
|
|
|
|
#ifdef CONFIG_PARAVIRT
|
|
/*
|
|
* The kernel can't run on a non-flat stack if paravirt mode
|
|
* is active. Rather than try to fixup the high bits of
|
|
* ESP, bypass this code entirely. This may break DOSemu
|
|
* and/or Wine support in a paravirt VM, although the option
|
|
* is still available to implement the setting of the high
|
|
* 16-bits in the INTERRUPT_RETURN paravirt-op.
|
|
*/
|
|
cmpl $0, pv_info+PARAVIRT_enabled
|
|
jne restore_nocheck
|
|
#endif
|
|
|
|
/*
|
|
* Setup and switch to ESPFIX stack
|
|
*
|
|
* We're returning to userspace with a 16 bit stack. The CPU will not
|
|
* restore the high word of ESP for us on executing iret... This is an
|
|
* "official" bug of all the x86-compatible CPUs, which we can work
|
|
* around to make dosemu and wine happy. We do this by preloading the
|
|
* high word of ESP with the high word of the userspace ESP while
|
|
* compensating for the offset by changing to the ESPFIX segment with
|
|
* a base address that matches for the difference.
|
|
*/
|
|
#define GDT_ESPFIX_SS PER_CPU_VAR(gdt_page) + (GDT_ENTRY_ESPFIX_SS * 8)
|
|
mov %esp, %edx /* load kernel esp */
|
|
mov PT_OLDESP(%esp), %eax /* load userspace esp */
|
|
mov %dx, %ax /* eax: new kernel esp */
|
|
sub %eax, %edx /* offset (low word is 0) */
|
|
shr $16, %edx
|
|
mov %dl, GDT_ESPFIX_SS + 4 /* bits 16..23 */
|
|
mov %dh, GDT_ESPFIX_SS + 7 /* bits 24..31 */
|
|
pushl_cfi $__ESPFIX_SS
|
|
pushl_cfi %eax /* new kernel esp */
|
|
/* Disable interrupts, but do not irqtrace this section: we
|
|
* will soon execute iret and the tracer was already set to
|
|
* the irqstate after the iret */
|
|
DISABLE_INTERRUPTS(CLBR_EAX)
|
|
lss (%esp), %esp /* switch to espfix segment */
|
|
CFI_ADJUST_CFA_OFFSET -8
|
|
jmp restore_nocheck
|
|
CFI_ENDPROC
|
|
ENDPROC(system_call)
|
|
|
|
# perform work that needs to be done immediately before resumption
|
|
ALIGN
|
|
RING0_PTREGS_FRAME # can't unwind into user space anyway
|
|
work_pending:
|
|
testb $_TIF_NEED_RESCHED, %cl
|
|
jz work_notifysig
|
|
work_resched:
