arch/x86/ia32/ia32entry.S - kernel/msm-4.9 - Gitiles

 /*
  * Compatibility mode system call entry point for x86-64.
  *
  * Copyright 2000-2002 Andi Kleen, SuSE Labs.
  */

 #include <asm/dwarf2.h>
 #include <asm/calling.h>
 #include <asm/asm-offsets.h>
 #include <asm/current.h>
 #include <asm/errno.h>
 #include <asm/ia32_unistd.h>
 #include <asm/thread_info.h>
 #include <asm/segment.h>
 #include <asm/irqflags.h>
 #include <asm/asm.h>
 #include <asm/smap.h>
 #include <linux/linkage.h>
 #include <linux/err.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 sysexit_audit ia32_ret_from_sys_call
 #define sysretl_audit ia32_ret_from_sys_call
 #endif

 	.section .entry.text, "ax"

 	/* clobbers %rax */
 	.macro  CLEAR_RREGS _r9=rax
 	xorl 	%eax,%eax
 	movq	%rax,R11(%rsp)
 	movq	%rax,R10(%rsp)
 	movq	%\_r9,R9(%rsp)
 	movq	%rax,R8(%rsp)
 	.endm

 	/*
 	 * Reload arg registers from stack in case ptrace changed them.
 	 * We don't reload %eax because syscall_trace_enter() returned
 	 * the %rax value we should see.  Instead, we just truncate that
 	 * value to 32 bits again as we did on entry from user mode.
 	 * If it's a new value set by user_regset during entry tracing,
 	 * this matches the normal truncation of the user-mode value.
 	 * If it's -1 to make us punt the syscall, then (u32)-1 is still
 	 * an appropriately invalid value.
 	 */
 	.macro LOAD_ARGS32 _r9=0
 	.if \_r9
 	movl R9(%rsp),%r9d
 	.endif
 	movl RCX(%rsp),%ecx
 	movl RDX(%rsp),%edx
 	movl RSI(%rsp),%esi
 	movl RDI(%rsp),%edi
 	movl %eax,%eax			/* zero extension */
 	.endm

 	.macro CFI_STARTPROC32 simple
 	CFI_STARTPROC	\simple
 	CFI_UNDEFINED	r8
 	CFI_UNDEFINED	r9
 	CFI_UNDEFINED	r10
 	CFI_UNDEFINED	r11
 	CFI_UNDEFINED	r12
 	CFI_UNDEFINED	r13
 	CFI_UNDEFINED	r14
 	CFI_UNDEFINED	r15
 	.endm

 #ifdef CONFIG_PARAVIRT
 ENTRY(native_usergs_sysret32)
 	swapgs
 	sysretl
 ENDPROC(native_usergs_sysret32)

 ENTRY(native_irq_enable_sysexit)
 	swapgs
 	sti
 	sysexit
 ENDPROC(native_irq_enable_sysexit)
 #endif

 /*
  * 32bit SYSENTER instruction entry.
  *
  * SYSENTER loads ss, rsp, cs, and rip from previously programmed MSRs.
  * IF and VM in rflags are cleared (IOW: interrupts are off).
  * SYSENTER does not save anything on the stack,
  * and does not save old rip (!!!) and rflags.
  *
  * Arguments:
  * eax  system call number
  * ebx  arg1
  * ecx  arg2
  * edx  arg3
  * esi  arg4
  * edi  arg5
  * ebp  user stack
  * 0(%ebp) arg6
  *
  * This is purely a fast path. For anything complicated we use the int 0x80
  * path below. We set up a complete hardware stack frame to share code
  * with the int 0x80 path.
  */
 ENTRY(ia32_sysenter_target)
 	CFI_STARTPROC32	simple
 	CFI_SIGNAL_FRAME
 	CFI_DEF_CFA	rsp,0
 	CFI_REGISTER	rsp,rbp
 	SWAPGS_UNSAFE_STACK
 	movq	PER_CPU_VAR(kernel_stack), %rsp
 	addq	$(KERNEL_STACK_OFFSET),%rsp
 	/*
 	 * No need to follow this irqs on/off section: the syscall
 	 * disabled irqs, here we enable it straight after entry:
 	 */
 	ENABLE_INTERRUPTS(CLBR_NONE)
 	/* Construct iret frame (ss,rsp,rflags,cs,rip) */
  	movl	%ebp,%ebp		/* zero extension */
 	pushq_cfi $__USER32_DS
 	/*CFI_REL_OFFSET ss,0*/
 	pushq_cfi %rbp
 	CFI_REL_OFFSET rsp,0
 	pushfq_cfi
 	/*CFI_REL_OFFSET rflags,0*/
 	movl	TI_sysenter_return+THREAD_INFO(%rsp,3*8-KERNEL_STACK_OFFSET),%r10d
 	CFI_REGISTER rip,r10
 	pushq_cfi $__USER32_CS
 	/*CFI_REL_OFFSET cs,0*/
 	movl	%eax, %eax
 	/* Store thread_info->sysenter_return in rip stack slot */
 	pushq_cfi %r10
 	CFI_REL_OFFSET rip,0
 	/* Store orig_ax */
 	pushq_cfi %rax
 	/* Construct the rest of "struct pt_regs" */
 	cld
 	ALLOC_PT_GPREGS_ON_STACK
 	SAVE_C_REGS_EXCEPT_R891011
 	/*
 	 * no need to do an access_ok check here because rbp has been
 	 * 32bit zero extended
 	 */
 	ASM_STAC
 1:	movl	(%rbp),%ebp
 	_ASM_EXTABLE(1b,ia32_badarg)
 	ASM_CLAC

