diff options
Diffstat (limited to 'io_uring/kbuf.c')
| -rw-r--r-- | io_uring/kbuf.c | 18 |
1 files changed, 18 insertions, 0 deletions
diff --git a/io_uring/kbuf.c b/io_uring/kbuf.c index cd1d9dddf58e..79c25459e8de 100644 --- a/io_uring/kbuf.c +++ b/io_uring/kbuf.c @@ -491,6 +491,24 @@ static int io_pin_pbuf_ring(struct io_uring_buf_reg *reg, return PTR_ERR(pages); br = page_address(pages[0]); +#ifdef SHM_COLOUR + /* + * On platforms that have specific aliasing requirements, SHM_COLOUR + * is set and we must guarantee that the kernel and user side align + * nicely. We cannot do that if IOU_PBUF_RING_MMAP isn't set and + * the application mmap's the provided ring buffer. Fail the request + * if we, by chance, don't end up with aligned addresses. The app + * should use IOU_PBUF_RING_MMAP instead, and liburing will handle + * this transparently. + */ + if ((reg->ring_addr | (unsigned long) br) & (SHM_COLOUR - 1)) { + int i; + + for (i = 0; i < nr_pages; i++) + unpin_user_page(pages[i]); + return -EINVAL; + } +#endif bl->buf_pages = pages; bl->buf_nr_pages = nr_pages; bl->buf_ring = br; |