|
|
call schedule
|
|
LOCKDEP_SYS_EXIT
|
|
DISABLE_INTERRUPTS(CLBR_ANY) # make sure we don't miss an interrupt
|
|
# setting need_resched or sigpending
|
|
# between sampling and the iret
|
|
TRACE_IRQS_OFF
|
|
movl TI_flags(%ebp), %ecx
|
|
andl $_TIF_WORK_MASK, %ecx # is there any work to be done other
|
|
# than syscall tracing?
|
|
jz restore_all
|
|
testb $_TIF_NEED_RESCHED, %cl
|
|
jnz work_resched
|
|
|
|
work_notifysig: # deal with pending signals and
|
|
# notify-resume requests
|
|
#ifdef CONFIG_VM86
|
|
testl $X86_EFLAGS_VM, PT_EFLAGS(%esp)
|
|
movl %esp, %eax
|
|
jne work_notifysig_v86 # returning to kernel-space or
|
|
# vm86-space
|
|
1:
|
|
#else
|
|
movl %esp, %eax
|
|
#endif
|
|
TRACE_IRQS_ON
|
|
ENABLE_INTERRUPTS(CLBR_NONE)
|
|
movb PT_CS(%esp), %bl
|
|
andb $SEGMENT_RPL_MASK, %bl
|
|
cmpb $USER_RPL, %bl
|
|
jb resume_kernel
|
|
xorl %edx, %edx
|
|
call do_notify_resume
|
|
jmp resume_userspace
|
|
|
|
#ifdef CONFIG_VM86
|
|
ALIGN
|
|
work_notifysig_v86:
|
|
pushl_cfi %ecx # save ti_flags for do_notify_resume
|
|
call save_v86_state # %eax contains pt_regs pointer
|
|
popl_cfi %ecx
|
|
movl %eax, %esp
|
|
jmp 1b
|
|
#endif
|
|
END(work_pending)
|
|
|
|
# perform syscall exit tracing
|
|
ALIGN
|
|
syscall_trace_entry:
|
|
movl $-ENOSYS,PT_EAX(%esp)
|
|
movl %esp, %eax
|
|
call syscall_trace_enter
|
|
/* What it returned is what we'll actually use. */
|
|
cmpl $(NR_syscalls), %eax
|
|
jnae syscall_call
|
|
jmp syscall_exit
|
|
END(syscall_trace_entry)
|
|
|
|
# perform syscall exit tracing
|
|
ALIGN
|
|
syscall_exit_work:
|
|
testl $_TIF_WORK_SYSCALL_EXIT, %ecx
|
|
jz work_pending
|
|
TRACE_IRQS_ON
|
|
ENABLE_INTERRUPTS(CLBR_ANY) # could let syscall_trace_leave() call
|
|
# schedule() instead
|
|
movl %esp, %eax
|
|
call syscall_trace_leave
|
|
jmp resume_userspace
|
|
END(syscall_exit_work)
|
|
CFI_ENDPROC
|
|
|
|
RING0_INT_FRAME # can't unwind into user space anyway
|
|
syscall_fault:
|
|
ASM_CLAC
|
|
GET_THREAD_INFO(%ebp)
|
|
movl $-EFAULT,PT_EAX(%esp)
|
|
jmp resume_userspace
|
|
END(syscall_fault)
|
|
|
|
syscall_badsys:
|
|
movl $-ENOSYS,PT_EAX(%esp)
|
|
jmp resume_userspace
|
|
END(syscall_badsys)
|
|
CFI_ENDPROC
|
|
/*
|
|
* End of kprobes section
|
|
*/
|
|
.popsection
|
|
|
|
.macro FIXUP_ESPFIX_STACK
|
|
/*
|
|
* Switch back for ESPFIX stack to the normal zerobased stack
|
|
*
|
|
* We can't call C functions using the ESPFIX stack. This code reads
|
|
* the high word of the segment base from the GDT and swiches to the
|
|
* normal stack and adjusts ESP with the matching offset.
|
|
*/
|
|
/* fixup the stack */
|
|
mov GDT_ESPFIX_SS + 4, %al /* bits 16..23 */
|
|
mov GDT_ESPFIX_SS + 7, %ah /* bits 24..31 */
|
|
shl $16, %eax
|
|
addl %esp, %eax /* the adjusted stack pointer */
|
|
pushl_cfi $__KERNEL_DS
|
|
pushl_cfi %eax
|
|
lss (%esp), %esp /* switch to the normal stack segment */
|
|
CFI_ADJUST_CFA_OFFSET -8
|
|
.endm
|
|
.macro UNWIND_ESPFIX_STACK
|
|
movl %ss, %eax
|
|
/* see if on espfix stack */
|
|
cmpw $__ESPFIX_SS, %ax
|
|
jne 27f
|
|
movl $__KERNEL_DS, %eax
|
|
movl %eax, %ds
|
|
movl %eax, %es
|
|
/* switch to normal stack */
|
|
FIXUP_ESPFIX_STACK
|
|
27:
|
|
.endm
|
|
|
|
/*
|
|
* Build the entry stubs and pointer table with some assembler magic.
|
|
* We pack 7 stubs into a single 32-byte chunk, which will fit in a
|
|
* single cache line on all modern x86 implementations.
