Re: [PATCH 5/7] util: Add read_remainder() and read_all_buf()

[David Gibson <david@gibson.dropbear.id.au>]

[-- Attachment #1: Type: text/plain, Size: 1389 bytes --]

On Tue, Jan 28, 2025 at 07:48:49AM +0100, Stefano Brivio wrote:
> On Tue, 28 Jan 2025 11:59:28 +1100
> David Gibson <david@gibson.dropbear.id.au> wrote:
> 
> > On Tue, Jan 28, 2025 at 12:15:30AM +0100, Stefano Brivio wrote:
> > > These are symmetric to write_remainder() and write_all_buf() and
> > > almost a copy and paste of them, with the most notable differences
> > > being reversed reads/writes and a couple of better-safe-than-sorry
> > > asserts to keep Coverity happy.  
> > 
> > So, there's one thing that needs to be not quite symmetric for the
> > read() version: we need to handle EOF.  At present, I believe these
> > will enter an infinite loop on EOF, which is not a graceful failure
> > mode.
> 
> It doesn't happen in our current usage where we close the socket once
> we're done,

I don't see how what we do with the socket is relevant.  Couldn't we
hit this case if qemu unexpectedly closed the socket or died?

> but sure, if we use it for something else, boom. Let me add
> a rc == 0 case (which gets EIO or EINVAL, I'm not sure yet).
> 
> Or feel free to re-post this if you have clearer ideas how to fix this
> up (but only if tested).
> 

-- 
David Gibson (he or they)	| I'll have my music baroque, and my code
david AT gibson.dropbear.id.au	| minimalist, thank you, not the other way
				| around.
http://www.ozlabs.org/~dgibson

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 833 bytes --]