Dan Carpenter <dan.carpen...@oracle.com> writes: > On Mon, Jan 19, 2015 at 05:56:11PM +0100, Vitaly Kuznetsov wrote: >> vmbus_device_create() result is not being checked in vmbus_process_offer() >> and >> it can fail if kzalloc() fails. Add the check and do minor cleanup to avoid >> additional duplication of "free_channel(); return;" block. >> >> Reported-by: Jason Wang <jasow...@redhat.com> >> Signed-off-by: Vitaly Kuznetsov <vkuzn...@redhat.com> > > "out" is always a bad name for a label. It's too vague. It implies > that the code uses "One Err" style error handling which is bug prone and > I've ranted about that in the past so I won't here. This kind of coding > is buggier than direct returns. But recently I've been looking at bugs > where we return zero where the code should return a negative error code > and, wow, do I hate "out" labels! > > if (function_whatever(xxx)) > goto out; > > [ thousands of lines removed. ] > > out: > return ret; > > Oh crap... Did the coder mean to return success or not??? > > If you use a direct return then the code looks like: > > if (function_whatever(xxx)) > return 0; > > In that case, you can immediately see that the coder typed "0" > deliberately. Direct returns are best. I guess that's not directly > related to this code. But I didn't know that until I read to the bottom > of the patch and I already had this rant prepared in my head ready to > go...
Thank you for your rant, Dan! It contains an explanation _why_ and so is useful. However ... :-) 1) vmbus_process_offer() returns void so we won't forget to set proper return code. 2) this patch is a preparation for the PATCH 3/3 where the label is being used to do some useful (non-trivial) work. "Direct returns" approach would require us to duplicate the code or move it to a function and call it from all return places. I consider adding "out" label being less evil. Anyway, I can rename it to something less provocative in PATCH 3/3, e.g. init_rescind. > > "error" is a crap label name because it doesn't tell you what the code > does. A better name is "err_free_chan" or something which talks about > freeing the channel. And here I have to completely agree with you, I'll rename it in v3. > > regards, > dan carpenter -- Vitaly -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
