Re: [Qemu-devel] [PATCH 02/10] xen: backend driver core

[Gerd Hoffmann]

On 04/07/09 21:41, Anthony Liguori wrote:
> > +/* private */
> > +static TAILQ_HEAD(XenDeviceHead, XenDevice) xendevs =
> > TAILQ_HEAD_INITIALIZER(xendevs);
> > +static int debug = 0;
>
> Would be better to have all of this in a structure that had a single
> static instance. Would be even better if you could avoid requiring the
> static instance.

Huh?  Point being?  This is just a list head, i.e. a pointer (or two?).

> > +char *xenstore_read_str(const char *base, const char *node)
> > +{
> > + char abspath[XEN_BUFSIZE];
> > + unsigned int len;
> > +
> > + snprintf(abspath, sizeof(abspath), "%s/%s", base, node);
> > + return xs_read(xenstore, 0, abspath, &len);
>
> xs_read() is a xenstore API, it's returning malloc()'d memory.

> > +int xenstore_read_int(const char *base, const char *node, int *ival)
> > +{
> > + char *val;
> > + int rc = -1;
> > +
> > + val = xenstore_read_str(base, node);
> > + if (val && 1 == sscanf(val, "%d", ival))
> > + rc = 0;
> > + qemu_free(val);
>
> And here you're free()'ing with qemu_free.

Oops.  Good catch.

> > + xendev = qemu_mallocz(ops->size);
> > + if (!xendev)
> > + return NULL;
>
> No need to check malloc failures.

Will fix.

> > + dev = xs_directory(xenstore, 0, path, &cdev);
> > + qemu_free(dev);
>
> Mixing qemu_free() with malloc'd memory.

This too.

> You also have open coded calls to fprintf(stderr)
> whereas you've introduced a higher level function.

The high-level function wants a device instance and thus doesn't work 
everythere.  Nevertheless the code probably should use the new 
qemu_log() function instead.  I'll look into this.

cheers,
 Gerd