> The requirement is to be __aligned(2). I've added 4 instances of > ether_addr_copy with 8 addresses as arguments. Of these, the 4 > src arguments are really the same type (i.e. nla_data acting on a > const nlattr*), so I'll try to reason about the 5 total cases below - > 1. cfg->dst_mac should be 16-bit aligned due to the layout of > struct cfg80211_wowlan_tcp. Its offset is 10 or 12 bytes in the > structure depending on the system.
I wouldn't want to rely on that, since internal structures can be changed pretty easily. If necessary, add __aligned(2) to the struct members where appropriate. > 2 and 3. For mac_addr and mac_addr_mask, nl80211_parse_random_mac > takes these in as u8* (and hence does not guarantee alignment?) > Both the callers of this function today pass in arguments that are > explicitly __aligned(2). But this cannot be said of future potential > callers > - so perhaps my patch introduces a bug? That should be documented, but it's also pretty tricky to review/maintain that. I general, I don't really see much reason to use ether_addr_copy() in any of these code paths - it's not really a performance thing (in part due to the alignment, ether_addr_copy can be faster) > 4. Based on struct cfg80211_acl_data, acl->mac_addrs[i] should be not > guaranteed to be __aligned(2). See above. > 5. For all the nla_data src arguments, the nla_data function returns > ((char*) foo + 5) for pointer foo. So likely not __aligned(2). Those should be aligned since the data is copied into an SKB, and +5 doesn't seem right - nla_data() should be +4. johannes
