From 55ccf3fe3f9a3441731aa79cf42a628fc4ecace9 Mon Sep 17 00:00:00 2001 From: Suresh Siddha Date: Wed, 16 May 2012 15:03:51 -0700 Subject: fork: move the real prepare_to_copy() users to arch_dup_task_struct() Historical prepare_to_copy() is mostly a no-op, duplicated for majority of the architectures and the rest following the x86 model of flushing the extended register state like fpu there. Remove it and use the arch_dup_task_struct() instead. Suggested-by: Oleg Nesterov Suggested-by: Linus Torvalds Signed-off-by: Suresh Siddha Link: http://lkml.kernel.org/r/1336692811-30576-1-git-send-email-suresh.b.siddha@intel.com Acked-by: Benjamin Herrenschmidt Cc: David Howells Cc: Koichi Yasutake Cc: Paul Mackerras Cc: Paul Mundt Cc: Chris Zankel Cc: Richard Henderson Cc: Russell King Cc: Haavard Skinnemoen Cc: Mike Frysinger Cc: Mark Salter Cc: Aurelien Jacquiot Cc: Mikael Starvik Cc: Yoshinori Sato Cc: Richard Kuo Cc: Tony Luck Cc: Michal Simek Cc: Ralf Baechle Cc: Jonas Bonn Cc: James E.J. Bottomley Cc: Helge Deller Cc: Martin Schwidefsky Cc: Heiko Carstens Cc: Chen Liqin Cc: Lennox Wu Cc: David S. Miller Cc: Chris Metcalf Cc: Jeff Dike Cc: Richard Weinberger Cc: Guan Xuetao Signed-off-by: H. Peter Anvin --- arch/x86/kernel/process.c | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'arch/x86/kernel/process.c') diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c index 1d92a5ab6e8b..b7e1e0e53987 100644 --- a/arch/x86/kernel/process.c +++ b/arch/x86/kernel/process.c @@ -47,10 +47,16 @@ EXPORT_SYMBOL_GPL(idle_notifier_unregister); struct kmem_cache *task_xstate_cachep; EXPORT_SYMBOL_GPL(task_xstate_cachep); +/* + * this gets called so that we can store lazy state into memory and copy the + * current task into the new thread. + */ int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src) { int ret; + unlazy_fpu(src); + *dst = *src; if (fpu_allocated(&src->thread.fpu)) { memset(&dst->thread.fpu, 0, sizeof(dst->thread.fpu)); -- cgit v1.2.2