[PATCH 1/1] MIPS: Fix fpu trap invoked by io-worker

[wangyangbo]

From: wangyangbo <wangyangbo@xxxxxxxxxxxxx>

Create worker thread from original user task in mips, possibly copying
FPU flag from user task, introducing save_fp when switch_to, triggering
do_cpu trap. So clear USEDFPU flag for IO_WORKER in copy_thread.

Signed-off-by: wangyangbo <yangbonis@xxxxxxxxxx>
---
 arch/mips/kernel/process.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/arch/mips/kernel/process.c b/arch/mips/kernel/process.c
index 95aa86fa6077..0095006d48c7 100644
--- a/arch/mips/kernel/process.c
+++ b/arch/mips/kernel/process.c
@@ -135,6 +135,9 @@ int copy_thread(unsigned long clone_flags, unsigned long usp,
 		status |= ST0_EXL;
 #endif
 		childregs->cp0_status = status;
+
+		if (p->flags & PF_IO_WORKER)
+			clear_tsk_thread_flag(p, TIF_USEDFPU);
 		return 0;
 	}
 
-- 
2.20.1