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Commit baa07158 authored by Martin Schwidefsky's avatar Martin Schwidefsky Committed by Martin Schwidefsky
Browse files

[S390] cleanup system call parameter setup 



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: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
parent 178514d7

arch/s390/include/asm/syscall.h

+0 −4
Original line number Diff line number Diff line
@@ -65,8 +65,6 @@ static inline void syscall_get_arguments(struct task_struct *task, 
	if (test_tsk_thread_flag(task, TIF_31BIT))

		mask = 0xffffffff;

#endif

	if (i + n == 6)

		args[--n] = regs->args[0] & mask;

	while (n-- > 0)

		if (i + n > 0)

			args[n] = regs->gprs[2 + i + n] & mask;
@@ -80,8 +78,6 @@ static inline void syscall_set_arguments(struct task_struct *task, 
					 const unsigned long *args)

{

	BUG_ON(i + n > 6);

	if (i + n == 6)

		regs->args[0] = args[--n];

	while (n-- > 0)

		if (i + n > 0)

			regs->gprs[2 + i + n] = args[n];

arch/s390/kernel/entry.S

+3 −3
Original line number Diff line number Diff line
@@ -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

arch/s390/kernel/entry64.S

+2 −2
Original line number Diff line number Diff line
@@ -246,7 +246,6 @@ sysc_saveall: 
	CREATE_STACK_FRAME __LC_SAVE_AREA

	mvc	SP_PSW(16,%r15),__LC_SVC_OLD_PSW

	mvc	SP_ILC(4,%r15),__LC_SVC_ILC

	stg	%r7,SP_ARGS(%r15)

	lg	%r12,__LC_THREAD_INFO	# load pointer to thread_info struct

sysc_vtime:

	UPDATE_VTIME __LC_EXIT_TIMER,__LC_SYNC_ENTER_TIMER,__LC_USER_TIMER
@@ -274,6 +273,7 @@ sysc_nr_ok: 
sysc_noemu:

#endif

	tm	__TI_flags+6(%r12),_TIF_SYSCALL

	mvc	SP_ARGS(8,%r15),SP_R7(%r15)

	lgf	%r8,0(%r7,%r10) # load address of system call routine

	jnz	sysc_tracesys

	basr	%r14,%r8	# call sys_xxxx
@@ -387,6 +387,7 @@ sysc_tracesys: 
	lgf	%r8,0(%r7,%r10)

sysc_tracego:

	lmg	%r3,%r6,SP_R3(%r15)

	mvc	SP_ARGS(8,%r15),SP_R7(%r15)

	lg	%r2,SP_ORIG_R2(%r15)

	basr	%r14,%r8		# call sys_xxx

	stg	%r2,SP_R2(%r15)		# store return value
@@ -953,7 +954,6 @@ cleanup_system_call: 
	CREATE_STACK_FRAME __LC_SAVE_AREA

	mvc	SP_PSW(16,%r15),__LC_SVC_OLD_PSW

	mvc	SP_ILC(4,%r15),__LC_SVC_ILC

	stg	%r7,SP_ARGS(%r15)

	mvc	8(8,%r12),__LC_THREAD_INFO

cleanup_vtime:

	clc	__LC_RETURN_PSW+8(8),BASED(cleanup_system_call_insn+24)