On 05.08.2019 11:40, Julien Grall wrote: > Hi, > > On 09/04/2019 12:42, Jan Beulich wrote: >>>>> On 09.04.19 at 13:26, <julien.gr...@arm.com> wrote: >>> On 03/04/2019 14:04, Jan Beulich wrote: >>>> Also please note the quotation used by the mentioned >>>> existing doc comments, as well as a few other formal aspects >>>> (like them also making clear what the return type is). I think >>>> that's a model used elsewhere as well, so I think you should >>>> follow it here. >>> >>> I haven't replicated the ` because I have no idea what they are used for. I >>> would appreciate if you provide pointer how to use them. >> >> Well, I can only point you at the history of things, e.g. >> 262e118a37 "docs/html/: Annotations for two hypercalls". >> >>>> The other thing is: As mentioned elsewhere, I don't think the >>>> first two parameters should be plain int. I'm not happy to see >>>> this proliferate into documentation as well, i.e. I'd prefer if >>>> this was corrected before adding documentation. Would you >>>> be willing to do this, or should I add it to my todo list? >>> >>> While switching from cmd from signed to unsigned should be ok. This would >>> introduce a different behavior of for count. >> >> Since this removes an error condition, I think this is an okay change >> to happen, without ... >> >>> Are we happy with that, or shall we add a check ((int)count) > 0? >> >> ... any such extra check. This also isn't going to introduce any new >> real risk of a long running operation or some such - if 2Gb of input >> data are fine, I can't see why 4Gb wouldn't be, too. > > Actually, it will not be fine at least for the read case. The return value is > a 32-bit value (on AArch32 and if you want to keep compat between 64-bit and > 32-bit). A negative value indicates an error. As we return the number of > characters read, it means we can only handle 2GB.
Hmm, valid point. > So I would rather limit the buffer to 2GB for everyone. Probably fair enough then (if explicitly stated). Personally I would nevertheless allow sizes up to 4Gb-4kb, but I can see why this may not be liked by everyone. I'd like to point out though that the PTR_ERR() machinery we've inherited from Linux utilizes exactly that. Jan _______________________________________________ Xen-devel mailing list Xen-devel@lists.xenproject.org https://lists.xenproject.org/mailman/listinfo/xen-devel
