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[S390] System call cleanup.

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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>
This commit is contained in:
Martin Schwidefsky
2007-04-27 16:01:40 +02:00
parent ef99516c96
commit 03ff9a235a
8 changed files with 161 additions and 224 deletions
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100
arch/s390/kernel/entry64.S
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@@ -244,8 +244,6 @@ sysc_noemu:
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 @@ ret_from_fork:
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