mirror of
https://github.com/torvalds/linux
synced 2024-11-05 18:23:50 +00:00
0c88ee5b75
"lockdep: Fix backtraces" reveales a bug in early setup code: when lockdep tries to save a stack backtrace before setup_arch has been called the lowcore pointer for the current thread info pointer isn't initialized yet. However our save stack backtrace code relies on it. If the pointer isn't initialized the saved backtrace will have zero entries. lockdep however relies (correctly) on the fact that that cannot happen. A write access to some random memory region is the result. Fix this by initializing the thread info pointer early. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
105 lines
2.8 KiB
ArmAsm
105 lines
2.8 KiB
ArmAsm
/*
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* arch/s390/kernel/head31.S
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*
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* Copyright (C) IBM Corp. 2005,2006
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*
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* Author(s): Hartmut Penner <hp@de.ibm.com>
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* Martin Schwidefsky <schwidefsky@de.ibm.com>
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* Rob van der Heij <rvdhei@iae.nl>
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* Heiko Carstens <heiko.carstens@de.ibm.com>
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*
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*/
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.org 0x11000
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startup_continue:
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basr %r13,0 # get base
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.LPG1:
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mvi __LC_AR_MODE_ID,0 # set ESA flag (mode 0)
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lctl %c0,%c15,.Lctl-.LPG1(%r13) # load control registers
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l %r12,.Lparmaddr-.LPG1(%r13) # pointer to parameter area
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# move IPL device to lowcore
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#
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# Setup stack
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#
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l %r15,.Linittu-.LPG1(%r13)
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st %r15,__LC_THREAD_INFO # cache thread info in lowcore
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mvc __LC_CURRENT(4),__TI_task(%r15)
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ahi %r15,1<<(PAGE_SHIFT+THREAD_ORDER) # init_task_union+THREAD_SIZE
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st %r15,__LC_KERNEL_STACK # set end of kernel stack
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ahi %r15,-96
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#
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# Save ipl parameters, clear bss memory, initialize storage key for kernel pages,
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# and create a kernel NSS if the SAVESYS= parm is defined
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#
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l %r14,.Lstartup_init-.LPG1(%r13)
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basr %r14,%r14
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lpsw .Lentry-.LPG1(13) # jump to _stext in primary-space,
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# virtual and never return ...
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.align 8
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.Lentry:.long 0x00080000,0x80000000 + _stext
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.Lctl: .long 0x04b50002 # cr0: various things
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.long 0 # cr1: primary space segment table
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.long .Lduct # cr2: dispatchable unit control table
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.long 0 # cr3: instruction authorization
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.long 0 # cr4: instruction authorization
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.long .Lduct # cr5: primary-aste origin
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.long 0 # cr6: I/O interrupts
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.long 0 # cr7: secondary space segment table
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.long 0 # cr8: access registers translation
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.long 0 # cr9: tracing off
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.long 0 # cr10: tracing off
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.long 0 # cr11: tracing off
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.long 0 # cr12: tracing off
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.long 0 # cr13: home space segment table
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.long 0xc0000000 # cr14: machine check handling off
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.long 0 # cr15: linkage stack operations
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.Lmchunk:.long memory_chunk
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.Lbss_bgn: .long __bss_start
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.Lbss_end: .long _end
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.Lparmaddr: .long PARMAREA
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.Linittu: .long init_thread_union
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.Lstartup_init:
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.long startup_init
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.align 64
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.Lduct: .long 0,0,0,0,.Lduald,0,0,0
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.long 0,0,0,0,0,0,0,0
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.align 128
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.Lduald:.rept 8
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.long 0x80000000,0,0,0 # invalid access-list entries
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.endr
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.org 0x12000
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.globl _ehead
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_ehead:
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#ifdef CONFIG_SHARED_KERNEL
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.org 0x100000
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#endif
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#
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# startup-code, running in absolute addressing mode
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#
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.globl _stext
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_stext: basr %r13,0 # get base
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.LPG3:
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# check control registers
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stctl %c0,%c15,0(%r15)
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oi 2(%r15),0x40 # enable sigp emergency signal
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oi 0(%r15),0x10 # switch on low address protection
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lctl %c0,%c15,0(%r15)
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#
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lam 0,15,.Laregs-.LPG3(%r13) # load access regs needed by uaccess
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l %r14,.Lstart-.LPG3(%r13)
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basr %r14,%r14 # call start_kernel
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#
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# We returned from start_kernel ?!? PANIK
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#
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basr %r13,0
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lpsw .Ldw-.(%r13) # load disabled wait psw
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#
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.align 8
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.Ldw: .long 0x000a0000,0x00000000
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.Lstart:.long start_kernel
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.Laregs:.long 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
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