|
|
*/
|
|
.section .init.rodata,"a"
|
|
ENTRY(interrupt)
|
|
.section .entry.text, "ax"
|
|
.p2align 5
|
|
.p2align CONFIG_X86_L1_CACHE_SHIFT
|
|
ENTRY(irq_entries_start)
|
|
RING0_INT_FRAME
|
|
vector=FIRST_EXTERNAL_VECTOR
|
|
.rept (NR_VECTORS-FIRST_EXTERNAL_VECTOR+6)/7
|
|
.balign 32
|
|
.rept 7
|
|
.if vector < NR_VECTORS
|
|
.if vector <> FIRST_EXTERNAL_VECTOR
|
|
CFI_ADJUST_CFA_OFFSET -4
|
|
.endif
|
|
1: pushl_cfi $(~vector+0x80) /* Note: always in signed byte range */
|
|
.if ((vector-FIRST_EXTERNAL_VECTOR)%7) <> 6
|
|
jmp 2f
|
|
.endif
|
|
.previous
|
|
.long 1b
|
|
.section .entry.text, "ax"
|
|
vector=vector+1
|
|
.endif
|
|
.endr
|
|
2: jmp common_interrupt
|
|
.endr
|
|
END(irq_entries_start)
|
|
|
|
.previous
|
|
END(interrupt)
|
|
.previous
|
|
|
|
/*
|
|
* the CPU automatically disables interrupts when executing an IRQ vector,
|
|
* so IRQ-flags tracing has to follow that:
|
|
*/
|
|
.p2align CONFIG_X86_L1_CACHE_SHIFT
|
|
common_interrupt:
|
|
ASM_CLAC
|
|
addl $-0x80,(%esp) /* Adjust vector into the [-256,-1] range */
|
|
SAVE_ALL
|
|
TRACE_IRQS_OFF
|
|
movl %esp,%eax
|
|
call do_IRQ
|
|
jmp ret_from_intr
|
|
ENDPROC(common_interrupt)
|
|
CFI_ENDPROC
|
|
|
|
/*
|
|
* Irq entries should be protected against kprobes
|
|
*/
|
|
.pushsection .kprobes.text, "ax"
|
|
#define BUILD_INTERRUPT3(name, nr, fn) \
|
|
ENTRY(name) \
|
|
RING0_INT_FRAME; \
|
|
ASM_CLAC; \
|
|
pushl_cfi $~(nr); \
|
|
SAVE_ALL; \
|
|
TRACE_IRQS_OFF \
|
|
movl %esp,%eax; \
|
|
call fn; \
|
|
jmp ret_from_intr; \
|
|
CFI_ENDPROC; \
|
|
ENDPROC(name)
|
|
|
|
|
|
#ifdef CONFIG_TRACING
|
|
#define TRACE_BUILD_INTERRUPT(name, nr) \
|
|
BUILD_INTERRUPT3(trace_##name, nr, smp_trace_##name)
|
|
#else
|
|
#define TRACE_BUILD_INTERRUPT(name, nr)
|
|
#endif
|
|
|
|
#define BUILD_INTERRUPT(name, nr) \
|
|
BUILD_INTERRUPT3(name, nr, smp_##name); \
|
|
TRACE_BUILD_INTERRUPT(name, nr)
|
|
|
|
/* The include is where all of the SMP etc. interrupts come from */
|
|
#include <asm/entry_arch.h>
|
|
|
|
ENTRY(coprocessor_error)
|
|
RING0_INT_FRAME
|
|
ASM_CLAC
|
|
pushl_cfi $0
|
|
pushl_cfi $do_coprocessor_error
|
|
jmp error_code
|
|
CFI_ENDPROC
|
|
END(coprocessor_error)
|
|
|
|
ENTRY(simd_coprocessor_error)
|
|
RING0_INT_FRAME
|
|
ASM_CLAC
|
|
pushl_cfi $0
|
|
#ifdef CONFIG_X86_INVD_BUG
|
|
/* AMD 486 bug: invd from userspace calls exception 19 instead of #GP */
|
|
661: pushl_cfi $do_general_protection
|
|
662:
|
|
.section .altinstructions,"a"
|
|
altinstruction_entry 661b, 663f, X86_FEATURE_XMM, 662b-661b, 664f-663f
|
|
.previous
|
|
.section .altinstr_replacement,"ax"
|
|
663: pushl $do_simd_coprocessor_error
|
|
664:
|
|
.previous
|
|
#else
|
|
pushl_cfi $do_simd_coprocessor_error
|
|
#endif
|
|
jmp error_code
|
|
CFI_ENDPROC
|
|
END(simd_coprocessor_error)
|
|
|
|
ENTRY(device_not_available)
|
|
RING0_INT_FRAME
|
|
ASM_CLAC
|
|
pushl_cfi $-1 # mark this as an int
|
|
pushl_cfi $do_device_not_available
|
|
jmp error_code
|
|
CFI_ENDPROC
|
|
END(device_not_available)
|
|
|
|
#ifdef CONFIG_PARAVIRT
|
|
ENTRY(native_iret)
|
|
iret
|
|
_ASM_EXTABLE(native_iret, iret_exc)
|
|
END(native_iret)