 	/*
 	 * Sysenter doesn't filter flags, so we need to clear NT
 	 * ourselves.  To save a few cycles, we can check whether
 	 * NT was set instead of doing an unconditional popfq.
 	 */
 	testl $X86_EFLAGS_NT,EFLAGS(%rsp)
 	jnz sysenter_fix_flags
 sysenter_flags_fixed:

 	orl     $TS_COMPAT,TI_status+THREAD_INFO(%rsp,RIP)
 	testl   $_TIF_WORK_SYSCALL_ENTRY,TI_flags+THREAD_INFO(%rsp,RIP)
 	CFI_REMEMBER_STATE
 	jnz  sysenter_tracesys
 	cmpq	$(IA32_NR_syscalls-1),%rax
 	ja	ia32_badsys
 sysenter_do_call:
 	/* 32bit syscall -> 64bit C ABI argument conversion */
 	movl	%edi,%r8d	/* arg5 */
 	movl	%ebp,%r9d	/* arg6 */
 	xchg	%ecx,%esi	/* rsi:arg2, rcx:arg4 */
 	movl	%ebx,%edi	/* arg1 */
 	movl	%edx,%edx	/* arg3 (zero extension) */
 sysenter_dispatch:
 	call	*ia32_sys_call_table(,%rax,8)
 	movq	%rax,RAX(%rsp)
 	DISABLE_INTERRUPTS(CLBR_NONE)
 	TRACE_IRQS_OFF
 	testl	$_TIF_ALLWORK_MASK,TI_flags+THREAD_INFO(%rsp,RIP)
 	jnz	sysexit_audit
 sysexit_from_sys_call:
 	andl    $~TS_COMPAT,TI_status+THREAD_INFO(%rsp,RIP)
 	/* clear IF, that popfq doesn't enable interrupts early */
 	andl	$~0x200,EFLAGS(%rsp)
 	movl	RIP(%rsp),%edx		/* User %eip */
 	CFI_REGISTER rip,rdx
 	RESTORE_RSI_RDI
 	/* pop everything except ss,rsp,rflags slots */
 	REMOVE_PT_GPREGS_FROM_STACK 3*8
 	xorq	%r8,%r8
 	xorq	%r9,%r9
 	xorq	%r10,%r10
 	xorq	%r11,%r11
 	popfq_cfi
 	/*CFI_RESTORE rflags*/
 	popq_cfi %rcx				/* User %esp */
 	CFI_REGISTER rsp,rcx
 	TRACE_IRQS_ON
 	/*
 	 * 32bit SYSEXIT restores eip from edx, esp from ecx.
 	 * cs and ss are loaded from MSRs.
 	 */
 	ENABLE_INTERRUPTS_SYSEXIT32

 	CFI_RESTORE_STATE

 #ifdef CONFIG_AUDITSYSCALL
 	.macro auditsys_entry_common
 	movl %esi,%r8d			/* 5th arg: 4th syscall arg */
 	movl %ecx,%r9d			/*swap with edx*/
 	movl %edx,%ecx			/* 4th arg: 3rd syscall arg */
 	movl %r9d,%edx			/* 3rd arg: 2nd syscall arg */
 	movl %ebx,%esi			/* 2nd arg: 1st syscall arg */
 	movl %eax,%edi			/* 1st arg: syscall number */
 	call __audit_syscall_entry
 	movl RAX(%rsp),%eax	/* reload syscall number */
 	cmpq $(IA32_NR_syscalls-1),%rax
 	ja ia32_badsys
 	movl %ebx,%edi			/* reload 1st syscall arg */
 	movl RCX(%rsp),%esi	/* reload 2nd syscall arg */
 	movl RDX(%rsp),%edx	/* reload 3rd syscall arg */
 	movl RSI(%rsp),%ecx	/* reload 4th syscall arg */
 	movl RDI(%rsp),%r8d	/* reload 5th syscall arg */
 	.endm

 	.macro auditsys_exit exit
 	testl $(_TIF_ALLWORK_MASK & ~_TIF_SYSCALL_AUDIT),TI_flags+THREAD_INFO(%rsp,RIP)
 	jnz ia32_ret_from_sys_call
 	TRACE_IRQS_ON
 	ENABLE_INTERRUPTS(CLBR_NONE)
 	movl %eax,%esi		/* second arg, syscall return value */
 	cmpl $-MAX_ERRNO,%eax	/* is it an error ? */
 	jbe 1f
 	movslq %eax, %rsi	/* if error sign extend to 64 bits */
 1:	setbe %al		/* 1 if error, 0 if not */
 	movzbl %al,%edi		/* zero-extend that into %edi */
 	call __audit_syscall_exit
 	movq RAX(%rsp),%rax	/* reload syscall return value */
 	movl $(_TIF_ALLWORK_MASK & ~_TIF_SYSCALL_AUDIT),%edi
 	DISABLE_INTERRUPTS(CLBR_NONE)
 	TRACE_IRQS_OFF
 	testl %edi,TI_flags+THREAD_INFO(%rsp,RIP)
 	jz \exit
 	CLEAR_RREGS
 	jmp int_with_check
 	.endm

 sysenter_auditsys:
 	auditsys_entry_common
 	movl %ebp,%r9d			/* reload 6th syscall arg */
 	jmp sysenter_dispatch

 sysexit_audit:
 	auditsys_exit sysexit_from_sys_call
 #endif

 sysenter_fix_flags:
 	pushq_cfi $(X86_EFLAGS_IF|X86_EFLAGS_FIXED)
 	popfq_cfi
 	jmp sysenter_flags_fixed

 sysenter_tracesys:
 #ifdef CONFIG_AUDITSYSCALL
 	testl	$(_TIF_WORK_SYSCALL_ENTRY & ~_TIF_SYSCALL_AUDIT),TI_flags+THREAD_INFO(%rsp,RIP)
 	jz	sysenter_auditsys
 #endif
 	SAVE_EXTRA_REGS
 	CLEAR_RREGS
 	movq	$-ENOSYS,RAX(%rsp)/* ptrace can change this for a bad syscall */
 	movq	%rsp,%rdi        /* &pt_regs -> arg1 */
 	call	syscall_trace_enter
 	LOAD_ARGS32  /* reload args from stack in case ptrace changed it */
 	RESTORE_EXTRA_REGS
 	cmpq	$(IA32_NR_syscalls-1),%rax
 	ja	int_ret_from_sys_call /* sysenter_tracesys has set RAX(%rsp) */
 	jmp	sysenter_do_call
 	CFI_ENDPROC
 ENDPROC(ia32_sysenter_target)

