Merge branch 'x86-fpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git...

[karo-tx-linux.git] / arch / x86 / kernel / process.c

diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c
index 0c8992dbead5e9ccdf00f1b87dfe3ec72d58c7fc..8213da62b1b79c1c37798b598494add6802881d7 100644 (file)
--- a/arch/x86/kernel/process.c
+++ b/arch/x86/kernel/process.c
@@ -89,8 +89,8 @@ int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src)
 
        dst->thread.fpu_counter = 0;
        dst->thread.fpu.has_fpu = 0;
-       dst->thread.fpu.last_cpu = ~0;
        dst->thread.fpu.state = NULL;
+       task_disable_lazy_fpu_restore(dst);
        if (tsk_used_math(src)) {
                int err = fpu_alloc(&dst->thread.fpu);
                if (err)
@@ -151,13 +151,18 @@ void flush_thread(void)
 
        flush_ptrace_hw_breakpoint(tsk);
        memset(tsk->thread.tls_array, 0, sizeof(tsk->thread.tls_array));
-       drop_init_fpu(tsk);
-       /*
-        * Free the FPU state for non xsave platforms. They get reallocated
-        * lazily at the first use.
-        */
-       if (!use_eager_fpu())
+
+       if (!use_eager_fpu()) {
+               /* FPU state will be reallocated lazily at the first use. */
+               drop_fpu(tsk);
                free_thread_xstate(tsk);
+       } else if (!used_math()) {
+               /* kthread execs. TODO: cleanup this horror. */
+               if (WARN_ON(init_fpu(tsk)))
+                       force_sig(SIGKILL, tsk);
+               user_fpu_begin();
+               restore_init_xstate();
+       }
 }
 
 static void hard_disable_TSC(void)