riscv: vector: use a mask to write vstate_ctrl

AndybnACT · palmer-dabbelt · commit 5b6048f2ff71 · 2024-01-16T07:14:00.000-08:00
riscv_v_ctrl_set() should only touch bits within PR_RISCV_V_VSTATE_CTRL_MASK. So, use the mask when we really set task's vstate_ctrl. Signed-off-by: Andy Chiu <andy.chiu@sifive.com> Tested-by: Björn Töpel <bjorn@rivosinc.com> Tested-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com> Link: https://lore.kernel.org/r/20240115055929.4736-9-andy.chiu@sifive.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
diff --git a/arch/riscv/kernel/vector.c b/arch/riscv/kernel/vector.c
@@ -122,7 +122,8 @@ static inline void riscv_v_ctrl_set(struct task_struct *tsk, int cur, int nxt,
 	ctrl |= VSTATE_CTRL_MAKE_NEXT(nxt);
 	if (inherit)
 		ctrl |= PR_RISCV_V_VSTATE_CTRL_INHERIT;
-	tsk->thread.vstate_ctrl = ctrl;
+	tsk->thread.vstate_ctrl &= ~PR_RISCV_V_VSTATE_CTRL_MASK;
+	tsk->thread.vstate_ctrl |= ctrl;
 }
 
 bool riscv_v_vstate_ctrl_user_allowed(void)

Original file line number	Diff line number	Diff line change
`@@ -122,7 +122,8 @@ static inline void riscv_v_ctrl_set(struct task_struct *tsk, int cur, int nxt,`
`122`	`122`	`ctrl \|= VSTATE_CTRL_MAKE_NEXT(nxt);`
`123`	`123`	`if (inherit)`
`124`	`124`	`ctrl \|= PR_RISCV_V_VSTATE_CTRL_INHERIT;`
`125`		`- tsk->thread.vstate_ctrl = ctrl;`
	`125`	`+ tsk->thread.vstate_ctrl &= ~PR_RISCV_V_VSTATE_CTRL_MASK;`
	`126`	`+ tsk->thread.vstate_ctrl \|= ctrl;`
`126`	`127`	`}`
`127`	`128`
`128`	`129`	`bool riscv_v_vstate_ctrl_user_allowed(void)`