| Message ID | 20171005120547.328687-1-arnd@arndb.de |
|---|---|
| State | Accepted |
| Commit | a39644b235c1a45f84d6e16603cacb93740ed2d4 |
| Headers | show |
| Series | rsi: fix integer overflow warning | expand |
On Thu, 2017-10-05 at 14:05 +0200, Arnd Bergmann wrote: > gcc produces a harmless warning about a recently introduced > signed integer overflow: > > drivers/net/wireless/rsi/rsi_91x_hal.c: In function 'rsi_prepare_mgmt_desc': > include/uapi/linux/swab.h:13:15: error: integer overflow in expression [-Werror=overflow] > (((__u16)(x) & (__u16)0x00ffU) << 8) | \ > ~~~~~~~~~~~~^~~~~~~~~~~~~~~~~ > include/uapi/linux/swab.h:104:2: note: in expansion of macro '___constant_swab16' > ___constant_swab16(x) : \ > ^~~~~~~~~~~~~~~~~~ > include/uapi/linux/byteorder/big_endian.h:34:43: note: in expansion of macro '__swab16' > #define __cpu_to_le16(x) ((__force __le16)__swab16((x))) [] > The problem is that the 'mask' value is a signed integer that gets > turned into a negative number when truncated to 16 bits. Making it > an unsigned constant avoids this. I would expect there are more of these. Perhaps this define in include/uapi/linux/swab.h: #define __swab16(x) \ (__builtin_constant_p((__u16)(x)) ? \ ___constant_swab16(x) : \ __fswab16(x)) should be #define __swab16(x) \ (__builtin_c onstant_p((__u16)(x)) ? \ ___constant_swab16((__u16)(x)) : \ __fswab16((__u16)(x)))
From: Joe Perches > Sent: 05 October 2017 13:19 > On Thu, 2017-10-05 at 14:05 +0200, Arnd Bergmann wrote: > > gcc produces a harmless warning about a recently introduced > > signed integer overflow: > > > > drivers/net/wireless/rsi/rsi_91x_hal.c: In function 'rsi_prepare_mgmt_desc': > > include/uapi/linux/swab.h:13:15: error: integer overflow in expression [-Werror=overflow] > > (((__u16)(x) & (__u16)0x00ffU) << 8) | \ > > ~~~~~~~~~~~~^~~~~~~~~~~~~~~~~ > > include/uapi/linux/swab.h:104:2: note: in expansion of macro '___constant_swab16' > > ___constant_swab16(x) : \ > > ^~~~~~~~~~~~~~~~~~ > > include/uapi/linux/byteorder/big_endian.h:34:43: note: in expansion of macro '__swab16' > > #define __cpu_to_le16(x) ((__force __le16)__swab16((x))) > > [] > > > The problem is that the 'mask' value is a signed integer that gets > > turned into a negative number when truncated to 16 bits. Making it > > an unsigned constant avoids this. > > I would expect there are more of these. > > Perhaps this define in include/uapi/linux/swab.h: > > #define __swab16(x) \ > (__builtin_constant_p((__u16)(x)) ? \ > ___constant_swab16(x) : \ > __fswab16(x)) > > should be > > #define __swab16(x) \ > (__builtin_constant_p((__u16)(x)) ? \ > ___constant_swab16((__u16)(x)) : \ > __fswab16((__u16)(x))) You probably don't want the cast in the call to __fswab16() since that is likely to generate an explicit and with 0xffff. You will likely also get one if the argument is _u16 (not unsigned int). David
On Thu, 2017-10-05 at 15:12 +0000, David Laight wrote: > From: Joe Perches > > Sent: 05 October 2017 13:19 > > On Thu, 2017-10-05 at 14:05 +0200, Arnd Bergmann wrote: > > > gcc produces a harmless warning about a recently introduced > > > signed integer overflow: > > > > > > drivers/net/wireless/rsi/rsi_91x_hal.c: In function 'rsi_prepare_mgmt_desc': > > > include/uapi/linux/swab.h:13:15: error: integer overflow in expression [-Werror=overflow] > > > (((__u16)(x) & (__u16)0x00ffU) << 8) | \ > > > ~~~~~~~~~~~~^~~~~~~~~~~~~~~~~ > > > include/uapi/linux/swab.h:104:2: note: in expansion of macro '___constant_swab16' > > > ___constant_swab16(x) : \ > > > ^~~~~~~~~~~~~~~~~~ > > > include/uapi/linux/byteorder/big_endian.h:34:43: note: in expansion of macro '__swab16' > > > #define __cpu_to_le16(x) ((__force __le16)__swab16((x))) > > > > [] > > > > > The problem is that the 'mask' value is a signed integer that gets > > > turned into a negative number when truncated to 16 bits. Making it > > > an unsigned constant avoids this. > > > > I