 /*
  * 32bit SYSCALL instruction entry.
  *
  * 32bit SYSCALL saves rip to rcx, clears rflags.RF, then saves rflags to r11,
  * then loads new ss, cs, and rip from previously programmed MSRs.
  * rflags gets masked by a value from another MSR (so CLD and CLAC
  * are not needed). SYSCALL does not save anything on the stack
  * and does not change rsp.
  *
  * Note: rflags saving+masking-with-MSR happens only in Long mode
  * (in legacy 32bit mode, IF, RF and VM bits are cleared and that's it).
  * Don't get confused: rflags saving+masking depends on Long Mode Active bit
  * (EFER.LMA=1), NOT on bitness of userspace where SYSCALL executes
  * or target CS descriptor's L bit (SYSCALL does not read segment descriptors).
  *
  * Arguments:
  * eax  system call number
  * ecx  return address
  * ebx  arg1
  * ebp  arg2	(note: not saved in the stack frame, should not be touched)
  * edx  arg3
  * esi  arg4
  * edi  arg5
  * esp  user stack
  * 0(%esp) arg6
  *
  * This is purely a fast path. For anything complicated we use the int 0x80
  * path below. We set up a complete hardware stack frame to share code
  * with the int 0x80 path.
  */
 ENTRY(ia32_cstar_target)
 	CFI_STARTPROC32	simple
 	CFI_SIGNAL_FRAME
 	CFI_DEF_CFA	rsp,KERNEL_STACK_OFFSET
 	CFI_REGISTER	rip,rcx
 	/*CFI_REGISTER	rflags,r11*/
 	SWAPGS_UNSAFE_STACK
 	movl	%esp,%r8d
 	CFI_REGISTER	rsp,r8
 	movq	PER_CPU_VAR(kernel_stack),%rsp
 	/*
 	 * No need to follow this irqs on/off section: the syscall
 	 * disabled irqs and here we enable it straight after entry:
 	 */
 	ENABLE_INTERRUPTS(CLBR_NONE)
 	ALLOC_PT_GPREGS_ON_STACK 8	/* +8: space for orig_ax */
 	SAVE_C_REGS_EXCEPT_RCX_R891011
 	movl 	%eax,%eax	/* zero extension */
 	movq	%rax,ORIG_RAX(%rsp)
 	movq	%rcx,RIP(%rsp)
 	CFI_REL_OFFSET rip,RIP
 	movq	%rbp,RCX(%rsp) /* this lies slightly to ptrace */
 	movl	%ebp,%ecx
 	movq	$__USER32_CS,CS(%rsp)
 	movq	$__USER32_DS,SS(%rsp)
 	movq	%r11,EFLAGS(%rsp)
 	/*CFI_REL_OFFSET rflags,EFLAGS*/
 	movq	%r8,RSP(%rsp)
 	CFI_REL_OFFSET rsp,RSP
 	/* iret stack frame is complete now */
 	/*
 	 * no need to do an access_ok check here because r8 has been
 	 * 32bit zero extended
 	 */
 	ASM_STAC
 1:	movl	(%r8),%r9d
 	_ASM_EXTABLE(1b,ia32_badarg)
 	ASM_CLAC
 	orl     $TS_COMPAT,TI_status+THREAD_INFO(%rsp,RIP)
 	testl   $_TIF_WORK_SYSCALL_ENTRY,TI_flags+THREAD_INFO(%rsp,RIP)
 	CFI_REMEMBER_STATE
 	jnz   cstar_tracesys
 	cmpq $IA32_NR_syscalls-1,%rax
 	ja  ia32_badsys
 cstar_do_call:
 	/* 32bit syscall -> 64bit C ABI argument conversion */
 	movl	%edi,%r8d	/* arg5 */
 	/* r9 already loaded */	/* arg6 */
 	xchg	%ecx,%esi	/* rsi:arg2, rcx:arg4 */
 	movl	%ebx,%edi	/* arg1 */
 	movl	%edx,%edx	/* arg3 (zero extension) */
 cstar_dispatch:
 	call *ia32_sys_call_table(,%rax,8)
 	movq %rax,RAX(%rsp)
 	DISABLE_INTERRUPTS(CLBR_NONE)
 	TRACE_IRQS_OFF
 	testl $_TIF_ALLWORK_MASK,TI_flags+THREAD_INFO(%rsp,RIP)
 	jnz sysretl_audit
 sysretl_from_sys_call:
 	andl $~TS_COMPAT,TI_status+THREAD_INFO(%rsp,RIP)
 	RESTORE_RSI_RDI_RDX
 	movl RIP(%rsp),%ecx
 	CFI_REGISTER rip,rcx
 	movl EFLAGS(%rsp),%r11d
 	/*CFI_REGISTER rflags,r11*/
 	xorq	%r10,%r10
 	xorq	%r9,%r9
 	xorq	%r8,%r8
 	TRACE_IRQS_ON
 	movl RSP(%rsp),%esp
 	CFI_RESTORE rsp
 	/*
 	 * 64bit->32bit SYSRET restores eip from ecx,
 	 * eflags from r11 (but RF and VM bits are forced to 0),
 	 * cs and ss are loaded from MSRs.
 	 * (Note: 32bit->32bit SYSRET is different: since r11
 	 * does not exist, it merely sets eflags.IF=1).
 	 */
 	USERGS_SYSRET32

