diff options
| author | Vincent Donnefort <vdonnefort@google.com> | 2026-09-11 20:39:35 +0100 |
|---|---|---|
| committer | Steven Rostedt <rostedt@goodmis.org> | 2026-09-13 13:06:29 -0400 |
| commit | 442ffa742daa65a0e8fe003abe9fbe472366e4de (patch) | |
| tree | 1f72c21dd26526d26b19bee8d453a6b8387755a0 /kernel | |
| parent | bcfe2816e6ec46c3f4c58aa4264476665ddb3f69 (diff) | |
tracing/remotes: Account for ring buffer page header in size calculation
trace_buffer_desc_size() and trace_remote_alloc_buffer() undercount the
required pages because every ring buffer page contains a header
(BUF_PAGE_HDR_SIZE). Account for that header to ensure allocated remote
ring buffers aren't smaller than requested by the user.
The newly introduced helper __calc_nr_pages_ring_buffer_desc() can
return a value that overflows the descriptor nr_pages field (32 bits).
Link: https://patch.msgid.link/20260911193937.602202-2-vdonnefort@google.com
Fixes: 2e67fabd8b77 ("ring-buffer: Introduce ring-buffer remotes")
Signed-off-by: Vincent Donnefort <vdonnefort@google.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/trace/trace_remote.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/kernel/trace/trace_remote.c b/kernel/trace/trace_remote.c index 75fa1ffc4c96..c17902e42ef1 100644 --- a/kernel/trace/trace_remote.c +++ b/kernel/trace/trace_remote.c @@ -980,7 +980,7 @@ int trace_remote_alloc_buffer(struct trace_buffer_desc *desc, size_t desc_size, const struct cpumask *cpumask) { size_t min_desc_size = trace_buffer_desc_size(buffer_size, cpumask_weight(cpumask)); - unsigned int nr_pages = max(DIV_ROUND_UP(buffer_size, PAGE_SIZE), 2UL) + 1; + unsigned int nr_pages = __calc_nr_pages_ring_buffer_desc(buffer_size); struct ring_buffer_desc *rb_desc; int cpu, ret = -ENOMEM; |