Skip to contentSkip to conversation

rtw89: avoid stringop-overflow warning

PATCH In review Arnd Bergmann 4 participants 6 messages Dec 4, 2023 – Dec 12, 2023 Realtek wireless driver (rtw89)

lore
Share & tools
lore

Arnd Bergmann

author
#0 lore raw

PATCH 1/1 rtw89: avoid stringop-overflow warning

From: Arnd Bergmann <[email protected]>

After -Wstringop-overflow got enabled, the rtw89 driver produced two odd warnings with gcc-13:

drivers/net/wireless/realtek/rtw89/coex.c: In function 'rtw89_btc_ntfy_scan_start':
drivers/net/wireless/realtek/rtw89/coex.c:5362:50: error: writing 1 byte into a region of size 0 [-Werror=stringop-overflow=]

 5362 |                 wl->dbcc_info.scan_band[phy_idx] = band;
      |                 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~

In file included from drivers/net/wireless/realtek/rtw89/coex.h:8,
from drivers/net/wireless/realtek/rtw89/coex.c:5:
drivers/net/wireless/realtek/rtw89/core.h:1441:12: note: at offset [64, 255] into destination object 'scan_band' of size 2
1441 | u8 scan_band[RTW89_PHY_MAX]; /* scan band in each phy */

      |            ^~~~~~~~~
drivers/net/wireless/realtek/rtw89/coex.c: In function 'rtw89_btc_ntfy_switch_band':
drivers/net/wireless/realtek/rtw89/coex.c:5406:50: error: writing 1 byte into a region of size 0 [-Werror=stringop-overflow=]
 5406 |                 wl->dbcc_info.scan_band[phy_idx] = band;
      |                 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~
drivers/net/wireless/realtek/rtw89/core.h:1441:12: note: at offset [64, 255] into destination object 'scan_band' of size 2
 1441 |         u8 scan_band[RTW89_PHY_MAX]; /* scan band in  each phy */
      |            ^~~~~~~~~

I don't know what happened here, but adding an explicit range check shuts up the output.

Fixes 89741e7e42f6 ("Makefile: Enable -Wstringop-overflow globally")
Signed-off-by Arnd Bergmann <[email protected]>
---
 drivers/net/wireless/realtek/rtw89/coex.c | 8 ++++++++
 1 file changed, 8 insertions(+)
drivers/net/wireless/realtek/rtw89/coex.c +8 -0
index b842cd9a86f8..9c0db35d3e13 100644
@@ -5352,6 +5352,10 @@ void rtw89_btc_ntfy_scan_start(struct rtw89_dev *rtwdev, u8 phy_idx, u8 band)
 	rtw89_debug(rtwdev, RTW89_DBG_BTC,
 		    "[BTC], %s(): phy_idx=%d, band=%d\n",
 		    __func__, phy_idx, band);
+
+	if (phy_idx >= RTW89_PHY_MAX)
+		return;
+
 	btc->dm.cnt_notify[BTC_NCNT_SCAN_START]++;
 	wl->status.map.scan = true;
 	wl->scan_info.band[phy_idx] = band;

@@ -5396,6 +5400,10 @@ void rtw89_btc_ntfy_switch_band(struct rtw89_dev *rtwdev, u8 phy_idx, u8 band)
 	rtw89_debug(rtwdev, RTW89_DBG_BTC,
 		    "[BTC], %s(): phy_idx=%d, band=%d\n",
 		    __func__, phy_idx, band);
+
+	if (phy_idx >= RTW89_PHY_MAX)
+		return;
+
 	btc->dm.cnt_notify[BTC_NCNT_SWITCH_BAND]++;
 
 	wl->scan_info.band[phy_idx] = band;
Signature · 1 line
2.39.2
maintainer
#1 lore raw
Quoted 10 lines

-----Original Message-----
From: Arnd Bergmann <[email protected]>
Sent: Monday, December 4, 2023 3:30 PM
To: Ping-Ke Shih <[email protected]>; Kalle Valo <[email protected]>; Gustavo A. R. Silva <[email protected]>
Cc: Arnd Bergmann <[email protected]>; DeanKu <[email protected]>; [email protected]; [email protected]
Subject: [PATCH] rtw89: avoid stringop-overflow warning

Subject prefix should be "wifi: rtw89: ..."