 #ifdef CONFIG_AUDITSYSCALL
 cstar_auditsys:
 	CFI_RESTORE_STATE
 	movl %r9d,R9(%rsp)	/* register to be clobbered by call */
 	auditsys_entry_common
 	movl R9(%rsp),%r9d	/* reload 6th syscall arg */
 	jmp cstar_dispatch

 sysretl_audit:
 	auditsys_exit sysretl_from_sys_call
 #endif

 cstar_tracesys:
 #ifdef CONFIG_AUDITSYSCALL
 	testl $(_TIF_WORK_SYSCALL_ENTRY & ~_TIF_SYSCALL_AUDIT),TI_flags+THREAD_INFO(%rsp,RIP)
 	jz cstar_auditsys
 #endif
 	xchgl %r9d,%ebp
 	SAVE_EXTRA_REGS
 	CLEAR_RREGS r9
 	movq $-ENOSYS,RAX(%rsp)	/* ptrace can change this for a bad syscall */
 	movq %rsp,%rdi        /* &pt_regs -> arg1 */
 	call syscall_trace_enter
 	LOAD_ARGS32 1	/* reload args from stack in case ptrace changed it */
 	RESTORE_EXTRA_REGS
 	xchgl %ebp,%r9d
 	cmpq $(IA32_NR_syscalls-1),%rax
 	ja int_ret_from_sys_call /* cstar_tracesys has set RAX(%rsp) */
 	jmp cstar_do_call
 END(ia32_cstar_target)

 ia32_badarg:
 	ASM_CLAC
 	movq $-EFAULT,%rax
 	jmp ia32_sysret
 	CFI_ENDPROC

 /*
  * Emulated IA32 system calls via int 0x80.
  *
  * Arguments:
  * eax  system call number
  * ebx  arg1
  * ecx  arg2
  * edx  arg3
  * esi  arg4
  * edi  arg5
  * ebp  arg6	(note: not saved in the stack frame, should not be touched)
  *
  * Notes:
  * Uses the same stack frame as the x86-64 version.
  * All registers except eax must be saved (but ptrace may violate that).
  * Arguments are zero extended. For system calls that want sign extension and
  * take long arguments a wrapper is needed. Most calls can just be called
  * directly.
  * Assumes it is only called from user space and entered with interrupts off.
  */

 ENTRY(ia32_syscall)
 	CFI_STARTPROC32	simple
 	CFI_SIGNAL_FRAME
 	CFI_DEF_CFA	rsp,SS+8-RIP
 	/*CFI_REL_OFFSET	ss,SS-RIP*/
 	CFI_REL_OFFSET	rsp,RSP-RIP
 	/*CFI_REL_OFFSET	rflags,EFLAGS-RIP*/
 	/*CFI_REL_OFFSET	cs,CS-RIP*/
 	CFI_REL_OFFSET	rip,RIP-RIP
 	PARAVIRT_ADJUST_EXCEPTION_FRAME
 	SWAPGS
 	/*
 	 * No need to follow this irqs on/off section: the syscall
 	 * disabled irqs and here we enable it straight after entry:
 	 */
 	ENABLE_INTERRUPTS(CLBR_NONE)
 	movl %eax,%eax
 	pushq_cfi %rax		/* store orig_ax */
 	cld
 	/* note the registers are not zero extended to the sf.
 	   this could be a problem. */
 	ALLOC_PT_GPREGS_ON_STACK
 	SAVE_C_REGS_EXCEPT_R891011
 	orl $TS_COMPAT,TI_status+THREAD_INFO(%rsp,RIP)
 	testl $_TIF_WORK_SYSCALL_ENTRY,TI_flags+THREAD_INFO(%rsp,RIP)
 	jnz ia32_tracesys
 	cmpq $(IA32_NR_syscalls-1),%rax
 	ja ia32_badsys
 ia32_do_call:
 	/* 32bit syscall -> 64bit C ABI argument conversion */
 	movl %edi,%r8d	/* arg5 */
 	movl %ebp,%r9d	/* arg6 */
 	xchg %ecx,%esi	/* rsi:arg2, rcx:arg4 */
 	movl %ebx,%edi	/* arg1 */
 	movl %edx,%edx	/* arg3 (zero extension) */
 	call *ia32_sys_call_table(,%rax,8) # xxx: rip relative
 ia32_sysret:
 	movq %rax,RAX(%rsp)
 ia32_ret_from_sys_call:
 	CLEAR_RREGS
 	jmp int_ret_from_sys_call

 ia32_tracesys:
 	SAVE_EXTRA_REGS
 	CLEAR_RREGS
 	movq $-ENOSYS,RAX(%rsp)	/* ptrace can change this for a bad syscall */
 	movq %rsp,%rdi        /* &pt_regs -> arg1 */
 	call syscall_trace_enter
 	LOAD_ARGS32	/* reload args from stack in case ptrace changed it */
 	RESTORE_EXTRA_REGS
 	cmpq $(IA32_NR_syscalls-1),%rax
 	ja  int_ret_from_sys_call	/* ia32_tracesys has set RAX(%rsp) */
 	jmp ia32_do_call
 END(ia32_syscall)

 ia32_badsys:
 	movq $0,ORIG_RAX(%rsp)
 	movq $-ENOSYS,%rax
 	jmp ia32_sysret

 	CFI_ENDPROC

 	.macro PTREGSCALL label, func
 	ALIGN
 GLOBAL(\label)
 	leaq \func(%rip),%rax
 	jmp  ia32_ptregs_common
 	.endm

 	CFI_STARTPROC32

 	PTREGSCALL stub32_rt_sigreturn, sys32_rt_sigreturn
 	PTREGSCALL stub32_sigreturn, sys32_sigreturn
 	PTREGSCALL stub32_execve, compat_sys_execve
 	PTREGSCALL stub32_execveat, compat_sys_execveat
 	PTREGSCALL stub32_fork, sys_fork
 	PTREGSCALL stub32_vfork, sys_vfork