|
|
|
|
ENTRY(native_irq_enable_sysexit)
|
|
sti
|
|
sysexit
|
|
END(native_irq_enable_sysexit)
|
|
#endif
|
|
|
|
ENTRY(overflow)
|
|
RING0_INT_FRAME
|
|
ASM_CLAC
|
|
pushl_cfi $0
|
|
pushl_cfi $do_overflow
|
|
jmp error_code
|
|
CFI_ENDPROC
|
|
END(overflow)
|
|
|
|
ENTRY(bounds)
|
|
RING0_INT_FRAME
|
|
ASM_CLAC
|
|
pushl_cfi $0
|
|
pushl_cfi $do_bounds
|
|
jmp error_code
|
|
CFI_ENDPROC
|
|
END(bounds)
|
|
|
|
ENTRY(invalid_op)
|
|
RING0_INT_FRAME
|
|
ASM_CLAC
|
|
pushl_cfi $0
|
|
pushl_cfi $do_invalid_op
|
|
jmp error_code
|
|
CFI_ENDPROC
|
|
END(invalid_op)
|
|
|
|
ENTRY(coprocessor_segment_overrun)
|
|
RING0_INT_FRAME
|
|
ASM_CLAC
|
|
pushl_cfi $0
|
|
pushl_cfi $do_coprocessor_segment_overrun
|
|
jmp error_code
|
|
CFI_ENDPROC
|
|
END(coprocessor_segment_overrun)
|
|
|
|
ENTRY(invalid_TSS)
|
|
RING0_EC_FRAME
|
|
ASM_CLAC
|
|
pushl_cfi $do_invalid_TSS
|
|
jmp error_code
|
|
CFI_ENDPROC
|
|
END(invalid_TSS)
|
|
|
|
ENTRY(segment_not_present)
|
|
RING0_EC_FRAME
|
|
ASM_CLAC
|
|
pushl_cfi $do_segment_not_present
|
|
jmp error_code
|
|
CFI_ENDPROC
|
|
END(segment_not_present)
|
|
|
|
ENTRY(stack_segment)
|
|
RING0_EC_FRAME
|
|
ASM_CLAC
|
|
pushl_cfi $do_stack_segment
|
|
jmp error_code
|
|
CFI_ENDPROC
|
|
END(stack_segment)
|
|
|
|
ENTRY(alignment_check)
|
|
RING0_EC_FRAME
|
|
ASM_CLAC
|
|
pushl_cfi $do_alignment_check
|
|
jmp error_code
|
|
CFI_ENDPROC
|
|
END(alignment_check)
|
|
|
|
ENTRY(divide_error)
|
|
RING0_INT_FRAME
|
|
ASM_CLAC
|
|
pushl_cfi $0 # no error code
|
|
pushl_cfi $do_divide_error
|
|
jmp error_code
|
|
CFI_ENDPROC
|
|
END(divide_error)
|
|
|
|
#ifdef CONFIG_X86_MCE
|
|
ENTRY(machine_check)
|
|
RING0_INT_FRAME
|
|
ASM_CLAC
|
|
pushl_cfi $0
|
|
pushl_cfi machine_check_vector
|
|
jmp error_code
|
|
CFI_ENDPROC
|
|
END(machine_check)
|
|
#endif
|
|
|
|
ENTRY(spurious_interrupt_bug)
|
|
RING0_INT_FRAME
|
|
ASM_CLAC
|
|
pushl_cfi $0
|
|
pushl_cfi $do_spurious_interrupt_bug
|
|
jmp error_code
|
|
CFI_ENDPROC
|
|
END(spurious_interrupt_bug)
|
|
/*
|
|
* End of kprobes section
|
|
*/
|
|
.popsection
|
|
|
|
#ifdef CONFIG_XEN
|
|
/* Xen doesn't set %esp to be precisely what the normal sysenter
|
|
entrypoint expects, so fix it up before using the normal path. */
|
|
ENTRY(xen_sysenter_target)
|
|
RING0_INT_FRAME
|
|
addl $5*4, %esp /* remove xen-provided frame */
|
|
CFI_ADJUST_CFA_OFFSET -5*4
|
|
jmp sysenter_past_esp
|
|
CFI_ENDPROC
|
|
|
|
ENTRY(xen_hypervisor_callback)
|
|
CFI_STARTPROC
|
|
pushl_cfi $-1 /* orig_ax = -1 => not a system call */
|
|
SAVE_ALL
|
|
TRACE_IRQS_OFF
|
|
|
|
/* Check to see if we got the event in the critical
|
|
region in xen_iret_direct, after we've reenabled
|
|
events and checked for pending events. This simulates
|
|
iret instruction's behaviour where it delivers a
|
|
pending interrupt when enabling interrupts. */
|
|
movl PT_EIP(%esp),%eax
|
|
cmpl $xen_iret_start_crit,%eax
|
|
jb 1f
|
|
cmpl $xen_iret_end_crit,%eax
|
|
jae 1f
|
|
|
|
jmp xen_iret_crit_fixup
|
|
|
|
ENTRY(xen_do_upcall)
|
|
1: mov %esp, %eax
|
|
call xen_evtchn_do_upcall
|
|
jmp ret_from_intr
|
|
CFI_ENDPROC
|
|
ENDPROC(xen_hypervisor_callback)
