linux-wireless.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
* [PATCH v3] rtw88: Remove unnecessary check code
@ 2021-07-18  8:42 Len Baker
  2021-07-27  6:34 ` Kalle Valo
  0 siblings, 1 reply; 4+ messages in thread
From: Len Baker @ 2021-07-18  8:42 UTC (permalink / raw)
  To: Yan-Hsuan Chuang, Kalle Valo, David S. Miller, Jakub Kicinski
  Cc: Len Baker, Greg KH, Brian Norris, Pkshih, linux-wireless, netdev,
	linux-kernel

The rtw_pci_init_rx_ring function is only ever called with a fixed
constant or RTK_MAX_RX_DESC_NUM for the "len" argument. Since this
constant is defined as 512, the "if (len > TRX_BD_IDX_MASK)" check
can never happen (TRX_BD_IDX_MASK is defined as GENMASK(11, 0) or in
other words as 4095).

So, remove this check.

Signed-off-by: Len Baker <len.baker@gmx.com>
---
Changelog v1 -> v2
- Remove the macro ARRAY_SIZE from the for loop (Pkshih, Brian Norris).
- Add a new check for the len variable (Pkshih, Brian Norris).

Changelog v2 -> v3
- Change the subject of the patch.
- Remove the "if" check statement (Greg KH)
- Remove the "Fixes" tag, "Addresses-Coverity-ID" tag and Cc to stable.

The previous versions can be found at:

v1
https://lore.kernel.org/lkml/20210711141634.6133-1-len.baker@gmx.com/

v2
https://lore.kernel.org/lkml/20210716155311.5570-1-len.baker@gmx.com/

 drivers/net/wireless/realtek/rtw88/pci.c | 5 -----
 1 file changed, 5 deletions(-)

diff --git a/drivers/net/wireless/realtek/rtw88/pci.c b/drivers/net/wireless/realtek/rtw88/pci.c
index e7d17ab8f113..f17e7146f20f 100644
--- a/drivers/net/wireless/realtek/rtw88/pci.c
+++ b/drivers/net/wireless/realtek/rtw88/pci.c
@@ -268,11 +268,6 @@ static int rtw_pci_init_rx_ring(struct rtw_dev *rtwdev,
 	int i, allocated;
 	int ret = 0;

-	if (len > TRX_BD_IDX_MASK) {
-		rtw_err(rtwdev, "len %d exceeds maximum RX entries\n", len);
-		return -EINVAL;
-	}
-
 	head = dma_alloc_coherent(&pdev->dev, ring_sz, &dma, GFP_KERNEL);
 	if (!head) {
 		rtw_err(rtwdev, "failed to allocate rx ring\n");
--
2.25.1


^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: [PATCH v3] rtw88: Remove unnecessary check code
  2021-07-18  8:42 [PATCH v3] rtw88: Remove unnecessary check code Len Baker
@ 2021-07-27  6:34 ` Kalle Valo
  2021-07-27 18:16   ` Brian Norris
  0 siblings, 1 reply; 4+ messages in thread
From: Kalle Valo @ 2021-07-27  6:34 UTC (permalink / raw)
  To: Len Baker
  Cc: Yan-Hsuan Chuang, David S. Miller, Jakub Kicinski, Greg KH,
	Brian Norris, Pkshih, linux-wireless, netdev, linux-kernel

Len Baker <len.baker@gmx.com> writes:

> The rtw_pci_init_rx_ring function is only ever called with a fixed
> constant or RTK_MAX_RX_DESC_NUM for the "len" argument. Since this
> constant is defined as 512, the "if (len > TRX_BD_IDX_MASK)" check
> can never happen (TRX_BD_IDX_MASK is defined as GENMASK(11, 0) or in
> other words as 4095).
>
> So, remove this check.
>
> Signed-off-by: Len Baker <len.baker@gmx.com>

Are everyone ok with this version?

