[S390] add TIF_SYSCALL thread flag
Add an explicit TIF_SYSCALL bit that indicates if a task is inside
a system call. The svc_code in the pt_regs structure is now only
valid if TIF_SYSCALL is set. With this definition TIF_RESTART_SVC
can be replaced with TIF_SYSCALL. Overall do_signal is a bit more
readable and it saves a few lines of code.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/arch/s390/kernel/entry.S b/arch/s390/kernel/entry.S
index afe3685..b131570 100644
--- a/arch/s390/kernel/entry.S
+++ b/arch/s390/kernel/entry.S
@@ -47,11 +47,11 @@
SP_SIZE = STACK_FRAME_OVERHEAD + __PT_SIZE
_TIF_WORK_SVC = (_TIF_SIGPENDING | _TIF_NOTIFY_RESUME | _TIF_NEED_RESCHED | \
- _TIF_MCCK_PENDING | _TIF_RESTART_SVC | _TIF_PER_TRAP )
+ _TIF_MCCK_PENDING | _TIF_PER_TRAP )
_TIF_WORK_INT = (_TIF_SIGPENDING | _TIF_NOTIFY_RESUME | _TIF_NEED_RESCHED | \
_TIF_MCCK_PENDING)
-_TIF_SYSCALL = (_TIF_SYSCALL_TRACE>>8 | _TIF_SYSCALL_AUDIT>>8 | \
- _TIF_SECCOMP>>8 | _TIF_SYSCALL_TRACEPOINT>>8)
+_TIF_TRACE = (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_AUDIT | _TIF_SECCOMP | \
+ _TIF_SYSCALL_TRACEPOINT)
STACK_SHIFT = PAGE_SHIFT + THREAD_ORDER
STACK_SIZE = 1 << STACK_SHIFT
@@ -227,9 +227,10 @@
sysc_saveall:
SAVE_ALL_SVC __LC_SVC_OLD_PSW,__LC_SAVE_AREA
CREATE_STACK_FRAME __LC_SAVE_AREA
+ l %r12,__LC_THREAD_INFO # load pointer to thread_info struct
mvc SP_PSW(8,%r15),__LC_SVC_OLD_PSW
mvc SP_SVC_CODE(4,%r15),__LC_SVC_ILC
- l %r12,__LC_THREAD_INFO # load pointer to thread_info struct
+ oi __TI_flags+3(%r12),_TIF_SYSCALL
sysc_vtime:
UPDATE_VTIME __LC_EXIT_TIMER,__LC_SYNC_ENTER_TIMER,__LC_USER_TIMER
sysc_stime:
@@ -248,7 +249,7 @@
sysc_nr_ok:
sll %r7,2 # svc number *4
l %r10,BASED(.Lsysc_table)
- tm __TI_flags+2(%r12),_TIF_SYSCALL
+ tm __TI_flags+2(%r12),_TIF_TRACE >> 8
mvc SP_ARGS(4,%r15),SP_R7(%r15)
l %r8,0(%r7,%r10) # get system call addr.
bnz BASED(sysc_tracesys)
@@ -258,23 +259,19 @@
sysc_return:
LOCKDEP_SYS_EXIT
sysc_tif:
+ tm SP_PSW+1(%r15),0x01 # returning to user ?
+ bno BASED(sysc_restore)
tm __TI_flags+3(%r12),_TIF_WORK_SVC
bnz BASED(sysc_work) # there is work to do (signals etc.)
+ ni __TI_flags+3(%r12),255-_TIF_SYSCALL
sysc_restore:
RESTORE_ALL __LC_RETURN_PSW,1
sysc_done:
#
-# There is work to do, but first we need to check if we return to userspace.
-#
-sysc_work:
- tm SP_PSW+1(%r15),0x01 # returning to user ?
- bno BASED(sysc_restore)
