Commit 87f1ca8f authored by Al Viro's avatar Al Viro
Browse files

s390: switch to generic fork/vfork/clone 



Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent f3268edb

arch/s390/Kconfig

+1 −0
Original line number Diff line number Diff line
@@ -141,6 +141,7 @@ config S390 
	select GENERIC_KERNEL_EXECVE

	select HAVE_MOD_ARCH_SPECIFIC

	select MODULES_USE_ELF_RELA

	select CLONE_BACKWARDS2



config SCHED_OMIT_FRAME_POINTER

	def_bool y

arch/s390/include/asm/unistd.h

+3 −0
Original line number Diff line number Diff line
@@ -54,6 +54,9 @@ 
#   define __ARCH_WANT_COMPAT_SYS_RT_SIGSUSPEND

# endif

#define __ARCH_WANT_SYS_EXECVE

#define __ARCH_WANT_SYS_FORK

#define __ARCH_WANT_SYS_VFORK

#define __ARCH_WANT_SYS_CLONE



/*

 * "Conditional" syscalls

arch/s390/kernel/process.c

+10 −42
Original line number Diff line number Diff line
@@ -118,7 +118,7 @@ void release_thread(struct task_struct *dead_task) 


int copy_thread(unsigned long clone_flags, unsigned long new_stackp,

		unsigned long arg,

		struct task_struct *p, struct pt_regs *regs)

		struct task_struct *p, struct pt_regs *unused)

{

	struct thread_info *ti;

	struct fake_frame
@@ -150,7 +150,7 @@ int copy_thread(unsigned long clone_flags, unsigned long new_stackp, 
	frame->sf.gprs[9] = (unsigned long) frame;



	/* Store access registers to kernel stack of new process. */

	if (unlikely(!regs)) {

	if (unlikely(p->flags & PF_KTHREAD)) {

		/* kernel thread */

		memset(&frame->childregs, 0, sizeof(struct pt_regs));

		frame->childregs.psw.mask = psw_kernel_bits | PSW_MASK_DAT |
@@ -164,8 +164,9 @@ int copy_thread(unsigned long clone_flags, unsigned long new_stackp, 


		return 0;

	}

	frame->childregs = *regs;

	frame->childregs = *current_pt_regs();

	frame->childregs.gprs[2] = 0;	/* child returns 0 on fork. */

	if (new_stackp)

		frame->childregs.gprs[15] = new_stackp;



	/* Don't copy runtime instrumentation info */
@@ -183,57 +184,24 @@ int copy_thread(unsigned long clone_flags, unsigned long new_stackp, 
	       sizeof(s390_fp_regs));

	/* Set a new TLS ?  */

	if (clone_flags & CLONE_SETTLS)

		p->thread.acrs[0] = regs->gprs[6];

		p->thread.acrs[0] = frame->childregs.gprs[6];

#else /* CONFIG_64BIT */

	/* Save the fpu registers to new thread structure. */

	save_fp_regs(&p->thread.fp_regs);

	/* Set a new TLS ?  */

	if (clone_flags & CLONE_SETTLS) {

		unsigned long tls = frame->childregs.gprs[6];

		if (is_compat_task()) {

			p->thread.acrs[0] = (unsigned int) regs->gprs[6];

			p->thread.acrs[0] = (unsigned int)tls;

		} else {

			p->thread.acrs[0] = (unsigned int)(regs->gprs[6] >> 32);

			p->thread.acrs[1] = (unsigned int) regs->gprs[6];

			p->thread.acrs[0] = (unsigned int)(tls >> 32);

			p->thread.acrs[1] = (unsigned int)tls;

		}

	}

#endif /* CONFIG_64BIT */

	return 0;

}



SYSCALL_DEFINE0(fork)

{

	struct pt_regs *regs = task_pt_regs(current);

	return do_fork(SIGCHLD, regs->gprs[15], regs, 0, NULL, NULL);

}



SYSCALL_DEFINE4(clone, unsigned long, newsp, unsigned long, clone_flags,

		int __user *, parent_tidptr, int __user *, child_tidptr)

{

	struct pt_regs *regs = task_pt_regs(current);



	if (!newsp)

		newsp = regs->gprs[15];

	return do_fork(clone_flags, newsp, regs, 0,

		       parent_tidptr, child_tidptr);

}



/*

 * This is trivial, and on the face of it looks like it

 * could equally well be done in user mode.

 *

 * Not so, for quite unobvious reasons - register pressure.

 * In user mode vfork() cannot have a stack frame, and if

 * done by calling the "clone()" system call directly, you

 * do not have enough call-clobbered registers to hold all

 * the information you need.

 */

SYSCALL_DEFINE0(vfork)

{

	struct pt_regs *regs = task_pt_regs(current);

	return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD,

		       regs->gprs[15], regs, 0, NULL, NULL);

}



asmlinkage void execve_tail(void)

{

	current->thread.fp_regs.fpc = 0;