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[S390] add breaking event address for user space

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Copy the last breaking event address from the lowcore to a new
field in the thread_struct on each system entry. Add a new
ptrace request PTRACE_GET_LAST_BREAK and a new utrace regset
REGSET_LAST_BREAK to query the last breaking event.

This is useful for debugging wild branches in user space code.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This commit is contained in:
Martin Schwidefsky 2010-05-17 10:00:05 +02:00 committed by Martin Schwidefsky
parent cd3b70f5d4
commit 86f2552bbd
8 changed files with 223 additions and 127 deletions
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3
arch/s390/include/asm/ptrace.h
View file

@ -328,8 +328,8 @@ struct pt_regs
psw_t psw;
unsigned long gprs[NUM_GPRS];
unsigned long orig_gpr2;
unsigned short svcnr;
unsigned short ilc;
unsigned short svcnr;
};
#endif
@ -436,6 +436,7 @@ typedef struct
#define PTRACE_PEEKDATA_AREA 0x5003
#define PTRACE_POKETEXT_AREA 0x5004
#define PTRACE_POKEDATA_AREA 0x5005
#define PTRACE_GET_LAST_BREAK 0x5006
/*
* PT_PROT definition is loosely based on hppa bsd definition in

1
arch/s390/include/asm/thread_info.h
View file

@ -50,6 +50,7 @@ struct thread_info {
struct restart_block restart_block;
__u64 user_timer;
__u64 system_timer;
unsigned long last_break; /* last breaking-event-address. */
};
/*

1
arch/s390/kernel/asm-offsets.c
View file

@ -39,6 +39,7 @@ int main(void)
DEFINE(__TI_precount, offsetof(struct thread_info, preempt_count));
DEFINE(__TI_user_timer, offsetof(struct thread_info, user_timer));
DEFINE(__TI_system_timer, offsetof(struct thread_info, system_timer));
DEFINE(__TI_last_break, offsetof(struct thread_info, last_break));
BLANK();
DEFINE(__PT_ARGS, offsetof(struct pt_regs, args));
DEFINE(__PT_PSW, offsetof(struct pt_regs, psw));

4
arch/s390/kernel/entry.S
View file

@ -180,9 +180,9 @@ STACK_SIZE = 1 << STACK_SHIFT
s %r15,BASED(.Lc_spsize) # make room for registers & psw
mvc SP_PSW(8,%r15),0(%r12) # move user PSW to stack
st %r2,SP_ORIG_R2(%r15) # store original content of gpr 2
icm %r12,3,__LC_SVC_ILC
icm %r12,12,__LC_SVC_ILC
stm %r0,%r11,SP_R0(%r15) # store gprs %r0-%r11 to kernel stack
st %r12,SP_SVCNR(%r15)
st %r12,SP_ILC(%r15)
mvc SP_R12(16,%r15),\savearea # move %r12-%r15 to stack
la %r12,0
st %r12,__SF_BACKCHAIN(%r15) # clear back chain

