1 files changed, 19 insertions, 29 deletions

diff --git a/arch/s390/kernel/entry64.S b/arch/s390/kernel/entry64.S
index 9c837c101297..4c17eece707e 100644
--- a/arch/s390/kernel/entry64.S
+++ b/arch/s390/kernel/entry64.S
@@ -39,6 +39,7 @@ __PT_R15     =	__PT_GPRS + 120
 
 STACK_SHIFT = PAGE_SHIFT + THREAD_ORDER
 STACK_SIZE  = 1 << STACK_SHIFT
+STACK_INIT = STACK_SIZE - STACK_FRAME_OVERHEAD - __PT_SIZE
 
 _TIF_WORK_SVC = (_TIF_SIGPENDING | _TIF_NOTIFY_RESUME | _TIF_NEED_RESCHED | \
                  _TIF_MCCK_PENDING | _TIF_PER_TRAP )
@@ -124,10 +125,10 @@ _TIF_EXIT_SIE = (_TIF_SIGPENDING | _TIF_NEED_RESCHED | _TIF_MCCK_PENDING)
         srag    %r14,%r14,\shift
         jnz     1f
         CHECK_STACK 1<<\shift,\savearea
+        aghi    %r15,-(STACK_FRAME_OVERHEAD + __PT_SIZE)
         j       2f
 1:      lg      %r15,\stack             # load target stack
-2:      aghi    %r15,-(STACK_FRAME_OVERHEAD + __PT_SIZE)
-        la      %r11,STACK_FRAME_OVERHEAD(%r15)
+2:      la      %r11,STACK_FRAME_OVERHEAD(%r15)
         .endm
 
