linux/arch/s390/kernel/head64.S
Gerald Schaefer 482b05dd53 [S390] Fixed handling of access register mode faults.
Replaced check_user_space() + __check_access_register with the new
check_space(). The old functions made wrong assumptions about kernel
and user space when the kernel and user address spaces are switched
(kernel in home space, user in primary/secondary space).
Secondly the user process can switch to the accress register mode if
it is running in primary or secondary mode. In addition it can load
an arbitrary value to the access registers. If any other value than
0 for primary space or 1 for secondary space is loaded and memory
is accessed using the base register related to the access register,
the program should be terminated with a SIGSEGV. To achieve that the
DUALD pointer in the DUCT and the PSALD pointer in the PASTE need
to point to an array of 8 invalid access-list entries to get a
ALEN-translation exception if an invalid alet is used.

Signed-off-by: Gerald Schaefer <geraldsc@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2007-03-05 23:35:54 +01:00

192 lines
4.9 KiB
ArmAsm

/*
* arch/s390/kernel/head64.S
*
* Copyright (C) IBM Corp. 1999,2006
*
* Author(s): Hartmut Penner <hp@de.ibm.com>
* Martin Schwidefsky <schwidefsky@de.ibm.com>
* Rob van der Heij <rvdhei@iae.nl>
* Heiko Carstens <heiko.carstens@de.ibm.com>
*
*/
#
# startup-code at 0x10000, running in absolute addressing mode
# this is called either by the ipl loader or directly by PSW restart
# or linload or SALIPL
#
.org 0x10000
startup:basr %r13,0 # get base
.LPG0: l %r13,0f-.LPG0(%r13)
b 0(%r13)
0: .long startup_continue
#
# params at 10400 (setup.h)
#
.org PARMAREA
.quad 0 # IPL_DEVICE
.quad 0 # INITRD_START
.quad 0 # INITRD_SIZE
.org COMMAND_LINE
.byte "root=/dev/ram0 ro"
.byte 0
.org 0x11000
startup_continue:
basr %r13,0 # get base
.LPG1: sll %r13,1 # remove high order bit
srl %r13,1
lhi %r1,1 # mode 1 = esame
mvi __LC_AR_MODE_ID,1 # set esame flag
slr %r0,%r0 # set cpuid to zero
sigp %r1,%r0,0x12 # switch to esame mode
sam64 # switch to 64 bit mode
lctlg %c0,%c15,.Lctl-.LPG1(%r13) # load control registers
lg %r12,.Lparmaddr-.LPG1(%r13) # pointer to parameter area
# move IPL device to lowcore
mvc __LC_IPLDEV(4),IPL_DEVICE+4-PARMAREA(%r12)
#
# Setup stack
#
larl %r15,init_thread_union
lg %r14,__TI_task(%r15) # cache current in lowcore
stg %r14,__LC_CURRENT
aghi %r15,1<<(PAGE_SHIFT+THREAD_ORDER) # init_task_union + THREAD_SIZE
stg %r15,__LC_KERNEL_STACK # set end of kernel stack
aghi %r15,-160
xc __SF_BACKCHAIN(4,%r15),__SF_BACKCHAIN(%r15) # clear backchain
#
# Save ipl parameters, clear bss memory, initialize storage key for kernel pages,
# and create a kernel NSS if the SAVESYS= parm is defined
#
brasl %r14,startup_init
# set program check new psw mask
mvc __LC_PGM_NEW_PSW(8),.Lpcmsk-.LPG1(%r13)
larl %r12,machine_flags
#
# find out if we have the MVPG instruction
#
la %r1,0f-.LPG1(%r13) # set program check address
stg %r1,__LC_PGM_NEW_PSW+8
