Hello Michal, On Fri, Aug 06, 2010 at 11:23:01AM +0200, Michal Nazarewicz wrote: > The __ref* tags may have been confusing for new kernel > developers (I was confused by them for sure) so adding a few > more sentences to comment to clear things up for people who > see those for the first time. > > Signed-off-by: Michal Nazarewicz <m.nazarewicz@xxxxxxxxxxx> > Cc: Sam Ravnborg <sam@xxxxxxxxxxxx> > --- > include/linux/init.h | 13 ++++++++++--- > 1 files changed, 10 insertions(+), 3 deletions(-) > > > On Fri, Aug 06, 2010 at 10:45:00AM +0200, Micha?‚ Nazarewicz wrote: > >> I just realised that I misunderstood the __ref* tags. The __ref* > >> means that the thing references an __init* thing, correct? > > On Fri, 06 Aug 2010 10:50:03 +0200, Uwe Kleine-K철nig wrote: > > That's what I tried to explain earlier in this thread. And more exact > > it means that modpost won't warn about structures/functions that are > > marked with it. > > Yep, I now understood it. I first thought __ref* is a replacement for > __init* and it's not so. Thanks for clarifying that. I would even go > as far as proposed the following patch. > > diff --git a/include/linux/init.h b/include/linux/init.h > index de99430..3059329 100644 > --- a/include/linux/init.h > +++ b/include/linux/init.h > @@ -46,16 +46,23 @@ > #define __exitdata __section(.exit.data) > #define __exit_call __used __section(.exitcall.exit) > > -/* modpost check for section mismatches during the kernel build. > +/* > + * modpost check for section mismatches during the kernel build. > * A section mismatch happens when there are references from a > * code or data section to an init section (both code or data). > * The init sections are (for most archs) discarded by the kernel > * when early init has completed so all such references are potential bugs. > * For exit sections the same issue exists. > + * > * The following markers are used for the cases where the reference to > * the *init / *exit section (code or data) is valid and will teach > - * modpost not to issue a warning. > - * The markers follow same syntax rules as __init / __initdata. */ > + * modpost not to issue a warning. Intended semantics is that a code or > + * data tagged __ref* can reference code or data from init section without > + * producing warning (of course, no warning does not mean code is correct, s/producing warning/producing a warning/ ? > + * so this need to be checked). and maybe add something like: So optimally document why the __ref is needed and why it's OK. Best regards Uwe -- Pengutronix e.K. | Uwe Kleine-König | Industrial Linux Solutions | http://www.pengutronix.de/ | -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
