1 files changed, 17 insertions, 22 deletions

diff --git a/arch/s390/kernel/entry.S b/arch/s390/kernel/entry.S
index 94feff7d6132..4d5e6f8a7978 100644
--- a/arch/s390/kernel/entry.S
+++ b/arch/s390/kernel/entry.S
@@ -45,6 +45,7 @@ _TIF_TRACE    = (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_AUDIT | _TIF_SECCOMP | \
 
 STACK_SHIFT = PAGE_SHIFT + THREAD_ORDER
 STACK_SIZE  = 1 << STACK_SHIFT
+STACK_INIT  = STACK_SIZE - STACK_FRAME_OVERHEAD - __PT_SIZE
 
 #define BASED(name) name-system_call(%r13)
 
@@ -97,10 +98,10 @@ STACK_SIZE  = 1 << STACK_SHIFT
         sra     %r14,\shift
         jnz     1f
         CHECK_STACK 1<<\shift,\savearea
+        ahi     %r15,-(STACK_FRAME_OVERHEAD + __PT_SIZE)
         j       2f
 1:      l       %r15,\stack             # load target stack
-2:      ahi     %r15,-(STACK_FRAME_OVERHEAD + __PT_SIZE)
-        la      %r11,STACK_FRAME_OVERHEAD(%r15)
+2:      la      %r11,STACK_FRAME_OVERHEAD(%r15)
         .endm
 
         .macro  ADD64 high,low,timer
@@ -150,7 +151,7 @@ ENTRY(__switch_to)
         l       %r4,__THREAD_info(%r2)          # get thread_info of prev
         l       %r5,__THREAD_info(%r3)          # get thread_info of next
         lr      %r15,%r5
-        ahi     %r15,STACK_SIZE                 # end of kernel stack of next
+        ahi     %r15,STACK_INIT                 # end of kernel stack of next
         st      %r3,__LC_CURRENT                # store task struct of next
         st      %r5,__LC_THREAD_INFO            # store thread info of next
         st      %r15,__LC_KERNEL_STACK          # store end of kernel stack
@@ -178,7 +179,6 @@ sysc_stm:
         l       %r13,__LC_SVC_NEW_PSW+4
 sysc_per:
         l       %r15,__LC_KERNEL_STACK
-        ahi     %r15,-(STACK_FRAME_OVERHEAD + __PT_SIZE)
         la      %r11,STACK_FRAME_OVERHEAD(%r15) # pointer to pt_regs
 sysc_vtime:
         UPDATE_VTIME %r8,%r9,__LC_SYNC_ENTER_TIMER
@@ -188,6 +188,7 @@ sysc_vtime:
         mvc     __PT_INT_CODE(4,%r11),__LC_SVC_ILC
 sysc_do_svc:
         oi      __TI_flags+3(%r12),_TIF_SYSCALL
+        l       %r10,__TI_sysc_table(%r12)      # 31 bit system call table
         lh      %r8,__PT_INT_CODE+2(%r11)
         sla     %r8,2                           # shift and test for svc0
         jnz     sysc_nr_ok
@@ -198,7 +199,6 @@ sysc_do_svc:
         lr      %r8,%r1
         sla     %r8,2
 sysc_nr_ok:
-        l       %r10,BASED(.Lsys_call_table)    # 31 bit system call table
         xc      __SF_BACKCHAIN(4,%r15),__SF_BACKCHAIN(%r15)
         st      %r2,__PT_ORIG_GPR2(%r11)
         st      %r7,STACK_FRAME_OVERHEAD(%r15)
@@ -359,11 +359,11 @@ ENTRY(pgm_check_handler)
         tm      __LC_PGM_ILC+3,0x80     # check for per exception
         jnz     pgm_svcper              # -> single stepped svc
 0:      CHECK_STACK STACK_SIZE,__LC_SAVE_AREA_SYNC
+        ahi     %r15,-(STACK_FRAME_OVERHEAD + __PT_SIZE)
         j       2f
 1:      UPDATE_VTIME %r14,%r15,__LC_SYNC_ENTER_TIMER
         l       %r15,__LC_KERNEL_STACK
-2:      ahi     %r15,-(STACK_FRAME_OVERHEAD + __PT_SIZE)
-        la      %r11,STACK_FRAME_OVERHEAD(%r15)
+2:      la      %r11,STACK_FRAME_OVERHEAD(%r15)
         stm     %r0,%r7,__PT_R0(%r11)
         mvc     __PT_R8(32,%r11),__LC_SAVE_AREA_SYNC
         stm     %r8,%r9,__PT_PSW(%r11)
@@ -485,7 +485,6 @@ io_work:
 #
 io_work_user:
         l       %r1,__LC_KERNEL_STACK
-        ahi     %r1,-(STACK_FRAME_OVERHEAD + __PT_SIZE)
         mvc     STACK_FRAME_OVERHEAD(__PT_SIZE,%r1),0(%r11)
         xc      __SF_BACKCHAIN(4,%r1),__SF_BACKCHAIN(%r1)
         la      %r11,STACK_FRAME_OVERHEAD(%r1)
@@ -646,7 +645,6 @@ mcck_skip:
         tm      __PT_PSW+1(%r11),0x01   # returning to user ?
         jno     mcck_return
         l       %r1,__LC_KERNEL_STACK   # switch to kernel stack
-        ahi     %r1,-(STACK_FRAME_OVERHEAD + __PT_SIZE)
         mvc     STACK_FRAME_OVERHEAD(__PT_SIZE,%r1),0(%r11)
         xc      __SF_BACKCHAIN(4,%r1),__SF_BACKCHAIN(%r1)
         la      %r11,STACK_FRAME_OVERHEAD(%r15)
@@ -674,6 +672,7 @@ mcck_panic:
         sra     %r14,PAGE_SHIFT
         jz      0f
         l       %r15,__LC_PANIC_STACK
+        j       mcck_skip
 0:      ahi     %r15,-(STACK_FRAME_OVERHEAD + __PT_SIZE)
         j       mcck_skip
 
