From mboxrd@z Thu Jan 1 00:00:00 1970 From: Benjamin Herrenschmidt Subject: Re: [PATCH] of/irq: Fix device_node refcount in of_irq_parse_raw() Date: Mon, 30 Dec 2013 14:59:37 +1100 Message-ID: <1388375977.4373.26.camel@pasglop> References: <1387301573-30502-1-git-send-email-clg@fr.ibm.com> <1388371049.4373.22.camel@pasglop> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-Reply-To: Sender: devicetree-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Rob Herring Cc: =?ISO-8859-1?Q?C=E9dric?= Le Goater , Grant Likely , "devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , linuxppc-dev , Thierry Reding , Linux Kernel list List-Id: devicetree@vger.kernel.org On Sun, 2013-12-29 at 20:42 -0600, Rob Herring wrote: > On Sun, Dec 29, 2013 at 8:37 PM, Benjamin Herrenschmidt > wrote: >=20 > On Tue, 2013-12-17 at 18:32 +0100, C=C3=A9dric Le Goater wrot= e: > > Commit 2361613206e6, "of/irq: Refactor interrupt-map > parsing" changed > > the refcount on the device_node causing an error in > of_node_put(): > =20 > =20 > Grant, Thierry, this is a regression, please send to Linus > ASAP... > =20 >=20 >=20 > I'm working on doing that right this moment. Thanks, looks like I'm not the only trying to get some work done today :) Cheers, Ben. >=20 > Rob >=20 > Cheers, > Ben. > =20 > > ERROR: Bad of_node_put() on /pci@800000020000000 > > CPU: 0 PID: 1 Comm: swapper/0 Not tainted 3.13.0-rc3-dirty > #2 > > Call Trace: > > [c00000003e403500] [c0000000000144fc] .show_stack+0x7c/0x1f= 0 > (unreliable) > > [c00000003e4035d0] [c00000000070f250] .dump_stack+0x88/0xb4 > > [c00000003e403650] [c0000000005e8768] .of_node_release > +0xd8/0xf0 > > [c00000003e4036e0] [c0000000005eeafc] .of_irq_parse_one > +0x10c/0x280 > > [c00000003e4037a0] [c0000000005efd4c] .of_irq_parse_pci > +0x3c/0x1d0 > > [c00000003e403840] [c000000000038240] .pcibios_setup_device > +0xa0/0x2e0 > > [c00000003e403910] > [c0000000000398f0] .pcibios_setup_bus_devices+0x60/0xd0 > > [c00000003e403990] [c00000000003b3a4] .__of_scan_bus > +0x1a4/0x2b0 > > [c00000003e403a80] [c00000000003a62c] .pcibios_scan_phb > +0x30c/0x410 > > [c00000003e403b60] [c0000000009fe430] .pcibios_init > +0x7c/0xd4 > > > > This patch adjusts the refcount in the walk of the interrup= t > tree. > > When a match is found, there is no need to increase the > refcount > > on 'out_irq->np' as 'newpar' is already holding a ref. The > refcount > > balance between 'ipar' and 'newpar' is maintained in the > skiplevel: > > goto label. > > > > This patch also removes the usage of the device_node > variable 'old' > > which seems useless after the latest changes. > > > > Signed-off-by: C=C3=A9dric Le Goater > > --- > > > > This patch was tested on powerpc, pseries and powernv. This > is a > > new area for me so I might have missed a path. Please take = a > look. > > > > We could now introduce an helper routine to look for > #address-cells in > > of_irq_parse_raw(). This can be the subject of another > patch. > > > > Thanks, > > > > C. > > > > drivers/of/irq.c | 5 +---- > > 1 file changed, 1 insertion(+), 4 deletions(-) > > > > diff --git a/drivers/of/irq.c b/drivers/of/irq.c > > index 786b0b47fae4..27212402c532 100644 > > --- a/drivers/of/irq.c > > +++ b/drivers/of/irq.c > > @@ -165,7 +165,6 @@ int of_irq_parse_raw(const __be32 *addr= , > struct of_phandle_args *out_irq) > > if (of_get_property(ipar, > "interrupt-controller", NULL) !=3D > > NULL) { > > pr_debug(" -> got it !\n"); > > - of_node_put(old); > > return 0; > > } > > > > @@ -250,8 +249,7 @@ int of_irq_parse_raw(const __be32 *addr= , > struct of_phandle_args *out_irq) > > * Successfully parsed an interrrupt-map > translation; copy new > > * interrupt specifier into the out_irq > structure > > */ > > - of_node_put(out_irq->np); > > - out_irq->np =3D of_node_get(newpar); > > + out_irq->np =3D newpar; > > > > match_array =3D imap - newaddrsize - newintsi= ze; > > for (i =3D 0; i < newintsize; i++) > > @@ -268,7 +266,6 @@ int of_irq_parse_raw(const __be32 *addr= , > struct of_phandle_args *out_irq) > > } > > fail: > > of_node_put(ipar); > > - of_node_put(out_irq->np); > > of_node_put(newpar); > > > > return -EINVAL; > =20 > =20 > -- > =20 > To unsubscribe from this list: send the line "unsubscribe > devicetree" in > the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org > More majordomo info at > http://vger.kernel.org/majordomo-info.html > =20 >=20 >=20 -- To unsubscribe from this list: send the line "unsubscribe devicetree" i= n the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html