-- 
https://patchwork.kernel.org/project/linux-wireless/list/

https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches

^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: [PATCH v3] rtw88: Remove unnecessary check code
  2021-07-27  6:34 ` Kalle Valo
@ 2021-07-27 18:16   ` Brian Norris
  2021-07-28 17:50     ` Len Baker
  0 siblings, 1 reply; 4+ messages in thread
From: Brian Norris @ 2021-07-27 18:16 UTC (permalink / raw)
  To: Kalle Valo
  Cc: Len Baker, Yan-Hsuan Chuang, David S. Miller, Jakub Kicinski,
	Greg KH, Pkshih, linux-wireless, <netdev@vger.kernel.org>,
	Linux Kernel

On Mon, Jul 26, 2021 at 11:34 PM Kalle Valo <kvalo@codeaurora.org> wrote:
>
> Len Baker <len.baker@gmx.com> writes:
>
> > The rtw_pci_init_rx_ring function is only ever called with a fixed
> > constant or RTK_MAX_RX_DESC_NUM for the "len" argument. Since this
> > constant is defined as 512, the "if (len > TRX_BD_IDX_MASK)" check
> > can never happen (TRX_BD_IDX_MASK is defined as GENMASK(11, 0) or in
> > other words as 4095).
> >
> > So, remove this check.
> >
> > Signed-off-by: Len Baker <len.baker@gmx.com>
>
> Are everyone ok with this version?

I suppose? I'm not really sure where the line should be drawn on
excessive bounds checking, false warnings from otherwise quite useful
static analysis tools, etc., but I suppose it doesn't make much sense
to add additional excess bounds checks just to quiet Coverity.

It might be nice to include the true motivation in the patch
description though, which is: "this also quiets a false warning from
Coverity".

Anyway, feel free to pick one of these:

Shrug-by: Brian Norris <briannorris@chromium.org>

or

Reviewed-by: Brian Norris <briannorris@chromium.org>

^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: [PATCH v3] rtw88: Remove unnecessary check code
  2021-07-27 18:16   ` Brian Norris
@ 2021-07-28 17:50     ` Len Baker
  0 siblings, 0 replies; 4+ messages in thread
From: Len Baker @ 2021-07-28 17:50 UTC (permalink / raw)
  To: Brian Norris, Kalle Valo
  Cc: Len Baker, Yan-Hsuan Chuang, David S. Miller, Jakub Kicinski,
	Greg KH, Pkshih, linux-wireless, <netdev@vger.kernel.org>,
	Linux Kernel

On Tue, Jul 27, 2021 at 11:16:11AM -0700, Brian Norris wrote:
> On Mon, Jul 26, 2021 at 11:34 PM Kalle Valo <kvalo@codeaurora.org> wrote:
> >
> > Len Baker <len.baker@gmx.com> writes:
> >
> > > The rtw_pci_init_rx_ring function is only ever called with a fixed
> > > constant or RTK_MAX_RX_DESC_NUM for the "len" argument. Since this
> > > constant is defined as 512, the "if (len > TRX_BD_IDX_MASK)" check
> > > can never happen (TRX_BD_IDX_MASK is defined as GENMASK(11, 0) or in
> > > other words as 4095).
> > >
> > > So, remove this check.
> > >
> > > Signed-off-by: Len Baker <len.baker@gmx.com>
> >
> > Are everyone ok with this version?
>
> I suppose? I'm not really sure where the line should be drawn on
> excessive bounds checking, false warnings from otherwise quite useful
> static analysis tools, etc., but I suppose it doesn't make much sense
> to add additional excess bounds checks just to quiet Coverity.
>
> It might be nice to include the true motivation in the patch
> description though, which is: "this also quiets a false warning from
> Coverity".

Ok, I will send a new version with the commit changelog updated.

>
> Anyway, feel free to pick one of these:
>
> Shrug-by: Brian Norris <briannorris@chromium.org>
>
> or
>
> Reviewed-by: Brian Norris <briannorris@chromium.org>

Thanks,
Len

^ permalink raw reply	[flat|nested] 4+ messages in thread

end of thread, other threads:[~2021-07-28 17:51 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-07-18  8:42 [PATCH v3] rtw88: Remove unnecessary check code Len Baker
2021-07-27  6:34 ` Kalle Valo
2021-07-27 18:16   ` Brian Norris
2021-07-28 17:50     ` Len Baker

This is a public inbox, see mirroring instructions
on how to clone and mirror all data and code used for this inbox