Unverified Commit ffb4c6b3 authored by openeuler-ci-bot's avatar openeuler-ci-bot Committed by Gitee
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!1896 [sync] PR-1853: ring-buffer: Fix deadloop issue on reading trace_pipe 

Merge Pull Request from: @openeuler-sync-bot 
 

Origin pull request: 
https://gitee.com/openeuler/kernel/pulls/1853 
 
PR sync from: Zheng Yejian <zhengyejian1@huawei.com>
https://mailweb.openeuler.org/hyperkitty/list/kernel@openeuler.org/message/Z3U5IIBFKGQEGPESNSJ6KDC2MC7NFUCF/ 
 
https://gitee.com/openeuler/kernel/issues/I7TKEB 
 
Link:https://gitee.com/openeuler/kernel/pulls/1896

 

Reviewed-by: default avatarXu Kuohai <xukuohai@huawei.com>
Signed-off-by: default avatarJialin Zhang <zhangjialin11@huawei.com>
parents 4d014504 4fb3b34e

kernel/trace/ring_buffer.c

+15 −9
Original line number Diff line number Diff line
@@ -4890,28 +4890,34 @@ unsigned long ring_buffer_size(struct trace_buffer *buffer, int cpu) 
}

EXPORT_SYMBOL_GPL(ring_buffer_size);



static void rb_clear_buffer_page(struct buffer_page *page)

{

	local_set(&page->write, 0);

	local_set(&page->entries, 0);

	rb_init_page(page->page);

	page->read = 0;

}



static void

rb_reset_cpu(struct ring_buffer_per_cpu *cpu_buffer)

{

	struct buffer_page *page;



	rb_head_page_deactivate(cpu_buffer);



	cpu_buffer->head_page

		= list_entry(cpu_buffer->pages, struct buffer_page, list);

	local_set(&cpu_buffer->head_page->write, 0);

	local_set(&cpu_buffer->head_page->entries, 0);

	local_set(&cpu_buffer->head_page->page->commit, 0);



	cpu_buffer->head_page->read = 0;

	rb_clear_buffer_page(cpu_buffer->head_page);

	list_for_each_entry(page, cpu_buffer->pages, list) {

		rb_clear_buffer_page(page);

	}



	cpu_buffer->tail_page = cpu_buffer->head_page;

	cpu_buffer->commit_page = cpu_buffer->head_page;



	INIT_LIST_HEAD(&cpu_buffer->reader_page->list);

	INIT_LIST_HEAD(&cpu_buffer->new_pages);

	local_set(&cpu_buffer->reader_page->write, 0);

	local_set(&cpu_buffer->reader_page->entries, 0);

	local_set(&cpu_buffer->reader_page->page->commit, 0);

	cpu_buffer->reader_page->read = 0;

	rb_clear_buffer_page(cpu_buffer->reader_page);



	local_set(&cpu_buffer->entries_bytes, 0);

	local_set(&cpu_buffer->overrun, 0);