On Tue, Jun 14, 2016 at 01:51:24PM +0000, Kalle Valo wrote: > > It's not clear that's the same situation, since tun->sk is very likely > > to have been an actual pointer, not an embedded thing like drv_priv. Just to follow up on that thread, I did research it a bit yesterday and came to the conclusion that it is UB even when the target is in the same struct. However, in a not very scientific survey, I didn't see either clang or gcc remove the test in a simplified test case (with -O3 and without -fno-delete-null-pointer-checks). If drv_priv were an actual pointer, gcc did remove it but clang did not. So, there's that. > > However, with all this, I think I'd simply not take any chances - the > > patch isn't exactly invasive and in some cases (for example the first > > hunk of the patch) will even improve the code to the point where the > > compiler could warn about uninitialized usage of the pointer when the > > code gets modified to use it in case of !txq->sta. > > > > I'd take it, but I guess it's Kalle's decision :) > > Yeah, I'm leaning towards Johannes. These are not really invasive. Thanks, and sorry about the checkpatch -- I did run checkpatch on it but for some reason my version only complained about some of them. -- Bob Copeland %% http://bobcopeland.com/ -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
