261 lines
5.8 KiB
ArmAsm
261 lines
5.8 KiB
ArmAsm
![]() |
/*
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* linux/arch/arm/kernel/entry-common.S
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*
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* Copyright (C) 2000 Russell King
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#include <linux/config.h>
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#include <asm/thread_info.h>
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#include <asm/ptrace.h>
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#include <asm/unistd.h>
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#include "entry-header.S"
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/*
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* We rely on the fact that R0 is at the bottom of the stack (due to
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* slow/fast restore user regs).
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*/
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#if S_R0 != 0
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#error "Please fix"
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#endif
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.align 5
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/*
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* This is the fast syscall return path. We do as little as
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* possible here, and this includes saving r0 back into the SVC
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* stack.
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*/
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ret_fast_syscall:
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disable_irq r1 @ disable interrupts
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ldr r1, [tsk, #TI_FLAGS]
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tst r1, #_TIF_WORK_MASK
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bne fast_work_pending
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fast_restore_user_regs
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/*
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* Ok, we need to do extra processing, enter the slow path.
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*/
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fast_work_pending:
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str r0, [sp, #S_R0+S_OFF]! @ returned r0
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work_pending:
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tst r1, #_TIF_NEED_RESCHED
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bne work_resched
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tst r1, #_TIF_NOTIFY_RESUME | _TIF_SIGPENDING
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beq no_work_pending
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mov r0, sp @ 'regs'
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mov r2, why @ 'syscall'
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bl do_notify_resume
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disable_irq r1 @ disable interrupts
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b no_work_pending
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work_resched:
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bl schedule
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/*
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* "slow" syscall return path. "why" tells us if this was a real syscall.
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*/
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ENTRY(ret_to_user)
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ret_slow_syscall:
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disable_irq r1 @ disable interrupts
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ldr r1, [tsk, #TI_FLAGS]
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tst r1, #_TIF_WORK_MASK
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bne work_pending
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no_work_pending:
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slow_restore_user_regs
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/*
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* This is how we return from a fork.
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*/
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ENTRY(ret_from_fork)
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bl schedule_tail
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get_thread_info tsk
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ldr r1, [tsk, #TI_FLAGS] @ check for syscall tracing
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mov why, #1
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tst r1, #_TIF_SYSCALL_TRACE @ are we tracing syscalls?
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beq ret_slow_syscall
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mov r1, sp
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mov r0, #1 @ trace exit [IP = 1]
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bl syscall_trace
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b ret_slow_syscall
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#include "calls.S"
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/*=============================================================================
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* SWI handler
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*-----------------------------------------------------------------------------
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*/
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/* If we're optimising for StrongARM the resulting code won't
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run on an ARM7 and we can save a couple of instructions.
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--pb */
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#ifdef CONFIG_CPU_ARM710
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.macro arm710_bug_check, instr, temp
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and \temp, \instr, #0x0f000000 @ check for SWI
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teq \temp, #0x0f000000
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bne .Larm700bug
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.endm
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.Larm700bug:
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ldr r0, [sp, #S_PSR] @ Get calling cpsr
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sub lr, lr, #4
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str lr, [r8]
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msr spsr_cxsf, r0
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ldmia sp, {r0 - lr}^ @ Get calling r0 - lr
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mov r0, r0
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ldr lr, [sp, #S_PC] @ Get PC
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add sp, sp, #S_FRAME_SIZE
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movs pc, lr
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#else
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.macro arm710_bug_check, instr, temp
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.endm
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#endif
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.align 5
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ENTRY(vector_swi)
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save_user_regs
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zero_fp
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get_scno
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arm710_bug_check scno, ip
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#ifdef CONFIG_ALIGNMENT_TRAP
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ldr ip, __cr_alignment
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ldr ip, [ip]
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mcr p15, 0, ip, c1, c0 @ update control register
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#endif
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enable_irq ip
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str r4, [sp, #-S_OFF]! @ push fifth arg
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get_thread_info tsk
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ldr ip, [tsk, #TI_FLAGS] @ check for syscall tracing
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bic scno, scno, #0xff000000 @ mask off SWI op-code
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eor scno, scno, #OS_NUMBER << 20 @ check OS number
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adr tbl, sys_call_table @ load syscall table pointer
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tst ip, #_TIF_SYSCALL_TRACE @ are we tracing syscalls?
