cris: switch to generic kernel_thread()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/arch/cris/arch-v32/kernel/process.c b/arch/cris/arch-v32/kernel/process.c
index 4e99922..3edbdb8 100644
--- a/arch/cris/arch-v32/kernel/process.c
+++ b/arch/cris/arch-v32/kernel/process.c
@@ -16,6 +16,7 @@
#include <hwregs/reg_map.h>
#include <hwregs/timer_defs.h>
#include <hwregs/intr_vect_defs.h>
+#include <asm/ptrace.h>
extern void stop_watchdog(void);
@@ -94,31 +95,6 @@
return task_pt_regs(t)->erp;
}
-static void
-kernel_thread_helper(void* dummy, int (*fn)(void *), void * arg)
-{
- fn(arg);
- do_exit(-1); /* Should never be called, return bad exit value. */
-}
-
-/* Create a kernel thread. */
-int
-kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
-{
- struct pt_regs regs;
-
- memset(®s, 0, sizeof(regs));
-
- /* Don't use r10 since that is set to 0 in copy_thread. */
- regs.r11 = (unsigned long) fn;
- regs.r12 = (unsigned long) arg;
- regs.erp = (unsigned long) kernel_thread_helper;
- regs.ccs = 1 << (I_CCS_BITNR + CCS_SHIFT);
-
- /* Create the new process. */
- return do_fork(flags | CLONE_VM | CLONE_UNTRACED, 0, ®s, 0, NULL, NULL);
-}
-
/*
* Setup the child's kernel stack with a pt_regs and call switch_stack() on it.
* It will be unnested during _resume and _ret_from_sys_call when the new thread
@@ -129,23 +105,33 @@
*/
extern asmlinkage void ret_from_fork(void);
+extern asmlinkage void ret_from_kernel_thread(void);
int
copy_thread(unsigned long clone_flags, unsigned long usp,
- unsigned long unused,
+ unsigned long arg,
struct task_struct *p, struct pt_regs *regs)
{
- struct pt_regs *childregs;
- struct switch_stack *swstack;
+ struct pt_regs *childregs = task_pt_regs(p);
+ struct switch_stack *swstack = ((struct switch_stack *) childregs) - 1;
/*
* Put the pt_regs structure at the end of the new kernel stack page and
* fix it up. Note: the task_struct doubles as the kernel stack for the
* task.
*/
- childregs = task_pt_regs(p);
+ if (unlikely(p->flags & PF_KTHREAD)) {
+ memset(swstack, 0,
+ sizeof(struct switch_stack) + sizeof(struct pt_regs));
+ swstack->r1 = usp;
+ swstack->r2 = arg;
+ childregs->ccs = 1 << (I_CCS_BITNR + CCS_SHIFT);
+ swstack->return_ip = (unsigned long) ret_from_kernel_thread;
+ p->thread.ksp = (unsigned long) swstack;
+ p->thread.usp = 0;
+ return 0;
+ }
*childregs = *regs; /* Struct copy of pt_regs. */
- p->set_child_tid = p->clear_child_tid = NULL;
childregs->r10 = 0; /* Child returns 0 after a fork/clone. */
/* Set a new TLS ?
@@ -156,7 +142,6 @@
}
/* Put the switch stack right below the pt_regs. */
- swstack = ((struct switch_stack *) childregs) - 1;
/* Parameter to ret_from_sys_call. 0 is don't restart the syscall. */
swstack->r9 = 0;
@@ -174,35 +159,21 @@
return 0;
}
-/*
- * Be aware of the "magic" 7th argument in the four system-calls below.
- * They need the latest stackframe, which is put as the 7th argument by
- * entry.S. The previous arguments are dummies or actually used, but need
- * to be defined to reach the 7th argument.
- *
- * N.B.: Another method to get the stackframe is to use current_regs(). But
- * it returns the latest stack-frame stacked when going from _user mode_ and
- * some of these (at least sys_clone) are called from kernel-mode sometimes
- * (for example during kernel_thread, above) and thus cannot use it. Thus,
- * to be sure not to get any surprises, we use the method for the other calls
- * as well.
- */
asmlinkage int
-sys_fork(long r10, long r11, long r12, long r13, long mof, long srp,
- struct pt_regs *regs)
+sys_fork(void)
{
- return do_fork(SIGCHLD, rdusp(), regs, 0, NULL, NULL);
+ return do_fork(SIGCHLD, rdusp(), current_pt_regs(), 0, NULL, NULL);
}
/* FIXME: Is parent_tid/child_tid really third/fourth argument? Update lib? */
asmlinkage int
sys_clone(unsigned long newusp, unsigned long flags, int *parent_tid, int *child_tid,
- unsigned long tls, long srp, struct pt_regs *regs)
+ unsigned long tls)
{
if (!newusp)
newusp = rdusp();
- return do_fork(flags, newusp, regs, 0, parent_tid, child_tid);
+ return do_fork(flags, newusp, current_pt_regs(), 0, parent_tid, child_tid);
}
/*
@@ -210,10 +181,9 @@
* we can remove it and handle it in libc but we put it here until then.
*/
asmlinkage int
-sys_vfork(long r10, long r11, long r12, long r13, long mof, long srp,
- struct pt_regs *regs)
+sys_vfork(void)
{
- return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, rdusp(), regs, 0, NULL, NULL);
+ return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, rdusp(), current_pt_regs(), 0, NULL, NULL);
}
/* sys_execve() executes a new program. */