staging: r8188eu: handle rtw_init_netdev_name() failure appropriately

PATCH In review Vihas Mak 2 participants 3 messages Jan 23, 2022 – Jan 24, 2022 Staging

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Vihas Mak

author

2022-01-23 18:18 UTC #0 lore raw

PATCH v2 1/1 staging: r8188eu: handle rtw_init_netdev_name() failure appropriately

rtw_init_netdev_name() calls dev_alloc_name() which allocates the name for the device as per the given name format.
The name format is specified by the module parameter "ifname". It returns a negative err code if the format is invalid. Handle this error appropriately.
Cancel the timers ininitliazed by rtw_init_drv_sw() before calling rtw_free_drv_sw() and then proceed to free the adapter.

Also, if register_netdev() fails then goto free_drv_sw instead of goto handle_dualmac.

Signed-off-by Vihas Mak <[email protected]>

---
v1->v2:
free the adapter and netdev instead of warning the user about allocation failure.

 drivers/staging/r8188eu/os_dep/usb_intf.c | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

drivers/staging/r8188eu/os_dep/usb_intf.c +11 -2

index 91792dfd3..85b5d0bd7 100644
@@ -399,7 +399,11 @@ static struct adapter *rtw_usb_if1_init(struct dvobj_priv *dvobj,
 			DBG_88E("can't get autopm:\n");
 
 	/*  alloc dev name after read efuse. */
-	rtw_init_netdev_name(pnetdev, padapter->registrypriv.ifname);
+	if (rtw_init_netdev_name(pnetdev, padapter->registrypriv.ifname) < 0) {
+		DBG_88E("rtw_init_netdev_name failed, ifname:%s\n",
+			padapter->registrypriv.ifname);
+		goto free_drv_sw;
+	}
 	rtw_macaddr_cfg(padapter->eeprompriv.mac_addr);
 	rtw_init_wifidirect_addrs(padapter, padapter->eeprompriv.mac_addr,
 				  padapter->eeprompriv.mac_addr);

@@ -409,7 +413,7 @@ static struct adapter *rtw_usb_if1_init(struct dvobj_priv *dvobj,
 
 	/* step 6. Tell the network stack we exist */
 	if (register_netdev(pnetdev) != 0)
-		goto handle_dualmac;
+		goto free_drv_sw;
 
 	DBG_88E("bDriverStopped:%d, bSurpriseRemoved:%d, bup:%d, hw_init_completed:%d\n"
 		, padapter->bDriverStopped

@@ -420,6 +424,11 @@ static struct adapter *rtw_usb_if1_init(struct dvobj_priv *dvobj,
 
 	status = _SUCCESS;
 
+free_drv_sw:
+	if (status != _SUCCESS) {
+		rtw_cancel_all_timer(padapter);
+		rtw_free_drv_sw(padapter);
+	}
 handle_dualmac:
 	if (status != _SUCCESS)
 		rtw_handle_dualmac(padapter, 0);

Signature · 1 line

2.30.2

Dan Carpenter

Reviewed-by on v2 1/1

2022-01-24 06:49 UTC #1 lore raw

Quoted 8 lines · Vihas Mak

rtw_init_netdev_name() calls dev_alloc_name() which allocates the name for the device as per the given name format.
The name format is specified by the module parameter "ifname". It returns a negative err code if the format is invalid. Handle this error appropriately.
Cancel the timers ininitliazed by rtw_init_drv_sw() before calling rtw_free_drv_sw() and then proceed to free the adapter.

Quoted 8 lines

Also, if register_netdev() fails then goto free_drv_sw instead of goto handle_dualmac.
Signed-off-by Vihas Mak <[email protected]>
---
v1->v2:
free the adapter and netdev instead of warning the user about allocation failure.

Thanks!

Reviewed-by Dan Carpenter <[email protected]>

Of course, all this code is staging code and terrible. This function is needlessly difficult to read/review.

TODO: re-write probe error handling

Step 1: Keep the success path and error path separate.

- status = _SUCCESS;
+ return padapter;

Step 2: Eliminate do-nothing-gotos. s/goto exit/return NULL/

Step 3: Delete the vfree(pnpi->priv); from rtw_free_netdev() and call
vfree(pnpi->priv); from probe and rtw_usb_if1_deinit() instead. Avoid a layering violation.

Step 4: Every allocation function needs a matching free function. Move
the rtw_cancel_all_timer() into the rtw_free_drv_sw() function. Open coding it is a layering violation.

Step 5: Get rid of the rtw_handle_dualmac() function. It has a bad
name and a global variable. What is the point of this function?

But that stuff is for later patches.

regards,
dan carpenter

Vihas Mak

author

2022-01-24 09:16 UTC #2 lore raw

Thanks for reviewing the patch Dan.

Quoted 1 line

Quoted 1 line
TODO: re-write probe error handling

Will submit a series of patches in upcoming days, based on the steps you provided.

Quoted 51 lines · Dan Carpenter

Quoted 8 lines · Vihas Mak
rtw_init_netdev_name() calls dev_alloc_name() which allocates the name for the device as per the given name format.
The name format is specified by the module parameter "ifname". It returns a negative err code if the format is invalid. Handle this error appropriately.
Cancel the timers ininitliazed by rtw_init_drv_sw() before calling rtw_free_drv_sw() and then proceed to free the adapter.
Quoted 8 lines
Also, if register_netdev() fails then goto free_drv_sw instead of goto handle_dualmac.
Signed-off-by Vihas Mak <[email protected]>
---
v1->v2:
free the adapter and netdev instead of warning the user about allocation failure.
Thanks!
Reviewed-by Dan Carpenter <[email protected]>
Of course, all this code is staging code and terrible. This function is needlessly difficult to read/review.
TODO: re-write probe error handling
Step 1: Keep the success path and error path separate.
(quoted diff) +1 -1
-       status = _SUCCESS;
+       return padapter;
Step 2: Eliminate do-nothing-gotos. s/goto exit/return NULL/
Step 3: Delete the vfree(pnpi->priv); from rtw_free_netdev() and call
vfree(pnpi->priv); from probe and rtw_usb_if1_deinit() instead. Avoid a layering violation.
Step 4: Every allocation function needs a matching free function. Move
the rtw_cancel_all_timer() into the rtw_free_drv_sw() function. Open coding it is a layering violation.
Step 5: Get rid of the rtw_handle_dualmac() function. It has a bad
name and a global variable. What is the point of this function?
But that stuff is for later patches.
regards,
dan carpenter

Signature · 2 lines

Thanks,
Vihas