[PATCH v4 25/43] usb: gadget: f_hid: handle requests lifetime properly

From: Robert Baldyga
Date: Wed Feb 03 2016 - 07:41:43 EST


So far USB requests allocated in hidg_set_alt() were not freed. Now we
free them in case of hidg_set_alt() failure (when we are not able to
allocate and enqueue all the requests) or in hidg_disable() function.

Signed-off-by: Robert Baldyga <r.baldyga@xxxxxxxxxxx>
---
drivers/usb/gadget/function/f_hid.c | 22 +++++++++++++++++++++-
1 file changed, 21 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/gadget/function/f_hid.c b/drivers/usb/gadget/function/f_hid.c
index 99285b4..0456a53 100644
--- a/drivers/usb/gadget/function/f_hid.c
+++ b/drivers/usb/gadget/function/f_hid.c
@@ -59,6 +59,7 @@ struct f_hidg {
bool write_pending;
wait_queue_head_t write_queue;
struct usb_request *req;
+ struct usb_request **out_reqs;

int minor;
struct cdev cdev;
@@ -490,6 +491,7 @@ static void hidg_disable(struct usb_function *f)
{
struct f_hidg *hidg = func_to_hidg(f);
struct f_hidg_req_list *list, *next;
+ int i;

usb_ep_disable(hidg->in_ep);
usb_ep_disable(hidg->out_ep);
@@ -498,6 +500,12 @@ static void hidg_disable(struct usb_function *f)
list_del(&list->list);
kfree(list);
}
+
+ for (i = 0; i < hidg->qlen; ++i) {
+ kfree(hidg->out_reqs[i]->buf);
+ kfree(hidg->out_reqs[i]);
+ }
+ kfree(hidg->out_reqs);
}

static int hidg_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
@@ -547,11 +555,14 @@ static int hidg_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
/*
* allocate a bunch of read buffers and queue them all at once.
*/
+ hidg->out_reqs = kzalloc(hidg->qlen *
+ sizeof(*hidg->out_reqs), GFP_KERNEL);
for (i = 0; i < hidg->qlen && status == 0; i++) {
struct usb_request *req =
hidg_alloc_ep_req(hidg->out_ep,
hidg->report_length);
if (req) {
+ hidg->out_reqs[i] = req;
req->complete = hidg_set_report_complete;
req->context = hidg;
status = usb_ep_queue(hidg->out_ep, req,
@@ -562,11 +573,20 @@ static int hidg_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
} else {
usb_ep_disable(hidg->out_ep);
status = -ENOMEM;
- goto fail;
+ goto free_req;
}
}
}

+free_req:
+ if (status < 0) {
+ while (i--) {
+ kfree(hidg->out_reqs[i]->buf);
+ kfree(hidg->out_reqs[i]);
+ }
+ kfree(hidg->out_reqs);
+ }
+
fail:
return status;
}
--
1.9.1