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[S390] cleanup system call parameter setup

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Do the setup of the stack overflow argument for the sixth system
call parameter right before the branch to the system call function.
That simplifies the system call parameter access code.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This commit is contained in:
Martin Schwidefsky
2010-10-25 16:10:40 +02:00
committed by Martin Schwidefsky
parent 178514d7e3
commit baa071588c
3 changed files with 5 additions and 9 deletions
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6
arch/s390/kernel/entry.S
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@@ -254,12 +254,11 @@ sysc_do_svc:
bnl BASED(sysc_nr_ok)
lr %r7,%r1 # copy svc number to %r7
sysc_nr_ok:
mvc SP_ARGS(4,%r15),SP_R7(%r15)
sysc_do_restart:
sth %r7,SP_SVCNR(%r15)
sll %r7,2 # svc number *4
l %r8,BASED(.Lsysc_table)
tm __TI_flags+2(%r9),_TIF_SYSCALL
mvc SP_ARGS(4,%r15),SP_R7(%r15)
l %r8,0(%r7,%r8) # get system call addr.
bnz BASED(sysc_tracesys)
basr %r14,%r8 # call sys_xxxx
@@ -347,7 +346,7 @@ sysc_restart:
l %r7,SP_R2(%r15) # load new svc number
mvc SP_R2(4,%r15),SP_ORIG_R2(%r15) # restore first argument
lm %r2,%r6,SP_R2(%r15) # load svc arguments
b BASED(sysc_do_restart) # restart svc
b BASED(sysc_nr_ok) # restart svc
#
# _TIF_SINGLE_STEP is set, call do_single_step
@@ -380,6 +379,7 @@ sysc_tracesys:
l %r8,0(%r7,%r8)
sysc_tracego:
lm %r3,%r6,SP_R3(%r15)
mvc SP_ARGS(4,%r15),SP_R7(%r15)
l %r2,SP_ORIG_R2(%r15)
basr %r14,%r8 # call sys_xxx
st %r2,SP_R2(%r15) # store return value