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 <[email protected]>
---
drivers/bluetooth/btusb.c | 4 ++--
net/bluetooth/hci_core.c | 2 +-
2 files changed, 3 insertions(+), 3 deletions(-)
diff --git a/drivers/bluetooth/btusb.c b/drivers/bluetooth/btusb.c
index e25fcd49db70..3407762b3b15 100644
--- a/drivers/bluetooth/btusb.c
+++ b/drivers/bluetooth/btusb.c
@@ -3692,8 +3692,8 @@ static int btusb_probe(struct usb_interface *intf,
data->recv_acl = hci_recv_frame;
hdev = hci_alloc_dev_priv(priv_size);
- if (!hdev)
- return -ENOMEM;
+ if (IS_ERR(hdev))
+ return PTR_ERR(hdev);
hdev->bus = HCI_USB;
hci_set_drvdata(hdev, data);
diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c
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);
hdev->pkt_type = (HCI_DM1 | HCI_DH1 | HCI_HV1);
hdev->esco_type = (ESCO_HV1);
--
2.36.1
This is automated email and please do not reply to this email!
Dear submitter,
Thank you for submitting the patches to the linux bluetooth mailing list.
This is a CI test results with your patch series:
PW Link:https://patchwork.kernel.org/project/bluetooth/list/?series=660435
---Test result---
Test Summary:
CheckPatch PASS 1.44 seconds
GitLint PASS 0.84 seconds
SubjectPrefix PASS 0.65 seconds
BuildKernel PASS 31.55 seconds
BuildKernel32 PASS 27.58 seconds
Incremental Build with patchesPASS 37.85 seconds
TestRunner: Setup PASS 468.67 seconds
TestRunner: l2cap-tester PASS 16.39 seconds
TestRunner: bnep-tester PASS 5.54 seconds
TestRunner: mgmt-tester PASS 94.94 seconds
TestRunner: rfcomm-tester PASS 8.95 seconds
TestRunner: sco-tester PASS 8.67 seconds
TestRunner: smp-tester PASS 8.79 seconds
TestRunner: userchan-tester PASS 5.78 seconds
---
Regards,
Linux Bluetooth
Hi Khalid,
Khalid Masum <[email protected]> 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 <[email protected]>
> ---
[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.
Also, allocation functionS return an error only in case of ENOMEM, so
initial code is fine, IMO
Thanks,
--Pavel Skripkin
On Sun, Jul 17, 2022 at 10:17 PM Pavel Skripkin <[email protected]> wrote:
>
> Hi Khalid,
>
> Khalid Masum <[email protected]> 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 <[email protected]>
> > ---
>
> [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
>
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
>
> Thanks,
> --Pavel Skripkin
Thanks,
-- Khalid Masum
Hi Khalid,
On Sun, Jul 17, 2022 at 11:34 AM Khalid Masum <[email protected]> wrote:
>
> On Sun, Jul 17, 2022 at 10:17 PM Pavel Skripkin <[email protected]> wrote:
> >
> > Hi Khalid,
> >
> > Khalid Masum <[email protected]> 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 <[email protected]>
> > > ---
> >
> > [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