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authorAl Viro <viro@zeniv.linux.org.uk>2012-10-21 16:44:27 -0400
committerAl Viro <viro@zeniv.linux.org.uk>2012-11-28 22:44:37 -0500
commit87f1ca8fd9f00cc024a141623d042ca4319e12c1 (patch)
treed2826a08eda6b3fcbe55dcde75f89661cbaefbfd
parentf3268edbe6fe0ce56e62c6d6b14640aeb04864b7 (diff)
s390: switch to generic fork/vfork/clone
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
-rw-r--r--arch/s390/Kconfig1
-rw-r--r--arch/s390/include/asm/unistd.h3
-rw-r--r--arch/s390/kernel/process.c52
3 files changed, 14 insertions, 42 deletions
diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
index a163784e72c..3cbb8757704 100644
--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig
@@ -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
diff --git a/arch/s390/include/asm/unistd.h b/arch/s390/include/asm/unistd.h
index ccbcab7742c..086bb8eaf6a 100644
--- a/arch/s390/include/asm/unistd.h
+++ b/arch/s390/include/asm/unistd.h
@@ -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
diff --git a/arch/s390/kernel/process.c b/arch/s390/kernel/process.c
index cd31ad457a9..e37677796a0 100644
--- a/arch/s390/kernel/process.c
+++ b/arch/s390/kernel/process.c
@@ -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;