2013-09-12 22:29:31

by Larry Finger

Subject: Smatch messages that are not understood

Hi,

I am in the process of fixing smatch warnings and errors in the rtlwifi family
of drivers. Most are straight forward; however, some routines show info messages
originating from an inline routine in the header files as follows:

CHECK drivers/net/wireless/rtlwifi/rtl8192ce/dm.c
include/linux/etherdevice.h:278 ether_addr_equal_64bits() info: ignoring
unreachable code.
include/linux/etherdevice.h:278 ether_addr_equal_64bits() info: ignoring
unreachable code.

The source code is a current pull of the mainline git tree. I'm not sure if this
is a subtle case of unreachable code that I do not see, or if it is a smatch bug.

Thanks,

Larry

2013-09-12 22:43:27

by Dan Carpenter

Subject: Re: Smatch messages that are not understood

On Thu, Sep 12, 2013 at 05:29:26PM -0500, Larry Finger wrote:
> Hi,
>
> I am in the process of fixing smatch warnings and errors in the
> rtlwifi family of drivers. Most are straight forward; however, some
> routines show info messages originating from an inline routine in
> the header files as follows:
>
> CHECK drivers/net/wireless/rtlwifi/rtl8192ce/dm.c
> include/linux/etherdevice.h:278 ether_addr_equal_64bits() info:
> ignoring unreachable code.
> include/linux/etherdevice.h:278 ether_addr_equal_64bits() info:
> ignoring unreachable code.
>
> The source code is a current pull of the mainline git tree. I'm not
> sure if this is a subtle case of unreachable code that I do not see,
> or if it is a smatch bug.

include/linux/etherdevice.h
275 if (sizeof(fold) == 8)
276 return zap_last_2bytes(fold) == 0;
277
278 fold |= zap_last_2bytes((*(unsigned long *)(addr1 + 4)) ^
279 (*(unsigned long *)(addr2 + 4)));

It's hitting the (sizeof(fold) == 8) and returning.

regards,
dan carpenter