Commit 1f515434 authored by Andrew Morton's avatar Andrew Morton Committed by Linus Torvalds

[PATCH] s390: simplify single stepped svc code

From: Martin Schwidefsky <schwidefsky@de.ibm.com>

From: Martin Schwidefsky <schwidefsky@de.ibm.com>

Introduce a TIF_SINGLE_STEP bit that causes do_debugger_trap to get called
at the end of a system call.  This way some code duplication in the program
check handler can get removed.
Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent d8150491
......@@ -48,7 +48,8 @@ SP_ILC = STACK_FRAME_OVERHEAD + __PT_ILC
SP_TRAP = STACK_FRAME_OVERHEAD + __PT_TRAP
SP_SIZE = STACK_FRAME_OVERHEAD + __PT_SIZE
_TIF_WORK_SVC = (_TIF_SIGPENDING | _TIF_NEED_RESCHED | _TIF_RESTART_SVC)
_TIF_WORK_SVC = (_TIF_SIGPENDING | _TIF_NEED_RESCHED | \
_TIF_RESTART_SVC | _TIF_SINGLE_STEP )
_TIF_WORK_INT = (_TIF_SIGPENDING | _TIF_NEED_RESCHED)
#define BASED(name) name-system_call(%r13)
......@@ -230,6 +231,7 @@ system_call:
lh %r7,0x8a # get svc number from lowcore
sysc_enter:
GET_THREAD_INFO # load pointer to task_struct to R9
sysc_do_svc:
sla %r7,2 # *4 and test for svc 0
bnz BASED(sysc_nr_ok) # svc number > 0
# svc 0: system call number in %r1
......@@ -265,7 +267,6 @@ sysc_work_loop:
bz BASED(sysc_leave) # there is no work to do
#
# One of the work bits is on. Find out which one.
# Checked are: _TIF_SIGPENDING and _TIF_NEED_RESCHED
#
sysc_work:
tm __TI_flags+3(%r9),_TIF_NEED_RESCHED
......@@ -274,6 +275,8 @@ sysc_work:
bo BASED(sysc_sigpending)
tm __TI_flags+3(%r9),_TIF_RESTART_SVC
bo BASED(sysc_restart)
tm __TI_flags+3(%r9),_TIF_SINGLE_STEP
bo BASED(sysc_singlestep)
b BASED(sysc_leave)
#
......@@ -307,6 +310,17 @@ sysc_restart:
lm %r2,%r6,SP_R2(%r15) # load svc arguments
b BASED(sysc_do_restart) # restart svc
#
# _TIF_SINGLE_STEP is set, call do_debugger_trap
#
sysc_singlestep:
ni __TI_flags+3(%r9),255-_TIF_SINGLE_STEP # clear TIF_SINGLE_STEP
mvi SP_TRAP+1(%r15),0x28 # set trap indication to pgm check
la %r2,SP_PTREGS(%r15) # address of register-save area
l %r1,BASED(.Lhandle_per) # load adr. of per handler
la %r14,BASED(sysc_return) # load adr. of system return
br %r1 # branch to do_debugger_trap
__critical_end:
#
......@@ -504,66 +518,9 @@ pgm_svcper:
mvc __THREAD_per+__PER_atmid(2,%r1),__LC_PER_ATMID
mvc __THREAD_per+__PER_address(4,%r1),__LC_PER_ADDRESS
mvc __THREAD_per+__PER_access_id(1,%r1),__LC_PER_ACCESS_ID
oi __TI_flags+3(%r9),_TIF_SINGLE_STEP # set TIF_SINGLE_STEP
stosm 24(%r15),0x03 # reenable interrupts
sla %r7,2 # *4 and test for svc 0
bnz BASED(pgm_svcstd) # svc number > 0 ?