Quoted 27 lines

From: Arnd Bergmann <[email protected]>

After -Wstringop-overflow got enabled, the rtw89 driver produced two odd warnings with gcc-13:

drivers/net/wireless/realtek/rtw89/coex.c: In function 'rtw89_btc_ntfy_scan_start':
drivers/net/wireless/realtek/rtw89/coex.c:5362:50: error: writing 1 byte into a region of size 0 [-Werror=stringop-overflow=]

 5362 |                 wl->dbcc_info.scan_band[phy_idx] = band;
      |                 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~

In file included from drivers/net/wireless/realtek/rtw89/coex.h:8,
from drivers/net/wireless/realtek/rtw89/coex.c:5:
drivers/net/wireless/realtek/rtw89/core.h:1441:12: note: at offset [64, 255] into destination object 'scan_band' of size 2
1441 | u8 scan_band[RTW89_PHY_MAX]; /* scan band in each phy */

      |            ^~~~~~~~~
drivers/net/wireless/realtek/rtw89/coex.c: In function 'rtw89_btc_ntfy_switch_band':
drivers/net/wireless/realtek/rtw89/coex.c:5406:50: error: writing 1 byte into a region of size 0
[-Werror=stringop-overflow=]
 5406 |                 wl->dbcc_info.scan_band[phy_idx] = band;
      |                 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~
drivers/net/wireless/realtek/rtw89/core.h:1441:12: note: at offset [64, 255] into destination object
'scan_band' of size 2
 1441 |         u8 scan_band[RTW89_PHY_MAX]; /* scan band in  each phy */
      |            ^~~~~~~~~
Quoted 2 lines

I don't know what happened here, but adding an explicit range check shuts up the output.

The callers of these two cases will pass RTW89_PHY_0 (0) as argument of phy_idx, and will extend to pass RTW89_PHY_1 (1) in the future, but should not be larger than 1.

I don't mind to add this checking, but I really don't know what happened neither. A statement 'wl->scan_info.band[phy_idx] = band;' did similar thing in the same function, but why doesn't gcc complain this?

#2 lore raw
In reply to Arnd Bergmann
Quoted 22 lines · Arnd Bergmann

From: Arnd Bergmann <[email protected]>

After -Wstringop-overflow got enabled, the rtw89 driver produced two odd warnings with gcc-13:

drivers/net/wireless/realtek/rtw89/coex.c: In function 'rtw89_btc_ntfy_scan_start':
drivers/net/wireless/realtek/rtw89/coex.c:5362:50: error: writing 1 byte into a region of size 0 [-Werror=stringop-overflow=]

 5362 |                 wl->dbcc_info.scan_band[phy_idx] = band;
      |                 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~

In file included from drivers/net/wireless/realtek/rtw89/coex.h:8,
from drivers/net/wireless/realtek/rtw89/coex.c:5:
drivers/net/wireless/realtek/rtw89/core.h:1441:12: note: at offset [64, 255] into destination object 'scan_band' of size 2
1441 | u8 scan_band[RTW89_PHY_MAX]; /* scan band in each phy */

      |            ^~~~~~~~~
drivers/net/wireless/realtek/rtw89/coex.c: In function 'rtw89_btc_ntfy_switch_band':
drivers/net/wireless/realtek/rtw89/coex.c:5406:50: error: writing 1 byte into a region of size 0 [-Werror=stringop-overflow=]
 5406 |                 wl->dbcc_info.scan_band[phy_idx] = band;
      |                 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~
drivers/net/wireless/realtek/rtw89/core.h:1441:12: note: at offset [64, 255] into destination object 'scan_band' of size 2
 1441 |         u8 scan_band[RTW89_PHY_MAX]; /* scan band in  each phy */
      |            ^~~~~~~~~
Quoted 5 lines

I don't know what happened here, but adding an explicit range check shuts up the output.

Fixes 89741e7e42f6 ("Makefile: Enable -Wstringop-overflow globally")
Signed-off-by Arnd Bergmann <[email protected]>

ERROR: 'wifi:' prefix missing: '[PATCH] rtw89: avoid stringop-overflow warning'
ERROR: Failed to find commit id: Fixes: 89741e7e42f6 ("Makefile: Enable -Wstringop-overflow globally")

I can add the "wifi:" prefix but where can I find the commit 89741e7e42f6?

