flagday: don't pass regs to copy_thread()

[mirror_ubuntu-bionic-kernel.git] / arch / avr32 / kernel / process.c

diff --git a/arch/avr32/kernel/process.c b/arch/avr32/kernel/process.c
index 1bb0a8abd79b5078267ad4e6c9c84832033d0e92..fd78f58ea79a7ece57d8bae9ed970ade03629a13 100644 (file)
--- a/arch/avr32/kernel/process.c
+++ b/arch/avr32/kernel/process.c
@@ -68,44 +68,6 @@ void machine_restart(char *cmd)
        while (1) ;
 }
 
-/*
- * PC is actually discarded when returning from a system call -- the
- * return address must be stored in LR. This function will make sure
- * LR points to do_exit before starting the thread.
- *
- * Also, when returning from fork(), r12 is 0, so we must copy the
- * argument as well.
- *
- *  r0 : The argument to the main thread function
- *  r1 : The address of do_exit
- *  r2 : The address of the main thread function
- */
-asmlinkage extern void kernel_thread_helper(void);
-__asm__("      .type   kernel_thread_helper, @function\n"
-       "kernel_thread_helper:\n"
-       "       mov     r12, r0\n"
-       "       mov     lr, r2\n"
-       "       mov     pc, r1\n"
-       "       .size   kernel_thread_helper, . - kernel_thread_helper");
-
-int kernel_thread(int (*fn)(void *), void *arg, unsigned long flags)
-{
-       struct pt_regs regs;
-
-       memset(&regs, 0, sizeof(regs));
-
-       regs.r0 = (unsigned long)arg;
-       regs.r1 = (unsigned long)fn;
-       regs.r2 = (unsigned long)do_exit;
-       regs.lr = (unsigned long)kernel_thread_helper;
-       regs.pc = (unsigned long)kernel_thread_helper;
-       regs.sr = MODE_SUPERVISOR;
-
-       return do_fork(flags | CLONE_VM | CLONE_UNTRACED,
-                      0, &regs, 0, NULL, NULL);
-}
-EXPORT_SYMBOL(kernel_thread);
-
 /*
  * Free current thread data structures etc
  */
@@ -332,26 +294,32 @@ int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fpu)
 }
 
 asmlinkage void ret_from_fork(void);
+asmlinkage void ret_from_kernel_thread(void);
+asmlinkage void syscall_return(void);
 
 int copy_thread(unsigned long clone_flags, unsigned long usp,
-               unsigned long unused,
-               struct task_struct *p, struct pt_regs *regs)
+               unsigned long arg,
+               struct task_struct *p)
 {
-       struct pt_regs *childregs;
-
-       childregs = ((struct pt_regs *)(THREAD_SIZE + (unsigned long)task_stack_page(p))) - 1;
-       *childregs = *regs;
-
-       if (user_mode(regs))
-               childregs->sp = usp;
-       else
-               childregs->sp = (unsigned long)task_stack_page(p) + THREAD_SIZE;
-
-       childregs->r12 = 0; /* Set return value for child */
+       struct pt_regs *childregs = task_pt_regs(p);
+
+       if (unlikely(p->flags & PF_KTHREAD)) {
+               memset(childregs, 0, sizeof(struct pt_regs));
+               p->thread.cpu_context.r0 = arg;
+               p->thread.cpu_context.r1 = usp; /* fn */
+               p->thread.cpu_context.r2 = syscall_return;
+               p->thread.cpu_context.pc = (unsigned long)ret_from_kernel_thread;
+               childregs->sr = MODE_SUPERVISOR;
+       } else {
+               *childregs = *current_pt_regs();
+               if (usp)
+                       childregs->sp = usp;
+               childregs->r12 = 0; /* Set return value for child */
+               p->thread.cpu_context.pc = (unsigned long)ret_from_fork;
+       }
 
        p->thread.cpu_context.sr = MODE_SUPERVISOR | SR_GM;
        p->thread.cpu_context.ksp = (unsigned long)childregs;
-       p->thread.cpu_context.pc = (unsigned long)ret_from_fork;
 
        clear_tsk_thread_flag(p, TIF_DEBUG);
        if ((clone_flags & CLONE_PTRACE) && test_thread_flag(TIF_DEBUG))
@@ -360,49 +328,6 @@ int copy_thread(unsigned long clone_flags, unsigned long usp,
        return 0;
 }
 
-/* r12-r8 are dummy parameters to force the compiler to use the stack */
-asmlinkage int sys_fork(struct pt_regs *regs)
-{
-       return do_fork(SIGCHLD, regs->sp, regs, 0, NULL, NULL);
-}
-
-asmlinkage int sys_clone(unsigned long clone_flags, unsigned long newsp,
-               void __user *parent_tidptr, void __user *child_tidptr,
-               struct pt_regs *regs)
-{
-       if (!newsp)
-               newsp = regs->sp;
-       return do_fork(clone_flags, newsp, regs, 0, parent_tidptr,
-                       child_tidptr);
-}
-
-asmlinkage int sys_vfork(struct pt_regs *regs)
-{
-       return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs->sp, regs,
-                      0, NULL, NULL);
-}
-
-asmlinkage int sys_execve(const char __user *ufilename,
-                         const char __user *const __user *uargv,
-                         const char __user *const __user *uenvp,
-                         struct pt_regs *regs)
-{
-       int error;
-       struct filename *filename;
-
-       filename = getname(ufilename);
-       error = PTR_ERR(filename);
-       if (IS_ERR(filename))
-               goto out;
-
-       error = do_execve(filename->name, uargv, uenvp, regs);
-       putname(filename);
-
-out:
-       return error;
-}
-
-
 /*
  * This function is supposed to answer the question "who called
  * schedule()?"