[v11,1/5] ring-buffer: Zero ring-buffer sub-buffers
Commit Message
In preparation for the ring-buffer memory mapping where each subbuf will
be accessible to user-space, zero all the page allocations.
Signed-off-by: Vincent Donnefort <vdonnefort@google.com>
Comments
On Thu, 11 Jan 2024 16:17:08 +0000
Vincent Donnefort <vdonnefort@google.com> wrote:
> In preparation for the ring-buffer memory mapping where each subbuf will
> be accessible to user-space, zero all the page allocations.
>
> Signed-off-by: Vincent Donnefort <vdonnefort@google.com>
Looks good to me.
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Thank you!
>
> diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
> index 173d2595ce2d..db73e326fa04 100644
> --- a/kernel/trace/ring_buffer.c
> +++ b/kernel/trace/ring_buffer.c
> @@ -1466,7 +1466,8 @@ static int __rb_allocate_pages(struct ring_buffer_per_cpu *cpu_buffer,
>
> list_add(&bpage->list, pages);
>
> - page = alloc_pages_node(cpu_to_node(cpu_buffer->cpu), mflags,
> + page = alloc_pages_node(cpu_to_node(cpu_buffer->cpu),
> + mflags | __GFP_ZERO,
> cpu_buffer->buffer->subbuf_order);
> if (!page)
> goto free_pages;
> @@ -1551,7 +1552,8 @@ rb_allocate_cpu_buffer(struct trace_buffer *buffer, long nr_pages, int cpu)
>
> cpu_buffer->reader_page = bpage;
>
> - page = alloc_pages_node(cpu_to_node(cpu), GFP_KERNEL, cpu_buffer->buffer->subbuf_order);
> + page = alloc_pages_node(cpu_to_node(cpu), GFP_KERNEL | __GFP_ZERO,
> + cpu_buffer->buffer->subbuf_order);
> if (!page)
> goto fail_free_reader;
> bpage->page = page_address(page);
> @@ -5525,7 +5527,8 @@ ring_buffer_alloc_read_page(struct trace_buffer *buffer, int cpu)
> if (bpage->data)
> goto out;
>
> - page = alloc_pages_node(cpu_to_node(cpu), GFP_KERNEL | __GFP_NORETRY,
> + page = alloc_pages_node(cpu_to_node(cpu),
> + GFP_KERNEL | __GFP_NORETRY | __GFP_ZERO,
> cpu_buffer->buffer->subbuf_order);
> if (!page) {
> kfree(bpage);
> --
> 2.43.0.275.g3460e3d667-goog
>
@@ -1466,7 +1466,8 @@ static int __rb_allocate_pages(struct ring_buffer_per_cpu *cpu_buffer,
list_add(&bpage->list, pages);
- page = alloc_pages_node(cpu_to_node(cpu_buffer->cpu), mflags,
+ page = alloc_pages_node(cpu_to_node(cpu_buffer->cpu),
+ mflags | __GFP_ZERO,
cpu_buffer->buffer->subbuf_order);
if (!page)
goto free_pages;
@@ -1551,7 +1552,8 @@ rb_allocate_cpu_buffer(struct trace_buffer *buffer, long nr_pages, int cpu)
cpu_buffer->reader_page = bpage;
- page = alloc_pages_node(cpu_to_node(cpu), GFP_KERNEL, cpu_buffer->buffer->subbuf_order);
+ page = alloc_pages_node(cpu_to_node(cpu), GFP_KERNEL | __GFP_ZERO,
+ cpu_buffer->buffer->subbuf_order);
if (!page)
goto fail_free_reader;
bpage->page = page_address(page);
@@ -5525,7 +5527,8 @@ ring_buffer_alloc_read_page(struct trace_buffer *buffer, int cpu)
if (bpage->data)
goto out;
- page = alloc_pages_node(cpu_to_node(cpu), GFP_KERNEL | __GFP_NORETRY,
+ page = alloc_pages_node(cpu_to_node(cpu),
+ GFP_KERNEL | __GFP_NORETRY | __GFP_ZERO,
cpu_buffer->buffer->subbuf_order);
if (!page) {
kfree(bpage);