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 13:37:29 +1100 Message-ID: <1388371049.4373.22.camel@pasglop> References: <1387301573-30502-1-git-send-email-clg@fr.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-Reply-To: <1387301573-30502-1-git-send-email-clg-NmTC/0ZBporQT0dZR+AlfA@public.gmane.org> Sender: devicetree-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: =?ISO-8859-1?Q?C=E9dric?= Le Goater Cc: grant.likely-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org, devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linuxppc-dev-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org, Thierry Reding , Linux Kernel list List-Id: devicetree@vger.kernel.org On Tue, 2013-12-17 at 18:32 +0100, C=C3=A9dric Le Goater wrote: > Commit 2361613206e6, "of/irq: Refactor interrupt-map parsing" changed > the refcount on the device_node causing an error in of_node_put(): Grant, Thierry, this is a regression, please send to Linus ASAP... Cheers, Ben. > 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/0x1f0 (unrelia= ble) > [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+0xa0/0x2e= 0 > [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 >=20 > This patch adjusts the refcount in the walk of the interrupt tree. > When a match is found, there is no need to increase the refcount=20 > 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. >=20 > This patch also removes the usage of the device_node variable 'old'=20 > which seems useless after the latest changes. >=20 > Signed-off-by: C=C3=A9dric Le Goater > --- >=20 > This patch was tested on powerpc, pseries and powernv. This is a=20 > new area for me so I might have missed a path. Please take a look. >=20 > We could now introduce an helper routine to look for #address-cells i= n > of_irq_parse_raw(). This can be the subject of another patch. >=20 > Thanks, >=20 > C. >=20 > drivers/of/irq.c | 5 +---- > 1 file changed, 1 insertion(+), 4 deletions(-) >=20 > 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 o= f_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; > } > =20 > @@ -250,8 +249,7 @@ int of_irq_parse_raw(const __be32 *addr, struct o= f_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; > =20 > match_array =3D imap - newaddrsize - newintsize; > for (i =3D 0; i < newintsize; i++) > @@ -268,7 +266,6 @@ int of_irq_parse_raw(const __be32 *addr, struct o= f_phandle_args *out_irq) > } > fail: > of_node_put(ipar); > - of_node_put(out_irq->np); > of_node_put(newpar); > =20 > return -EINVAL; -- 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