270
arch/s390/kernel/entry64.S
View file

@ -126,31 +126,35 @@ _TIF_SYSCALL = (_TIF_SYSCALL_TRACE>>8 | _TIF_SYSCALL_AUDIT>>8 | \
* R15 - kernel stack pointer
*/
.macro SAVE_ALL_BASE savearea
stmg %r12,%r15,\savearea
larl %r13,system_call
.endm
.macro SAVE_ALL_SVC psworg,savearea
la %r12,\psworg
stmg %r11,%r15,\savearea
lg %r15,__LC_KERNEL_STACK # problem state -> load ksp
aghi %r15,-SP_SIZE # make room for registers & psw
lg %r11,__LC_LAST_BREAK
.endm
.macro SAVE_ALL_SYNC psworg,savearea
la %r12,\psworg
.macro SAVE_ALL_PGM psworg,savearea
stmg %r11,%r15,\savearea
tm \psworg+1,0x01 # test problem state bit
jz 2f # skip stack setup save
lg %r15,__LC_KERNEL_STACK # problem state -> load ksp
#ifdef CONFIG_CHECK_STACK
j 3f
2: tml %r15,STACK_SIZE - CONFIG_STACK_GUARD
jz stack_overflow
3:
jnz 1f
tml %r15,STACK_SIZE - CONFIG_STACK_GUARD
jnz 2f
la %r12,\psworg
j stack_overflow
#else
jz 2f
#endif
2:
1: lg %r15,__LC_KERNEL_STACK # problem state -> load ksp
2: aghi %r15,-SP_SIZE # make room for registers & psw
larl %r13,system_call
lg %r11,__LC_LAST_BREAK
.endm
.macro SAVE_ALL_ASYNC psworg,savearea
stmg %r11,%r15,\savearea
larl %r13,system_call
lg %r11,__LC_LAST_BREAK
la %r12,\psworg
tm \psworg+1,0x01 # test problem state bit
jnz 1f # from user -> load kernel stack
@ -164,27 +168,23 @@ _TIF_SYSCALL = (_TIF_SYSCALL_TRACE>>8 | _TIF_SYSCALL_AUDIT>>8 | \
0: lg %r14,__LC_ASYNC_STACK # are we already on the async. stack ?
slgr %r14,%r15
srag %r14,%r14,STACK_SHIFT
jz 2f
1: lg %r15,__LC_ASYNC_STACK # load async stack
#ifdef CONFIG_CHECK_STACK
j 3f
2: tml %r15,STACK_SIZE - CONFIG_STACK_GUARD
jz stack_overflow
3:
jnz 1f
tml %r15,STACK_SIZE - CONFIG_STACK_GUARD
jnz 2f
j stack_overflow
#else
jz 2f
#endif
2:
1: lg %r15,__LC_ASYNC_STACK # load async stack
2: aghi %r15,-SP_SIZE # make room for registers & psw
.endm
.macro CREATE_STACK_FRAME psworg,savearea
aghi %r15,-SP_SIZE # make room for registers & psw
mvc SP_PSW(16,%r15),0(%r12) # move user PSW to stack
.macro CREATE_STACK_FRAME savearea
xc __SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)
stg %r2,SP_ORIG_R2(%r15) # store original content of gpr 2
icm %r12,3,__LC_SVC_ILC
stmg %r0,%r11,SP_R0(%r15) # store gprs %r0-%r11 to kernel stack
st %r12,SP_SVCNR(%r15)
mvc SP_R12(32,%r15),\savearea # move %r12-%r15 to stack
la %r12,0
stg %r12,__SF_BACKCHAIN(%r15)
mvc SP_R11(40,%r15),\savearea # move %r11-%r15 to stack
stmg %r0,%r10,SP_R0(%r15) # store gprs %r0-%r10 to kernel stack
.endm
.macro RESTORE_ALL psworg,sync
@ -200,6 +200,13 @@ _TIF_SYSCALL = (_TIF_SYSCALL_TRACE>>8 | _TIF_SYSCALL_AUDIT>>8 | \
lpswe \psworg # back to caller
.endm
.macro LAST_BREAK
srag %r10,%r11,23
jz 0f
stg %r11,__TI_last_break(%r12)
0:
.endm
/*
* Scheduler resume function, called by switch_to
* gpr2 = (task_struct *) prev
@ -245,37 +252,38 @@ __critical_start:
system_call:
stpt __LC_SYNC_ENTER_TIMER
sysc_saveall:
SAVE_ALL_BASE __LC_SAVE_AREA
SAVE_ALL_SVC __LC_SVC_OLD_PSW,__LC_SAVE_AREA
CREATE_STACK_FRAME __LC_SVC_OLD_PSW,__LC_SAVE_AREA
llgh %r7,__LC_SVC_INT_CODE # get svc number from lowcore
CREATE_STACK_FRAME __LC_SAVE_AREA
mvc SP_PSW(16,%r15),__LC_SVC_OLD_PSW
mvc SP_ILC(4,%r15),__LC_SVC_ILC
stg %r7,SP_ARGS(%r15)
lg %r12,__LC_THREAD_INFO # load pointer to thread_info struct
sysc_vtime:
UPDATE_VTIME __LC_EXIT_TIMER,__LC_SYNC_ENTER_TIMER,__LC_USER_TIMER
sysc_stime:
UPDATE_VTIME __LC_LAST_UPDATE_TIMER,__LC_EXIT_TIMER,__LC_SYSTEM_TIMER
sysc_update:
mvc __LC_LAST_UPDATE_TIMER(8),__LC_SYNC_ENTER_TIMER
LAST_BREAK
sysc_do_svc:
lg %r9,__LC_THREAD_INFO # load pointer to thread_info struct
ltgr %r7,%r7 # test for svc 0
llgh %r7,SP_SVCNR(%r15)
slag %r7,%r7,2 # shift and test for svc 0
jnz sysc_nr_ok
# svc 0: system call number in %r1
cl %r1,BASED(.Lnr_syscalls)
llgfr %r1,%r1 # clear high word in r1
cghi %r1,NR_syscalls
jnl sysc_nr_ok
lgfr %r7,%r1 # clear high word in r1
sth %r1,SP_SVCNR(%r15)
slag %r7,%r1,2 # shift and test for svc 0
sysc_nr_ok:
mvc SP_ARGS(8,%r15),SP_R7(%r15)
sysc_do_restart:
sth %r7,SP_SVCNR(%r15)
sllg %r7,%r7,2 # svc number * 4
larl %r10,sys_call_table
#ifdef CONFIG_COMPAT
tm __TI_flags+5(%r9),(_TIF_31BIT>>16) # running in 31 bit mode ?
tm __TI_flags+5(%r12),(_TIF_31BIT>>16) # running in 31 bit mode ?
jno sysc_noemu
larl %r10,sys_call_table_emu # use 31 bit emulation system calls
sysc_noemu:
#endif
tm __TI_flags+6(%r9),_TIF_SYSCALL
tm __TI_flags+6(%r12),_TIF_SYSCALL
lgf %r8,0(%r7,%r10) # load address of system call routine
jnz sysc_tracesys
basr %r14,%r8 # call sys_xxxx
@ -284,7 +292,7 @@ sysc_noemu:
sysc_return:
LOCKDEP_SYS_EXIT
sysc_tif:
tm __TI_flags+7(%r9),_TIF_WORK_SVC
tm __TI_flags+7(%r12),_TIF_WORK_SVC
jnz sysc_work # there is work to do (signals etc.)
sysc_restore:
RESTORE_ALL __LC_RETURN_PSW,1
@ -301,17 +309,17 @@ sysc_work:
# One of the work bits is on. Find out which one.
#
sysc_work_tif:
tm __TI_flags+7(%r9),_TIF_MCCK_PENDING
tm __TI_flags+7(%r12),_TIF_MCCK_PENDING
jo sysc_mcck_pending
tm __TI_flags+7(%r9),_TIF_NEED_RESCHED
tm __TI_flags+7(%r12),_TIF_NEED_RESCHED
jo sysc_reschedule
tm __TI_flags+7(%r9),_TIF_SIGPENDING
tm __TI_flags+7(%r12),_TIF_SIGPENDING
jo sysc_sigpending
tm __TI_flags+7(%r9),_TIF_NOTIFY_RESUME
tm __TI_flags+7(%r12),_TIF_NOTIFY_RESUME
jo sysc_notify_resume
tm __TI_flags+7(%r9),_TIF_RESTART_SVC
tm __TI_flags+7(%r12),_TIF_RESTART_SVC
jo sysc_restart
tm __TI_flags+7(%r9),_TIF_SINGLE_STEP
tm __TI_flags+7(%r12),_TIF_SINGLE_STEP
jo sysc_singlestep
j sysc_return # beware of critical section cleanup
@ -333,12 +341,12 @@ sysc_mcck_pending:
# _TIF_SIGPENDING is set, call do_signal
#
sysc_sigpending:
ni __TI_flags+7(%r9),255-_TIF_SINGLE_STEP # clear TIF_SINGLE_STEP
ni __TI_flags+7(%r12),255-_TIF_SINGLE_STEP # clear TIF_SINGLE_STEP
la %r2,SP_PTREGS(%r15) # load pt_regs
brasl %r14,do_signal # call do_signal
tm __TI_flags+7(%r9),_TIF_RESTART_SVC
tm __TI_flags+7(%r12),_TIF_RESTART_SVC
jo sysc_restart
tm __TI_flags+7(%r9),_TIF_SINGLE_STEP
tm __TI_flags+7(%r12),_TIF_SINGLE_STEP
jo sysc_singlestep
j sysc_return
@ -354,17 +362,19 @@ sysc_notify_resume:
# _TIF_RESTART_SVC is set, set up registers and restart svc
#
sysc_restart:
ni __TI_flags+7(%r9),255-_TIF_RESTART_SVC # clear TIF_RESTART_SVC
ni __TI_flags+7(%r12),255-_TIF_RESTART_SVC # clear TIF_RESTART_SVC
lg %r7,SP_R2(%r15) # load new svc number
mvc SP_R2(8,%r15),SP_ORIG_R2(%r15) # restore first argument
lmg %r2,%r6,SP_R2(%r15) # load svc arguments
j sysc_do_restart # restart svc
sth %r7,SP_SVCNR(%r15)
slag %r7,%r7,2
j sysc_nr_ok # restart svc
#
# _TIF_SINGLE_STEP is set, call do_single_step
#
sysc_singlestep:
ni __TI_flags+7(%r9),255-_TIF_SINGLE_STEP # clear TIF_SINGLE_STEP
ni __TI_flags+7(%r12),255-_TIF_SINGLE_STEP # clear TIF_SINGLE_STEP
xc SP_SVCNR(2,%r15),SP_SVCNR(%r15) # clear svc number
la %r2,SP_PTREGS(%r15) # address of register-save area
larl %r14,sysc_return # load adr. of system return
@ -377,8 +387,8 @@ sysc_singlestep:
sysc_tracesys:
la %r2,SP_PTREGS(%r15) # load pt_regs
la %r3,0
srl %r7,2
stg %r7,SP_R2(%r15)
llgh %r0,SP_SVCNR(%r15)
stg %r0,SP_R2(%r15)
brasl %r14,do_syscall_trace_enter
lghi %r0,NR_syscalls
clgr %r0,%r2
@ -391,7 +401,7 @@ sysc_tracego:
basr %r14,%r8 # call sys_xxx
stg %r2,SP_R2(%r15) # store return value
sysc_tracenogo:
tm __TI_flags+6(%r9),_TIF_SYSCALL
tm __TI_flags+6(%r12),_TIF_SYSCALL
jz sysc_return
la %r2,SP_PTREGS(%r15) # load pt_regs
larl %r14,sysc_return # return point is sysc_return
@ -403,7 +413,7 @@ sysc_tracenogo:
.globl ret_from_fork
ret_from_fork:
lg %r13,__LC_SVC_NEW_PSW+8
lg %r9,__LC_THREAD_INFO # load pointer to thread_info struct
lg %r12,__LC_THREAD_INFO # load pointer to thread_info struct
tm SP_PSW+1(%r15),0x01 # forking a kernel thread ?
jo 0f
stg %r15,SP_R15(%r15) # store stack pointer for new kthread
@ -437,8 +447,8 @@ kernel_execve:
lg %r15,__LC_KERNEL_STACK # load ksp
aghi %r15,-SP_SIZE # make room for registers & psw
lg %r13,__LC_SVC_NEW_PSW+8
lg %r9,__LC_THREAD_INFO
mvc SP_PTREGS(__PT_SIZE,%r15),0(%r12) # copy pt_regs
lg %r12,__LC_THREAD_INFO
xc __SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)
# TRACE_IRQS_ON
stosm __SF_EMPTY(%r15),0x03 # reenable interrupts
@ -465,21 +475,23 @@ pgm_check_handler:
* for LPSW?).
*/
stpt __LC_SYNC_ENTER_TIMER
SAVE_ALL_BASE __LC_SAVE_AREA
tm __LC_PGM_INT_CODE+1,0x80 # check whether we got a per exception
jnz pgm_per # got per exception -> special case
SAVE_ALL_SYNC __LC_PGM_OLD_PSW,__LC_SAVE_AREA
CREATE_STACK_FRAME __LC_PGM_OLD_PSW,__LC_SAVE_AREA
SAVE_ALL_PGM __LC_PGM_OLD_PSW,__LC_SAVE_AREA
CREATE_STACK_FRAME __LC_SAVE_AREA
xc SP_ILC(4,%r15),SP_ILC(%r15)
mvc SP_PSW(16,%r15),__LC_PGM_OLD_PSW
lg %r12,__LC_THREAD_INFO # load pointer to thread_info struct
tm SP_PSW+1(%r15),0x01 # interrupting from user ?
jz pgm_no_vtime
UPDATE_VTIME __LC_EXIT_TIMER,__LC_SYNC_ENTER_TIMER,__LC_USER_TIMER
UPDATE_VTIME __LC_LAST_UPDATE_TIMER,__LC_EXIT_TIMER,__LC_SYSTEM_TIMER
mvc __LC_LAST_UPDATE_TIMER(8),__LC_SYNC_ENTER_TIMER
LAST_BREAK
pgm_no_vtime:
HANDLE_SIE_INTERCEPT
TRACE_IRQS_CHECK_OFF
lg %r9,__LC_THREAD_INFO # load pointer to thread_info struct
mvc SP_ARGS(8,%r15),__LC_LAST_BREAK
stg %r11,SP_ARGS(%r15)
lgf %r3,__LC_PGM_ILC # load program interruption code
lghi %r8,0x7f
ngr %r8,%r3
@ -503,31 +515,32 @@ pgm_per:
clc __LC_PGM_OLD_PSW(16),__LC_SVC_NEW_PSW
je pgm_svcper
# no interesting special case, ignore PER event
lmg %r12,%r15,__LC_SAVE_AREA
lpswe __LC_PGM_OLD_PSW
#
# Normal per exception
#
pgm_per_std:
SAVE_ALL_SYNC __LC_PGM_OLD_PSW,__LC_SAVE_AREA
CREATE_STACK_FRAME __LC_PGM_OLD_PSW,__LC_SAVE_AREA
SAVE_ALL_PGM __LC_PGM_OLD_PSW,__LC_SAVE_AREA
CREATE_STACK_FRAME __LC_SAVE_AREA
mvc SP_PSW(16,%r15),__LC_PGM_OLD_PSW
lg %r12,__LC_THREAD_INFO # load pointer to thread_info struct
tm SP_PSW+1(%r15),0x01 # interrupting from user ?
jz pgm_no_vtime2
UPDATE_VTIME __LC_EXIT_TIMER,__LC_SYNC_ENTER_TIMER,__LC_USER_TIMER