# svc 0: system call number in %r1
cl %r1,BASED(.Lnr_syscalls)
bnl BASED(pgm_svcstd)
lr %r7,%r1 # copy svc number to %r7
sla %r7,2 # *4
pgm_svcstd:
mvc SP_ARGS(4,%r15),SP_R7(%r15)
tm __TI_flags+3(%r9),(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT)
l %r8,sys_call_table-system_call(%r7,%r13) # get system call addr.
bnz BASED(pgm_tracesys)
basr %r14,%r8 # call sys_xxxx
st %r2,SP_R2(%r15) # store return value (change R2 on stack)
# ATTENTION: check sys_execve_glue before
# changing anything here !!
pgm_svcret:
tm __TI_flags+3(%r9),_TIF_SIGPENDING
bno BASED(pgm_svcper_nosig)
la %r2,SP_PTREGS(%r15) # load pt_regs
sr %r3,%r3 # clear *oldset
l %r1,BASED(.Ldo_signal)
basr %r14,%r1 # call do_signal
pgm_svcper_nosig:
mvi SP_TRAP+3(%r15),0x28 # set trap indication to pgm check
la %r2,SP_PTREGS(15) # address of register-save area
l %r1,BASED(.Lhandle_per) # load adr. of per handler
la %r14,BASED(sysc_return) # load adr. of system return
br %r1 # branch to do_debugger_trap
#
# call trace before and after sys_call
#
pgm_tracesys:
l %r1,BASED(.Ltrace)
la %r2,SP_PTREGS(%r15) # load pt_regs
la %r3,0
srl %r7,2
st %r7,SP_R2(%r15)
basr %r14,%r1
clc SP_R2(4,%r15),BASED(.Lnr_syscalls)
bnl BASED(pgm_svc_nogo)
l %r7,SP_R2(%r15) # strace changed the syscall
sll %r7,2
l %r8,sys_call_table-system_call(%r7,%r13)
pgm_svc_go:
lm %r3,%r6,SP_R3(%r15)
l %r2,SP_ORIG_R2(%r15)
basr %r14,%r8 # call sys_xxx
st %r2,SP_R2(%r15) # store return value
pgm_svc_nogo:
tm __TI_flags+3(%r9),(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT)
bz BASED(pgm_svcret)
l %r1,BASED(.Ltrace)
la %r2,SP_PTREGS(%r15) # load pt_regs
la %r3,1
la %r14,BASED(pgm_svcret)
br %r1
b BASED(sysc_do_svc)
/*
* IO interrupt handler routine
......
......@@ -48,7 +48,8 @@ SP_ILC = STACK_FRAME_OVERHEAD + __PT_ILC
SP_TRAP = STACK_FRAME_OVERHEAD + __PT_TRAP
SP_SIZE = STACK_FRAME_OVERHEAD + __PT_SIZE
_TIF_WORK_SVC = (_TIF_SIGPENDING | _TIF_NEED_RESCHED | _TIF_RESTART_SVC)
_TIF_WORK_SVC = (_TIF_SIGPENDING | _TIF_NEED_RESCHED | \
_TIF_RESTART_SVC | _TIF_SINGLE_STEP )
_TIF_WORK_INT = (_TIF_SIGPENDING | _TIF_NEED_RESCHED)
/*
......@@ -214,6 +215,7 @@ system_call:
llgh %r7,__LC_SVC_INT_CODE # get svc number from lowcore
sysc_enter:
GET_THREAD_INFO # load pointer to task_struct to R9
sysc_do_svc:
slag %r7,%r7,2 # *4 and test for svc 0
jnz sysc_nr_ok
# svc 0: system call number in %r1
......@@ -257,7 +259,6 @@ sysc_work_loop:
jz sysc_leave # there is no work to do
#
# One of the work bits is on. Find out which one.
# Checked are: _TIF_SIGPENDING and _TIF_NEED_RESCHED
#
sysc_work:
tm __TI_flags+7(%r9),_TIF_NEED_RESCHED
......@@ -266,6 +267,8 @@ sysc_work:
jo sysc_sigpending
tm __TI_flags+7(%r9),_TIF_RESTART_SVC
jo sysc_restart
tm __TI_flags+7(%r9),_TIF_SINGLE_STEP
jo sysc_singlestep
j sysc_leave
#
......@@ -297,6 +300,17 @@ sysc_restart:
lmg %r2,%r6,SP_R2(%r15) # load svc arguments
j sysc_do_restart # restart svc
#
# _TIF_SINGLE_STEP is set, call do_debugger_trap
#
sysc_singlestep:
ni __TI_flags+7(%r9),255-_TIF_SINGLE_STEP # clear TIF_SINGLE_STEP
mvi SP_TRAP+1(%r15),0x28 # set trap indication to pgm check
la %r2,SP_PTREGS(%r15) # address of register-save area
larl %r14,sysc_return # load adr. of system return
jg do_debugger_trap # branch to do_debugger_trap
__critical_end:
#
......@@ -537,70 +551,9 @@ pgm_svcper:
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
stosm 48(%r15),0x03 # reenable interrupts
slag %r7,%r7,2 # *4 and test for svc 0
jnz pgm_svcstd
# svc 0: system call number in %r1
lghi %r0,NR_syscalls
clr %r1,%r0
slag %r7,%r1,2
pgm_svcstd:
mvc SP_ARGS(8,%r15),SP_R7(%r15)
larl %r10,sys_call_table
#ifdef CONFIG_S390_SUPPORT
tm SP_PSW+3(%r15),0x01 # are we running in 31 bit mode ?