 	ALIGN
 GLOBAL(stub32_clone)
 	leaq sys_clone(%rip),%rax
 	mov	%r8, %rcx
 	jmp  ia32_ptregs_common

 	ALIGN
 ia32_ptregs_common:
 	CFI_ENDPROC
 	CFI_STARTPROC32	simple
 	CFI_SIGNAL_FRAME
 	CFI_DEF_CFA	rsp,SS+8
 	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*/
 	SAVE_EXTRA_REGS 8
 	call *%rax
 	RESTORE_EXTRA_REGS 8
 	ret
 	CFI_ENDPROC
 END(ia32_ptregs_common)
	/*
	* Compatibility mode system call entry point for x86-64.
	*
	* Copyright 2000-2002 Andi Kleen, SuSE Labs.
	*/

	#include <asm/dwarf2.h>
	#include <asm/calling.h>
	#include <asm/asm-offsets.h>
	#include <asm/current.h>
	#include <asm/errno.h>
	#include <asm/ia32_unistd.h>
	#include <asm/thread_info.h>
	#include <asm/segment.h>
	#include <asm/irqflags.h>
	#include <asm/asm.h>
	#include <asm/smap.h>
	#include <linux/linkage.h>
	#include <linux/err.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 sysexit_audit ia32_ret_from_sys_call
	#define sysretl_audit ia32_ret_from_sys_call
	#endif

	.section .entry.text, "ax"

	/* clobbers %rax */
	.macro CLEAR_RREGS _r9=rax
	xorl %eax,%eax
	movq %rax,R11(%rsp)
	movq %rax,R10(%rsp)
	movq %\_r9,R9(%rsp)
	movq %rax,R8(%rsp)
	.endm

	/*
	* Reload arg registers from stack in case ptrace changed them.
	* We don't reload %eax because syscall_trace_enter() returned
	* the %rax value we should see. Instead, we just truncate that
	* value to 32 bits again as we did on entry from user mode.
	* If it's a new value set by user_regset during entry tracing,
	* this matches the normal truncation of the user-mode value.
	* If it's -1 to make us punt the syscall, then (u32)-1 is still
	* an appropriately invalid value.
	*/
	.macro LOAD_ARGS32 _r9=0
	.if \_r9
	movl R9(%rsp),%r9d
	.endif
	movl RCX(%rsp),%ecx
	movl RDX(%rsp),%edx
	movl RSI(%rsp),%esi
	movl RDI(%rsp),%edi
	movl %eax,%eax /* zero extension */
	.endm

	.macro CFI_STARTPROC32 simple
	CFI_STARTPROC \simple
	CFI_UNDEFINED r8
	CFI_UNDEFINED r9
	CFI_UNDEFINED r10
	CFI_UNDEFINED r11
	CFI_UNDEFINED r12
	CFI_UNDEFINED r13
	CFI_UNDEFINED r14
	CFI_UNDEFINED r15
	.endm

	#ifdef CONFIG_PARAVIRT
	ENTRY(native_usergs_sysret32)
	swapgs
	sysretl
	ENDPROC(native_usergs_sysret32)

	ENTRY(native_irq_enable_sysexit)
	swapgs
	sti
	sysexit
	ENDPROC(native_irq_enable_sysexit)
	#endif

	/*
	* 32bit SYSENTER instruction entry.
	*
	* SYSENTER loads ss, rsp, cs, and rip from previously programmed MSRs.
	* IF and VM in rflags are cleared (IOW: interrupts are off).
	* SYSENTER does not save anything on the stack,
	* and does not save old rip (!!!) and rflags.
	*
	* Arguments:
	* eax system call number
	* ebx arg1
	* ecx arg2
	* edx arg3
	* esi arg4
	* edi arg5
	* ebp user stack
	* 0(%ebp) arg6
	*
	* This is purely a fast path. For anything complicated we use the int 0x80
	* path below. We set up a complete hardware stack frame to share code
	* with the int 0x80 path.
	*/
	ENTRY(ia32_sysenter_target)
	CFI_STARTPROC32 simple
	CFI_SIGNAL_FRAME
	CFI_DEF_CFA rsp,0
	CFI_REGISTER rsp,rbp
	SWAPGS_UNSAFE_STACK
	movq PER_CPU_VAR(kernel_stack), %rsp
	addq $(KERNEL_STACK_OFFSET),%rsp
	/*
	* No need to follow this irqs on/off section: the syscall
	* disabled irqs, here we enable it straight after entry:
	*/
	ENABLE_INTERRUPTS(CLBR_NONE)
	/* Construct iret frame (ss,rsp,rflags,cs,rip) */
	movl %ebp,%ebp /* zero extension */
	pushq_cfi $__USER32_DS
	/CFI_REL_OFFSET ss,0/
	pushq_cfi %rbp
	CFI_REL_OFFSET rsp,0
	pushfq_cfi
	/CFI_REL_OFFSET rflags,0/
	movl TI_sysenter_return+THREAD_INFO(%rsp,3*8-KERNEL_STACK_OFFSET),%r10d
	CFI_REGISTER rip,r10
	pushq_cfi $__USER32_CS
	/CFI_REL_OFFSET cs,0/
	movl %eax, %eax
	/* Store thread_info->sysenter_return in rip stack slot */
	pushq_cfi %r10
	CFI_REL_OFFSET rip,0
	/* Store orig_ax */
	pushq_cfi %rax
	/* Construct the rest of "struct pt_regs" */
	cld
	ALLOC_PT_GPREGS_ON_STACK
	SAVE_C_REGS_EXCEPT_R891011
	/*
	* no need to do an access_ok check here because rbp has been
	* 32bit zero extended
	*/
	ASM_STAC
	1: movl (%rbp),%ebp
	_ASM_EXTABLE(1b,ia32_badarg)
	ASM_CLAC