-
-#
# One of the work bits is on. Find out which one.
#
-sysc_work_tif:
+sysc_work:
tm __TI_flags+3(%r12),_TIF_MCCK_PENDING
bo BASED(sysc_mcck_pending)
tm __TI_flags+3(%r12),_TIF_NEED_RESCHED
@@ -283,8 +280,6 @@
bo BASED(sysc_sigpending)
tm __TI_flags+3(%r12),_TIF_NOTIFY_RESUME
bo BASED(sysc_notify_resume)
- tm __TI_flags+3(%r12),_TIF_RESTART_SVC
- bo BASED(sysc_restart)
tm __TI_flags+3(%r12),_TIF_PER_TRAP
bo BASED(sysc_singlestep)
b BASED(sysc_return) # beware of critical section cleanup
@@ -313,11 +308,14 @@
la %r2,SP_PTREGS(%r15) # load pt_regs
l %r1,BASED(.Ldo_signal)
basr %r14,%r1 # call do_signal
- tm __TI_flags+3(%r12),_TIF_RESTART_SVC
- bo BASED(sysc_restart)
- tm __TI_flags+3(%r12),_TIF_PER_TRAP
- bo BASED(sysc_singlestep)
- b BASED(sysc_return)
+ tm __TI_flags+3(%r12),_TIF_SYSCALL
+ bno BASED(sysc_return)
+ lm %r2,%r6,SP_R2(%r15) # load svc arguments
+ xr %r7,%r7 # svc 0 returns -ENOSYS
+ clc SP_SVC_CODE+2(2,%r15),BASED(.Lnr_syscalls+2)
+ bnl BASED(sysc_nr_ok) # invalid svc number -> do svc 0
+ icm %r7,3,SP_SVC_CODE+2(%r15)# load new svc number
+ b BASED(sysc_nr_ok) # restart svc
#
# _TIF_NOTIFY_RESUME is set, call do_notify_resume
@@ -328,25 +326,11 @@
la %r14,BASED(sysc_return)
br %r1 # call do_notify_resume
-
-#
-# _TIF_RESTART_SVC is set, set up registers and restart svc
-#
-sysc_restart:
- ni __TI_flags+3(%r12),255-_TIF_RESTART_SVC # clear TIF_RESTART_SVC
- lm %r2,%r6,SP_R2(%r15) # load svc arguments
- xr %r7,%r7 # svc 0 returns -ENOSYS
- clc SP_SVC_CODE+2(%r15),BASED(.Lnr_syscalls+2)
- bnl BASED(sysc_nr_ok) # invalid svc number -> do svc 0
- icm %r7,3,SP_SVC_CODE+2(%r15)# load new svc number
- b BASED(sysc_nr_ok) # restart svc
-
#
# _TIF_PER_TRAP is set, call do_per_trap
#
sysc_singlestep:
- ni __TI_flags+3(%r12),255-_TIF_PER_TRAP # clear TIF_PER_TRAP
- xc SP_SVC_CODE(4,%r15),SP_SVC_CODE(%r15) # clear svc code
+ ni __TI_flags+3(%r12),255-(_TIF_SYSCALL | _TIF_PER_TRAP)
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
@@ -376,7 +360,7 @@
basr %r14,%r8 # call sys_xxx
st %r2,SP_R2(%r15) # store return value
sysc_tracenogo:
- tm __TI_flags+2(%r12),_TIF_SYSCALL
+ tm __TI_flags+2(%r12),_TIF_TRACE >> 8
bz BASED(sysc_return)
l %r1,BASED(.Ltrace_exit)
la %r2,SP_PTREGS(%r15) # load pt_regs
@@ -454,7 +438,6 @@
bnz BASED(pgm_per) # got per exception -> special case
SAVE_ALL_PGM __LC_PGM_OLD_PSW,__LC_SAVE_AREA
CREATE_STACK_FRAME __LC_SAVE_AREA
- xc SP_SVC_CODE(4,%r15),SP_SVC_CODE(%r15)
mvc SP_PSW(8,%r15),__LC_PGM_OLD_PSW
l %r12,__LC_THREAD_INFO # load pointer to thread_info struct
tm SP_PSW+1(%r15),0x01 # interrupting from user ?
@@ -530,9 +513,10 @@
pgm_svcper:
SAVE_ALL_PGM __LC_SVC_OLD_PSW,__LC_SAVE_AREA
CREATE_STACK_FRAME __LC_SAVE_AREA
+ l %r12,__LC_THREAD_INFO # load pointer to thread_info struct
mvc SP_PSW(8,%r15),__LC_SVC_OLD_PSW
mvc SP_SVC_CODE(4,%r15),__LC_SVC_ILC
- l %r12,__LC_THREAD_INFO # load pointer to thread_info struct
+ oi __TI_flags+3(%r12),(_TIF_SYSCALL | _TIF_PER_TRAP)
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
@@ -540,7 +524,6 @@
mvc __THREAD_per_cause(2,%r8),__LC_PER_CAUSE
mvc __THREAD_per_address(4,%r8),__LC_PER_ADDRESS
mvc __THREAD_per_paid(1,%r8),__LC_PER_PAID
- oi __TI_flags+3(%r12),_TIF_PER_TRAP # set TIF_PER_TRAP
stosm __SF_EMPTY(%r15),0x03 # reenable interrupts
lm %r2,%r6,SP_R2(%r15) # load svc arguments
b BASED(sysc_do_svc)
@@ -550,7 +533,6 @@
#
kernel_per:
REENABLE_IRQS
- xc SP_SVC_CODE(4,%r15),SP_SVC_CODE(%r15)
la %r2,SP_PTREGS(%r15) # address of register-save area
l %r1,BASED(.Lhandle_per) # load adr. of per handler
basr %r14,%r1 # branch to do_single_step
@@ -965,9 +947,11 @@
s %r15,BASED(.Lc_spsize) # make room for registers & psw
st %r15,12(%r12)
CREATE_STACK_FRAME __LC_SAVE_AREA
+ mvc 0(4,%r12),__LC_THREAD_INFO
+ l %r12,__LC_THREAD_INFO
mvc SP_PSW(8,%r15),__LC_SVC_OLD_PSW
mvc SP_SVC_CODE(4,%r15),__LC_SVC_ILC
- mvc 0(4,%r12),__LC_THREAD_INFO
+ oi __TI_flags+3(%r12),_TIF_SYSCALL
cleanup_vtime:
clc __LC_RETURN_PSW+4(4),BASED(cleanup_system_call_insn+12)
bhe BASED(cleanup_stime)