diff options
Diffstat (limited to 'arch/avr32/kernel/process.c')
-rw-r--r-- | arch/avr32/kernel/process.c | 67 |
1 files changed, 17 insertions, 50 deletions
diff --git a/arch/avr32/kernel/process.c b/arch/avr32/kernel/process.c index 1bb0a8abd79b..07380c3a4f78 100644 --- a/arch/avr32/kernel/process.c +++ b/arch/avr32/kernel/process.c @@ -69,44 +69,6 @@ void machine_restart(char *cmd) } /* - * 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(®s, 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, ®s, 0, NULL, NULL); -} -EXPORT_SYMBOL(kernel_thread); - -/* * Free current thread data structures etc */ void exit_thread(void) @@ -332,26 +294,31 @@ 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, + unsigned long arg, struct task_struct *p, struct pt_regs *regs) { - struct pt_regs *childregs; - - childregs = ((struct pt_regs *)(THREAD_SIZE + (unsigned long)task_stack_page(p))) - 1; - *childregs = *regs; - - if (user_mode(regs)) + struct pt_regs *childregs = task_pt_regs(p); + + if (unlikely(!regs)) { + 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 = *regs; childregs->sp = usp; - else - childregs->sp = (unsigned long)task_stack_page(p) + THREAD_SIZE; - - childregs->r12 = 0; /* Set return value for child */ + 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)) |