UPDATE_VTIME __LC_LAST_UPDATE_TIMER,__LC_EXIT_TIMER,__LC_SYSTEM_TIMER
mvc __LC_LAST_UPDATE_TIMER(8),__LC_SYNC_ENTER_TIMER
LAST_BREAK
pgm_no_vtime2:
HANDLE_SIE_INTERCEPT
TRACE_IRQS_CHECK_OFF
lg %r9,__LC_THREAD_INFO # load pointer to thread_info struct
lg %r1,__TI_task(%r9)
lg %r1,__TI_task(%r12)
tm SP_PSW+1(%r15),0x01 # kernel per event ?
jz kernel_per
mvc __THREAD_per+__PER_atmid(2,%r1),__LC_PER_ATMID
mvc __THREAD_per+__PER_address(8,%r1),__LC_PER_ADDRESS
mvc __THREAD_per+__PER_access_id(1,%r1),__LC_PER_ACCESS_ID
oi __TI_flags+7(%r9),_TIF_SINGLE_STEP # set TIF_SINGLE_STEP
oi __TI_flags+7(%r12),_TIF_SINGLE_STEP # set TIF_SINGLE_STEP
lgf %r3,__LC_PGM_ILC # load program interruption code
lghi %r8,0x7f
ngr %r8,%r3 # clear per-event-bit and ilc
@ -538,19 +551,21 @@ pgm_no_vtime2:
# it was a single stepped SVC that is causing all the trouble
#
pgm_svcper:
SAVE_ALL_SYNC __LC_SVC_OLD_PSW,__LC_SAVE_AREA
CREATE_STACK_FRAME __LC_SVC_OLD_PSW,__LC_SAVE_AREA
SAVE_ALL_PGM __LC_SVC_OLD_PSW,__LC_SAVE_AREA
CREATE_STACK_FRAME __LC_SAVE_AREA
mvc SP_PSW(16,%r15),__LC_SVC_OLD_PSW
mvc SP_ILC(4,%r15),__LC_SVC_ILC
lg %r12,__LC_THREAD_INFO # load pointer to thread_info struct
UPDATE_VTIME __LC_EXIT_TIMER,__LC_SYNC_ENTER_TIMER,__LC_USER_TIMER
UPDATE_VTIME __LC_LAST_UPDATE_TIMER,__LC_EXIT_TIMER,__LC_SYSTEM_TIMER
mvc __LC_LAST_UPDATE_TIMER(8),__LC_SYNC_ENTER_TIMER
llgh %r7,__LC_SVC_INT_CODE # get svc number from lowcore
lg %r9,__LC_THREAD_INFO # load pointer to thread_info struct
LAST_BREAK
TRACE_IRQS_OFF
lg %r8,__TI_task(%r9)
lg %r8,__TI_task(%r12)
mvc __THREAD_per+__PER_atmid(2,%r8),__LC_PER_ATMID
mvc __THREAD_per+__PER_address(8,%r8),__LC_PER_ADDRESS
mvc __THREAD_per+__PER_access_id(1,%r8),__LC_PER_ACCESS_ID
oi __TI_flags+7(%r9),_TIF_SINGLE_STEP # set TIF_SINGLE_STEP
oi __TI_flags+7(%r12),_TIF_SINGLE_STEP # set TIF_SINGLE_STEP
TRACE_IRQS_ON
stosm __SF_EMPTY(%r15),0x03 # reenable interrupts
lmg %r2,%r6,SP_R2(%r15) # load svc arguments
@ -572,16 +587,17 @@ kernel_per:
io_int_handler:
stck __LC_INT_CLOCK
stpt __LC_ASYNC_ENTER_TIMER
SAVE_ALL_BASE __LC_SAVE_AREA+32
SAVE_ALL_ASYNC __LC_IO_OLD_PSW,__LC_SAVE_AREA+32
CREATE_STACK_FRAME __LC_IO_OLD_PSW,__LC_SAVE_AREA+32
SAVE_ALL_ASYNC __LC_IO_OLD_PSW,__LC_SAVE_AREA+40
CREATE_STACK_FRAME __LC_SAVE_AREA+40
mvc SP_PSW(16,%r15),0(%r12) # move user PSW to stack
lg %r12,__LC_THREAD_INFO # load pointer to thread_info struct
tm SP_PSW+1(%r15),0x01 # interrupting from user ?
jz io_no_vtime
UPDATE_VTIME __LC_EXIT_TIMER,__LC_ASYNC_ENTER_TIMER,__LC_USER_TIMER
UPDATE_VTIME __LC_LAST_UPDATE_TIMER,__LC_EXIT_TIMER,__LC_SYSTEM_TIMER
mvc __LC_LAST_UPDATE_TIMER(8),__LC_ASYNC_ENTER_TIMER
LAST_BREAK
io_no_vtime:
lg %r9,__LC_THREAD_INFO # load pointer to thread_info struct
HANDLE_SIE_INTERCEPT
TRACE_IRQS_OFF
la %r2,SP_PTREGS(%r15) # address of register-save area
@ -590,7 +606,7 @@ io_return:
LOCKDEP_SYS_EXIT
TRACE_IRQS_ON
io_tif:
tm __TI_flags+7(%r9),_TIF_WORK_INT
tm __TI_flags+7(%r12),_TIF_WORK_INT
jnz io_work # there is work to do (signals etc.)
io_restore:
RESTORE_ALL __LC_RETURN_PSW,0
@ -610,7 +626,7 @@ io_work:
jo io_work_user # yes -> do resched & signal
#ifdef CONFIG_PREEMPT
# check for preemptive scheduling
icm %r0,15,__TI_precount(%r9)
icm %r0,15,__TI_precount(%r12)
jnz io_restore # preemption is disabled