         .macro UPDATE_VTIME scratch,enter_timer
@@ -177,7 +178,7 @@ ENTRY(__switch_to)
         lg      %r4,__THREAD_info(%r2)          # get thread_info of prev
         lg      %r5,__THREAD_info(%r3)          # get thread_info of next
         lgr     %r15,%r5
-        aghi    %r15,STACK_SIZE                 # end of kernel stack of next
+        aghi    %r15,STACK_INIT                 # end of kernel stack of next
         stg     %r3,__LC_CURRENT                # store task struct of next
         stg     %r5,__LC_THREAD_INFO            # store thread info of next
         stg     %r15,__LC_KERNEL_STACK          # store end of kernel stack
@@ -203,10 +204,8 @@ sysc_stmg:
         stmg    %r8,%r15,__LC_SAVE_AREA_SYNC
         lg      %r10,__LC_LAST_BREAK
         lg      %r12,__LC_THREAD_INFO
-        larl    %r13,system_call
 sysc_per:
         lg      %r15,__LC_KERNEL_STACK
-        aghi    %r15,-(STACK_FRAME_OVERHEAD + __PT_SIZE)
         la      %r11,STACK_FRAME_OVERHEAD(%r15) # pointer to pt_regs
 sysc_vtime:
         UPDATE_VTIME %r13,__LC_SYNC_ENTER_TIMER
@@ -217,6 +216,7 @@ sysc_vtime:
         mvc     __PT_INT_CODE(4,%r11),__LC_SVC_ILC
 sysc_do_svc:
         oi      __TI_flags+7(%r12),_TIF_SYSCALL
+        lg      %r10,__TI_sysc_table(%r12)      # address of system call table
         llgh    %r8,__PT_INT_CODE+2(%r11)
         slag    %r8,%r8,2                       # shift and test for svc 0
         jnz     sysc_nr_ok
@@ -227,13 +227,6 @@ sysc_do_svc:
         sth     %r1,__PT_INT_CODE+2(%r11)
         slag    %r8,%r1,2
 sysc_nr_ok:
-        larl    %r10,sys_call_table             # 64 bit system call table
-#ifdef CONFIG_COMPAT
-        tm      __TI_flags+5(%r12),(_TIF_31BIT>>16)
-        jno     sysc_noemu
-        larl    %r10,sys_call_table_emu         # 31 bit system call table
-sysc_noemu:
-#endif
         xc      __SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)
         stg     %r2,__PT_ORIG_GPR2(%r11)
         stg     %r7,STACK_FRAME_OVERHEAD(%r15)
@@ -389,6 +382,7 @@ 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
+        aghi    %r15,-(STACK_FRAME_OVERHEAD + __PT_SIZE)
         j       2f
 1:      UPDATE_VTIME %r14,__LC_SYNC_ENTER_TIMER
         LAST_BREAK %r14
@@ -398,8 +392,7 @@ ENTRY(pgm_check_handler)
         tm      __LC_PGM_ILC+2,0x02     # check for transaction abort
         jz      2f
         mvc     __THREAD_trap_tdb(256,%r14),0(%r13)
-2:      aghi    %r15,-(STACK_FRAME_OVERHEAD + __PT_SIZE)
-        la      %r11,STACK_FRAME_OVERHEAD(%r15)
+2:      la      %r11,STACK_FRAME_OVERHEAD(%r15)
         stmg    %r0,%r7,__PT_R0(%r11)
         mvc     __PT_R8(64,%r11),__LC_SAVE_AREA_SYNC
         stmg    %r8,%r9,__PT_PSW(%r11)
@@ -526,7 +519,6 @@ io_work:
 #
 io_work_user:
         lg      %r1,__LC_KERNEL_STACK
-        aghi    %r1,-(STACK_FRAME_OVERHEAD + __PT_SIZE)
         mvc     STACK_FRAME_OVERHEAD(__PT_SIZE,%r1),0(%r11)
         xc      __SF_BACKCHAIN(8,%r1),__SF_BACKCHAIN(%r1)
         la      %r11,STACK_FRAME_OVERHEAD(%r1)
@@ -678,8 +670,9 @@ ENTRY(mcck_int_handler)
         UPDATE_VTIME %r14,__LC_MCCK_ENTER_TIMER
         LAST_BREAK %r14
 mcck_skip:
-        lghi    %r14,__LC_GPREGS_SAVE_AREA
-        mvc     __PT_R0(128,%r11),0(%r14)
+        lghi    %r14,__LC_GPREGS_SAVE_AREA+64
+        stmg    %r0,%r7,__PT_R0(%r11)
+        mvc     __PT_R8(64,%r11),0(%r14)
         stmg    %r8,%r9,__PT_PSW(%r11)
         xc      __SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)
         lgr     %r2,%r11                # pass pointer to pt_regs
@@ -687,7 +680,6 @@ mcck_skip:
         tm      __PT_PSW+1(%r11),0x01   # returning to user ?
         jno     mcck_return
         lg      %r1,__LC_KERNEL_STACK   # switch to kernel stack
-        aghi    %r1,-(STACK_FRAME_OVERHEAD + __PT_SIZE)
         mvc     STACK_FRAME_OVERHEAD(__PT_SIZE,%r1),0(%r11)
         xc      __SF_BACKCHAIN(8,%r1),__SF_BACKCHAIN(%r1)
         la      %r11,STACK_FRAME_OVERHEAD(%r1)
@@ -754,14 +746,12 @@ ENTRY(restart_int_handler)
  * Setup a pt_regs so that show_trace can provide a good call trace.
  */
 stack_overflow:
-        lg      %r11,__LC_PANIC_STACK   # change to panic stack
-        aghi    %r11,-__PT_SIZE         # create pt_regs
+        lg      %r15,__LC_PANIC_STACK   # change to panic stack
+        la      %r11,STACK_FRAME_OVERHEAD(%r15)
         stmg    %r0,%r7,__PT_R0(%r11)
         stmg    %r8,%r9,__PT_PSW(%r11)
         mvc     __PT_R8(64,%r11),0(%r14)
         stg     %r10,__PT_ORIG_GPR2(%r11) # store last break to orig_gpr2
-        lgr     %r15,%r11
-        aghi    %r15,-STACK_FRAME_OVERHEAD
         xc      __SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)
         lgr     %r2,%r11                # pass pointer to pt_regs
         jg      kernel_stack_overflow
@@ -845,15 +835,14 @@ cleanup_system_call:
         mvc     __TI_last_break(8,%r12),16(%r11)
 0:      # set up saved register r11
         lg      %r15,__LC_KERNEL_STACK
-        aghi    %r15,-__PT_SIZE
-        stg     %r15,24(%r11)           # r11 pt_regs pointer
+        la      %r9,STACK_FRAME_OVERHEAD(%r15)
+        stg     %r9,24(%r11)            # r11 pt_regs pointer
         # fill pt_regs
-        mvc     __PT_R8(64,%r15),__LC_SAVE_AREA_SYNC
-        stmg    %r0,%r7,__PT_R0(%r15)
-        mvc     __PT_PSW(16,%r15),__LC_SVC_OLD_PSW
-        mvc     __PT_INT_CODE(4,%r15),__LC_SVC_ILC
+        mvc     __PT_R8(64,%r9),__LC_SAVE_AREA_SYNC
+        stmg    %r0,%r7,__PT_R0(%r9)
+        mvc     __PT_PSW(16,%r9),__LC_SVC_OLD_PSW
+        mvc     __PT_INT_CODE(4,%r9),__LC_SVC_ILC
         # setup saved register r15
-        aghi    %r15,-STACK_FRAME_OVERHEAD
         stg     %r15,56(%r11)           # r15 stack pointer
         # set new psw address and exit
         larl    %r9,sysc_do_svc
@@ -1010,6 +999,7 @@ sys_call_table:
 #ifdef CONFIG_COMPAT
 
 #define SYSCALL(esa,esame,emu)  .long emu
+        .globl  sys_call_table_emu
 sys_call_table_emu:
 #include "syscalls.S"
 #undef SYSCALL