222 lines
5.1 KiB
ArmAsm
222 lines
5.1 KiB
ArmAsm
/*
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* This file is subject to the terms and conditions of the GNU General Public
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* License. See the file "COPYING" in the main directory of this archive
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* for more details.
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*
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* Copyright (C) 1995 - 2000, 2001 by Ralf Baechle
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* Copyright (C) 1999, 2000 Silicon Graphics, Inc.
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* Copyright (C) 2001 MIPS Technologies, Inc.
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* Copyright (C) 2004 Thiemo Seufer
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*
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* Hairy, the userspace application uses a different argument passing
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* convention than the kernel, so we have to translate things from o32
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* to ABI64 calling convention. 64-bit syscalls are also processed
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* here for now.
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*/
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#include <linux/errno.h>
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#include <asm/asm.h>
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#include <asm/asmmacro.h>
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#include <asm/irqflags.h>
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#include <asm/mipsregs.h>
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#include <asm/regdef.h>
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#include <asm/stackframe.h>
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#include <asm/thread_info.h>
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#include <asm/unistd.h>
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#include <asm/sysmips.h>
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.align 5
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NESTED(handle_sys, PT_SIZE, sp)
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.set noat
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SAVE_SOME
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TRACE_IRQS_ON_RELOAD
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STI
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.set at
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ld t1, PT_EPC(sp) # skip syscall on return
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dsubu t0, v0, __NR_O32_Linux # check syscall number
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sltiu t0, t0, __NR_O32_Linux_syscalls
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daddiu t1, 4 # skip to next instruction
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sd t1, PT_EPC(sp)
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beqz t0, not_o32_scall
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#if 0
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SAVE_ALL
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move a1, v0
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ASM_PRINT("Scall %ld\n")
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RESTORE_ALL
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#endif
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/* We don't want to stumble over broken sign extensions from
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userland. O32 does never use the upper half. */
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sll a0, a0, 0
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sll a1, a1, 0
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sll a2, a2, 0
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sll a3, a3, 0
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sd a3, PT_R26(sp) # save a3 for syscall restarting
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/*
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* More than four arguments. Try to deal with it by copying the
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* stack arguments from the user stack to the kernel stack.
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* This Sucks (TM).
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*
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* We intentionally keep the kernel stack a little below the top of
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* userspace so we don't have to do a slower byte accurate check here.
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*/
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ld t0, PT_R29(sp) # get old user stack pointer
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daddu t1, t0, 32
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bltz t1, bad_stack
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load_a4: lw a4, 16(t0) # argument #5 from usp
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load_a5: lw a5, 20(t0) # argument #6 from usp
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load_a6: lw a6, 24(t0) # argument #7 from usp
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load_a7: lw a7, 28(t0) # argument #8 from usp
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loads_done:
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.section __ex_table,"a"
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PTR_WD load_a4, bad_stack_a4
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PTR_WD load_a5, bad_stack_a5
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PTR_WD load_a6, bad_stack_a6
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PTR_WD load_a7, bad_stack_a7
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.previous
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li t1, _TIF_WORK_SYSCALL_ENTRY
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LONG_L t0, TI_FLAGS($28) # syscall tracing enabled?
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and t0, t1, t0
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bnez t0, trace_a_syscall
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syscall_common:
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dsll t0, v0, 3 # offset into table
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ld t2, (sys32_call_table - (__NR_O32_Linux * 8))(t0)
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jalr t2 # Do The Real Thing (TM)
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li t0, -EMAXERRNO - 1 # error?
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sltu t0, t0, v0
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sd t0, PT_R7(sp) # set error flag
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beqz t0, 1f
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ld t1, PT_R2(sp) # syscall number
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dnegu v0 # error
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sd t1, PT_R0(sp) # save it for syscall restarting
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1: sd v0, PT_R2(sp) # result
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o32_syscall_exit:
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j syscall_exit_partial
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/* ------------------------------------------------------------------------ */
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trace_a_syscall:
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SAVE_STATIC
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sd a4, PT_R8(sp) # Save argument registers
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sd a5, PT_R9(sp)
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sd a6, PT_R10(sp)
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sd a7, PT_R11(sp) # For indirect syscalls
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move a0, sp
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/*
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* absolute syscall number is in v0 unless we called syscall(__NR_###)
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* where the real syscall number is in a0
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* note: NR_syscall is the first O32 syscall but the macro is
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* only defined when compiling with -mabi=32 (CONFIG_32BIT)
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* therefore __NR_O32_Linux is used (4000)
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*/
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.set push
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.set reorder
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subu t1, v0, __NR_O32_Linux
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move a1, v0
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bnez t1, 1f /* __NR_syscall at offset 0 */
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ld a1, PT_R4(sp) /* Arg1 for __NR_syscall case */
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.set pop
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1: jal syscall_trace_enter
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bltz v0, 1f # seccomp failed? Skip syscall
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RESTORE_STATIC
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ld v0, PT_R2(sp) # Restore syscall (maybe modified)
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ld a0, PT_R4(sp) # Restore argument registers
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ld a1, PT_R5(sp)
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ld a2, PT_R6(sp)
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ld a3, PT_R7(sp)
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ld a4, PT_R8(sp)
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ld a5, PT_R9(sp)
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ld a6, PT_R10(sp)
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ld a7, PT_R11(sp) # For indirect syscalls
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dsubu t0, v0, __NR_O32_Linux # check (new) syscall number
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sltiu t0, t0, __NR_O32_Linux_syscalls
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beqz t0, not_o32_scall
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j syscall_common
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1: j syscall_exit
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/* ------------------------------------------------------------------------ */
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/*
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* The stackpointer for a call with more than 4 arguments is bad.
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*/
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bad_stack:
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li v0, EFAULT
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sd v0, PT_R2(sp)
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li t0, 1 # set error flag
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sd t0, PT_R7(sp)
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j o32_syscall_exit
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bad_stack_a4:
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li a4, 0
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b load_a5
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bad_stack_a5:
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li a5, 0
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b load_a6
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bad_stack_a6:
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li a6, 0
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b load_a7
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bad_stack_a7:
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li a7, 0
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b loads_done
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not_o32_scall:
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/*
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* This is not an o32 compatibility syscall, pass it on
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* to the 64-bit syscall handlers.
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*/
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#ifdef CONFIG_MIPS32_N32
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j handle_sysn32
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#else
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j handle_sys64
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#endif
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END(handle_sys)
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LEAF(sys32_syscall)
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subu t0, a0, __NR_O32_Linux # check syscall number
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sltiu v0, t0, __NR_O32_Linux_syscalls
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beqz t0, einval # do not recurse
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dsll t1, t0, 3
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beqz v0, einval
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ld t2, sys32_call_table(t1) # syscall routine
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move a0, a1 # shift argument registers
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move a1, a2
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move a2, a3
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move a3, a4
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move a4, a5
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move a5, a6
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move a6, a7
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jr t2
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/* Unreached */
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einval: li v0, -ENOSYS
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jr ra
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END(sys32_syscall)
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#define __SYSCALL_WITH_COMPAT(nr, native, compat) __SYSCALL(nr, compat)
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#define __SYSCALL(nr, entry) PTR_WD entry
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.align 3
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.type sys32_call_table,@object
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EXPORT(sys32_call_table)
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#include <asm/syscall_table_o32.h>
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