	/*
	* Sysenter doesn't filter flags, so we need to clear NT
	* ourselves. To save a few cycles, we can check whether
	* NT was set instead of doing an unconditional popfq.
	*/
	testl $X86_EFLAGS_NT,EFLAGS(%rsp)
	jnz sysenter_fix_flags
	sysenter_flags_fixed:

	orl $TS_COMPAT,TI_status+THREAD_INFO(%rsp,RIP)
	testl $_TIF_WORK_SYSCALL_ENTRY,TI_flags+THREAD_INFO(%rsp,RIP)
	CFI_REMEMBER_STATE
	jnz sysenter_tracesys
	cmpq $(IA32_NR_syscalls-1),%rax
	ja ia32_badsys
	sysenter_do_call:
	/* 32bit syscall -> 64bit C ABI argument conversion */
	movl %edi,%r8d /* arg5 */
	movl %ebp,%r9d /* arg6 */
	xchg %ecx,%esi /* rsi:arg2, rcx:arg4 */
	movl %ebx,%edi /* arg1 */
	movl %edx,%edx /* arg3 (zero extension) */
	sysenter_dispatch:
	call *ia32_sys_call_table(,%rax,8)
	movq %rax,RAX(%rsp)
	DISABLE_INTERRUPTS(CLBR_NONE)
	TRACE_IRQS_OFF
	testl $_TIF_ALLWORK_MASK,TI_flags+THREAD_INFO(%rsp,RIP)
	jnz sysexit_audit
	sysexit_from_sys_call:
	andl $~TS_COMPAT,TI_status+THREAD_INFO(%rsp,RIP)
	/* clear IF, that popfq doesn't enable interrupts early */
	andl $~0x200,EFLAGS(%rsp)
	movl RIP(%rsp),%edx /* User %eip */
	CFI_REGISTER rip,rdx
	RESTORE_RSI_RDI
	/* pop everything except ss,rsp,rflags slots */
	REMOVE_PT_GPREGS_FROM_STACK 3*8
	xorq %r8,%r8
	xorq %r9,%r9
	xorq %r10,%r10
	xorq %r11,%r11
	popfq_cfi
	/CFI_RESTORE rflags/
	popq_cfi %rcx /* User %esp */
	CFI_REGISTER rsp,rcx
	TRACE_IRQS_ON
	/*
	* 32bit SYSEXIT restores eip from edx, esp from ecx.
	* cs and ss are loaded from MSRs.
	*/
	ENABLE_INTERRUPTS_SYSEXIT32

	CFI_RESTORE_STATE

	#ifdef CONFIG_AUDITSYSCALL
	.macro auditsys_entry_common
	movl %esi,%r8d /* 5th arg: 4th syscall arg */
	movl %ecx,%r9d /swap with edx/
	movl %edx,%ecx /* 4th arg: 3rd syscall arg */
	movl %r9d,%edx /* 3rd arg: 2nd syscall arg */
	movl %ebx,%esi /* 2nd arg: 1st syscall arg */
	movl %eax,%edi /* 1st arg: syscall number */
	call __audit_syscall_entry
	movl RAX(%rsp),%eax /* reload syscall number */
	cmpq $(IA32_NR_syscalls-1),%rax
	ja ia32_badsys
	movl %ebx,%edi /* reload 1st syscall arg */
	movl RCX(%rsp),%esi /* reload 2nd syscall arg */
	movl RDX(%rsp),%edx /* reload 3rd syscall arg */
	movl RSI(%rsp),%ecx /* reload 4th syscall arg */
	movl RDI(%rsp),%r8d /* reload 5th syscall arg */
	.endm

	.macro auditsys_exit exit
	testl $(_TIF_ALLWORK_MASK & ~_TIF_SYSCALL_AUDIT),TI_flags+THREAD_INFO(%rsp,RIP)
	jnz ia32_ret_from_sys_call
	TRACE_IRQS_ON
	ENABLE_INTERRUPTS(CLBR_NONE)
	movl %eax,%esi /* second arg, syscall return value */
	cmpl $-MAX_ERRNO,%eax /* is it an error ? */
	jbe 1f
	movslq %eax, %rsi /* if error sign extend to 64 bits */
	1: setbe %al /* 1 if error, 0 if not */
	movzbl %al,%edi /* zero-extend that into %edi */
	call __audit_syscall_exit
	movq RAX(%rsp),%rax /* reload syscall return value */
	movl $(_TIF_ALLWORK_MASK & ~_TIF_SYSCALL_AUDIT),%edi
	DISABLE_INTERRUPTS(CLBR_NONE)
	TRACE_IRQS_OFF
	testl %edi,TI_flags+THREAD_INFO(%rsp,RIP)
	jz \exit
	CLEAR_RREGS
	jmp int_with_check
	.endm

	sysenter_auditsys:
	auditsys_entry_common
	movl %ebp,%r9d /* reload 6th syscall arg */
	jmp sysenter_dispatch

	sysexit_audit:
	auditsys_exit sysexit_from_sys_call
	#endif

	sysenter_fix_flags:
	pushq_cfi $(X86_EFLAGS_IF\|X86_EFLAGS_FIXED)
	popfq_cfi
	jmp sysenter_flags_fixed

	sysenter_tracesys:
	#ifdef CONFIG_AUDITSYSCALL
	testl $(_TIF_WORK_SYSCALL_ENTRY & ~_TIF_SYSCALL_AUDIT),TI_flags+THREAD_INFO(%rsp,RIP)
	jz sysenter_auditsys
	#endif
	SAVE_EXTRA_REGS
	CLEAR_RREGS
	movq $-ENOSYS,RAX(%rsp)/* ptrace can change this for a bad syscall */
	movq %rsp,%rdi /* &pt_regs -> arg1 */
	call syscall_trace_enter
	LOAD_ARGS32 /* reload args from stack in case ptrace changed it */
	RESTORE_EXTRA_REGS
	cmpq $(IA32_NR_syscalls-1),%rax
	ja int_ret_from_sys_call /* sysenter_tracesys has set RAX(%rsp) */
	jmp sysenter_do_call
	CFI_ENDPROC
	ENDPROC(ia32_sysenter_target)