|
|
|
|
# Hypervisor uses this for application faults while it executes.
|
|
# We get here for two reasons:
|
|
# 1. Fault while reloading DS, ES, FS or GS
|
|
# 2. Fault while executing IRET
|
|
# Category 1 we fix up by reattempting the load, and zeroing the segment
|
|
# register if the load fails.
|
|
# Category 2 we fix up by jumping to do_iret_error. We cannot use the
|
|
# normal Linux return path in this case because if we use the IRET hypercall
|
|
# to pop the stack frame we end up in an infinite loop of failsafe callbacks.
|
|
# We distinguish between categories by maintaining a status value in EAX.
|
|
ENTRY(xen_failsafe_callback)
|
|
CFI_STARTPROC
|
|
pushl_cfi %eax
|
|
movl $1,%eax
|
|
1: mov 4(%esp),%ds
|
|
2: mov 8(%esp),%es
|
|
3: mov 12(%esp),%fs
|
|
4: mov 16(%esp),%gs
|
|
/* EAX == 0 => Category 1 (Bad segment)
|
|
EAX != 0 => Category 2 (Bad IRET) */
|
|
testl %eax,%eax
|
|
popl_cfi %eax
|
|
lea 16(%esp),%esp
|
|
CFI_ADJUST_CFA_OFFSET -16
|
|
jz 5f
|
|
jmp iret_exc
|
|
5: pushl_cfi $-1 /* orig_ax = -1 => not a system call */
|
|
SAVE_ALL
|
|
jmp ret_from_exception
|
|
CFI_ENDPROC
|
|
|
|
.section .fixup,"ax"
|
|
6: xorl %eax,%eax
|
|
movl %eax,4(%esp)
|
|
jmp 1b
|
|
7: xorl %eax,%eax
|
|
movl %eax,8(%esp)
|
|
jmp 2b
|
|
8: xorl %eax,%eax
|
|
movl %eax,12(%esp)
|
|
jmp 3b
|
|
9: xorl %eax,%eax
|
|
movl %eax,16(%esp)
|
|
jmp 4b
|
|
.previous
|
|
_ASM_EXTABLE(1b,6b)
|
|
_ASM_EXTABLE(2b,7b)
|
|
_ASM_EXTABLE(3b,8b)
|
|
_ASM_EXTABLE(4b,9b)
|
|
ENDPROC(xen_failsafe_callback)
|
|
|
|
BUILD_INTERRUPT3(xen_hvm_callback_vector, HYPERVISOR_CALLBACK_VECTOR,
|
|
xen_evtchn_do_upcall)
|
|
|
|
#endif /* CONFIG_XEN */
|
|
|
|
#if IS_ENABLED(CONFIG_HYPERV)
|
|
|
|
BUILD_INTERRUPT3(hyperv_callback_vector, HYPERVISOR_CALLBACK_VECTOR,
|
|
hyperv_vector_handler)
|
|
|
|
#endif /* CONFIG_HYPERV */
|
|
|
|
#ifdef CONFIG_FUNCTION_TRACER
|
|
#ifdef CONFIG_DYNAMIC_FTRACE
|
|
|
|
ENTRY(mcount)
|
|
ret
|
|
END(mcount)
|
|
|
|
ENTRY(ftrace_caller)
|
|
cmpl $0, function_trace_stop
|
|
jne ftrace_stub
|
|
|
|
pushl %eax
|
|
pushl %ecx
|
|
pushl %edx
|
|
pushl $0 /* Pass NULL as regs pointer */
|
|
movl 4*4(%esp), %eax
|
|
movl 0x4(%ebp), %edx
|
|
movl function_trace_op, %ecx
|
|
subl $MCOUNT_INSN_SIZE, %eax
|
|
|
|
.globl ftrace_call
|
|
ftrace_call:
|
|
call ftrace_stub
|
|
|
|
addl $4,%esp /* skip NULL pointer */
|
|
popl %edx
|
|
popl %ecx
|
|
popl %eax
|
|
ftrace_ret:
|
|
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
|
|
.globl ftrace_graph_call
|
|
ftrace_graph_call:
|
|
jmp ftrace_stub
|
|
#endif
|
|
|
|
.globl ftrace_stub
|
|
ftrace_stub:
|
|
ret
|
|
END(ftrace_caller)
|
|
|
|
ENTRY(ftrace_regs_caller)
|
|
pushf /* push flags before compare (in cs location) */
|
|
cmpl $0, function_trace_stop
|
|
jne ftrace_restore_flags
|
|
|
|
/*
|
|
* i386 does not save SS and ESP when coming from kernel.
