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sh: switch to generic kernel_thread()/kernel_execve()

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Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Al Viro
2012-10-14 01:41:42 -04:00
parent ddffeb8c4d
commit 7147e21548
10 changed files with 71 additions and 174 deletions
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60
arch/sh/kernel/process_64.c
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@@ -284,39 +284,6 @@ void show_regs(struct pt_regs *regs)
}
}
/*
* Create a kernel thread
*/
__noreturn void kernel_thread_helper(void *arg, int (*fn)(void *))
{
do_exit(fn(arg));
}
/*
* This is the mechanism for creating a new kernel thread.
*
* NOTE! Only a kernel-only process(ie the swapper or direct descendants
* who haven't done an "execve()") should use this: it will work within
* a system call from a "real" process, but the process memory space will
* not be freed until both the parent and the child have exited.
*/
int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
{
struct pt_regs regs;
memset(&regs, 0, sizeof(regs));
regs.regs[2] = (unsigned long)arg;
regs.regs[3] = (unsigned long)fn;
regs.pc = (unsigned long)kernel_thread_helper;
regs.sr = (1 << 30);
/* Ok, create the new process.. */
return do_fork(flags | CLONE_VM | CLONE_UNTRACED, 0,
&regs, 0, NULL, NULL);
}
EXPORT_SYMBOL(kernel_thread);
/*
* Free current thread data structures etc..
*/
@@ -401,15 +368,17 @@ int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fpu)
EXPORT_SYMBOL(dump_fpu);
asmlinkage void ret_from_fork(void);
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;
#ifdef CONFIG_SH_FPU
if(last_task_used_math == current) {
/* can't happen for a kernel thread */
if (last_task_used_math == current) {
enable_fpu();
save_fpu(current);
disable_fpu();
@@ -419,7 +388,17 @@ int copy_thread(unsigned long clone_flags, unsigned long usp,
#endif
/* Copy from sh version */
childregs = (struct pt_regs *)(THREAD_SIZE + task_stack_page(p)) - 1;
p->thread.sp = (unsigned long) childregs;
if (unlikely(p->flags & PF_KTHREAD)) {
memset(childregs, 0, sizeof(struct pt_regs));
childregs->regs[2] = (unsigned long)arg;
childregs->regs[3] = (unsigned long)fn;
childregs->sr = (1 << 30); /* not user_mode */
childregs->sr |= SR_FD; /* Invalidate FPU flag */
p->thread.pc = (unsigned long) ret_from_kernel_thread;
return 0;
}
*childregs = *regs;
/*
@@ -428,19 +407,12 @@ int copy_thread(unsigned long clone_flags, unsigned long usp,
* 32-bit wide and context switch must take care
* of NEFF sign extension.
*/
if (user_mode(regs)) {
childregs->regs[15] = neff_sign_extend(usp);
p->thread.uregs = childregs;
} else {
childregs->regs[15] =
neff_sign_extend((unsigned long)task_stack_page(p) +
THREAD_SIZE);
}
childregs->regs[15] = neff_sign_extend(usp);
p->thread.uregs = childregs;
childregs->regs[9] = 0; /* Set return value for child */
childregs->sr |= SR_FD; /* Invalidate FPU flag */
p->thread.sp = (unsigned long) childregs;
p->thread.pc = (unsigned long) ret_from_fork;
return 0;