	/*
	* 32bit SYSCALL instruction entry.
	*
	* 32bit SYSCALL saves rip to rcx, clears rflags.RF, then saves rflags to r11,
	* then loads new ss, cs, and rip from previously programmed MSRs.
	* rflags gets masked by a value from another MSR (so CLD and CLAC
	* are not needed). SYSCALL does not save anything on the stack
	* and does not change rsp.
	*
	* Note: rflags saving+masking-with-MSR happens only in Long mode
	* (in legacy 32bit mode, IF, RF and VM bits are cleared and that's it).
	* Don't get confused: rflags saving+masking depends on Long Mode Active bit
	* (EFER.LMA=1), NOT on bitness of userspace where SYSCALL executes
	* or target CS descriptor's L bit (SYSCALL does not read segment descriptors).
	*
	* Arguments:
	* eax system call number
	* ecx return address
	* ebx arg1
	* ebp arg2 (note: not saved in the stack frame, should not be touched)
	* edx arg3
	* esi arg4
	* edi arg5
	* esp user stack
	* 0(%esp) arg6
	*
	* This is purely a fast path. For anything complicated we use the int 0x80
	* path below. We set up a complete hardware stack frame to share code
	* with the int 0x80 path.
	*/
	ENTRY(ia32_cstar_target)
	CFI_STARTPROC32 simple
	CFI_SIGNAL_FRAME
	CFI_DEF_CFA rsp,KERNEL_STACK_OFFSET
	CFI_REGISTER rip,rcx
	/CFI_REGISTER rflags,r11/
	SWAPGS_UNSAFE_STACK
	movl %esp,%r8d
	CFI_REGISTER rsp,r8
	movq PER_CPU_VAR(kernel_stack),%rsp
	/*
	* No need to follow this irqs on/off section: the syscall
	* disabled irqs and here we enable it straight after entry:
	*/
	ENABLE_INTERRUPTS(CLBR_NONE)
	ALLOC_PT_GPREGS_ON_STACK 8 /* +8: space for orig_ax */
	SAVE_C_REGS_EXCEPT_RCX_R891011
	movl %eax,%eax /* zero extension */
	movq %rax,ORIG_RAX(%rsp)
	movq %rcx,RIP(%rsp)
	CFI_REL_OFFSET rip,RIP
	movq %rbp,RCX(%rsp) /* this lies slightly to ptrace */
	movl %ebp,%ecx
	movq $__USER32_CS,CS(%rsp)
	movq $__USER32_DS,SS(%rsp)
	movq %r11,EFLAGS(%rsp)
	/CFI_REL_OFFSET rflags,EFLAGS/
	movq %r8,RSP(%rsp)
	CFI_REL_OFFSET rsp,RSP
	/* iret stack frame is complete now */
	/*
	* no need to do an access_ok check here because r8 has been
	* 32bit zero extended
	*/
	ASM_STAC
	1: movl (%r8),%r9d
	_ASM_EXTABLE(1b,ia32_badarg)
	ASM_CLAC
	orl $TS_COMPAT,TI_status+THREAD_INFO(%rsp,RIP)
	testl $_TIF_WORK_SYSCALL_ENTRY,TI_flags+THREAD_INFO(%rsp,RIP)
	CFI_REMEMBER_STATE
	jnz cstar_tracesys
	cmpq $IA32_NR_syscalls-1,%rax
	ja ia32_badsys
	cstar_do_call:
	/* 32bit syscall -> 64bit C ABI argument conversion */
	movl %edi,%r8d /* arg5 */
	/* r9 already loaded / / arg6 */
	xchg %ecx,%esi /* rsi:arg2, rcx:arg4 */
	movl %ebx,%edi /* arg1 */
	movl %edx,%edx /* arg3 (zero extension) */
	cstar_dispatch:
	call *ia32_sys_call_table(,%rax,8)
	movq %rax,RAX(%rsp)
	DISABLE_INTERRUPTS(CLBR_NONE)
	TRACE_IRQS_OFF
	testl $_TIF_ALLWORK_MASK,TI_flags+THREAD_INFO(%rsp,RIP)
	jnz sysretl_audit
	sysretl_from_sys_call:
	andl $~TS_COMPAT,TI_status+THREAD_INFO(%rsp,RIP)
	RESTORE_RSI_RDI_RDX
	movl RIP(%rsp),%ecx
	CFI_REGISTER rip,rcx
	movl EFLAGS(%rsp),%r11d
	/CFI_REGISTER rflags,r11/
	xorq %r10,%r10
	xorq %r9,%r9
	xorq %r8,%r8
	TRACE_IRQS_ON
	movl RSP(%rsp),%esp
	CFI_RESTORE rsp
	/*
	* 64bit->32bit SYSRET restores eip from ecx,
	* eflags from r11 (but RF and VM bits are forced to 0),
	* cs and ss are loaded from MSRs.
	* (Note: 32bit->32bit SYSRET is different: since r11
	* does not exist, it merely sets eflags.IF=1).
	*/
	USERGS_SYSRET32

