event_size contains the maximum size the iterator can read for each event. It corresponds to the maximum capacity of a ring-buffer page. During non-consuming read, resizing is disabled. It is therefore safe to just use rb_subbuf_capacity(), making event_size redundant. Remove it.
Signed-off-by: Vincent Donnefort <[email protected]> --- kernel/trace/ring_buffer.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c index 1a158a24b3c8..3129589e2d0e 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -680,7 +680,6 @@ struct ring_buffer_iter { u64 read_stamp; u64 page_stamp; struct ring_buffer_event *event; - size_t event_size; int missed_events; }; @@ -3558,9 +3557,11 @@ rb_iter_head_event(struct ring_buffer_iter *iter) */ barrier(); - if ((iter->head + length) > commit || length > iter->event_size) + if ((iter->head + length) > commit || + length > rb_subbuf_capacity(iter->cpu_buffer->buffer)) { /* Writer corrupted the read? */ goto reset; + } memcpy(iter->event, event, length); /* @@ -6488,8 +6489,7 @@ ring_buffer_read_start(struct trace_buffer *buffer, int cpu, gfp_t flags) mutex_unlock(&buffer->mutex); /* Holds the entire event: data and meta data. */ - iter->event_size = rb_page_capacity(READ_ONCE(cpu_buffer->reader_page)); - iter->event = kmalloc(iter->event_size, flags); + iter->event = kmalloc(rb_subbuf_capacity(buffer), flags); if (!iter->event) { atomic_dec(&cpu_buffer->resize_disabled); return NULL; -- 2.55.0.1082.g2b9226bbc0-goog
