From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755327Ab3E0QjS (ORCPT ); Mon, 27 May 2013 12:39:18 -0400 Received: from metis.ext.pengutronix.de ([92.198.50.35]:46646 "EHLO metis.ext.pengutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754379Ab3E0QjR (ORCPT ); Mon, 27 May 2013 12:39:17 -0400 Date: Mon, 27 May 2013 18:39:13 +0200 From: Sascha Hauer To: Alexandre Belloni Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Russell King , Shawn Guo , Sascha Hauer Subject: Re: [PATCH 1/3] net: phy: prevent linking breakage Message-ID: <20130527163913.GO32299@pengutronix.de> References: <1369671524-14797-1-git-send-email-alexandre.belloni@free-electrons.com> <1369671524-14797-2-git-send-email-alexandre.belloni@free-electrons.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1369671524-14797-2-git-send-email-alexandre.belloni@free-electrons.com> X-Sent-From: Pengutronix Hildesheim X-URL: http://www.pengutronix.de/ X-IRC: #ptxdist @freenode X-Accept-Language: de,en X-Accept-Content-Type: text/plain X-Uptime: 18:37:30 up 338 days, 7:49, 107 users, load average: 12.97, 10.38, 6.15 User-Agent: Mutt/1.5.21 (2010-09-15) X-SA-Exim-Connect-IP: 2001:6f8:1178:2:21e:67ff:fe11:9c5c X-SA-Exim-Mail-From: sha@pengutronix.de X-SA-Exim-Scanned: No (on metis.ext.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-kernel@vger.kernel.org Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, May 27, 2013 at 06:18:42PM +0200, Alexandre Belloni wrote: > phy_register_fixup{,_for_uid,_for_id} are called from arch/, quite > often, there is no protection to check whether CONFIG_PHYLIB=y which is > the only case where this would work. Having phylib as a module or not > compiled at all will result in that kind of linking failure: > > arch/arm/mach-at91/built-in.o: In function `ksz9021rn_phy_fixup': > :(.text+0x1174): undefined reference to `mdiobus_write' > :(.text+0x1188): undefined reference to `mdiobus_write' > :(.text+0x119c): undefined reference to `mdiobus_write' > :(.text+0x11b0): undefined reference to `mdiobus_write' > arch/arm/mach-at91/built-in.o: In function `sama5_dt_device_init': > :(.init.text+0x1e34): undefined reference to `phy_register_fixup_for_uid' > > Signed-off-by: Alexandre Belloni > --- > drivers/net/phy/phy_device.c | 6 ++++++ > include/linux/phy.h | 12 ++++++++++++ > 2 files changed, 18 insertions(+) > > diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c > index 3657b4a..df36367 100644 > --- a/drivers/net/phy/phy_device.c > +++ b/drivers/net/phy/phy_device.c > @@ -64,6 +64,11 @@ static int phy_attach_direct(struct net_device *dev, struct phy_device *phydev, > u32 flags, phy_interface_t interface); > > /* > + * phy_register_fixup{,_for_uid,_for_id} are called from arch/ so this won't > + * work unless phylib is compiled in the kernel. > + */ > +#ifdef CONFIG_PHYLIB > +/* > * Creates a new phy_fixup and adds it to the list > * @bus_id: A string which matches phydev->dev.bus_id (or PHY_ANY_ID) > * @phy_uid: Used to match against phydev->phy_id (the UID of the PHY) > @@ -109,6 +114,7 @@ int phy_register_fixup_for_id(const char *bus_id, > return phy_register_fixup(bus_id, PHY_ANY_UID, 0xffffffff, run); > } > EXPORT_SYMBOL(phy_register_fixup_for_id); > +#endif /* CONFIG_PHYLIB */ > > /* > * Returns 1 if fixup matches phydev in bus_id and phy_uid. > diff --git a/include/linux/phy.h b/include/linux/phy.h > index 9e11039..3f998a6 100644 > --- a/include/linux/phy.h > +++ b/include/linux/phy.h > @@ -556,12 +556,24 @@ int phy_start_interrupts(struct phy_device *phydev); > void phy_print_status(struct phy_device *phydev); > void phy_device_free(struct phy_device *phydev); > > +/* > + * phy_register_fixup{,_for_uid,_for_id} are called from arch/ so this won't > + * work unless phylib is compiled in the kernel. > + * Defining stubs allows to prevent linking errors. > + */ > +#ifdef CONFIG_PHYLIB > int phy_register_fixup(const char *bus_id, u32 phy_uid, u32 phy_uid_mask, > int (*run)(struct phy_device *)); > int phy_register_fixup_for_id(const char *bus_id, > int (*run)(struct phy_device *)); > int phy_register_fixup_for_uid(u32 phy_uid, u32 phy_uid_mask, > int (*run)(struct phy_device *)); > +#else > +#define phy_register_fixup(a, b, c, d) do { } while (0) > +#define phy_register_fixup_for_id(a, b) do { } while (0) > +#define phy_register_fixup_for_uid(a, b, c) do { } while (0) Use static inline functions here. This breaks if someone does result checking on the functions which then expands to ret = do {} while (0); Also we still have type safety for !CONFIG_PHYLIB. Sascha -- Pengutronix e.K. | | Industrial Linux Solutions | http://www.pengutronix.de/ | Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |