226 lines
5.1 KiB
ArmAsm
226 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) 1995-99, 2000- 02, 06 Ralf Baechle <ralf@linux-mips.org>
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* Copyright (C) 2001 MIPS Technologies, Inc.
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* Copyright (C) 2004 Thiemo Seufer
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* Copyright (C) 2014 Imagination Technologies Ltd.
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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/isadep.h>
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#include <asm/sysmips.h>
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#include <asm/thread_info.h>
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#include <asm/unistd.h>
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#include <asm/war.h>
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#include <asm/asm-offsets.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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lw t1, PT_EPC(sp) # skip syscall on return
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addiu t1, 4 # skip to next instruction
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sw t1, PT_EPC(sp)
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sw 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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lw t0, PT_R29(sp) # get old user stack pointer
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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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lw t5, TI_ADDR_LIMIT($28)
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addu t4, t0, 32
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and t5, t4
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bltz t5, bad_stack # -> sp is bad
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/*
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* Ok, copy the args from the luser stack to the kernel stack.
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*/
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.set push
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.set noreorder
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.set nomacro
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load_a4: user_lw(t5, 16(t0)) # argument #5 from usp
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load_a5: user_lw(t6, 20(t0)) # argument #6 from usp
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load_a6: user_lw(t7, 24(t0)) # argument #7 from usp
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load_a7: user_lw(t8, 28(t0)) # argument #8 from usp
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loads_done:
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sw t5, 16(sp) # argument #5 to ksp
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sw t6, 20(sp) # argument #6 to ksp
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sw t7, 24(sp) # argument #7 to ksp
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sw t8, 28(sp) # argument #8 to ksp
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.set pop
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.section __ex_table,"a"
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PTR load_a4, bad_stack_a4
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PTR load_a5, bad_stack_a5
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PTR load_a6, bad_stack_a6
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PTR load_a7, bad_stack_a7
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.previous
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lw t0, TI_FLAGS($28) # syscall tracing enabled?
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li t1, _TIF_WORK_SYSCALL_ENTRY
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and t0, t1
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bnez t0, syscall_trace_entry # -> yes
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syscall_common:
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subu v0, v0, __NR_O32_Linux # check syscall number
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sltiu t0, v0, __NR_O32_Linux_syscalls
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beqz t0, illegal_syscall
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sll t0, v0, 2
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la t1, sys_call_table
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addu t1, t0
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lw t2, (t1) # syscall routine
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beqz t2, illegal_syscall
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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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sw t0, PT_R7(sp) # set error flag
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beqz t0, 1f
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lw t1, PT_R2(sp) # syscall number
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negu v0 # error
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sw t1, PT_R0(sp) # save it for syscall restarting
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1: sw 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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syscall_trace_entry:
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SAVE_STATIC
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move a0, sp
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/*
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* 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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*/
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move a1, v0
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subu t2, v0, __NR_O32_Linux
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bnez t2, 1f /* __NR_syscall at offset 0 */
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lw a1, PT_R4(sp)
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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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lw v0, PT_R2(sp) # Restore syscall (maybe modified)
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lw a0, PT_R4(sp) # Restore argument registers
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lw a1, PT_R5(sp)
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lw a2, PT_R6(sp)
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lw a3, PT_R7(sp)
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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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* Our open-coded access area sanity test for the stack pointer
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* failed. We probably should handle this case a bit more drastic.
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*/
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bad_stack:
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li v0, EFAULT
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sw v0, PT_R2(sp)
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li t0, 1 # set error flag
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sw t0, PT_R7(sp)
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j o32_syscall_exit
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bad_stack_a4:
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li t5, 0
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b load_a5
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bad_stack_a5:
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li t6, 0
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b load_a6
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bad_stack_a6:
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li t7, 0
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b load_a7
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bad_stack_a7:
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li t8, 0
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b loads_done
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/*
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* The system call does not exist in this kernel
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*/
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illegal_syscall:
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li v0, ENOSYS # error
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sw v0, PT_R2(sp)
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li t0, 1 # set error flag
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sw t0, PT_R7(sp)
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j o32_syscall_exit
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END(handle_sys)
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LEAF(sys_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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sll t1, t0, 2
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beqz v0, einval
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lw t2, sys_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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lw a3, 16(sp)
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lw t4, 20(sp)
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lw t5, 24(sp)
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lw t6, 28(sp)
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sw t4, 16(sp)
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sw t5, 20(sp)
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sw t6, 24(sp)
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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(sys_syscall)
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#ifdef CONFIG_MIPS_MT_FPAFF
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/*
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* For FPU affinity scheduling on MIPS MT processors, we need to
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* intercept sys_sched_xxxaffinity() calls until we get a proper hook
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* in kernel/sched/core.c. Considered only temporary we only support
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* these hooks for the 32-bit kernel - there is no MIPS64 MT processor
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* atm.
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*/
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#define sys_sched_setaffinity mipsmt_sys_sched_setaffinity
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#define sys_sched_getaffinity mipsmt_sys_sched_getaffinity
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#endif /* CONFIG_MIPS_MT_FPAFF */
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#define __SYSCALL(nr, entry) PTR entry
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.align 2
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.type sys_call_table, @object
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EXPORT(sys_call_table)
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#include <asm/syscall_table_32_o32.h>
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#undef __SYSCALL
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