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Diffstat (limited to 'io_uring/kbuf.c')
-rw-r--r--io_uring/kbuf.c27
1 files changed, 19 insertions, 8 deletions
diff --git a/io_uring/kbuf.c b/io_uring/kbuf.c
index 556f4df25b0f..9123138aa9f4 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,