|
|
* Instead, to get sp, ®s->sp is used (see ptrace.h).
|
|
* Unfortunately, that means eflags must be at the same location
|
|
* as the current return ip is. We move the return ip into the
|
|
* ip location, and move flags into the return ip location.
|
|
*/
|
|
pushl 4(%esp) /* save return ip into ip slot */
|
|
|
|
pushl $0 /* Load 0 into orig_ax */
|
|
pushl %gs
|
|
pushl %fs
|
|
pushl %es
|
|
pushl %ds
|
|
pushl %eax
|
|
pushl %ebp
|
|
pushl %edi
|
|
pushl %esi
|
|
pushl %edx
|
|
pushl %ecx
|
|
pushl %ebx
|
|
|
|
movl 13*4(%esp), %eax /* Get the saved flags */
|
|
movl %eax, 14*4(%esp) /* Move saved flags into regs->flags location */
|
|
/* clobbering return ip */
|
|
movl $__KERNEL_CS,13*4(%esp)
|
|
|
|
movl 12*4(%esp), %eax /* Load ip (1st parameter) */
|
|
subl $MCOUNT_INSN_SIZE, %eax /* Adjust ip */
|
|
movl 0x4(%ebp), %edx /* Load parent ip (2nd parameter) */
|
|
movl function_trace_op, %ecx /* Save ftrace_pos in 3rd parameter */
|
|
pushl %esp /* Save pt_regs as 4th parameter */
|
|
|
|
GLOBAL(ftrace_regs_call)
|
|
call ftrace_stub
|
|
|
|
addl $4, %esp /* Skip pt_regs */
|
|
movl 14*4(%esp), %eax /* Move flags back into cs */
|
|
movl %eax, 13*4(%esp) /* Needed to keep addl from modifying flags */
|
|
movl 12*4(%esp), %eax /* Get return ip from regs->ip */
|
|
movl %eax, 14*4(%esp) /* Put return ip back for ret */
|
|
|
|
popl %ebx
|
|
popl %ecx
|
|
popl %edx
|
|
popl %esi
|
|
popl %edi
|
|
popl %ebp
|
|
popl %eax
|
|
popl %ds
|
|
popl %es
|
|
popl %fs
|
|
popl %gs
|
|
addl $8, %esp /* Skip orig_ax and ip */
|
|
popf /* Pop flags at end (no addl to corrupt flags) */
|
|
jmp ftrace_ret
|
|
|
|
ftrace_restore_flags:
|
|
popf
|
|
jmp ftrace_stub
|
|
#else /* ! CONFIG_DYNAMIC_FTRACE */
|
|
|
|
ENTRY(mcount)
|
|
cmpl $__PAGE_OFFSET, %esp
|
|
jb ftrace_stub /* Paging not enabled yet? */
|
|
|
|
cmpl $0, function_trace_stop
|
|
jne ftrace_stub
|
|
|
|
cmpl $ftrace_stub, ftrace_trace_function
|
|
jnz trace
|
|
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
|
|
cmpl $ftrace_stub, ftrace_graph_return
|
|
jnz ftrace_graph_caller
|
|
|
|
cmpl $ftrace_graph_entry_stub, ftrace_graph_entry
|
|
jnz ftrace_graph_caller
|
|
#endif
|
|
.globl ftrace_stub
|
|
ftrace_stub:
|
|
ret
|
|
|
|
/* taken from glibc */
|
|
trace:
|
|
pushl %eax
|
|
pushl %ecx
|
|
pushl %edx
|
|
movl 0xc(%esp), %eax
|
|
movl 0x4(%ebp), %edx
|
|
subl $MCOUNT_INSN_SIZE, %eax
|
|
|
|
call *ftrace_trace_function
|
|
|
|
popl %edx
|
|
popl %ecx
|
|
popl %eax
|
|
jmp ftrace_stub
|
|
END(mcount)
|
|
#endif /* CONFIG_DYNAMIC_FTRACE */
|
|
#endif /* CONFIG_FUNCTION_TRACER */
