* [PATCH] ring-buffer: Unlock resize on mmap error
@ 2025-02-13 18:19 Steven Rostedt
2025-02-14 0:10 ` Masami Hiramatsu
0 siblings, 1 reply; 2+ messages in thread
From: Steven Rostedt @ 2025-02-13 18:19 UTC (permalink / raw)
To: LKML, Linux Trace Kernel
Cc: Masami Hiramatsu, Mathieu Desnoyers, Vincent Donnefort
From: Steven Rostedt <rostedt@goodmis.org>
Memory mapping the tracing ring buffer will disable resizing the buffer.
But if there's an error in the memory mapping like an invalid parameter,
the function exits out without re-enabling the resizing of the ring
buffer, preventing the ring buffer from being resized after that.
Cc: stable@vger.kernel.org
Fixes: 117c39200d9d7 ("ring-buffer: Introducing ring-buffer mapping functions")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
---
kernel/trace/ring_buffer.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index b8e0ae15ca5b..07b421115692 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -7126,6 +7126,7 @@ int ring_buffer_map(struct trace_buffer *buffer, int cpu,
kfree(cpu_buffer->subbuf_ids);
cpu_buffer->subbuf_ids = NULL;
rb_free_meta_page(cpu_buffer);
+ atomic_dec(&cpu_buffer->resize_disabled);
}
unlock:
--
2.47.2
^ permalink raw reply [flat|nested] 2+ messages in thread* Re: [PATCH] ring-buffer: Unlock resize on mmap error
2025-02-13 18:19 [PATCH] ring-buffer: Unlock resize on mmap error Steven Rostedt
@ 2025-02-14 0:10 ` Masami Hiramatsu
0 siblings, 0 replies; 2+ messages in thread
From: Masami Hiramatsu @ 2025-02-14 0:10 UTC (permalink / raw)
To: Steven Rostedt
Cc: LKML, Linux Trace Kernel, Masami Hiramatsu, Mathieu Desnoyers,
Vincent Donnefort
On Thu, 13 Feb 2025 13:19:57 -0500
Steven Rostedt <rostedt@goodmis.org> wrote:
> From: Steven Rostedt <rostedt@goodmis.org>
>
> Memory mapping the tracing ring buffer will disable resizing the buffer.
> But if there's an error in the memory mapping like an invalid parameter,
> the function exits out without re-enabling the resizing of the ring
> buffer, preventing the ring buffer from being resized after that.
>
Looks good to me.
Reveiewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Thank you,
> Cc: stable@vger.kernel.org
> Fixes: 117c39200d9d7 ("ring-buffer: Introducing ring-buffer mapping functions")
> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
> ---
> kernel/trace/ring_buffer.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
> index b8e0ae15ca5b..07b421115692 100644
> --- a/kernel/trace/ring_buffer.c
> +++ b/kernel/trace/ring_buffer.c
> @@ -7126,6 +7126,7 @@ int ring_buffer_map(struct trace_buffer *buffer, int cpu,
> kfree(cpu_buffer->subbuf_ids);
> cpu_buffer->subbuf_ids = NULL;
> rb_free_meta_page(cpu_buffer);
> + atomic_dec(&cpu_buffer->resize_disabled);
> }
>
> unlock:
> --
> 2.47.2
>
--
Masami Hiramatsu (Google) <mhiramat@kernel.org>
^ permalink raw reply [flat|nested] 2+ messages in thread
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2025-02-13 18:19 [PATCH] ring-buffer: Unlock resize on mmap error Steven Rostedt
2025-02-14 0:10 ` Masami Hiramatsu
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