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1f778d500d
Smatch is confused by the fact that a 32-bit BIT(port) macro is passed as argument to the ocelot_ifh_set_dest function and warns: ocelot_xmit() warn: should '(((1))) << (dp->index)' be a 64 bit type? seville_xmit() warn: should '(((1))) << (dp->index)' be a 64 bit type? The destination port mask is copied into a 12-bit field of the packet, starting at bit offset 67 and ending at 56. So this DSA tagging protocol supports at most 12 bits, which is clearly less than 32. Attempting to send to a port number > 12 will cause the packing() call to truncate way before there will be 32-bit truncation due to type promotion of the BIT(port) argument towards u64. Therefore, smatch's fears that BIT(port) will do the wrong thing and cause unexpected truncation for "port" values >= 32 are unfounded. Nonetheless, let's silence the warning by explicitly passing an u64 value to ocelot_ifh_set_dest, such that the compiler does not need to do a questionable type promotion. Reported-by: kernel test robot <lkp@intel.com> Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.