sgr %r0,%r0
lghi %r1,0
lghi %r2,0
mvpg %r1,%r2 # test MVPG instruction
oi 7(%r12),16 # set MVPG flag
0:
#
# find out if the diag 0x44 works in 64 bit mode
#
la %r1,0f-.LPG1(%r13) # set program check address
stg %r1,__LC_PGM_NEW_PSW+8
diag 0,0,0x44 # test diag 0x44
oi 7(%r12),32 # set diag44 flag
0:
#
# find out if we have the IDTE instruction
#
la %r1,0f-.LPG1(%r13) # set program check address
stg %r1,__LC_PGM_NEW_PSW+8
.long 0xb2b10000 # store facility list
tm 0xc8,0x08 # check bit for clearing-by-ASCE
bno 0f-.LPG1(%r13)
lhi %r1,2094
lhi %r2,0
.long 0xb98e2001
oi 7(%r12),0x80 # set IDTE flag
0:
#
# find out if the diag 0x9c is available
#
la %r1,0f-.LPG1(%r13) # set program check address
stg %r1,__LC_PGM_NEW_PSW+8
stap __LC_CPUID+4 # store cpu address
lh %r1,__LC_CPUID+4
diag %r1,0,0x9c # test diag 0x9c
oi 6(%r12),1 # set diag9c flag
0:
#
# find out if we have the MVCOS instruction
#
la %r1,0f-.LPG1(%r13) # set program check address
stg %r1,__LC_PGM_NEW_PSW+8
.short 0xc800 # mvcos 0(%r0),0(%r0),%r0
.short 0x0000
.short 0x0000
0: tm 0x8f,0x13 # special-operation exception?
bno 1f-.LPG1(%r13) # if yes, MVCOS is present
oi 6(%r12),2 # set MVCOS flag
1:
lpswe .Lentry-.LPG1(13) # jump to _stext in primary-space,
# virtual and never return ...
.align 16
.Lentry:.quad 0x0000000180000000,_stext
.Lctl: .quad 0x04b50002 # cr0: various things
.quad 0 # cr1: primary space segment table
.quad .Lduct # cr2: dispatchable unit control table
.quad 0 # cr3: instruction authorization
.quad 0 # cr4: instruction authorization
.quad .Lduct # cr5: primary-aste origin
.quad 0 # cr6: I/O interrupts
.quad 0 # cr7: secondary space segment table
.quad 0 # cr8: access registers translation
.quad 0 # cr9: tracing off
.quad 0 # cr10: tracing off
.quad 0 # cr11: tracing off
.quad 0 # cr12: tracing off
.quad 0 # cr13: home space segment table
.quad 0xc0000000 # cr14: machine check handling off
.quad 0 # cr15: linkage stack operations
.Lpcmsk:.quad 0x0000000180000000
.L4malign:.quad 0xffffffffffc00000
.Lscan2g:.quad 0x80000000 + 0x20000 - 8 # 2GB + 128K - 8
.Lnop: .long 0x07000700
.Lparmaddr:
.quad PARMAREA
.align 64
.Lduct: .long 0,0,0,0,.Lduald,0,0,0
.long 0,0,0,0,0,0,0,0
.align 128
.Lduald:.rept 8
.long 0x80000000,0,0,0 # invalid access-list entries
.endr
.org 0x12000
.globl _ehead
_ehead:
#ifdef CONFIG_SHARED_KERNEL
.org 0x100000
#endif
#
# startup-code, running in absolute addressing mode
#
.globl _stext
_stext: basr %r13,0 # get base
.LPG3:
# check control registers
stctg %c0,%c15,0(%r15)
oi 6(%r15),0x40 # enable sigp emergency signal
oi 4(%r15),0x10 # switch on low address proctection
lctlg %c0,%c15,0(%r15)
lam 0,15,.Laregs-.LPG3(%r13) # load acrs needed by uaccess
brasl %r14,start_kernel # go to C code
#
# We returned from start_kernel ?!? PANIK
#
basr %r13,0
lpswe .Ldw-.(%r13) # load disabled wait psw
.align 8
.Ldw: .quad 0x0002000180000000,0x0000000000000000
.Laregs:.long 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0