Signature · 3 lines
https://patchwork.kernel.org/project/linux-wireless/patch/[email protected]/

https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches
#3 lore raw
Quoted 6 lines · Kalle Valo
Quoted 4 lines · Arnd Bergmann

From: Arnd Bergmann <[email protected]>

Fixes 89741e7e42f6 ("Makefile: Enable -Wstringop-overflow globally")
Signed-off-by Arnd Bergmann <[email protected]>
Quoted 6 lines

ERROR: 'wifi:' prefix missing: '[PATCH] rtw89: avoid stringop-overflow warning'
ERROR: Failed to find commit id: Fixes: 89741e7e42f6 ("Makefile: Enable -Wstringop-overflow globally")

I can add the "wifi:" prefix but where can I find the commit 89741e7e42f6?

It's in linux-next and came in from Gustavo's tree at
https://git.kernel.org/pub/scm/linux/kernel/git/gustavoars/linux.git/log/?h=for-next/kspp

Arnd

#4 lore raw
Quoted 12 lines · Arnd Bergmann
Quoted 11 lines · Kalle Valo
Quoted 4 lines · Arnd Bergmann

From: Arnd Bergmann <[email protected]>

Fixes 89741e7e42f6 ("Makefile: Enable -Wstringop-overflow globally")
Signed-off-by Arnd Bergmann <[email protected]>

ERROR: 'wifi:' prefix missing: '[PATCH] rtw89: avoid stringop-overflow warning'
ERROR: Failed to find commit id: Fixes: 89741e7e42f6 ("Makefile: Enable -Wstringop-overflow globally")

Quoted 4 lines
Quoted 1 line

I can add the "wifi:" prefix but where can I find the commit 89741e7e42f6?

It's in linux-next and came in from Gustavo's tree at
https://git.kernel.org/pub/scm/linux/kernel/git/gustavoars/linux.git/log/?h=for-next/kspp

Ah, I think then I'll drop the Fixes tag to avoid warnings or reports. My understanding is that a commit in the Fixes tag should be a parent.

Signature · 3 lines
https://patchwork.kernel.org/project/linux-wireless/list/

https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches
#5 lore raw

Re: wifi: rtw89: avoid stringop-overflow warning

In reply to Arnd Bergmann
Quoted 22 lines · Arnd Bergmann

From: Arnd Bergmann <[email protected]>

After -Wstringop-overflow got enabled, the rtw89 driver produced two odd warnings with gcc-13:

drivers/net/wireless/realtek/rtw89/coex.c: In function 'rtw89_btc_ntfy_scan_start':
drivers/net/wireless/realtek/rtw89/coex.c:5362:50: error: writing 1 byte into a region of size 0 [-Werror=stringop-overflow=]

 5362 |                 wl->dbcc_info.scan_band[phy_idx] = band;
      |                 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~

In file included from drivers/net/wireless/realtek/rtw89/coex.h:8,
from drivers/net/wireless/realtek/rtw89/coex.c:5:
drivers/net/wireless/realtek/rtw89/core.h:1441:12: note: at offset [64, 255] into destination object 'scan_band' of size 2
1441 | u8 scan_band[RTW89_PHY_MAX]; /* scan band in each phy */

      |            ^~~~~~~~~
drivers/net/wireless/realtek/rtw89/coex.c: In function 'rtw89_btc_ntfy_switch_band':
drivers/net/wireless/realtek/rtw89/coex.c:5406:50: error: writing 1 byte into a region of size 0 [-Werror=stringop-overflow=]
 5406 |                 wl->dbcc_info.scan_band[phy_idx] = band;
      |                 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~
drivers/net/wireless/realtek/rtw89/core.h:1441:12: note: at offset [64, 255] into destination object 'scan_band' of size 2
 1441 |         u8 scan_band[RTW89_PHY_MAX]; /* scan band in  each phy */
      |            ^~~~~~~~~
Quoted 4 lines

I don't know what happened here, but adding an explicit range check shuts up the output.

Signed-off-by Arnd Bergmann <[email protected]>

Patch applied to wireless-next.git, thanks.

595b1280e2c9 wifi: rtw89: avoid stringop-overflow warning

Signature · 3 lines
https://patchwork.kernel.org/project/linux-wireless/patch/[email protected]/

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