[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/entry64.S b/arch/s390/kernel/entry64.S
index 7ff07d3..e349075 100644
--- a/arch/s390/kernel/entry64.S
+++ b/arch/s390/kernel/entry64.S
@@ -50,11 +50,11 @@
STACK_SIZE = 1 << STACK_SHIFT
_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)
_TIF_EXIT_SIE = (_TIF_SIGPENDING | _TIF_NEED_RESCHED | _TIF_MCCK_PENDING)
#define BASED(name) name-system_call(%r13)
@@ -248,9 +248,10 @@
sysc_saveall:
SAVE_ALL_SVC __LC_SVC_OLD_PSW,__LC_SAVE_AREA
CREATE_STACK_FRAME __LC_SAVE_AREA
+ lg %r12,__LC_THREAD_INFO # load pointer to thread_info struct
mvc SP_PSW(16,%r15),__LC_SVC_OLD_PSW
mvc SP_SVC_CODE(4,%r15),__LC_SVC_ILC
- lg %r12,__LC_THREAD_INFO # load pointer to thread_info struct
+ oi __TI_flags+7(%r12),_TIF_SYSCALL
sysc_vtime:
UPDATE_VTIME __LC_EXIT_TIMER,__LC_SYNC_ENTER_TIMER,__LC_USER_TIMER
sysc_stime:
@@ -276,7 +277,7 @@
larl %r10,sys_call_table_emu # use 31 bit emulation system calls
sysc_noemu:
#endif
- tm __TI_flags+6(%r12),_TIF_SYSCALL
+ tm __TI_flags+6(%r12),_TIF_TRACE >> 8
mvc SP_ARGS(8,%r15),SP_R7(%r15)
lgf %r8,0(%r7,%r10) # load address of system call routine
jnz sysc_tracesys
@@ -286,23 +287,19 @@
sysc_return:
LOCKDEP_SYS_EXIT
sysc_tif:
+ tm SP_PSW+1(%r15),0x01 # returning to user ?
+ jno sysc_restore
tm __TI_flags+7(%r12),_TIF_WORK_SVC
jnz sysc_work # there is work to do (signals etc.)
+ ni __TI_flags+7(%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 ?
- jno sysc_restore
-
-#
# One of the work bits is on. Find out which one.
#
-sysc_work_tif:
+sysc_work:
tm __TI_flags+7(%r12),_TIF_MCCK_PENDING
jo sysc_mcck_pending
tm __TI_flags+7(%r12),_TIF_NEED_RESCHED
@@ -311,8 +308,6 @@
jo sysc_sigpending
tm __TI_flags+7(%r12),_TIF_NOTIFY_RESUME
jo sysc_notify_resume
- tm __TI_flags+7(%r12),_TIF_RESTART_SVC
- jo sysc_restart
tm __TI_flags+7(%r12),_TIF_PER_TRAP
jo sysc_singlestep
j sysc_return # beware of critical section cleanup
@@ -338,11 +333,15 @@
ni __TI_flags+7(%r12),255-_TIF_PER_TRAP # clear TIF_PER_TRAP
la %r2,SP_PTREGS(%r15) # load pt_regs
brasl %r14,do_signal # call do_signal
- tm __TI_flags+7(%r12),_TIF_RESTART_SVC
- jo sysc_restart
- tm __TI_flags+7(%r12),_TIF_PER_TRAP
- jo sysc_singlestep
- j sysc_return
+ tm __TI_flags+7(%r12),_TIF_SYSCALL
+ jno sysc_return
+ lmg %r2,%r6,SP_R2(%r15) # load svc arguments
+ lghi %r7,0 # svc 0 returns -ENOSYS
+ lh %r1,SP_SVC_CODE+2(%r15) # load new svc number
+ cghi %r1,NR_syscalls
+ jnl sysc_nr_ok # invalid svc number -> do svc 0
+ slag %r7,%r1,2
+ j sysc_nr_ok # restart svc
#
# _TIF_NOTIFY_RESUME is set, call do_notify_resume
@@ -353,24 +352,10 @@
