[PATCH] arm64: treat PF_IO_WORKER like PF_KTHREAD for mitigations

[Jens Axboe]

Like PF_KTHREAD, PF_IO_WORKER never exit to userspace. They exist
entirely within the kernel, and hence don't need any task mitigations
applied.

Signed-off-by: Jens Axboe <axboe at kernel.dk>

---

diff --git a/arch/arm64/kernel/proton-pack.c b/arch/arm64/kernel/proton-pack.c
index fca9cc6f5581..25a21c3d446c 100644
--- a/arch/arm64/kernel/proton-pack.c
+++ b/arch/arm64/kernel/proton-pack.c
@@ -654,7 +654,7 @@ static void __update_pstate_ssbs(struct pt_regs *regs, bool state)
 void spectre_v4_enable_task_mitigation(struct task_struct *tsk)
 {
 	struct pt_regs *regs = task_pt_regs(tsk);
-	bool ssbs = false, kthread = tsk->flags & PF_KTHREAD;
+	bool ssbs = false, kthread = tsk->flags & (PF_KTHREAD | PF_IO_WORKER);
 
 	if (spectre_v4_mitigations_off())
 		ssbs = true;

-- 
Jens Axboe