| Message ID | X/WCTxIRT4SHLemV@mwanda (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | io_uring: fix an IS_ERR() vs NULL check | expand |
On 06/01/2021 09:26, Dan Carpenter wrote: > The alloc_fixed_file_ref_node() function never returns NULL, it returns > error pointers on error. > > Fixes: 1ffc54220c44 ("io_uring: fix io_sqe_files_unregister() hangs") > Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> thanks Dan, Reviewed-by: Pavel Begunkov <asml.silence@gmail.com> Cc: stable@vger.kernel.org # 5.6+ > --- > fs/io_uring.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/fs/io_uring.c b/fs/io_uring.c > index ca46f314640b..2234ce03034a 100644 > --- a/fs/io_uring.c > +++ b/fs/io_uring.c > @@ -7255,8 +7255,8 @@ static int io_sqe_files_unregister(struct io_ring_ctx *ctx) > if (!data) > return -ENXIO; > backup_node = alloc_fixed_file_ref_node(ctx); > - if (!backup_node) > - return -ENOMEM; > + if (IS_ERR(backup_node)) > + return PTR_ERR(backup_node); > > spin_lock_bh(&data->lock); > ref_node = data->node; >
On 1/6/21 2:26 AM, Dan Carpenter wrote: > The alloc_fixed_file_ref_node() function never returns NULL, it returns > error pointers on error. Applied, thanks.
On Wed, Jan 06, 2021 at 12:32:45PM +0000, Pavel Begunkov wrote: > On 06/01/2021 09:26, Dan Carpenter wrote: > > The alloc_fixed_file_ref_node() function never returns NULL, it returns > > error pointers on error. > > > > Fixes: 1ffc54220c44 ("io_uring: fix io_sqe_files_unregister() hangs") > > Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> > > thanks Dan, > > Reviewed-by: Pavel Begunkov <asml.silence@gmail.com> > Cc: stable@vger.kernel.org # 5.6+ But the only error that alloc_fixed_file_ref_node() can return is -ENOMEM, so I think it'd be better to actually return NULL for errors. It makes the other callers simpler: +++ b/fs/io_uring.c @@ -7684,12 +7684,12 @@ static struct fixed_file_ref_node *alloc_fixed_file_ref_node( ref_node = kzalloc(sizeof(*ref_node), GFP_KERNEL); if (!ref_node) - return ERR_PTR(-ENOMEM); + return NULL; if (percpu_ref_init(&ref_node->refs, io_file_data_ref_zero, 0, GFP_KERNEL)) { kfree(ref_node); - return ERR_PTR(-ENOMEM); + return NULL; } INIT_LIST_HEAD(&ref_node->node); INIT_LIST_HEAD(&ref_node->file_list); @@ -7783,9 +7783,9 @@ static int io_sqe_files_register(struct io_ring_ctx *ctx, void __user *arg, } ref_node = alloc_fixed_file_ref_node(ctx); - if (IS_ERR(ref_node)) { + if (!ref_node) { io_sqe_files_unregister(ctx); - return PTR_ERR(ref_node); + return -ENOMEM; } io_sqe_files_set_node(file_data, ref_node); @@ -7885,8 +7885,8 @@ static int __io_sqe_files_update(struct io_ring_ctx *ctx, return -EINVAL; ref_node = alloc_fixed_file_ref_node(ctx); - if (IS_ERR(ref_node)) - return PTR_ERR(ref_node); + if (!ref_node) + return -ENOMEM; done = 0; fds = u64_to_user_ptr(up->fds); (not even compile tested)
Jens just applied my patch right before you sent this. I don't have strong feeling either way about this. I guess I sort of agree with you. If Jens can drop my patch then it should be pretty trivial for you to add a commit message to your patch and give me a Reported-by tag? regards, dan carpenter
On 1/6/21 7:56 AM, Dan Carpenter wrote: > Jens just applied my patch right before you sent this. I don't have > strong feeling either way about this. I guess I sort of agree with > you. If Jens can drop my patch then it should be pretty trivial for > you to add a commit message to your patch and give me a Reported-by > tag? I can just drop it, don't feel too strongly but would tend to agree that we might as well just make it NULL/pointer as it's a single error value. Willy, are you sending a patch?
diff --git a/fs/io_uring.c b/fs/io_uring.c index ca46f314640b..2234ce03034a 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -7255,8 +7255,8 @@ static int io_sqe_files_unregister(struct io_ring_ctx *ctx) if (!data) return -ENXIO; backup_node = alloc_fixed_file_ref_node(ctx); - if (!backup_node) - return -ENOMEM; + if (IS_ERR(backup_node)) + return PTR_ERR(backup_node); spin_lock_bh(&data->lock); ref_node = data->node;
The alloc_fixed_file_ref_node() function never returns NULL, it returns error pointers on error. Fixes: 1ffc54220c44 ("io_uring: fix io_sqe_files_unregister() hangs") Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> --- fs/io_uring.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)