tm __TI_flags+7(%r12),_TIF_NEED_RESCHED
jno io_restore
@ -645,13 +661,13 @@ io_work_user:
# and _TIF_MCCK_PENDING
#
io_work_tif:
tm __TI_flags+7(%r9),_TIF_MCCK_PENDING
tm __TI_flags+7(%r12),_TIF_MCCK_PENDING
jo io_mcck_pending
tm __TI_flags+7(%r9),_TIF_NEED_RESCHED
tm __TI_flags+7(%r12),_TIF_NEED_RESCHED
jo io_reschedule
tm __TI_flags+7(%r9),_TIF_SIGPENDING
tm __TI_flags+7(%r12),_TIF_SIGPENDING
jo io_sigpending
tm __TI_flags+7(%r9),_TIF_NOTIFY_RESUME
tm __TI_flags+7(%r12),_TIF_NOTIFY_RESUME
jo io_notify_resume
j io_return # beware of critical section cleanup
@ -706,16 +722,17 @@ io_notify_resume:
ext_int_handler:
stck __LC_INT_CLOCK
stpt __LC_ASYNC_ENTER_TIMER
SAVE_ALL_BASE __LC_SAVE_AREA+32
SAVE_ALL_ASYNC __LC_EXT_OLD_PSW,__LC_SAVE_AREA+32
CREATE_STACK_FRAME __LC_EXT_OLD_PSW,__LC_SAVE_AREA+32
SAVE_ALL_ASYNC __LC_EXT_OLD_PSW,__LC_SAVE_AREA+40
CREATE_STACK_FRAME __LC_SAVE_AREA+40
mvc SP_PSW(16,%r15),0(%r12) # move user PSW to stack
lg %r12,__LC_THREAD_INFO # load pointer to thread_info struct
tm SP_PSW+1(%r15),0x01 # interrupting from user ?
jz ext_no_vtime
UPDATE_VTIME __LC_EXIT_TIMER,__LC_ASYNC_ENTER_TIMER,__LC_USER_TIMER
UPDATE_VTIME __LC_LAST_UPDATE_TIMER,__LC_EXIT_TIMER,__LC_SYSTEM_TIMER
mvc __LC_LAST_UPDATE_TIMER(8),__LC_ASYNC_ENTER_TIMER
LAST_BREAK
ext_no_vtime:
lg %r9,__LC_THREAD_INFO # load pointer to thread_info struct
HANDLE_SIE_INTERCEPT
TRACE_IRQS_OFF
la %r2,SP_PTREGS(%r15) # address of register-save area
@ -734,7 +751,9 @@ mcck_int_handler:
la %r1,4095 # revalidate r1
spt __LC_CPU_TIMER_SAVE_AREA-4095(%r1) # revalidate cpu timer
lmg %r0,%r15,__LC_GPREGS_SAVE_AREA-4095(%r1)# revalidate gprs
SAVE_ALL_BASE __LC_SAVE_AREA+64
stmg %r11,%r15,__LC_SAVE_AREA+80
larl %r13,system_call
lg %r11,__LC_LAST_BREAK
la %r12,__LC_MCK_OLD_PSW
tm __LC_MCCK_CODE,0x80 # system damage?
jo mcck_int_main # yes -> rest of mcck code invalid
@ -769,7 +788,10 @@ mcck_int_main:
srag %r14,%r14,PAGE_SHIFT
jz 0f
lg %r15,__LC_PANIC_STACK # load panic stack
0: CREATE_STACK_FRAME __LC_MCK_OLD_PSW,__LC_SAVE_AREA+64
0: aghi %r15,-SP_SIZE # make room for registers & psw
CREATE_STACK_FRAME __LC_SAVE_AREA+80
mvc SP_PSW(16,%r15),0(%r12)
lg %r12,__LC_THREAD_INFO # load pointer to thread_info struct
tm __LC_MCCK_CODE+2,0x08 # mwp of old psw valid?
jno mcck_no_vtime # no -> no timer update
tm SP_PSW+1(%r15),0x01 # interrupting from user ?
@ -777,8 +799,8 @@ mcck_int_main:
UPDATE_VTIME __LC_EXIT_TIMER,__LC_MCCK_ENTER_TIMER,__LC_USER_TIMER
UPDATE_VTIME __LC_LAST_UPDATE_TIMER,__LC_EXIT_TIMER,__LC_SYSTEM_TIMER
mvc __LC_LAST_UPDATE_TIMER(8),__LC_MCCK_ENTER_TIMER
LAST_BREAK
mcck_no_vtime:
lg %r9,__LC_THREAD_INFO # load pointer to thread_info struct
la %r2,SP_PTREGS(%r15) # load pt_regs
brasl %r14,s390_do_machine_check
tm SP_PSW+1(%r15),0x01 # returning to user ?
@ -789,7 +811,7 @@ mcck_no_vtime:
xc __SF_BACKCHAIN(8,%r1),__SF_BACKCHAIN(%r1) # clear back chain
lgr %r15,%r1
stosm __SF_EMPTY(%r15),0x04 # turn dat on
tm __TI_flags+7(%r9),_TIF_MCCK_PENDING
tm __TI_flags+7(%r12),_TIF_MCCK_PENDING
jno mcck_return
HANDLE_SIE_INTERCEPT
TRACE_IRQS_OFF
@ -803,6 +825,7 @@ mcck_return:
jno 0f
stpt __LC_EXIT_TIMER
0: lpswe __LC_RETURN_MCCK_PSW # back to caller
mcck_done:
/*
* Restart interruption handler, kick starter for additional CPUs
