1 files changed, 25 insertions, 41 deletions

diff --git a/arch/s390/kernel/entry.S b/arch/s390/kernel/entry.S
index afe3685d30e7..b13157057e02 100644
--- a/arch/s390/kernel/entry.S
+++ b/arch/s390/kernel/entry.S
@@ -47,11 +47,11 @@ SP_SVC_CODE  =	STACK_FRAME_OVERHEAD + __PT_SVC_CODE
 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 @@ ENTRY(system_call)
 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_do_svc:
 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_nr_ok:
 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 @@ sysc_work_tif:
         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 @@ sysc_sigpending:
         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 @@ sysc_notify_resume:
         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 @@ sysc_tracego:
         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 @@ ENTRY(pgm_check_handler)
         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_exit2:
 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 @@ pgm_svcper:
         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 @@ pgm_svcper:
 #
 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 @@ cleanup_system_call:
         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)