|
|
|
|
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
|
|
ENTRY(ftrace_graph_caller)
|
|
pushl %eax
|
|
pushl %ecx
|
|
pushl %edx
|
|
movl 0xc(%esp), %edx
|
|
lea 0x4(%ebp), %eax
|
|
movl (%ebp), %ecx
|
|
subl $MCOUNT_INSN_SIZE, %edx
|
|
call prepare_ftrace_return
|
|
popl %edx
|
|
popl %ecx
|
|
popl %eax
|
|
ret
|
|
END(ftrace_graph_caller)
|
|
|
|
.globl return_to_handler
|
|
return_to_handler:
|
|
pushl %eax
|
|
pushl %edx
|
|
movl %ebp, %eax
|
|
call ftrace_return_to_handler
|
|
movl %eax, %ecx
|
|
popl %edx
|
|
popl %eax
|
|
jmp *%ecx
|
|
#endif
|
|
|
|
/*
|
|
* Some functions should be protected against kprobes
|
|
*/
|
|
.pushsection .kprobes.text, "ax"
|
|
|
|
#ifdef CONFIG_TRACING
|
|
ENTRY(trace_page_fault)
|
|
RING0_EC_FRAME
|
|
ASM_CLAC
|
|
pushl_cfi $trace_do_page_fault
|
|
jmp error_code
|
|
CFI_ENDPROC
|
|
END(trace_page_fault)
|
|
#endif
|
|
|
|
ENTRY(page_fault)
|
|
RING0_EC_FRAME
|
|
ASM_CLAC
|
|
pushl_cfi $do_page_fault
|
|
ALIGN
|
|
error_code:
|
|
/* the function address is in %gs's slot on the stack */
|
|
pushl_cfi %fs
|
|
/*CFI_REL_OFFSET fs, 0*/
|
|
pushl_cfi %es
|
|
/*CFI_REL_OFFSET es, 0*/
|
|
pushl_cfi %ds
|
|
/*CFI_REL_OFFSET ds, 0*/
|
|
pushl_cfi %eax
|
|
CFI_REL_OFFSET eax, 0
|
|
pushl_cfi %ebp
|
|
CFI_REL_OFFSET ebp, 0
|
|
pushl_cfi %edi
|
|
CFI_REL_OFFSET edi, 0
|
|
pushl_cfi %esi
|
|
CFI_REL_OFFSET esi, 0
|
|
pushl_cfi %edx
|
|
CFI_REL_OFFSET edx, 0
|
|
pushl_cfi %ecx
|
|
CFI_REL_OFFSET ecx, 0
|
|
pushl_cfi %ebx
|
|
CFI_REL_OFFSET ebx, 0
|
|
cld
|
|
movl $(__KERNEL_PERCPU), %ecx
|
|
movl %ecx, %fs
|
|
UNWIND_ESPFIX_STACK
|
|
GS_TO_REG %ecx
|
|
movl PT_GS(%esp), %edi # get the function address
|
|
movl PT_ORIG_EAX(%esp), %edx # get the error code
|
|
movl $-1, PT_ORIG_EAX(%esp) # no syscall to restart
|
|
REG_TO_PTGS %ecx
|
|
SET_KERNEL_GS %ecx
|
|
movl $(__USER_DS), %ecx
|
|
movl %ecx, %ds
|
|
movl %ecx, %es
|
|
TRACE_IRQS_OFF
|
|
movl %esp,%eax # pt_regs pointer
|
|
call *%edi
|
|
jmp ret_from_exception
|
|
CFI_ENDPROC
|
|
END(page_fault)
|
|
|
|
/*
|
|
* Debug traps and NMI can happen at the one SYSENTER instruction
|
|
* that sets up the real kernel stack. Check here, since we can't
|
|
* allow the wrong stack to be used.
|
|
*
|
|
* "TSS_sysenter_sp0+12" is because the NMI/debug handler will have
|
|
* already pushed 3 words if it hits on the sysenter instruction:
|
|
* eflags, cs and eip.
|
|
*
|
|
* We just load the right stack, and push the three (known) values
|
|
* by hand onto the new stack - while updating the return eip past
|
|
* the instruction that would have done it for sysenter.
