From: Rouven Czerwinski Date: Wed, 3 Jul 2019 10:03:50 +0000 (+0200) Subject: tee: optee: add might_sleep for RPC requests X-Git-Tag: v5.4-rc1~186^2~26^2 X-Git-Url: https://asedeno.scripts.mit.edu/gitweb/?a=commitdiff_plain;h=9f02b8f61f29f4518581770d57bfffe99b1ea599;p=linux.git tee: optee: add might_sleep for RPC requests If the kernel is compiled with CONFIG_PREEMPT_VOLUNTARY and OP-TEE is executing a long running workload, the following errors are raised: [ 1705.971228] rcu: INFO: rcu_sched detected stalls on CPUs/tasks: [ 1705.977195] rcu: (detected by 0, t=2102 jiffies, g=51977, q=3) [ 1705.983152] rcu: All QSes seen, last rcu_sched kthread activity 2102 (140596-138494), jiffies_till_next_fqs=1, root ->qsmask 0x0 [ 1705.994729] optee-xtest R running task 0 169 157 0x00000002 While OP-TEE is returning regularly to the kernel due to timer interrupts, the OPTEE_SMC_FUNC_FOREIGN_INTR case does not contain an explicit rescheduling point. Add a might_sleep() to the RPC request case to ensure that the kernel can reschedule another task if OP-TEE requests RPC handling. Signed-off-by: Rouven Czerwinski Signed-off-by: Jens Wiklander --- diff --git a/drivers/tee/optee/call.c b/drivers/tee/optee/call.c index aa942703ae65..13b0269a0abc 100644 --- a/drivers/tee/optee/call.c +++ b/drivers/tee/optee/call.c @@ -148,6 +148,7 @@ u32 optee_do_call_with_arg(struct tee_context *ctx, phys_addr_t parg) */ optee_cq_wait_for_completion(&optee->call_queue, &w); } else if (OPTEE_SMC_RETURN_IS_RPC(res.a0)) { + might_sleep(); param.a0 = res.a0; param.a1 = res.a1; param.a2 = res.a2;