Le 03/09/2023 à 16:23, Takashi Iwai a écrit :
On Sun, 03 Sep 2023 15:06:00 +0200,
Christophe JAILLET wrote:
If usb_alloc_coherent() or usb_urb_ep_type_check() fail, we should release
the resources previously allocated.
Those are freed in the caller side, start_input_streams() instead.
Thanks for the fast review.
Hmpm, If IIUC, resources allocated *before* the ending "ep->num_urbs++"
still need to be freed here, otherwise free_midi_urbs() in the caller
will not free them.
Do you agree?
If yes, I can send v2 which would look like:
usb_alloc_urb()
if (err)
return -ENOMEM
usb_alloc_coherent()
if (err) {
usb_free_urb()
urb = NULL
return -ENOMEM
}
usb_urb_ep_type_check()
if (err) {
usb_free_coherent()
usb_free_urb()
urb = NULL
return -err
}
Or, if yuo prefer, with an error handling path just like below, but
without the final free_midi_urbs() + a comment explaining that the
caller does this part of job instead.
CJ
thanks,
Takashi
Fixes: ff49d1df79ae ("ALSA: usb-audio: USB MIDI 2.0 UMP support")
Signed-off-by: Christophe JAILLET <christophe.jaillet@xxxxxxxxxx>
---
sound/usb/midi2.c | 17 ++++++++++++++---
1 file changed, 14 insertions(+), 3 deletions(-)
diff --git a/sound/usb/midi2.c b/sound/usb/midi2.c
index a27e244650c8..4109c82adff6 100644
--- a/sound/usb/midi2.c
+++ b/sound/usb/midi2.c
@@ -302,7 +302,8 @@ static int alloc_midi_urbs(struct snd_usb_midi2_endpoint *ep)
ctx->urb = usb_alloc_urb(0, GFP_KERNEL);
if (!ctx->urb) {
dev_err(&ep->dev->dev, "URB alloc failed\n");
- return -ENOMEM;
+ err = -ENOMEM;
+ goto err_free_all;
}
ctx->ep = ep;
buffer = usb_alloc_coherent(ep->dev, len, GFP_KERNEL,
@@ -310,7 +311,8 @@ static int alloc_midi_urbs(struct snd_usb_midi2_endpoint *ep)
if (!buffer) {
dev_err(&ep->dev->dev,
"URB buffer alloc failed (size %d)\n", len);
- return -ENOMEM;
+ err = -ENOMEM;
+ goto err_free_cur_urb;
}
if (ep->interval)
usb_fill_int_urb(ctx->urb, ep->dev, ep->pipe,
@@ -322,13 +324,22 @@ static int alloc_midi_urbs(struct snd_usb_midi2_endpoint *ep)
if (err < 0) {
dev_err(&ep->dev->dev, "invalid MIDI EP %x\n",
endpoint);
- return err;
+ goto err_free_cur_dma;
}
ctx->urb->transfer_flags = URB_NO_TRANSFER_DMA_MAP;
ep->num_urbs++;
}
ep->urb_free = ep->urb_free_mask = GENMASK(ep->num_urbs - 1, 0);
return 0;
+
+err_free_cur_dma:
+ usb_free_coherent(ep->dev, len, buffer, ctx->urb->transfer_dma);
+err_free_cur_urb:
+ usb_free_urb(ctx->urb);
+ ctx->urb = NULL;
+err_free_all:
+ free_midi_urbs(ep);
+ return err;
}
static struct snd_usb_midi2_endpoint *
--
2.34.1
