MIPS: Fix race condition with FPU thread task flag during context switch.

[karo-tx-linux.git] / arch / mips / include / asm / switch_to.h

diff --git a/arch/mips/include/asm/switch_to.h b/arch/mips/include/asm/switch_to.h
index 5d33621b5658f9c46314f4fcc1d2d123eaaf83d5..4f8ddba8c360050703d6d760b5909e92944e8b23 100644 (file)
--- a/arch/mips/include/asm/switch_to.h
+++ b/arch/mips/include/asm/switch_to.h
@@ -22,7 +22,7 @@ struct task_struct;
  * switch_to(n) should switch tasks to task nr n, first
  * checking that n isn't the current task, in which case it does nothing.
  */
-extern asmlinkage void *resume(void *last, void *next, void *next_ti);
+extern asmlinkage void *resume(void *last, void *next, void *next_ti, u32 __usedfpu);
 
 extern unsigned int ll_bit;
 extern struct task_struct *ll_task;
@@ -66,11 +66,13 @@ do {                                                                        \
 
 #define switch_to(prev, next, last)                                    \
 do {                                                                   \
+       u32 __usedfpu;                                                  \
        __mips_mt_fpaff_switch_to(prev);                                \
        if (cpu_has_dsp)                                                \
                __save_dsp(prev);                                       \
        __clear_software_ll_bit();                                      \
-       (last) = resume(prev, next, task_thread_info(next));            \
+       __usedfpu = test_and_clear_tsk_thread_flag(prev, TIF_USEDFPU);  \
+       (last) = resume(prev, next, task_thread_info(next), __usedfpu); \
 } while (0)
 
 #define finish_arch_switch(prev)                                       \