[PATCH 5.17 072/146] mt76: Fix undefined behavior due to shift overflowing the constant

From: Greg Kroah-Hartman
Date: Tue Apr 26 2022 - 05:27:34 EST


From: Borislav Petkov <bp@xxxxxxx>

[ Upstream commit dbc2b1764734857d68425468ffa8486e97ab89df ]

Fix:

drivers/net/wireless/mediatek/mt76/mt76x2/pci.c: In function ‘mt76x2e_probe’:
././include/linux/compiler_types.h:352:38: error: call to ‘__compiletime_assert_946’ \
declared with attribute error: FIELD_PREP: mask is not constant
_compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__)

See https://lore.kernel.org/r/YkwQ6%2BtIH8GQpuct@xxxxxxx for the gory
details as to why it triggers with older gccs only.

Signed-off-by: Borislav Petkov <bp@xxxxxxx>
Cc: Felix Fietkau <nbd@xxxxxxxx>
Cc: Lorenzo Bianconi <lorenzo.bianconi83@xxxxxxxxx>
Cc: Ryder Lee <ryder.lee@xxxxxxxxxxxx>
Cc: Shayne Chen <shayne.chen@xxxxxxxxxxxx>
Cc: Sean Wang <sean.wang@xxxxxxxxxxxx>
Cc: Kalle Valo <kvalo@xxxxxxxxxx>
Cc: "David S. Miller" <davem@xxxxxxxxxxxxx>
Cc: Jakub Kicinski <kuba@xxxxxxxxxx>
Cc: linux-wireless@xxxxxxxxxxxxxxx
Cc: netdev@xxxxxxxxxxxxxxx
Signed-off-by: Kalle Valo <kvalo@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20220405151517.29753-9-bp@xxxxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/net/wireless/mediatek/mt76/mt76x2/pci.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/wireless/mediatek/mt76/mt76x2/pci.c b/drivers/net/wireless/mediatek/mt76/mt76x2/pci.c
index 8a22ee581674..df85ebc6e1df 100644
--- a/drivers/net/wireless/mediatek/mt76/mt76x2/pci.c
+++ b/drivers/net/wireless/mediatek/mt76/mt76x2/pci.c
@@ -80,7 +80,7 @@ mt76x2e_probe(struct pci_dev *pdev, const struct pci_device_id *id)
mt76_rmw_field(dev, 0x15a10, 0x1f << 16, 0x9);

/* RG_SSUSB_G1_CDR_BIC_LTR = 0xf */
- mt76_rmw_field(dev, 0x15a0c, 0xf << 28, 0xf);
+ mt76_rmw_field(dev, 0x15a0c, 0xfU << 28, 0xf);

/* RG_SSUSB_CDR_BR_PE1D = 0x3 */
mt76_rmw_field(dev, 0x15c58, 0x3 << 6, 0x3);
--
2.35.1