Rob,
Got your point, will submit a new patch with a new error label.
Also I just found that in f_hid.c f_rndis.c and f_uac2.c do need the
freeing function.
Will clean it up and send the patch.
Thanks,
Pavitra
On Fri, Oct 10, 2014 at 6:05 PM, Robert Baldyga <r.baldyga@xxxxxxxxxxx> wrote:
> Hi,
>
> On 10/10/2014 01:51 PM, pavi1729 ivap wrote:
>>>From 3272817673910c63682e8b91ce0efaef190a399a Mon Sep 17 00:00:00 2001
>> From: Pavitra <pavitra1729@xxxxxxxxx>
>> Date: Fri, 10 Oct 2014 16:05:30 +0530
>> Subject: [PATCH] usb: gadget: function: Remove redundant
>> usb_free_all_descriptors
>>
>> Removed the usb_free_all_descriptors call in *_bind functions
>> as this call is already present in usb_assign_descriptors.
>> usb_assign_descriptors is the only call where usb descriptor
>> allocation happens, also in case of error freeing of the
>> allocated memory takes place in the same call. Hence the
>> call in the *_bind functions are redundant.
>> Also the presence of usb_free_all_descriptors in the *_bind
>> functions might result in double-free corruption of the
>> allocated mmeory.
>
> Double-free corruption is good point in this place, but your patch
> doesn't solve this problem properly. If usb_assign_descriptors() returns
> without error and one of following calls fails, we need to call
> usb_free_all_descriptors() in error handling code.
>
> There should be rather two error labels: one where you goto on errors
> before usb_assign_descriptors() call, and another one where you goto on
> errors after it. And in second case usb_free_all_descriptors() is
> called, because descriptors are already allocated and you need to free them.
>
> I also see that in some drivers usb_assign_descriptors() is the last
> call in bind() and then removing usb_free_all_descriptors() from error
> handling code makes sense.
>
> Best regards,
> Robert Baldyga
>
>>
>> Signed-off-by: Pavitra <pavitra1729@xxxxxxxxx>
>> ---
>> drivers/usb/gadget/function/f_eem.c | 1 -
>> drivers/usb/gadget/function/f_hid.c | 2 --
>> drivers/usb/gadget/function/f_ncm.c | 1 -
>> drivers/usb/gadget/function/f_phonet.c | 1 -
>> drivers/usb/gadget/function/f_rndis.c | 1 -
>> drivers/usb/gadget/function/f_subset.c | 1 -
>> drivers/usb/gadget/function/f_uac2.c | 1 -
>> 7 files changed, 8 deletions(-)
>>
>> diff --git a/drivers/usb/gadget/function/f_eem.c
>> b/drivers/usb/gadget/function/f_eem.c
>> index 4d8b236..c9e90de 100644
>> --- a/drivers/usb/gadget/function/f_eem.c
>> +++ b/drivers/usb/gadget/function/f_eem.c
>> @@ -325,7 +325,6 @@ static int eem_bind(struct usb_configuration *c,
>> struct usb_function *f)
>> return 0;
>>
>> fail:
>> - usb_free_all_descriptors(f);
>> if (eem->port.out_ep)
>> eem->port.out_ep->driver_data = NULL;
>> if (eem->port.in_ep)
>> diff --git a/drivers/usb/gadget/function/f_hid.c
>> b/drivers/usb/gadget/function/f_hid.c
>> index a95290a..5c67d28 100644
>> --- a/drivers/usb/gadget/function/f_hid.c
>> +++ b/drivers/usb/gadget/function/f_hid.c
>> @@ -652,8 +652,6 @@ static void hidg_unbind(struct usb_configuration
>> *c, struct usb_function *f)
>> kfree(hidg->req->buf);
>> usb_ep_free_request(hidg->in_ep, hidg->req);
>>
>> - usb_free_all_descriptors(f);
>> -
>> kfree(hidg->report_desc);
>> kfree(hidg);
>> }
>> diff --git a/drivers/usb/gadget/function/f_ncm.c
>> b/drivers/usb/gadget/function/f_ncm.c
>> index bcdc882..38a9279 100644
>> --- a/drivers/usb/gadget/function/f_ncm.c
>> +++ b/drivers/usb/gadget/function/f_ncm.c
>> @@ -1453,7 +1453,6 @@ static int ncm_bind(struct usb_configuration *c,
>> struct usb_function *f)
>> return 0;
>>
>> fail:
>> - usb_free_all_descriptors(f);
>> if (ncm->notify_req) {
>> kfree(ncm->notify_req->buf);
>> usb_ep_free_request(ncm->notify, ncm->notify_req);
>> diff --git a/drivers/usb/gadget/function/f_phonet.c
>> b/drivers/usb/gadget/function/f_phonet.c
>> index b9cfc15..74ddcac 100644
>> --- a/drivers/usb/gadget/function/f_phonet.c
>> +++ b/drivers/usb/gadget/function/f_phonet.c
>> @@ -571,7 +571,6 @@ err_req:
>> for (i = 0; i < phonet_rxq_size && fp->out_reqv[i]; i++)
>> usb_ep_free_request(fp->out_ep, fp->out_reqv[i]);
>> err:
>> - usb_free_all_descriptors(f);
>> if (fp->out_ep)
>> fp->out_ep->driver_data = NULL;
>> if (fp->in_ep)
>> diff --git a/drivers/usb/gadget/function/f_rndis.c
>> b/drivers/usb/gadget/function/f_rndis.c
>> index ddb09dc..e257eff 100644
>> --- a/drivers/usb/gadget/function/f_rndis.c
>> +++ b/drivers/usb/gadget/function/f_rndis.c
>> @@ -820,7 +820,6 @@ rndis_bind(struct usb_configuration *c, struct
>> usb_function *f)
>> fail:
>> kfree(f->os_desc_table);
>> f->os_desc_n = 0;
>> - usb_free_all_descriptors(f);
>>
>> if (rndis->notify_req) {
>> kfree(rndis->notify_req->buf);
>> diff --git a/drivers/usb/gadget/function/f_subset.c
>> b/drivers/usb/gadget/function/f_subset.c
>> index 1ea8baf..e3dfa67 100644
>> --- a/drivers/usb/gadget/function/f_subset.c
>> +++ b/drivers/usb/gadget/function/f_subset.c
>> @@ -380,7 +380,6 @@ geth_bind(struct usb_configuration *c, struct
>> usb_function *f)
>> return 0;
>>
>> fail:
>> - usb_free_all_descriptors(f);
>> /* we might as well release our claims on endpoints */
>> if (geth->port.out_ep)
>> geth->port.out_ep->driver_data = NULL;
>> diff --git a/drivers/usb/gadget/function/f_uac2.c
>> b/drivers/usb/gadget/function/f_uac2.c
>> index 3ed89ec..c294fb9 100644
>> --- a/drivers/usb/gadget/function/f_uac2.c
>> +++ b/drivers/usb/gadget/function/f_uac2.c
>> @@ -1012,7 +1012,6 @@ afunc_bind(struct usb_configuration *cfg, struct
>> usb_function *fn)
>> err:
>> kfree(agdev->uac2.p_prm.rbuf);
>> kfree(agdev->uac2.c_prm.rbuf);
>> - usb_free_all_descriptors(fn);
>> if (agdev->in_ep)
>> agdev->in_ep->driver_data = NULL;
>> if (agdev->out_ep)
>>
>
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