jo pgm_svcper_noemu
larl %r10,sys_call_table_emu # use 31 bit emulation system calls
pgm_svcper_noemu:
#endif
tm __TI_flags+7(%r9),(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT)
lgf %r8,0(%r7,%r10) # load address of system call routine
jnz pgm_tracesys
basr %r14,%r8 # call sys_xxxx
stg %r2,SP_R2(%r15) # store return value (change R2 on stack)
# ATTENTION: check sys_execve_glue before
# changing anything here !!
pgm_svcret:
tm __TI_flags+7(%r9),_TIF_SIGPENDING
jno pgm_svcper_nosig
la %r2,SP_PTREGS(%r15) # load pt_regs
sgr %r3,%r3 # clear *oldset
brasl %r14,do_signal
pgm_svcper_nosig:
lhi %r0,__LC_PGM_OLD_PSW # set trap indication back to pgm_chk
st %r0,SP_TRAP(%r15)
la %r2,SP_PTREGS(15) # address of register-save area
larl %r14,sysc_return # load adr. of system return
jg do_debugger_trap
#
# call trace before and after sys_call
#
pgm_tracesys:
la %r2,SP_PTREGS(%r15) # load pt_regs
la %r3,0
srlg %r7,%r7,2
stg %r7,SP_R2(%r15)
brasl %r14,syscall_trace
lghi %r0,NR_syscalls
clg %r0,SP_R2(%r15)
jnh pgm_svc_nogo
lg %r7,SP_R2(%r15)
sllg %r7,%r7,2 # strace wants to change the syscall
lgf %r8,0(%r7,%r10)
pgm_svc_go:
lmg %r3,%r6,SP_R3(%r15)
lg %r2,SP_ORIG_R2(%r15)
basr %r14,%r8 # call sys_xxx
stg %r2,SP_R2(%r15) # store return value
pgm_svc_nogo:
tm __TI_flags+7(%r9),(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT)
jz pgm_svcret
la %r2,SP_PTREGS(%r15) # load pt_regs
la %r3,1
larl %r14,pgm_svcret # return point is sysc_return
jg syscall_trace
j sysc_do_svc
/*
* IO interrupt handler routine
......
......@@ -85,6 +85,7 @@ static inline struct thread_info *current_thread_info(void)
#define TIF_NEED_RESCHED 3 /* rescheduling necessary */
#define TIF_RESTART_SVC 4 /* restart svc with new svc number */
#define TIF_SYSCALL_AUDIT 5 /* syscall auditing active */
#define TIF_SINGLE_STEP 6 /* single stepped svc */
#define TIF_USEDFPU 16 /* FPU was used by this task this quantum (SMP) */
#define TIF_POLLING_NRFLAG 17 /* true if poll_idle() is polling
TIF_NEED_RESCHED */
......@@ -96,6 +97,7 @@ static inline struct thread_info *current_thread_info(void)
#define _TIF_NEED_RESCHED (1<<TIF_NEED_RESCHED)
#define _TIF_RESTART_SVC (1<<TIF_RESTART_SVC)
#define _TIF_SYSCALL_AUDIT (1<<TIF_SYSCALL_AUDIT)
#define _TIF_SINGLE_STEP (1<<TIF_SINGLE_STEP)
#define _TIF_USEDFPU (1<<TIF_USEDFPU)
#define _TIF_POLLING_NRFLAG (1<<TIF_POLLING_NRFLAG)
#define _TIF_31BIT (1<<TIF_31BIT)
......
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