	#ifdef CONFIG_AUDITSYSCALL
	cstar_auditsys:
	CFI_RESTORE_STATE
	movl %r9d,R9(%rsp) /* register to be clobbered by call */
	auditsys_entry_common
	movl R9(%rsp),%r9d /* reload 6th syscall arg */
	jmp cstar_dispatch

	sysretl_audit:
	auditsys_exit sysretl_from_sys_call
	#endif

	cstar_tracesys:
	#ifdef CONFIG_AUDITSYSCALL
	testl $(_TIF_WORK_SYSCALL_ENTRY & ~_TIF_SYSCALL_AUDIT),TI_flags+THREAD_INFO(%rsp,RIP)
	jz cstar_auditsys
	#endif
	xchgl %r9d,%ebp
	SAVE_EXTRA_REGS
	CLEAR_RREGS r9
	movq $-ENOSYS,RAX(%rsp) /* ptrace can change this for a bad syscall */
	movq %rsp,%rdi /* &pt_regs -> arg1 */
	call syscall_trace_enter
	LOAD_ARGS32 1 /* reload args from stack in case ptrace changed it */
	RESTORE_EXTRA_REGS
	xchgl %ebp,%r9d
	cmpq $(IA32_NR_syscalls-1),%rax
	ja int_ret_from_sys_call /* cstar_tracesys has set RAX(%rsp) */
	jmp cstar_do_call
	END(ia32_cstar_target)

	ia32_badarg:
	ASM_CLAC
	movq $-EFAULT,%rax
	jmp ia32_sysret
	CFI_ENDPROC

	/*
	* Emulated IA32 system calls via int 0x80.
	*
	* Arguments:
	* eax system call number
	* ebx arg1
	* ecx arg2
	* edx arg3
	* esi arg4
	* edi arg5
	* ebp arg6 (note: not saved in the stack frame, should not be touched)
	*
	* Notes:
	* Uses the same stack frame as the x86-64 version.
	* All registers except eax must be saved (but ptrace may violate that).
	* Arguments are zero extended. For system calls that want sign extension and
	* take long arguments a wrapper is needed. Most calls can just be called
	* directly.
	* Assumes it is only called from user space and entered with interrupts off.
	*/

	ENTRY(ia32_syscall)
	CFI_STARTPROC32 simple
	CFI_SIGNAL_FRAME
	CFI_DEF_CFA rsp,SS+8-RIP
	/CFI_REL_OFFSET ss,SS-RIP/
	CFI_REL_OFFSET rsp,RSP-RIP
	/CFI_REL_OFFSET rflags,EFLAGS-RIP/
	/CFI_REL_OFFSET cs,CS-RIP/
	CFI_REL_OFFSET rip,RIP-RIP
	PARAVIRT_ADJUST_EXCEPTION_FRAME
	SWAPGS
	/*
	* No need to follow this irqs on/off section: the syscall
	* disabled irqs and here we enable it straight after entry:
	*/
	ENABLE_INTERRUPTS(CLBR_NONE)
	movl %eax,%eax
	pushq_cfi %rax /* store orig_ax */
	cld
	/* note the registers are not zero extended to the sf.
	this could be a problem. */
	ALLOC_PT_GPREGS_ON_STACK
	SAVE_C_REGS_EXCEPT_R891011
	orl $TS_COMPAT,TI_status+THREAD_INFO(%rsp,RIP)
	testl $_TIF_WORK_SYSCALL_ENTRY,TI_flags+THREAD_INFO(%rsp,RIP)
	jnz ia32_tracesys
	cmpq $(IA32_NR_syscalls-1),%rax
	ja ia32_badsys
	ia32_do_call:
	/* 32bit syscall -> 64bit C ABI argument conversion */
	movl %edi,%r8d /* arg5 */
	movl %ebp,%r9d /* arg6 */
	xchg %ecx,%esi /* rsi:arg2, rcx:arg4 */
	movl %ebx,%edi /* arg1 */
	movl %edx,%edx /* arg3 (zero extension) */
	call *ia32_sys_call_table(,%rax,8) # xxx: rip relative
	ia32_sysret:
	movq %rax,RAX(%rsp)
	ia32_ret_from_sys_call:
	CLEAR_RREGS
	jmp int_ret_from_sys_call

	ia32_tracesys:
	SAVE_EXTRA_REGS
	CLEAR_RREGS
	movq $-ENOSYS,RAX(%rsp) /* ptrace can change this for a bad syscall */
	movq %rsp,%rdi /* &pt_regs -> arg1 */
	call syscall_trace_enter
	LOAD_ARGS32 /* reload args from stack in case ptrace changed it */
	RESTORE_EXTRA_REGS
	cmpq $(IA32_NR_syscalls-1),%rax
	ja int_ret_from_sys_call /* ia32_tracesys has set RAX(%rsp) */
	jmp ia32_do_call
	END(ia32_syscall)

	ia32_badsys:
	movq $0,ORIG_RAX(%rsp)
	movq $-ENOSYS,%rax
	jmp ia32_sysret

	CFI_ENDPROC

	.macro PTREGSCALL label, func
	ALIGN
	GLOBAL(\label)
	leaq \func(%rip),%rax
	jmp ia32_ptregs_common
	.endm

	CFI_STARTPROC32

	PTREGSCALL stub32_rt_sigreturn, sys32_rt_sigreturn
	PTREGSCALL stub32_sigreturn, sys32_sigreturn
	PTREGSCALL stub32_execve, compat_sys_execve
	PTREGSCALL stub32_execveat, compat_sys_execveat
	PTREGSCALL stub32_fork, sys_fork
	PTREGSCALL stub32_vfork, sys_vfork

	ALIGN
	GLOBAL(stub32_clone)
	leaq sys_clone(%rip),%rax
	mov %r8, %rcx
	jmp ia32_ptregs_common

	ALIGN
	ia32_ptregs_common:
	CFI_ENDPROC
	CFI_STARTPROC32 simple
	CFI_SIGNAL_FRAME
	CFI_DEF_CFA rsp,SS+8
	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*/
	SAVE_EXTRA_REGS 8
	call *%rax
	RESTORE_EXTRA_REGS 8
	ret
	CFI_ENDPROC
	END(ia32_ptregs_common)