|
|
*/
|
|
.macro FIX_STACK offset ok label
|
|
cmpw $__KERNEL_CS, 4(%esp)
|
|
jne \ok
|
|
\label:
|
|
movl TSS_sysenter_sp0 + \offset(%esp), %esp
|
|
CFI_DEF_CFA esp, 0
|
|
CFI_UNDEFINED eip
|
|
pushfl_cfi
|
|
pushl_cfi $__KERNEL_CS
|
|
pushl_cfi $sysenter_past_esp
|
|
CFI_REL_OFFSET eip, 0
|
|
.endm
|
|
|
|
ENTRY(debug)
|
|
RING0_INT_FRAME
|
|
ASM_CLAC
|
|
cmpl $ia32_sysenter_target,(%esp)
|
|
jne debug_stack_correct
|
|
FIX_STACK 12, debug_stack_correct, debug_esp_fix_insn
|
|
debug_stack_correct:
|
|
pushl_cfi $-1 # mark this as an int
|
|
SAVE_ALL
|
|
TRACE_IRQS_OFF
|
|
xorl %edx,%edx # error code 0
|
|
movl %esp,%eax # pt_regs pointer
|
|
call do_debug
|
|
jmp ret_from_exception
|
|
CFI_ENDPROC
|
|
END(debug)
|
|
|
|
/*
|
|
* NMI is doubly nasty. It can happen _while_ we're handling
|
|
* a debug fault, and the debug fault hasn't yet been able to
|
|
* clear up the stack. So we first check whether we got an
|
|
* NMI on the sysenter entry path, but after that we need to
|
|
* check whether we got an NMI on the debug path where the debug
|
|
* fault happened on the sysenter path.
|
|
*/
|
|
ENTRY(nmi)
|
|
RING0_INT_FRAME
|
|
ASM_CLAC
|
|
pushl_cfi %eax
|
|
movl %ss, %eax
|
|
cmpw $__ESPFIX_SS, %ax
|
|
popl_cfi %eax
|
|
je nmi_espfix_stack
|
|
cmpl $ia32_sysenter_target,(%esp)
|
|
je nmi_stack_fixup
|
|
pushl_cfi %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_cfi %eax
|
|
jae nmi_stack_correct
|
|
cmpl $ia32_sysenter_target,12(%esp)
|
|
je nmi_debug_stack_check
|
|
nmi_stack_correct:
|
|
/* We have a RING0_INT_FRAME here */
|
|
pushl_cfi %eax
|
|
SAVE_ALL
|
|
xorl %edx,%edx # zero error code
|
|
movl %esp,%eax # pt_regs pointer
|
|
call do_nmi
|
|
jmp restore_all_notrace
|
|
CFI_ENDPROC
|
|
|
|
nmi_stack_fixup:
|
|
RING0_INT_FRAME
|
|
FIX_STACK 12, nmi_stack_correct, 1
|
|
jmp nmi_stack_correct
|
|
|
|
nmi_debug_stack_check:
|
|
/* We have a RING0_INT_FRAME here */
|
|
cmpw $__KERNEL_CS,16(%esp)
|
|
jne nmi_stack_correct
|
|
cmpl $debug,(%esp)
|
|
jb nmi_stack_correct
|
|
cmpl $debug_esp_fix_insn,(%esp)
|
|
ja nmi_stack_correct
|
|
FIX_STACK 24, nmi_stack_correct, 1
|
|
jmp nmi_stack_correct
|
|
|
|
nmi_espfix_stack:
|
|
/* We have a RING0_INT_FRAME here.
|
|
*
|
|
* create the pointer to lss back
|
|
*/
|
|
pushl_cfi %ss
|
|
pushl_cfi %esp
|
|
addl $4, (%esp)
|
|
/* copy the iret frame of 12 bytes */
|
|
.rept 3
|
|
pushl_cfi 16(%esp)
|
|
.endr
|
|
pushl_cfi %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 espfix stack
|
|
CFI_ADJUST_CFA_OFFSET -24
|
|
jmp irq_return
|
|
CFI_ENDPROC
|
|
END(nmi)
|
|
|
|
ENTRY(int3)
|
|
RING0_INT_FRAME
|
|
ASM_CLAC
|
|
pushl_cfi $-1 # mark this as an int
|
|
SAVE_ALL
|
|
TRACE_IRQS_OFF
|
|
xorl %edx,%edx # zero error code
|
|
movl %esp,%eax # pt_regs pointer
|
|
call do_int3
|
|
jmp ret_from_exception
|
|
CFI_ENDPROC
|
|
END(int3)
|
|
|
|
ENTRY(general_protection)
|
|
RING0_EC_FRAME
|
|
pushl_cfi $do_general_protection
|
|
jmp error_code
|
|
CFI_ENDPROC
|
|
END(general_protection)
|
|
|
|
#ifdef CONFIG_KVM_GUEST
|
|
ENTRY(async_page_fault)
|
|
RING0_EC_FRAME
|
|
ASM_CLAC
|
|
pushl_cfi $do_async_page_fault
|
|
jmp error_code
|
|
CFI_ENDPROC
|
|
END(async_page_fault)
|
|
#endif
|
|
|
|
/*
|
|
* End of kprobes section
|
|
*/
|
|
.popsection
|