ublk: fix ublk_ch_mmap() for 64K page size

In ublk_ch_mmap(), queue id is calculated in the following way:

	(vma->vm_pgoff << PAGE_SHIFT) / `max_cmd_buf_size`

'max_cmd_buf_size' is equal to

	`UBLK_MAX_QUEUE_DEPTH * sizeof(struct ublksrv_io_desc)`

and UBLK_MAX_QUEUE_DEPTH is 4096 and part of UAPI, so 'max_cmd_buf_size'
is always page aligned in 4K page size kernel. However, it isn't true in
64K page size kernel.

Fixes the issue by always rounding up 'max_cmd_buf_size' with PAGE_SIZE.

Cc: stable@vger.kernel.org
Fixes: 71f28f3136 ("ublk_drv: add io_uring based userspace block driver")
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20241111110718.1394001-1-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Ming Lei 2024-11-11 19:07:18 +08:00 committed by Jens Axboe
parent b2113edaa9
commit d369735e02

View File

@ -669,12 +669,21 @@ static inline char *ublk_queue_cmd_buf(struct ublk_device *ub, int q_id)
return ublk_get_queue(ub, q_id)->io_cmd_buf; return ublk_get_queue(ub, q_id)->io_cmd_buf;
} }
static inline int __ublk_queue_cmd_buf_size(int depth)
{
return round_up(depth * sizeof(struct ublksrv_io_desc), PAGE_SIZE);
}
static inline int ublk_queue_cmd_buf_size(struct ublk_device *ub, int q_id) static inline int ublk_queue_cmd_buf_size(struct ublk_device *ub, int q_id)
{ {
struct ublk_queue *ubq = ublk_get_queue(ub, q_id); struct ublk_queue *ubq = ublk_get_queue(ub, q_id);
return round_up(ubq->q_depth * sizeof(struct ublksrv_io_desc), return __ublk_queue_cmd_buf_size(ubq->q_depth);
PAGE_SIZE); }
static int ublk_max_cmd_buf_size(void)
{
return __ublk_queue_cmd_buf_size(UBLK_MAX_QUEUE_DEPTH);
} }
/* /*
@ -1358,7 +1367,7 @@ static int ublk_ch_mmap(struct file *filp, struct vm_area_struct *vma)
{ {
struct ublk_device *ub = filp->private_data; struct ublk_device *ub = filp->private_data;
size_t sz = vma->vm_end - vma->vm_start; size_t sz = vma->vm_end - vma->vm_start;
unsigned max_sz = UBLK_MAX_QUEUE_DEPTH * sizeof(struct ublksrv_io_desc); unsigned max_sz = ublk_max_cmd_buf_size();
unsigned long pfn, end, phys_off = vma->vm_pgoff << PAGE_SHIFT; unsigned long pfn, end, phys_off = vma->vm_pgoff << PAGE_SHIFT;
int q_id, ret = 0; int q_id, ret = 0;