diff options
| author | Vincent Donnefort <vdonnefort@google.com> | 2026-08-13 14:11:44 +0100 |
|---|---|---|
| committer | Steven Rostedt <rostedt@goodmis.org> | 2026-08-14 13:13:38 -0400 |
| commit | 24974bd0da1b47fd56c975533ead50abf754e74d (patch) | |
| tree | 06d13cd2b95749c85089852434cce9470298bfa0 /kernel/trace | |
| parent | 234b1a72e9706fe20c08c96f4374ec8e83b934cb (diff) | |
ring-buffer: Hold cpu_buffer::lock when resizing a subbuf
Because, ring_buffer_subbuf_order_set() can clear cpu_buffer->free_page,
hold cpu_buffer->lock to prevent races with
ring_buffer_alloc_read_page() and ring_buffer_free_read_page().
Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/20260813131152.3589632-3-vdonnefort@google.com
Fixes: 8e7b58c27b3c ("ring-buffer: Just update the subbuffers when changing their allocation order")
Reported-by: Sashiko <sashiko-bot@kernel.org>
Closes: https://sashiko.dev/#/patchset/20260810125633.3344684-1-vdonnefort%40google.com # patch 3
Signed-off-by: Vincent Donnefort <vdonnefort@google.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Diffstat (limited to 'kernel/trace')
| -rw-r--r-- | kernel/trace/ring_buffer.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c index 73a3fb76ba4d..0479c404db03 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -7431,8 +7431,10 @@ int ring_buffer_subbuf_order_set(struct trace_buffer *buffer, int order) cpu_buffer->nr_pages = cpu_buffer->nr_pages_to_update; cpu_buffer->nr_pages_to_update = 0; + arch_spin_lock(&cpu_buffer->lock); old_free_data_page = cpu_buffer->free_page; cpu_buffer->free_page = NULL; + arch_spin_unlock(&cpu_buffer->lock); rb_head_page_activate(cpu_buffer); |