would expect there are more of these. > > > > Perhaps this define in include/uapi/linux/swab.h: > > > > #define __swab16(x) \ > > (__builtin_constant_p((__u16)(x)) ? \ > > ___constant_swab16(x) : \ > > __fswab16(x)) > > > > should be > > > > #define __swab16(x) \ > > (__builtin_constant_p((__u16)(x)) ? \ > > ___constant_swab16((__u16)(x)) : \ > > __fswab16((__u16)(x))) > > You probably don't want the cast in the call to __fswab16() since > that is likely to generate an explicit and with 0xffff. > You will likely also get one if the argument is _u16 (not unsigned int). It would just an explicit vs implicit cast as __fswab16 is a static inline with a __u16 argument
Arnd Bergmann <arnd@arndb.de> wrote: > gcc produces a harmless warning about a recently introduced > signed integer overflow: > > drivers/net/wireless/rsi/rsi_91x_hal.c: In function 'rsi_prepare_mgmt_desc': > include/uapi/linux/swab.h:13:15: error: integer overflow in expression [-Werror=overflow] > (((__u16)(x) & (__u16)0x00ffU) << 8) | \ > ~~~~~~~~~~~~^~~~~~~~~~~~~~~~~ > include/uapi/linux/swab.h:104:2: note: in expansion of macro '___constant_swab16' > ___constant_swab16(x) : \ > ^~~~~~~~~~~~~~~~~~ > include/uapi/linux/byteorder/big_endian.h:34:43: note: in expansion of macro '__swab16' > #define __cpu_to_le16(x) ((__force __le16)__swab16((x))) > ^~~~~~~~ > include/linux/byteorder/generic.h:89:21: note: in expansion of macro '__cpu_to_le16' > #define cpu_to_le16 __cpu_to_le16 > ^~~~~~~~~~~~~ > drivers/net/wireless/rsi/rsi_91x_hal.c:136:3: note: in expansion of macro 'cpu_to_le16' > cpu_to_le16((tx_params->vap_id << RSI_DESC_VAP_ID_OFST) & > ^~~~~~~~~~~ > > The problem is that the 'mask' value is a signed integer that gets > turned into a negative number when truncated to 16 bits. Making it > an unsigned constant avoids this. > > Fixes: eac4eed3224b ("rsi: tx and rx path enhancements for p2p mode") > Signed-off-by: Arnd Bergmann <arnd@arndb.de> Patch applied to wireless-drivers-next.git, thanks. a39644b235c1 rsi: fix integer overflow warning -- https://patchwork.kernel.org/patch/9986961/ https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches
diff --git a/drivers/net/wireless/rsi/rsi_mgmt.h b/drivers/net/wireless/rsi/rsi_mgmt.h index b9d0802c1b0f..e21723013f8d 100644 --- a/drivers/net/wireless/rsi/rsi_mgmt.h +++ b/drivers/net/wireless/rsi/rsi_mgmt.h @@ -189,7 +189,7 @@ IEEE80211_WMM_IE_STA_QOSINFO_AC_BE | \ IEEE80211_WMM_IE_STA_QOSINFO_AC_BK) -#define RSI_DESC_VAP_ID_MASK 0xC000 +#define RSI_DESC_VAP_ID_MASK 0xC000u #define RSI_DESC_VAP_ID_OFST 14 #define RSI_DATA_DESC_MAC_BBP_INFO BIT(0) #define RSI_DATA_DESC_NO_ACK_IND BIT(9)
gcc produces a harmless warning about a recently introduced signed integer overflow: drivers/net/wireless/rsi/rsi_91x_hal.c: In function 'rsi_prepare_mgmt_desc': include/uapi/linux/swab.h:13:15: error: integer overflow in expression [-Werror=overflow] (((__u16)(x) & (__u16)0x00ffU) << 8) | \ ~~~~~~~~~~~~^~~~~~~~~~~~~~~~~ include/uapi/linux/swab.h:104:2: note: in expansion of macro '___constant_swab16' ___constant_swab16(x) : \ ^~~~~~~~~~~~~~~~~~ include/uapi/linux/byteorder/big_endian.h:34:43: note: in expansion of macro '__swab16' #define __cpu_to_le16(x) ((__force __le16)__swab16((x))) ^~~~~~~~ include/linux/byteorder/generic.h:89:21: note: in expansion of macro '__cpu_to_le16' #define cpu_to_le16 __cpu_to_le16 ^~~~~~~~~~~~~ drivers/net/wireless/rsi/rsi_91x_hal.c:136:3: note: in expansion of macro 'cpu_to_le16' cpu_to_le16((tx_params->vap_id << RSI_DESC_VAP_ID_OFST) & ^~~~~~~~~~~ The problem is that the 'mask' value is a signed integer that gets turned into a negative number when truncated to 16 bits. Making it an unsigned constant avoids this. Fixes: eac4eed3224b ("rsi: tx and rx path enhancements for p2p mode") Signed-off-by: Arnd Bergmann <arnd@arndb.de> --- drivers/net/wireless/rsi/rsi_mgmt.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) -- 2.9.0