Unverified Commit 28f89d80 authored by openeuler-ci-bot's avatar openeuler-ci-bot Committed by Gitee
Browse files

!1986 tracing: Fix race issue between cpu buffer write and swap 

Merge Pull Request from: @ci-robot 
 
PR sync from: Zheng Yejian <zhengyejian1@huawei.com>
https://mailweb.openeuler.org/hyperkitty/list/kernel@openeuler.org/message/F32ONRHZ3VFZHMNCWOVELR2TYVU5FHQ6/ 
 
https://gitee.com/openeuler/kernel/issues/I7YE3Y 
 
Link:https://gitee.com/openeuler/kernel/pulls/1986

 

Reviewed-by: default avatarXu Kuohai <xukuohai@huawei.com>
Signed-off-by: default avatarJialin Zhang <zhangjialin11@huawei.com>
parents ecedbab0 0cd59e11

kernel/trace/trace.c

+12 −5
Original line number Diff line number Diff line
@@ -7068,6 +7068,11 @@ static int tracing_snapshot_open(struct inode *inode, struct file *file) 
	return ret;

}



static void tracing_swap_cpu_buffer(void *tr)

{

	update_max_tr_single((struct trace_array *)tr, current, smp_processor_id());

}



static ssize_t

tracing_snapshot_write(struct file *filp, const char __user *ubuf, size_t cnt,

		       loff_t *ppos)
@@ -7126,13 +7131,15 @@ tracing_snapshot_write(struct file *filp, const char __user *ubuf, size_t cnt, 
			ret = tracing_alloc_snapshot_instance(tr);

		if (ret < 0)

			break;

		local_irq_disable();

		/* Now, we're going to swap */

		if (iter->cpu_file == RING_BUFFER_ALL_CPUS)

		if (iter->cpu_file == RING_BUFFER_ALL_CPUS) {

			local_irq_disable();

			update_max_tr(tr, current, smp_processor_id(), NULL);

		else

			update_max_tr_single(tr, current, iter->cpu_file);

			local_irq_enable();

		} else {

			smp_call_function_single(iter->cpu_file, tracing_swap_cpu_buffer,

						 (void *)tr, 1);

		}

		break;

	default:

		if (tr->allocated_snapshot) {