@ -858,14 +881,14 @@ stack_overflow:
lg %r15,__LC_PANIC_STACK # change to panic stack
aghi %r15,-SP_SIZE
mvc SP_PSW(16,%r15),0(%r12) # move user PSW to stack
stmg %r0,%r11,SP_R0(%r15) # store gprs %r0-%r11 to kernel stack
stmg %r0,%r10,SP_R0(%r15) # store gprs %r0-%r10 to kernel stack
la %r1,__LC_SAVE_AREA
chi %r12,__LC_SVC_OLD_PSW
je 0f
chi %r12,__LC_PGM_OLD_PSW
je 0f
la %r1,__LC_SAVE_AREA+32
0: mvc SP_R12(32,%r15),0(%r1) # move %r12-%r15 to stack
la %r1,__LC_SAVE_AREA+40
0: mvc SP_R11(40,%r15),0(%r1) # move %r11-%r15 to stack
mvc SP_ARGS(8,%r15),__LC_LAST_BREAK
xc __SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15) # clear back chain
la %r2,SP_PTREGS(%r15) # load pt_regs
@ -920,21 +943,23 @@ cleanup_system_call:
je 0f
mvc __LC_SYNC_ENTER_TIMER(8),__LC_ASYNC_ENTER_TIMER
0: cghi %r12,__LC_MCK_OLD_PSW
la %r12,__LC_SAVE_AREA+64
la %r12,__LC_SAVE_AREA+80
je 0f
la %r12,__LC_SAVE_AREA+32
la %r12,__LC_SAVE_AREA+40
0: clc __LC_RETURN_PSW+8(8),BASED(cleanup_system_call_insn+16)
jhe cleanup_vtime
clc __LC_RETURN_PSW+8(8),BASED(cleanup_system_call_insn)
jh 0f
mvc __LC_SAVE_AREA(32),0(%r12)
0: stg %r13,8(%r12)
stg %r12,__LC_SAVE_AREA+96 # argh
SAVE_ALL_SYNC __LC_SVC_OLD_PSW,__LC_SAVE_AREA
CREATE_STACK_FRAME __LC_SVC_OLD_PSW,__LC_SAVE_AREA
lg %r12,__LC_SAVE_AREA+96 # argh
stg %r15,24(%r12)
llgh %r7,__LC_SVC_INT_CODE
mvc __LC_SAVE_AREA(40),0(%r12)
0: lg %r15,__LC_KERNEL_STACK # problem state -> load ksp
aghi %r15,-SP_SIZE # make room for registers & psw
stg %r15,32(%r12)
stg %r11,0(%r12)
CREATE_STACK_FRAME __LC_SAVE_AREA
mvc SP_PSW(16,%r15),__LC_SVC_OLD_PSW
mvc SP_ILC(4,%r15),__LC_SVC_ILC
stg %r7,SP_ARGS(%r15)
mvc 8(8,%r12),__LC_THREAD_INFO
cleanup_vtime:
clc __LC_RETURN_PSW+8(8),BASED(cleanup_system_call_insn+24)
jhe cleanup_stime
@ -945,7 +970,11 @@ cleanup_stime:
UPDATE_VTIME __LC_LAST_UPDATE_TIMER,__LC_EXIT_TIMER,__LC_SYSTEM_TIMER
cleanup_update:
mvc __LC_LAST_UPDATE_TIMER(8),__LC_SYNC_ENTER_TIMER
mvc __LC_RETURN_PSW+8(8),BASED(cleanup_table_system_call+8)
srag %r12,%r11,23
lg %r12,__LC_THREAD_INFO
jz 0f
stg %r11,__TI_last_break(%r12)
0: mvc __LC_RETURN_PSW+8(8),BASED(cleanup_table_system_call+8)
la %r12,__LC_RETURN_PSW
br %r14
cleanup_system_call_insn:
@ -972,11 +1001,11 @@ cleanup_sysc_restore:
mvc __LC_EXIT_TIMER(8),__LC_ASYNC_ENTER_TIMER
0: mvc __LC_RETURN_PSW(16),SP_PSW(%r15)
cghi %r12,__LC_MCK_OLD_PSW
la %r12,__LC_SAVE_AREA+64
la %r12,__LC_SAVE_AREA+80
je 1f
la %r12,__LC_SAVE_AREA+32
1: mvc 0(32,%r12),SP_R12(%r15)
lmg %r0,%r11,SP_R0(%r15)
la %r12,__LC_SAVE_AREA+40
1: mvc 0(40,%r12),SP_R11(%r15)
lmg %r0,%r10,SP_R0(%r15)
lg %r15,SP_R15(%r15)
2: la %r12,__LC_RETURN_PSW
br %r14
@ -997,8 +1026,8 @@ cleanup_io_restore:
jhe 0f
mvc __LC_EXIT_TIMER(8),__LC_MCCK_ENTER_TIMER
0: mvc __LC_RETURN_PSW(16),SP_PSW(%r15)
mvc __LC_SAVE_AREA+64(32),SP_R12(%r15)
lmg %r0,%r11,SP_R0(%r15)
mvc __LC_SAVE_AREA+80(40),SP_R11(%r15)
lmg %r0,%r10,SP_R0(%r15)
lg %r15,SP_R15(%r15)
1: la %r12,__LC_RETURN_PSW
br %r14
@ -1010,13 +1039,6 @@ cleanup_io_restore_insn:
* Integer constants
*/
.align 4
.Lconst:
.Lnr_syscalls: .long NR_syscalls
.L0x0130: .short 0x130
.L0x0140: .short 0x140
.L0x0150: .short 0x150
.L0x0160: .short 0x160
.L0x0170: .short 0x170
.Lcritical_start:
.quad __critical_start
.Lcritical_end:

