[S390] System call cleanup.
Remove system call glue for sys_clone, sys_fork, sys_vfork, sys_execve,
sys_sigreturn, sys_rt_sigreturn and sys_sigaltstack. Call do_execve from
kernel_execve directly, move pt_regs to the right place and branch to
sysc_return to start the user space program. This removes the last
in-kernel system call.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
diff --git a/arch/s390/kernel/entry64.S b/arch/s390/kernel/entry64.S
index 0f758c3..93745fd 100644
--- a/arch/s390/kernel/entry64.S
+++ b/arch/s390/kernel/entry64.S
@@ -244,8 +244,6 @@
jnz sysc_tracesys
basr %r14,%r8 # call sys_xxxx
stg %r2,SP_R2(%r15) # store return value (change R2 on stack)
- # ATTENTION: check sys_execve_glue before
- # changing anything here !!
sysc_return:
tm SP_PSW+1(%r15),0x01 # returning to user ?
@@ -371,77 +369,35 @@
j sysc_return
#
-# clone, fork, vfork, exec and sigreturn need glue,
-# because they all expect pt_regs as parameter,
-# but are called with different parameter.
-# return-address is set up above
+# kernel_execve function needs to deal with pt_regs that is not
+# at the usual place
#
-sys_clone_glue:
- la %r2,SP_PTREGS(%r15) # load pt_regs
- jg sys_clone # branch to sys_clone
-
-#ifdef CONFIG_COMPAT
-sys32_clone_glue:
- la %r2,SP_PTREGS(%r15) # load pt_regs
- jg sys32_clone # branch to sys32_clone
-#endif
-
-sys_fork_glue:
- la %r2,SP_PTREGS(%r15) # load pt_regs
- jg sys_fork # branch to sys_fork
-
-sys_vfork_glue:
- la %r2,SP_PTREGS(%r15) # load pt_regs
- jg sys_vfork # branch to sys_vfork
-
-sys_execve_glue:
- la %r2,SP_PTREGS(%r15) # load pt_regs
- lgr %r12,%r14 # save return address
- brasl %r14,sys_execve # call sys_execve
- ltgr %r2,%r2 # check if execve failed
- bnz 0(%r12) # it did fail -> store result in gpr2
- b 6(%r12) # SKIP STG 2,SP_R2(15) in
- # system_call/sysc_tracesys
-#ifdef CONFIG_COMPAT
-sys32_execve_glue:
- la %r2,SP_PTREGS(%r15) # load pt_regs
- lgr %r12,%r14 # save return address
- brasl %r14,sys32_execve # call sys32_execve
- ltgr %r2,%r2 # check if execve failed
- bnz 0(%r12) # it did fail -> store result in gpr2
- b 6(%r12) # SKIP STG 2,SP_R2(15) in
- # system_call/sysc_tracesys
-#endif
-
-sys_sigreturn_glue:
- la %r2,SP_PTREGS(%r15) # load pt_regs as parameter
- jg sys_sigreturn # branch to sys_sigreturn
-
-#ifdef CONFIG_COMPAT
-sys32_sigreturn_glue:
- la %r2,SP_PTREGS(%r15) # load pt_regs as parameter
- jg sys32_sigreturn # branch to sys32_sigreturn
-#endif
-
-sys_rt_sigreturn_glue:
- la %r2,SP_PTREGS(%r15) # load pt_regs as parameter
- jg sys_rt_sigreturn # branch to sys_sigreturn
-
-#ifdef CONFIG_COMPAT
-sys32_rt_sigreturn_glue:
- la %r2,SP_PTREGS(%r15) # load pt_regs as parameter
- jg sys32_rt_sigreturn # branch to sys32_sigreturn
-#endif
-
-sys_sigaltstack_glue:
- la %r4,SP_PTREGS(%r15) # load pt_regs as parameter
- jg sys_sigaltstack # branch to sys_sigreturn
-
-#ifdef CONFIG_COMPAT
-sys32_sigaltstack_glue:
- la %r4,SP_PTREGS(%r15) # load pt_regs as parameter
- jg sys32_sigaltstack_wrapper # branch to sys_sigreturn
-#endif
+ .globl kernel_execve
+kernel_execve:
+ stmg %r12,%r15,96(%r15)
+ lgr %r14,%r15
+ aghi %r15,-SP_SIZE
+ stg %r14,__SF_BACKCHAIN(%r15)
+ la %r12,SP_PTREGS(%r15)
+ xc 0(__PT_SIZE,%r12),0(%r12)
+ lgr %r5,%r12
+ brasl %r14,do_execve
+ ltgfr %r2,%r2
+ je 0f
+ aghi %r15,SP_SIZE
+ lmg %r12,%r15,96(%r15)
+ br %r14
+ # execve succeeded.
+0: stnsm __SF_EMPTY(%r15),0xfc # disable interrupts
+ lg %r15,__LC_KERNEL_STACK # load ksp
+ aghi %r15,-SP_SIZE # make room for registers & psw
+ lg %r13,__LC_SVC_NEW_PSW+8
+ lg %r9,__LC_THREAD_INFO
+ mvc SP_PTREGS(__PT_SIZE,%r15),0(%r12) # copy pt_regs
+ xc __SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)
+ stosm __SF_EMPTY(%r15),0x03 # reenable interrupts
+ brasl %r14,execve_tail
+ j sysc_return
/*
* Program check handler routine