jg do_notify_resume # call do_notify_resume
#
-# _TIF_RESTART_SVC is set, set up registers and restart svc
-#
-sysc_restart:
- ni __TI_flags+7(%r12),255-_TIF_RESTART_SVC # clear TIF_RESTART_SVC
- lmg %r2,%r6,SP_R2(%r15) # load svc arguments
- lghi %r7,0 # svc 0 returns -ENOSYS
- lh %r1,SP_SVC_CODE+2(%r15) # load new svc number
- cghi %r1,NR_syscalls
- jnl sysc_nr_ok # invalid svc number -> do svc 0
- slag %r7,%r1,2
- j sysc_nr_ok # restart svc
-
-#
# _TIF_PER_TRAP is set, call do_per_trap
#
sysc_singlestep:
- ni __TI_flags+7(%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+7(%r12),255-(_TIF_SYSCALL | _TIF_PER_TRAP)
la %r2,SP_PTREGS(%r15) # address of register-save area
larl %r14,sysc_return # load adr. of system return
jg do_per_trap
@@ -397,7 +382,7 @@
basr %r14,%r8 # call sys_xxx
stg %r2,SP_R2(%r15) # store return value
sysc_tracenogo:
- tm __TI_flags+6(%r12),_TIF_SYSCALL
+ tm __TI_flags+6(%r12),_TIF_TRACE >> 8
jz sysc_return
la %r2,SP_PTREGS(%r15) # load pt_regs
larl %r14,sysc_return # return point is sysc_return
@@ -470,7 +455,6 @@
jnz 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(16,%r15),__LC_PGM_OLD_PSW
lg %r12,__LC_THREAD_INFO # load pointer to thread_info struct
HANDLE_SIE_INTERCEPT
@@ -550,9 +534,10 @@
pgm_svcper:
SAVE_ALL_PGM __LC_SVC_OLD_PSW,__LC_SAVE_AREA
CREATE_STACK_FRAME __LC_SAVE_AREA
+ lg %r12,__LC_THREAD_INFO # load pointer to thread_info struct
mvc SP_PSW(16,%r15),__LC_SVC_OLD_PSW
mvc SP_SVC_CODE(4,%r15),__LC_SVC_ILC
- lg %r12,__LC_THREAD_INFO # load pointer to thread_info struct
+ oi __TI_flags+7(%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
@@ -561,7 +546,6 @@
mvc __THREAD_per_cause(2,%r8),__LC_PER_CAUSE
mvc __THREAD_per_address(8,%r8),__LC_PER_ADDRESS
mvc __THREAD_per_paid(1,%r8),__LC_PER_PAID
- oi __TI_flags+7(%r12),_TIF_PER_TRAP # set TIF_PER_TRAP
stosm __SF_EMPTY(%r15),0x03 # reenable interrupts
lmg %r2,%r6,SP_R2(%r15) # load svc arguments
j sysc_do_svc
@@ -571,7 +555,6 @@
#
kernel_per:
REENABLE_IRQS
- xc SP_SVC_CODE(4,%r15),SP_SVC_CODE(%r15) # clear svc number
la %r2,SP_PTREGS(%r15) # address of register-save area
brasl %r14,do_per_trap
j pgm_exit
@@ -972,9 +955,11 @@
stg %r15,32(%r12)
stg %r11,0(%r12)
CREATE_STACK_FRAME __LC_SAVE_AREA
+ mvc 8(8,%r12),__LC_THREAD_INFO
+ lg %r12,__LC_THREAD_INFO
mvc SP_PSW(16,%r15),__LC_SVC_OLD_PSW
mvc SP_SVC_CODE(4,%r15),__LC_SVC_ILC
- mvc 8(8,%r12),__LC_THREAD_INFO
+ oi __TI_flags+7(%r12),_TIF_SYSCALL
cleanup_vtime:
clc __LC_RETURN_PSW+8(8),BASED(cleanup_system_call_insn+24)
jhe cleanup_stime