68
arch/s390/kernel/ptrace.c
View file

@ -57,6 +57,7 @@
enum s390_regset {
REGSET_GENERAL,
REGSET_FP,
REGSET_LAST_BREAK,
REGSET_GENERAL_EXTENDED,
};
@ -381,6 +382,10 @@ long arch_ptrace(struct task_struct *child, long request, long addr, long data)
copied += sizeof(unsigned long);
}
return 0;
case PTRACE_GET_LAST_BREAK:
put_user(task_thread_info(child)->last_break,
(unsigned long __user *) data);
return 0;
default:
/* Removing high order bit from addr (only for 31 bit). */
addr &= PSW_ADDR_INSN;
@ -633,6 +638,10 @@ long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
copied += sizeof(unsigned int);
}
return 0;
case PTRACE_GET_LAST_BREAK:
put_user(task_thread_info(child)->last_break,
(unsigned int __user *) data);
return 0;
}
return compat_ptrace_request(child, request, addr, data);
}
@ -797,6 +806,28 @@ static int s390_fpregs_set(struct task_struct *target,
return rc;
}
#ifdef CONFIG_64BIT
static int s390_last_break_get(struct task_struct *target,
const struct user_regset *regset,
unsigned int pos, unsigned int count,
void *kbuf, void __user *ubuf)
{
if (count > 0) {
if (kbuf) {
unsigned long *k = kbuf;
*k = task_thread_info(target)->last_break;
} else {
unsigned long __user *u = ubuf;
if (__put_user(task_thread_info(target)->last_break, u))
return -EFAULT;
}
}
return 0;
}
#endif
static const struct user_regset s390_regsets[] = {
[REGSET_GENERAL] = {
.core_note_type = NT_PRSTATUS,
@ -814,6 +845,15 @@ static const struct user_regset s390_regsets[] = {
.get = s390_fpregs_get,
.set = s390_fpregs_set,
},
#ifdef CONFIG_64BIT
[REGSET_LAST_BREAK] = {
.core_note_type = NT_S390_LAST_BREAK,
.n = 1,
.size = sizeof(long),
.align = sizeof(long),
.get = s390_last_break_get,
},
#endif
};
static const struct user_regset_view user_s390_view = {
@ -948,6 +988,27 @@ static int s390_compat_regs_high_set(struct task_struct *target,
return rc;
}
static int s390_compat_last_break_get(struct task_struct *target,
const struct user_regset *regset,
unsigned int pos, unsigned int count,
void *kbuf, void __user *ubuf)
{
compat_ulong_t last_break;
if (count > 0) {
last_break = task_thread_info(target)->last_break;
if (kbuf) {
unsigned long *k = kbuf;
*k = last_break;
} else {
unsigned long __user *u = ubuf;
if (__put_user(last_break, u))
return -EFAULT;
}
}
return 0;
}
static const struct user_regset s390_compat_regsets[] = {
[REGSET_GENERAL] = {
.core_note_type = NT_PRSTATUS,
@ -965,6 +1026,13 @@ static const struct user_regset s390_compat_regsets[] = {
.get = s390_fpregs_get,
.set = s390_fpregs_set,
},
[REGSET_LAST_BREAK] = {
.core_note_type = NT_S390_LAST_BREAK,
.n = 1,
.size = sizeof(long),
.align = sizeof(long),
.get = s390_compat_last_break_get,
},
[REGSET_GENERAL_EXTENDED] = {
.core_note_type = NT_S390_HIGH_GPRS,
.n = sizeof(s390_compat_regs_high) / sizeof(compat_long_t),

2
arch/s390/kernel/signal.c
View file

@ -313,6 +313,7 @@ static int setup_frame(int sig, struct k_sigaction *ka,
To avoid breaking binary compatibility, they are passed as args. */
regs->gprs[4] = current->thread.trap_no;
regs->gprs[5] = current->thread.prot_addr;
regs->gprs[6] = task_thread_info(current)->last_break;
/* Place signal number on stack to allow backtrace from handler. */
if (__put_user(regs->gprs[2], (int __user *) &frame->signo))
@ -376,6 +377,7 @@ static int setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
regs->gprs[2] = map_signal(sig);
regs->gprs[3] = (unsigned long) &frame->info;
regs->gprs[4] = (unsigned long) &frame->uc;
regs->gprs[5] = task_thread_info(current)->last_break;
return 0;
give_sigsegv:

1
include/linux/elf.h
View file

@ -394,6 +394,7 @@ typedef struct elf64_shdr {
#define NT_S390_TODPREG 0x303 /* s390 TOD programmable register */
#define NT_S390_CTRS 0x304 /* s390 control registers */
#define NT_S390_PREFIX 0x305 /* s390 prefix register */
#define NT_S390_LAST_BREAK 0x306 /* s390 breaking event address */
/* Note header in a PT_NOTE section */