#define RINGBUF_MAX_RECORD_SZ (UINT_MAX/4)
-/* Maximum size of ring buffer area is limited by 32-bit page offset within
- * record header, counted in pages. Reserve 8 bits for extensibility, and take
- * into account few extra pages for consumer/producer pages and
- * non-mmap()'able parts. This gives 64GB limit, which seems plenty for single
- * ring buffer.
- */
-#define RINGBUF_MAX_DATA_SZ \
- (((1ULL << 24) - RINGBUF_POS_PAGES - RINGBUF_PGOFF) * PAGE_SIZE)
-
struct bpf_ringbuf {
wait_queue_head_t waitq;
struct irq_work work;
wake_up_all(&rb->waitq);
}
+/* Maximum size of ring buffer area is limited by 32-bit page offset within
+ * record header, counted in pages. Reserve 8 bits for extensibility, and
+ * take into account few extra pages for consumer/producer pages and
+ * non-mmap()'able parts, the current maximum size would be:
+ *
+ * (((1ULL << 24) - RINGBUF_POS_PAGES - RINGBUF_PGOFF) * PAGE_SIZE)
+ *
+ * This gives 64GB limit, which seems plenty for single ring buffer. Now
+ * considering that the maximum value of data_sz is (4GB - 1), there
+ * will be no overflow, so just note the size limit in the comments.
+ */
static struct bpf_ringbuf *bpf_ringbuf_alloc(size_t data_sz, int numa_node)
{
struct bpf_ringbuf *rb;
!PAGE_ALIGNED(attr->max_entries))
return ERR_PTR(-EINVAL);
-#ifdef CONFIG_64BIT
- /* on 32-bit arch, it's impossible to overflow record's hdr->pgoff */
- if (attr->max_entries > RINGBUF_MAX_DATA_SZ)
- return ERR_PTR(-E2BIG);
-#endif
-
rb_map = bpf_map_area_alloc(sizeof(*rb_map), NUMA_NO_NODE);
if (!rb_map)
return ERR_PTR(-ENOMEM);