Hi Khalid, On Sun, Jul 17, 2022 at 11:34 AM Khalid Masum <khalid.masum.92@xxxxxxxxx> wrote: > > On Sun, Jul 17, 2022 at 10:17 PM Pavel Skripkin <paskripkin@xxxxxxxxx> wrote: > > > > Hi Khalid, > > > > Khalid Masum <khalid.masum.92@xxxxxxxxx> says: > > > Failure of kzalloc to allocate memory is not reported. Return Error > > > pointer to ENOMEM if memory allocation fails. This will increase > > > readability and will make the function easier to use in future. > > > > > > Signed-off-by: Khalid Masum <khalid.masum.92@xxxxxxxxx> > > > --- > > > > [snip] > > > > > index a0f99baafd35..ea50767e02bf 100644 > > > --- a/net/bluetooth/hci_core.c > > > +++ b/net/bluetooth/hci_core.c > > > @@ -2419,7 +2419,7 @@ struct hci_dev *hci_alloc_dev_priv(int sizeof_priv) > > > > > > hdev = kzalloc(alloc_size, GFP_KERNEL); > > > if (!hdev) > > > - return NULL; > > > + return ERR_PTR(-ENOMEM); > > > > > > > This will break all callers of hci_alloc_dev(). All callers expect NULL > > in case of an error, so you will leave them with wrong pointer. > > You are right. All callers of hci_alloc_dev() need to be able to handle > the error pointer. I shall send a V2 with all the callers of hci_alloc_dev > handling the ERR_PTR. > > > Also, allocation functionS return an error only in case of ENOMEM, so > > initial code is fine, IMO > > If there just a single error like ENOMEM then Id say this is fine, just as it is fine for kzalloc. > I think it makes the memory allocation error handling look to be a bit > different from what we usually do while allocating memory which is, > returning an error or an error pointer. Here we are returning a NULL > without any context, making it a bit unreadable. So I think returning > an error pointer is better. If I am not mistaken, this also complies with > the return convention: > https://www.kernel.org/doc/htmldocs/kernel-hacking/convention-returns.html Not sure if that would apply to code that is basically a wrapper of kzalloc. > > > > Thanks, > > --Pavel Skripkin > > > Thanks, > -- Khalid Masum -- Luiz Augusto von Dentz
