diff options
Diffstat (limited to 'io_uring')
| -rw-r--r-- | io_uring/kbuf.c | 27 |
1 files changed, 19 insertions, 8 deletions
diff --git a/io_uring/kbuf.c b/io_uring/kbuf.c index 556f4df25b0fa..9123138aa9f48 100644 --- a/io_uring/kbuf.c +++ b/io_uring/kbuf.c @@ -477,7 +477,7 @@ static int io_pin_pbuf_ring(struct io_uring_buf_reg *reg, { struct io_uring_buf_ring *br; struct page **pages; - int nr_pages; + int i, nr_pages; pages = io_pin_pages(reg->ring_addr, flex_array_size(br, bufs, reg->ring_entries), @@ -485,6 +485,17 @@ static int io_pin_pbuf_ring(struct io_uring_buf_reg *reg, if (IS_ERR(pages)) return PTR_ERR(pages); + /* + * Apparently some 32-bit boxes (ARM) will return highmem pages, + * which then need to be mapped. We could support that, but it'd + * complicate the code and slowdown the common cases quite a bit. + * So just error out, returning -EINVAL just like we did on kernels + * that didn't support mapped buffer rings. + */ + for (i = 0; i < nr_pages; i++) + if (PageHighMem(pages[i])) + goto error_unpin; + br = page_address(pages[0]); #ifdef SHM_COLOUR /* @@ -496,13 +507,8 @@ static int io_pin_pbuf_ring(struct io_uring_buf_reg *reg, * 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; - } + if ((reg->ring_addr | (unsigned long) br) & (SHM_COLOUR - 1)) + goto error_unpin; #endif bl->buf_pages = pages; bl->buf_nr_pages = nr_pages; @@ -510,6 +516,11 @@ static int io_pin_pbuf_ring(struct io_uring_buf_reg *reg, bl->is_mapped = 1; bl->is_mmap = 0; return 0; +error_unpin: + for (i = 0; i < nr_pages; i++) + unpin_user_page(pages[i]); + kvfree(pages); + return -EINVAL; } static int io_alloc_pbuf_ring(struct io_uring_buf_reg *reg, |