3 files changed, 13 insertions, 49 deletions

diff --git a/arch/s390/include/asm/unistd.h b/arch/s390/include/asm/unistd.h
index 9afacff38edc..3c500174459a 100644
--- a/arch/s390/include/asm/unistd.h
+++ b/arch/s390/include/asm/unistd.h
@@ -416,6 +416,7 @@
 #   define __ARCH_WANT_COMPAT_SYS_RT_SIGSUSPEND
 # endif
 #define __ARCH_WANT_SYS_EXECVE
+#define __ARCH_WANT_KERNEL_EXECVE
 
 /*
  * "Conditional" syscalls
diff --git a/arch/s390/kernel/entry.S b/arch/s390/kernel/entry.S
index 24de1cd3754b..ef46f66bc0d6 100644
--- a/arch/s390/kernel/entry.S
+++ b/arch/s390/kernel/entry.S
@@ -355,30 +355,13 @@ ENTRY(kernel_thread_starter)
 # kernel_execve function needs to deal with pt_regs that is not
 # at the usual place
 #
-ENTRY(kernel_execve)
-        stm     %r12,%r15,48(%r15)
-        lr      %r14,%r15
-        l       %r13,__LC_SVC_NEW_PSW+4
-        ahi     %r15,-(STACK_FRAME_OVERHEAD + __PT_SIZE)
-        st      %r14,__SF_BACKCHAIN(%r15)
-        la      %r12,STACK_FRAME_OVERHEAD(%r15)
-        xc      0(__PT_SIZE,%r12),0(%r12)
-        l       %r1,BASED(.Ldo_execve)
-        lr      %r5,%r12
-        basr    %r14,%r1                # call do_execve
-        ltr     %r2,%r2
-        je      0f
-        ahi     %r15,(STACK_FRAME_OVERHEAD + __PT_SIZE)
-        lm      %r12,%r15,48(%r15)
-        br      %r14
-        # execve succeeded.
-0:      ssm     __LC_PGM_NEW_PSW        # disable I/O and ext. interrupts
-        l       %r15,__LC_KERNEL_STACK  # load ksp
-        ahi     %r15,-(STACK_FRAME_OVERHEAD + __PT_SIZE)
-        la      %r11,STACK_FRAME_OVERHEAD(%r15)
-        mvc     0(__PT_SIZE,%r11),0(%r12)       # copy pt_regs
-        l       %r12,__LC_THREAD_INFO
+ENTRY(ret_from_kernel_execve)
+        ssm     __LC_PGM_NEW_PSW        # disable I/O and ext. interrupts
+        lr      %r15,%r2
+        lr      %r11,%r2
+        ahi     %r15,-STACK_FRAME_OVERHEAD
         xc      __SF_BACKCHAIN(4,%r15),__SF_BACKCHAIN(%r15)
+        l       %r12,__LC_THREAD_INFO
         ssm     __LC_SVC_NEW_PSW        # reenable interrupts
         j       sysc_return
 
@@ -941,7 +924,6 @@ cleanup_idle_wait:
 .Ldo_signal:            .long   do_signal
 .Ldo_notify_resume:     .long   do_notify_resume
 .Ldo_per_trap:          .long   do_per_trap
-.Ldo_execve:            .long   do_execve
 .Ljump_table:           .long   pgm_check_table
 .Lschedule:             .long   schedule
 #ifdef CONFIG_PREEMPT
diff --git a/arch/s390/kernel/entry64.S b/arch/s390/kernel/entry64.S
index 39c84e65f74f..3d188f74d4c0 100644
--- a/arch/s390/kernel/entry64.S
+++ b/arch/s390/kernel/entry64.S
@@ -369,32 +369,13 @@ ENTRY(kernel_thread_starter)
         la      %r2,0
         br      %r11                    # do_exit
 
-#
-# kernel_execve function needs to deal with pt_regs that is not
-# at the usual place
-#
-ENTRY(kernel_execve)
-        stmg    %r12,%r15,96(%r15)
-        lgr     %r14,%r15
-        aghi    %r15,-(STACK_FRAME_OVERHEAD + __PT_SIZE)
-        stg     %r14,__SF_BACKCHAIN(%r15)
-        la      %r12,STACK_FRAME_OVERHEAD(%r15)
-        xc      0(__PT_SIZE,%r12),0(%r12)
-        lgr     %r5,%r12
-        brasl   %r14,do_execve
-        ltgfr   %r2,%r2
-        je      0f
-        aghi    %r15,(STACK_FRAME_OVERHEAD + __PT_SIZE)
-        lmg     %r12,%r15,96(%r15)
-        br      %r14
-        # execve succeeded.
-0:      ssm     __LC_PGM_NEW_PSW        # disable I/O and ext. interrupts
-        lg      %r15,__LC_KERNEL_STACK  # load ksp
-        aghi    %r15,-(STACK_FRAME_OVERHEAD + __PT_SIZE)
-        la      %r11,STACK_FRAME_OVERHEAD(%r15)
-        mvc     0(__PT_SIZE,%r11),0(%r12)       # copy pt_regs
-        lg      %r12,__LC_THREAD_INFO
+ENTRY(ret_from_kernel_execve)
+        ssm     __LC_PGM_NEW_PSW        # disable I/O and ext. interrupts
+        lgr     %r15,%r2
+        lgr     %r11,%r2
+        aghi    %r15,-STACK_FRAME_OVERHEAD
         xc      __SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)
+        lg      %r12,__LC_THREAD_INFO
         ssm     __LC_SVC_NEW_PSW        # reenable interrupts
         j       sysc_return