Re: [Xen-devel] [Xen-users] Xen 4.2 TODO (io and irq parameter are not evaluated by xl)

[Ian Campbell <Ian.Campbell@xxxxxxxxxx>]

On Fri, 2012-08-31 at 16:57 +0100, Ian Jackson wrote:
> Ian Campbell writes ("Re: [Xen-users] Xen 4.2 TODO (io and irq parameter are 
> not evaluated by xl)"):
> > On Fri, 2012-08-31 at 16:13 +0100, Ian Jackson wrote:
> > > This code fails to properly handle (reject)
> > >    - (*ep!=0 && *ep!='-')
> > 
> > Oops, will fix.
> > 
> > >    - value > LONG_MAX
> > >    - INT_MAX < value <= LONG_MAX
> > 
> > These all get checked inside the (eventual) hypercall. Or were you
> > thinking of something else?
> 
> Suppose buf contains "1100000055\0".
> 
> If a long is 32-bit, strtoul will return ULONG_MAX (0xffffffffUL)
> setting errno to ERANGE.  Converting that to a 32-bit signed int will
> do something implementation-defined (C99 6.3.1.3(3)) - in reality,
> give -1.  Relying on this being rejected later seems poor practice.

The target variable here is an unsigned 32-bit int though.

> If a long is 64-bit and an int 32-bit, strtoul will return
> 0x1100000055UL.  Converting that to a 32-bit int will again do
> something implementation-defined - in reality, give 0x55.

I've added checks for this and posted as V2.

Ian.


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