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
......@@ -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
......
......@@ -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
......
......@@ -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 |
......@@ -164,9 +164,10 @@ 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. */
frame->childregs.gprs[15] = new_stackp;
if (new_stackp)
frame->childregs.gprs[15] = new_stackp;
/* Don't copy runtime instrumentation info */
p->thread.ri_cb = NULL;
......@@ -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;
......
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