@@ -714,12 +713,10 @@ ENTRY(restart_int_handler)
  */
 stack_overflow:
         l       %r15,__LC_PANIC_STACK   # change to panic stack
-        ahi     %r15,-__PT_SIZE         # create pt_regs
-        stm     %r0,%r7,__PT_R0(%r15)
-        stm     %r8,%r9,__PT_PSW(%r15)
+        la      %r11,STACK_FRAME_OVERHEAD(%r15)
+        stm     %r0,%r7,__PT_R0(%r11)
+        stm     %r8,%r9,__PT_PSW(%r11)
         mvc     __PT_R8(32,%r11),0(%r14)
-        lr      %r15,%r11
-        ahi     %r15,-STACK_FRAME_OVERHEAD
         l       %r1,BASED(1f)
         xc      __SF_BACKCHAIN(4,%r15),__SF_BACKCHAIN(%r15)
         lr      %r2,%r11                # pass pointer to pt_regs
@@ -799,15 +796,14 @@ cleanup_system_call:
         mvc     __LC_LAST_UPDATE_TIMER(8),__LC_SYNC_ENTER_TIMER
         # set up saved register 11
         l       %r15,__LC_KERNEL_STACK
-        ahi     %r15,-__PT_SIZE
-        st      %r15,12(%r11)           # r11 pt_regs pointer
+        la      %r9,STACK_FRAME_OVERHEAD(%r15)
+        st      %r9,12(%r11)            # r11 pt_regs pointer
         # fill pt_regs
-        mvc     __PT_R8(32,%r15),__LC_SAVE_AREA_SYNC
-        stm     %r0,%r7,__PT_R0(%r15)
-        mvc     __PT_PSW(8,%r15),__LC_SVC_OLD_PSW
-        mvc     __PT_INT_CODE(4,%r15),__LC_SVC_ILC
+        mvc     __PT_R8(32,%r9),__LC_SAVE_AREA_SYNC
+        stm     %r0,%r7,__PT_R0(%r9)
+        mvc     __PT_PSW(8,%r9),__LC_SVC_OLD_PSW
+        mvc     __PT_INT_CODE(4,%r9),__LC_SVC_ILC
         # setup saved register 15
-        ahi     %r15,-STACK_FRAME_OVERHEAD
         st      %r15,28(%r11)           # r15 stack pointer
         # set new psw address and exit
         l       %r9,BASED(cleanup_table+4)      # sysc_do_svc + 0x80000000
@@ -910,7 +906,6 @@ cleanup_idle_wait:
 .Ltrace_enter:          .long   do_syscall_trace_enter
 .Ltrace_exit:           .long   do_syscall_trace_exit
 .Lschedule_tail:        .long   schedule_tail
-.Lsys_call_table:       .long   sys_call_table
 .Lsysc_per:             .long   sysc_per + 0x80000000
 #ifdef CONFIG_TRACE_IRQFLAGS
 .Lhardirqs_on:          .long   trace_hardirqs_on_caller