Commit 99d23280 authored by Steven Rostedt's avatar Steven Rostedt Committed by Steven Rostedt (Google)
Browse files

ring-buffer: Simplify functions with __free(kfree) to free allocations 

The function rb_allocate_pages() allocates cpu_buffer and on error needs
to free it. It has a single return. Use __free(kfree) and return directly
on errors and have the return use return_ptr(cpu_buffer).

The function alloc_buffer() allocates buffer and on error needs to free
it. It has a single return. Use __free(kfree) and return directly on
errors and have the return use return_ptr(buffer).

The function __rb_map_vma() allocates a temporary array "pages". Have it
use __free() and not worry about freeing it when returning.

Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/20250527143144.6edc4625@gandalf.local.home


Reviewed-by: default avatarMasami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: default avatarSteven Rostedt (Google) <rostedt@goodmis.org>
parent 60bc720e

kernel/trace/ring_buffer.c

+9 −18
Original line number Diff line number Diff line
@@ -2226,7 +2226,7 @@ static int rb_allocate_pages(struct ring_buffer_per_cpu *cpu_buffer, 
static struct ring_buffer_per_cpu *

rb_allocate_cpu_buffer(struct trace_buffer *buffer, long nr_pages, int cpu)

{

	struct ring_buffer_per_cpu *cpu_buffer;

	struct ring_buffer_per_cpu *cpu_buffer __free(kfree) = NULL;

	struct ring_buffer_cpu_meta *meta;

	struct buffer_page *bpage;

	struct page *page;
@@ -2252,7 +2252,7 @@ rb_allocate_cpu_buffer(struct trace_buffer *buffer, long nr_pages, int cpu) 
	bpage = kzalloc_node(ALIGN(sizeof(*bpage), cache_line_size()),

			    GFP_KERNEL, cpu_to_node(cpu));

	if (!bpage)

		goto fail_free_buffer;

		return NULL;



	rb_check_bpage(cpu_buffer, bpage);
@@ -2318,13 +2318,11 @@ rb_allocate_cpu_buffer(struct trace_buffer *buffer, long nr_pages, int cpu) 
		rb_head_page_activate(cpu_buffer);

	}



	return cpu_buffer;

	return_ptr(cpu_buffer);



 fail_free_reader:

	free_buffer_page(cpu_buffer->reader_page);



 fail_free_buffer:

	kfree(cpu_buffer);

	return NULL;

}
@@ -2359,7 +2357,7 @@ static struct trace_buffer *alloc_buffer(unsigned long size, unsigned flags, 
					 unsigned long scratch_size,

					 struct lock_class_key *key)

{

	struct trace_buffer *buffer;

	struct trace_buffer *buffer __free(kfree) = NULL;

	long nr_pages;

	int subbuf_size;

	int bsize;
@@ -2373,7 +2371,7 @@ static struct trace_buffer *alloc_buffer(unsigned long size, unsigned flags, 
		return NULL;



	if (!zalloc_cpumask_var(&buffer->cpumask, GFP_KERNEL))

		goto fail_free_buffer;

		return NULL;



	buffer->subbuf_order = order;

	subbuf_size = (PAGE_SIZE << order);
@@ -2472,7 +2470,7 @@ static struct trace_buffer *alloc_buffer(unsigned long size, unsigned flags, 


	mutex_init(&buffer->mutex);



	return buffer;

	return_ptr(buffer);



 fail_free_buffers:

	for_each_buffer_cpu(buffer, cpu) {
@@ -2484,8 +2482,6 @@ static struct trace_buffer *alloc_buffer(unsigned long size, unsigned flags, 
 fail_free_cpumask:

	free_cpumask_var(buffer->cpumask);



 fail_free_buffer:

	kfree(buffer);

	return NULL;

}
@@ -7057,7 +7053,7 @@ static int __rb_map_vma(struct ring_buffer_per_cpu *cpu_buffer, 
{

	unsigned long nr_subbufs, nr_pages, nr_vma_pages, pgoff = vma->vm_pgoff;

	unsigned int subbuf_pages, subbuf_order;

	struct page **pages;

	struct page **pages __free(kfree) = NULL;

	int p = 0, s = 0;

	int err;
@@ -7125,10 +7121,8 @@ static int __rb_map_vma(struct ring_buffer_per_cpu *cpu_buffer, 
		struct page *page;

		int off = 0;



		if (WARN_ON_ONCE(s >= nr_subbufs)) {

			err = -EINVAL;

			goto out;

		}

		if (WARN_ON_ONCE(s >= nr_subbufs))

			return -EINVAL;



		page = virt_to_page((void *)cpu_buffer->subbuf_ids[s]);
@@ -7143,9 +7137,6 @@ static int __rb_map_vma(struct ring_buffer_per_cpu *cpu_buffer, 


	err = vm_insert_pages(vma, vma->vm_start, pages, &nr_pages);



out:

	kfree(pages);



	return err;

}

#else