[for-next][PATCH 06/11] ring-buffer: Zero ring-buffer sub-buffers

Steven Rostedt
2024-02-21T14:06:40Z

In preparation for the ring-buffer memory mapping where each subbuf will
be accessible to user-space, zero all the page allocations.

Link: https://lore.kernel.org/linux-trace-kernel/20240220202310.2489614-2-vdonnefort@google.com

Signed-off-by: Vincent Donnefort <vdonnefort@google.com>
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
---
kernel/trace/ring_buffer.c | 9 ++++++---
1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index fd4bfe3ecf01..ca796675c0a1 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -1472,7 +1472,8 @@ 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;
@@ -1557,7 +1558,8 @@ 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