On 25 May 2017 at 13:35, Ben Pfaff <[email protected]> wrote: > On Thu, May 25, 2017 at 01:05:11PM -0700, Joe Stringer wrote: >> On 24 May 2017 at 20:02, Ben Pfaff <[email protected]> wrote: >> > On Tue, May 23, 2017 at 04:02:12PM -0700, Joe Stringer wrote: >> >> Clang 4.0 complains: >> >> >> >> ../lib/odp-execute.c:61:37: error: taking address of packed member >> >> 'eth_dst' of >> >> class or structure 'eth_header' may result in an unaligned pointer value >> >> [-Werror,-Waddress-of-packed-member] >> >> ether_addr_copy_masked(&eh->eth_src, key->eth_src, >> >> mask->eth_src); >> >> ^~~~~~~~~~~ >> >> ../lib/odp-execute.c:62:37: error: taking address of packed member >> >> 'eth_dst' of >> >> class or structure 'eth_header' may result in an unaligned pointer value >> >> [-Werror,-Waddress-of-packed-member] >> >> ether_addr_copy_masked(&eh->eth_dst, key->eth_dst, >> >> mask->eth_dst); >> >> >> >> Ethernet source addresses are 48 bits offset into the Ethernet header, >> >> so taking a pointer for this is not guaranteed to be valid on all >> >> architectures. Fix this by referencing the memory direct from the >> >> Ethernet header pointer. >> >> >> >> Signed-off-by: Joe Stringer <[email protected]> >> > >> > I don't understand--why does Clang think that there's something packed >> > here? I don't see any packed annotation on struct eth_header (and I >> > don't think it needs one). >> >> https://github.com/openvswitch/ovs/blob/master/lib/packets.h#L398 >> >> I believe that this is the wire-formatted version that we use for >> assembling PDUs for protocols such as STP, so I think it needs to be >> properly packed. > > Oh, oops, somehow I was blind to the difference between eth_header and > eth_addr. > > But I don't actually see a need to pack this structure. There's nothing > in it that would cause a compile to insert padding. It has all 16-bit > members (including nested members), and you never get padding (on normal > architectures) when all the members of a struct have the same size; > otherwise arrays wouldn't work reasonably. > > I'll send some patches.
Ok thanks, I'll abandon this series and look for your patches. _______________________________________________ dev mailing list [email protected] https://mail.openvswitch.org/mailman/listinfo/ovs-dev
