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alpha: switch to generic kernel_thread()

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Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Al Viro
2012-09-09 22:03:42 -04:00
parent 756144f8ea
commit cba1ec7e88
5 changed files with 30 additions and 71 deletions
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37
arch/alpha/kernel/process.c
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@ -259,33 +259,35 @@ alpha_vfork(struct pt_regs *regs)
/*
* Copy an alpha thread..
*
* Note the "stack_offset" stuff: when returning to kernel mode, we need
* to have some extra stack-space for the kernel stack that still exists
* after the "ret_from_fork". When returning to user mode, we only want
* the space needed by the syscall stack frame (ie "struct pt_regs").
* Use the passed "regs" pointer to determine how much space we need
* for a kernel fork().
*/
int
copy_thread(unsigned long clone_flags, unsigned long usp,
unsigned long unused,
unsigned long arg,
struct task_struct * p, struct pt_regs * regs)
{
extern void ret_from_fork(void);
extern void ret_from_kernel_thread(void);
struct thread_info *childti = task_thread_info(p);
struct pt_regs * childregs;
struct switch_stack * childstack, *stack;
unsigned long stack_offset, settls;
struct pt_regs *childregs = task_pt_regs(p);
struct switch_stack *childstack, *stack;
unsigned long settls;
stack_offset = PAGE_SIZE - sizeof(struct pt_regs);
if (!(regs->ps & 8))
stack_offset = (PAGE_SIZE-1) & (unsigned long) regs;
childregs = (struct pt_regs *)
(stack_offset + PAGE_SIZE + task_stack_page(p));
childstack = ((struct switch_stack *) childregs) - 1;
if (unlikely(!regs)) {
/* kernel thread */
memset(childstack, 0,
sizeof(struct switch_stack) + sizeof(struct pt_regs));
childstack->r26 = (unsigned long) ret_from_kernel_thread;
childstack->r9 = usp; /* function */
childstack->r10 = arg;
childregs->hae = alpha_mv.hae_cache,
childti->pcb.usp = 0;
childti->pcb.ksp = (unsigned long) childstack;
childti->pcb.flags = 1; /* set FEN, clear everything else */
return 0;
}
*childregs = *regs;
settls = regs->r20;
childregs->r0 = 0;
@ -293,7 +295,6 @@ copy_thread(unsigned long clone_flags, unsigned long usp,
childregs->r20 = 1; /* OSF/1 has some strange fork() semantics. */
regs->r20 = 0;
stack = ((struct switch_stack *) regs) - 1;
childstack = ((struct switch_stack *) childregs) - 1;
*childstack = *stack;
childstack->r26 = (unsigned long) ret_from_fork;
childti->pcb.usp = usp;