Unverified Commit 592dd126 authored by openeuler-ci-bot's avatar openeuler-ci-bot Committed by Gitee
Browse files

!1444 ring-buffer: Fix deadloop issue on reading trace_pipe 

Merge Pull Request from: @LiuYongQiang0816 
 
two patches from Zheng Yejian 
 
Link:https://gitee.com/openeuler/kernel/pulls/1444

 

Reviewed-by: default avatarXu Kuohai <xukuohai@huawei.com>
Signed-off-by: default avatarZhang Changzhong <zhangchangzhong@huawei.com>
parents d7ba8395 1d801741

kernel/trace/ftrace.c

+29 −12
Original line number Original line Diff line number Diff line
@@ -3048,12 +3048,25 @@ static int ftrace_allocate_records(struct ftrace_page *pg, int count) 
	return cnt;

	return cnt;

}

}





static void ftrace_free_pages(struct ftrace_page *pages)

{

	struct ftrace_page *pg = pages;

	int order;



	while (pg) {

		order = get_count_order(pg->size / ENTRIES_PER_PAGE);

		free_pages((unsigned long)pg->records, order);

		pages = pg->next;

		kfree(pg);

		pg = pages;

	}

}



static struct ftrace_page *

static struct ftrace_page *

ftrace_allocate_pages(unsigned long num_to_init)

ftrace_allocate_pages(unsigned long num_to_init)

{

{

	struct ftrace_page *start_pg;

	struct ftrace_page *start_pg;

	struct ftrace_page *pg;

	struct ftrace_page *pg;

	int order;

	int cnt;

	int cnt;





	if (!num_to_init)

	if (!num_to_init)
@@ -3087,14 +3100,7 @@ ftrace_allocate_pages(unsigned long num_to_init) 
	return start_pg;

	return start_pg;





 free_pages:

 free_pages:

	pg = start_pg;

	ftrace_free_pages(start_pg);

	while (pg) {

		order = get_count_order(pg->size / ENTRIES_PER_PAGE);

		free_pages((unsigned long)pg->records, order);

		start_pg = pg->next;

		kfree(pg);

		pg = start_pg;

	}

	pr_info("ftrace: FAILED to allocate memory for functions\n");

	pr_info("ftrace: FAILED to allocate memory for functions\n");

	return NULL;

	return NULL;

}

}
@@ -5575,9 +5581,11 @@ static int ftrace_process_locs(struct module *mod, 
			       unsigned long *start,

			       unsigned long *start,

			       unsigned long *end)

			       unsigned long *end)

{

{

	struct ftrace_page *pg_unuse = NULL;

	struct ftrace_page *start_pg;

	struct ftrace_page *start_pg;

	struct ftrace_page *pg;

	struct ftrace_page *pg;

	struct dyn_ftrace *rec;

	struct dyn_ftrace *rec;

	unsigned long skipped = 0;

	unsigned long count;

	unsigned long count;

	unsigned long *p;

	unsigned long *p;

	unsigned long addr;

	unsigned long addr;
@@ -5630,8 +5638,10 @@ static int ftrace_process_locs(struct module *mod, 
		 * object files to satisfy alignments.

		 * object files to satisfy alignments.

		 * Skip any NULL pointers.

		 * Skip any NULL pointers.

		 */

		 */

		if (!addr)

		if (!addr) {

			skipped++;

			continue;

			continue;

		}





		if (pg->index == pg->size) {

		if (pg->index == pg->size) {

			/* We should have allocated enough */

			/* We should have allocated enough */
@@ -5644,8 +5654,10 @@ static int ftrace_process_locs(struct module *mod, 
		rec->ip = addr;

		rec->ip = addr;

	}

	}





	/* We should have used all pages */

	if (pg->next) {

	WARN_ON(pg->next);

		pg_unuse = pg->next;

		pg->next = NULL;

	}





	/* Assign the last page to ftrace_pages */

	/* Assign the last page to ftrace_pages */

	ftrace_pages = pg;

	ftrace_pages = pg;
@@ -5667,6 +5679,11 @@ static int ftrace_process_locs(struct module *mod, 
 out:

 out:

	mutex_unlock(&ftrace_lock);

	mutex_unlock(&ftrace_lock);





	/* We should have used all pages unless we skipped some */

	if (pg_unuse) {

		WARN_ON(!skipped);

		ftrace_free_pages(pg_unuse);

	}

	return ret;

	return ret;

}

}

kernel/trace/ring_buffer.c

+15 −9
Original line number Original line Diff line number Diff line
@@ -4407,28 +4407,34 @@ unsigned long ring_buffer_size(struct ring_buffer *buffer, int cpu) 
}

}

EXPORT_SYMBOL_GPL(ring_buffer_size);

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

static void

rb_reset_cpu(struct ring_buffer_per_cpu *cpu_buffer)

rb_reset_cpu(struct ring_buffer_per_cpu *cpu_buffer)

{

{

	struct buffer_page *page;



	rb_head_page_deactivate(cpu_buffer);

	rb_head_page_deactivate(cpu_buffer);





	cpu_buffer->head_page

	cpu_buffer->head_page

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

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

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

	rb_clear_buffer_page(cpu_buffer->head_page);

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

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

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

		rb_clear_buffer_page(page);



	}

	cpu_buffer->head_page->read = 0;





	cpu_buffer->tail_page = cpu_buffer->head_page;

	cpu_buffer->tail_page = cpu_buffer->head_page;

	cpu_buffer->commit_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->reader_page->list);

	INIT_LIST_HEAD(&cpu_buffer->new_pages);

	INIT_LIST_HEAD(&cpu_buffer->new_pages);

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

	rb_clear_buffer_page(cpu_buffer->reader_page);

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

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

	cpu_buffer->reader_page->read = 0;





	local_set(&cpu_buffer->entries_bytes, 0);

	local_set(&cpu_buffer->entries_bytes, 0);

	local_set(&cpu_buffer->overrun, 0);

	local_set(&cpu_buffer->overrun, 0);