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bne __sys_trace
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adr lr, ret_fast_syscall @ return address
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cmp scno, #NR_syscalls @ check upper syscall limit
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ldrcc pc, [tbl, scno, lsl #2] @ call sys_* routine
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add r1, sp, #S_OFF
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2: mov why, #0 @ no longer a real syscall
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cmp scno, #ARMSWI_OFFSET
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eor r0, scno, #OS_NUMBER << 20 @ put OS number back
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bcs arm_syscall
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b sys_ni_syscall @ not private func
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/*
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* This is the really slow path. We're going to be doing
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* context switches, and waiting for our parent to respond.
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*/
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__sys_trace:
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add r1, sp, #S_OFF
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mov r0, #0 @ trace entry [IP = 0]
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bl syscall_trace
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adr lr, __sys_trace_return @ return address
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add r1, sp, #S_R0 + S_OFF @ pointer to regs
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cmp scno, #NR_syscalls @ check upper syscall limit
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ldmccia r1, {r0 - r3} @ have to reload r0 - r3
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ldrcc pc, [tbl, scno, lsl #2] @ call sys_* routine
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b 2b
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__sys_trace_return:
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str r0, [sp, #S_R0 + S_OFF]! @ save returned r0
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mov r1, sp
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mov r0, #1 @ trace exit [IP = 1]
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bl syscall_trace
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b ret_slow_syscall
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.align 5
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#ifdef CONFIG_ALIGNMENT_TRAP
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.type __cr_alignment, #object
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__cr_alignment:
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.word cr_alignment
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#endif
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.type sys_call_table, #object
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ENTRY(sys_call_table)
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#include "calls.S"
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/*============================================================================
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* Special system call wrappers
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*/
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@ r0 = syscall number
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@ r5 = syscall table
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.type sys_syscall, #function
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sys_syscall:
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eor scno, r0, #OS_NUMBER << 20
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cmp scno, #__NR_syscall - __NR_SYSCALL_BASE
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cmpne scno, #NR_syscalls @ check range
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stmloia sp, {r5, r6} @ shuffle args
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movlo r0, r1
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movlo r1, r2
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movlo r2, r3
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movlo r3, r4
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ldrlo pc, [tbl, scno, lsl #2]
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b sys_ni_syscall
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sys_fork_wrapper:
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add r0, sp, #S_OFF
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b sys_fork
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sys_vfork_wrapper:
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add r0, sp, #S_OFF
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b sys_vfork
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sys_execve_wrapper:
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add r3, sp, #S_OFF
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b sys_execve
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sys_clone_wrapper:
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add ip, sp, #S_OFF
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str ip, [sp, #4]
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b sys_clone
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sys_sigsuspend_wrapper:
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add r3, sp, #S_OFF
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b sys_sigsuspend
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sys_rt_sigsuspend_wrapper:
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add r2, sp, #S_OFF
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b sys_rt_sigsuspend
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sys_sigreturn_wrapper:
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add r0, sp, #S_OFF
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b sys_sigreturn
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sys_rt_sigreturn_wrapper:
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add r0, sp, #S_OFF
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b sys_rt_sigreturn
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sys_sigaltstack_wrapper:
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ldr r2, [sp, #S_OFF + S_SP]
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b do_sigaltstack
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sys_futex_wrapper:
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str r5, [sp, #4] @ push sixth arg
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b sys_futex
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/*
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* Note: off_4k (r5) is always units of 4K. If we can't do the requested
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* offset, we return EINVAL.
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*/
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sys_mmap2:
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#if PAGE_SHIFT > 12
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tst r5, #PGOFF_MASK
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moveq r5, r5, lsr #PAGE_SHIFT - 12
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streq r5, [sp, #4]
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beq do_mmap2
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mov r0, #-EINVAL
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RETINSTR(mov,pc, lr)
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#else
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str r5, [sp, #4]
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b do_mmap2
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#endif
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