Re: [Xen-devel] [PATCH 1/3] tools/libxc: Drop xc_cpuid_to_str()

[Roger Pau Monné <roger.pau@xxxxxxxxxx>]

On Mon, Jul 02, 2018 at 01:15:10PM +0100, Andrew Cooper wrote:
> On 02/07/18 11:41, Roger Pau Monné wrote:
> > On Mon, Jul 02, 2018 at 10:57:25AM +0100, Andrew Cooper wrote:
> >> This helper appears to have been introduced 10 years ago by c/s 5f14a87ceb
> >> "x86, hvm: Guest CPUID configuration" and never had any users at all.
> >>
> >> alloc_str() is actually an opencoded calloc(), and now only has a single
> >> caller.  Use calloc() directly and drop alloc_str().
> >>
> >> Signed-off-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
> > Reviewed-by: Roger Pau Monné <roger.pau@xxxxxxxxxx>
> 
> Thanks,
> 
> >
> >> @@ -832,7 +809,7 @@ int xc_cpuid_set(
> >>              continue;
> >>          }
> >>          
> >> -        config_transformed[i] = alloc_str();
> >> +        config_transformed[i] = calloc(33, 1); /* 32 bits, NUL 
> >> terminator. */
> > I would rather do sizeof(*config_transformed[i]), but I'm not going to
> > insist.
> 
> Without a structure of the form:
> 
> struct {
>     char cfg[33];
> };
> 
> not amount of sizeof trickery will work here.  Your example reduces to
> sizeof(char), rather than 32/33.

I was thinking about using:

config_transformed[i] = calloc(33, *config_transformed[i]);

So just change the last hardcoded '1'.

Although using some kind of structure to convey this information
instead of a plain char array doesn't seem bad IMHO.

Roger.

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxxx
https://lists.xenproject.org/mailman/listinfo/xen-devel