mirror of https://gitee.com/openkylin/linux.git
m68k: split ret_from_fork(), simplify kernel_thread()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Al Viro
parent
0973c687e0
commit
533e6903be
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@ -13,6 +13,7 @@ config M68K
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select FPU if MMU
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select ARCH_WANT_IPC_PARSE_VERSION
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select ARCH_USES_GETTIMEOFFSET if MMU && !COLDFIRE
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select GENERIC_KERNEL_THREAD
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config RWSEM_GENERIC_SPINLOCK
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bool
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@ -154,8 +154,6 @@ static inline void release_thread(struct task_struct *dead_task)
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{
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}
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extern int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags);
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/*
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* Free current thread data structures etc..
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*/
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@ -111,6 +111,17 @@ ENTRY(ret_from_fork)
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addql #4,%sp
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jra ret_from_exception
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ENTRY(ret_from_kernel_thread)
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| a3 contains the kernel thread payload, d7 - its argument
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movel %d1,%sp@-
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jsr schedule_tail
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GET_CURRENT(%d0)
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movel %d7,(%sp)
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jsr %a3@
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addql #4,%sp
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movel %d0,(%sp)
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jra sys_exit
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#if defined(CONFIG_COLDFIRE) || !defined(CONFIG_MMU)
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#ifdef TRAP_DBG_INTERRUPT
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@ -34,6 +34,7 @@
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asmlinkage void ret_from_fork(void);
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asmlinkage void ret_from_kernel_thread(void);
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/*
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@ -120,51 +121,6 @@ void show_regs(struct pt_regs * regs)
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printk("USP: %08lx\n", rdusp());
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}
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/*
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* Create a kernel thread
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*/
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int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
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{
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int pid;
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mm_segment_t fs;
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fs = get_fs();
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set_fs (KERNEL_DS);
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{
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register long retval __asm__ ("d0");
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register long clone_arg __asm__ ("d1") = flags | CLONE_VM | CLONE_UNTRACED;
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retval = __NR_clone;
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__asm__ __volatile__
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("clrl %%d2\n\t"
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"trap #0\n\t" /* Linux/m68k system call */
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"tstl %0\n\t" /* child or parent */
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"jne 1f\n\t" /* parent - jump */
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#ifdef CONFIG_MMU
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"lea %%sp@(%c7),%6\n\t" /* reload current */
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"movel %6@,%6\n\t"
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#endif
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"movel %3,%%sp@-\n\t" /* push argument */
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"jsr %4@\n\t" /* call fn */
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"movel %0,%%d1\n\t" /* pass exit value */
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"movel %2,%%d0\n\t" /* exit */
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"trap #0\n"
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"1:"
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: "+d" (retval)
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: "i" (__NR_clone), "i" (__NR_exit),
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"r" (arg), "a" (fn), "d" (clone_arg), "r" (current),
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"i" (-THREAD_SIZE)
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: "d2");
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pid = retval;
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}
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set_fs (fs);
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return pid;
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}
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EXPORT_SYMBOL(kernel_thread);
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void flush_thread(void)
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{
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current->thread.fs = __USER_DS;
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@ -216,30 +172,18 @@ asmlinkage int m68k_clone(struct pt_regs *regs)
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}
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int copy_thread(unsigned long clone_flags, unsigned long usp,
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unsigned long unused,
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unsigned long arg,
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struct task_struct * p, struct pt_regs * regs)
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{
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struct pt_regs * childregs;
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struct switch_stack * childstack, *stack;
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unsigned long *retp;
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struct switch_stack *childstack;
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childregs = (struct pt_regs *) (task_stack_page(p) + THREAD_SIZE) - 1;
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*childregs = *regs;
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childregs->d0 = 0;
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retp = ((unsigned long *) regs);
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stack = ((struct switch_stack *) retp) - 1;
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childstack = ((struct switch_stack *) childregs) - 1;
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*childstack = *stack;
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childstack->retpc = (unsigned long)ret_from_fork;
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p->thread.usp = usp;
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p->thread.ksp = (unsigned long)childstack;
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if (clone_flags & CLONE_SETTLS)
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task_thread_info(p)->tp_value = regs->d5;
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p->thread.esp0 = (unsigned long)childregs;
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/*
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* Must save the current SFC/DFC value, NOT the value when
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@ -247,6 +191,26 @@ int copy_thread(unsigned long clone_flags, unsigned long usp,
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*/
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p->thread.fs = get_fs().seg;
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if (unlikely(!regs)) {
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/* kernel thread */
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memset(childstack, 0,
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sizeof(struct switch_stack) + sizeof(struct pt_regs));
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childregs->sr = PS_S;
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childstack->a3 = usp; /* function */
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childstack->d7 = arg;
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childstack->retpc = (unsigned long)ret_from_kernel_thread;
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p->thread.usp = 0;
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return 0;
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}
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*childregs = *regs;
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childregs->d0 = 0;
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*childstack = ((struct switch_stack *) regs)[-1];
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childstack->retpc = (unsigned long)ret_from_fork;
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if (clone_flags & CLONE_SETTLS)
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task_thread_info(p)->tp_value = regs->d5;
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#ifdef CONFIG_FPU
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if (!FPU_IS_EMU) {
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/* Copy the current fpu state */
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