flagday: don't pass regs to copy_thread()

[mirror_ubuntu-zesty-kernel.git] / arch / unicore32 / kernel / process.c

diff --git a/arch/unicore32/kernel/process.c b/arch/unicore32/kernel/process.c
index b008586dad753a1b29010735b95ee71e1a704900..62bad9fed03e08ad494266664a805d73f467aaea 100644 (file)
--- a/arch/unicore32/kernel/process.c
+++ b/arch/unicore32/kernel/process.c
@@ -258,25 +258,32 @@ void release_thread(struct task_struct *dead_task)
 }
 
 asmlinkage void ret_from_fork(void) __asm__("ret_from_fork");
+asmlinkage void ret_from_kernel_thread(void) __asm__("ret_from_kernel_thread");
 
 int
 copy_thread(unsigned long clone_flags, unsigned long stack_start,
-           unsigned long stk_sz, struct task_struct *p, struct pt_regs *regs)
+           unsigned long stk_sz, struct task_struct *p)
 {
        struct thread_info *thread = task_thread_info(p);
        struct pt_regs *childregs = task_pt_regs(p);
 
-       *childregs = *regs;
-       childregs->UCreg_00 = 0;
-       childregs->UCreg_sp = stack_start;
-
        memset(&thread->cpu_context, 0, sizeof(struct cpu_context_save));
        thread->cpu_context.sp = (unsigned long)childregs;
-       thread->cpu_context.pc = (unsigned long)ret_from_fork;
-
-       if (clone_flags & CLONE_SETTLS)
-               childregs->UCreg_16 = regs->UCreg_03;
-
+       if (unlikely(p->flags & PF_KTHREAD)) {
+               thread->cpu_context.pc = (unsigned long)ret_from_kernel_thread;
+               thread->cpu_context.r4 = stack_start;
+               thread->cpu_context.r5 = stk_sz;
+               memset(childregs, 0, sizeof(struct pt_regs));
+       } else {
+               thread->cpu_context.pc = (unsigned long)ret_from_fork;
+               *childregs = *current_pt_regs();
+               childregs->UCreg_00 = 0;
+               if (stack_start)
+                       childregs->UCreg_sp = stack_start;
+
+               if (clone_flags & CLONE_SETTLS)
+                       childregs->UCreg_16 = childregs->UCreg_03;
+       }
        return 0;
 }
 
@@ -305,42 +312,6 @@ int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fp)
 }
 EXPORT_SYMBOL(dump_fpu);
 
-/*
- * Shuffle the argument into the correct register before calling the
- * thread function.  r1 is the thread argument, r2 is the pointer to
- * the thread function, and r3 points to the exit function.
- */
-asm(".pushsection .text\n"
-"      .align\n"
-"      .type   kernel_thread_helper, #function\n"
-"kernel_thread_helper:\n"
-"      mov.a   asr, r7\n"
-"      mov     r0, r4\n"
-"      mov     lr, r6\n"
-"      mov     pc, r5\n"
-"      .size   kernel_thread_helper, . - kernel_thread_helper\n"
-"      .popsection");
-
-/*
- * Create a kernel thread.
- */
-pid_t kernel_thread(int (*fn)(void *), void *arg, unsigned long flags)
-{
-       struct pt_regs regs;
-
-       memset(&regs, 0, sizeof(regs));
-
-       regs.UCreg_04 = (unsigned long)arg;
-       regs.UCreg_05 = (unsigned long)fn;
-       regs.UCreg_06 = (unsigned long)do_exit;
-       regs.UCreg_07 = PRIV_MODE;
-       regs.UCreg_pc = (unsigned long)kernel_thread_helper;
-       regs.UCreg_asr = regs.UCreg_07 | PSR_I_BIT;
-
-       return do_fork(flags|CLONE_VM|CLONE_UNTRACED, 0, &regs, 0, NULL, NULL);
-}
-EXPORT_SYMBOL(kernel_thread);
-
 unsigned long get_wchan(struct task_struct *p)
 {
        struct stackframe frame;