From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-bl2nam02on0139.outbound.protection.outlook.com ([104.47.38.139]:53867 "EHLO NAM02-BL2-obe.outbound.protection.outlook.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1753007AbeBCSFE (ORCPT ); Sat, 3 Feb 2018 13:05:04 -0500 From: Sasha Levin To: "linux-kernel@vger.kernel.org" , "stable@vger.kernel.org" CC: Michael Ellerman , Sasha Levin Subject: [PATCH AUTOSEL for 4.14 095/110] powerpc/pseries: Make RAS IRQ explicitly dependent on DLPAR WQ Date: Sat, 3 Feb 2018 18:01:28 +0000 Message-ID: <20180203180015.29073-95-alexander.levin@microsoft.com> References: <20180203180015.29073-1-alexander.levin@microsoft.com> In-Reply-To: <20180203180015.29073-1-alexander.levin@microsoft.com> Content-Language: en-US Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Sender: stable-owner@vger.kernel.org List-ID: From: Michael Ellerman [ Upstream commit e2d5915293ffdff977ddcfc12b817b08c53ffa7a ] The hotplug code uses its own workqueue to handle IRQ requests (pseries_hp_wq), however that workqueue is initialized after init_ras_IRQ(). That can lead to a kernel panic if any hotplug interrupts fire after init_ras_IRQ() but before pseries_hp_wq is initialised. eg: UDP-Lite hash table entries: 2048 (order: 0, 65536 bytes) NET: Registered protocol family 1 Unpacking initramfs... (qemu) object_add memory-backend-ram,id=3Dmem1,size=3D10G (qemu) device_add pc-dimm,id=3Ddimm1,memdev=3Dmem1 Unable to handle kernel paging request for data at address 0xf94d03007c42= 1378 Faulting instruction address: 0xc00000000012d744 Oops: Kernel access of bad area, sig: 11 [#1] LE SMP NR_CPUS=3D2048 NUMA pSeries Modules linked in: CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.15.0-rc2-ziviani+ #26 task: (ptrval) task.stack: (ptrval) NIP: c00000000012d744 LR: c00000000012d744 CTR: 0000000000000000 REGS: (ptrval) TRAP: 0380 Not tainted (4.15.0-rc2-ziviani+) MSR: 8000000000009033 CR: 28088042 XER: 2004000= 0 CFAR: c00000000012d3c4 SOFTE: 0 ... NIP [c00000000012d744] __queue_work+0xd4/0x5c0 LR [c00000000012d744] __queue_work+0xd4/0x5c0 Call Trace: [c0000000fffefb90] [c00000000012d744] __queue_work+0xd4/0x5c0 (unreliable= ) [c0000000fffefc70] [c00000000012dce4] queue_work_on+0xb4/0xf0 This commit makes the RAS IRQ registration explicitly dependent on the creation of the pseries_hp_wq. Reported-by: Min Deng Reported-by: Daniel Henrique Barboza Tested-by: Jose Ricardo Ziviani Signed-off-by: Michael Ellerman Reviewed-by: David Gibson Signed-off-by: Sasha Levin --- arch/powerpc/platforms/pseries/dlpar.c | 21 ++++++++++++++++++--- arch/powerpc/platforms/pseries/pseries.h | 2 ++ arch/powerpc/platforms/pseries/ras.c | 3 ++- 3 files changed, 22 insertions(+), 4 deletions(-) diff --git a/arch/powerpc/platforms/pseries/dlpar.c b/arch/powerpc/platform= s/pseries/dlpar.c index e45b5f10645a..e9149d05d30b 100644 --- a/arch/powerpc/platforms/pseries/dlpar.c +++ b/arch/powerpc/platforms/pseries/dlpar.c @@ -586,11 +586,26 @@ static ssize_t dlpar_show(struct class *class, struct= class_attribute *attr, =20 static CLASS_ATTR_RW(dlpar); =20 -static int __init pseries_dlpar_init(void) +int __init dlpar_workqueue_init(void) { + if (pseries_hp_wq) + return 0; + pseries_hp_wq =3D alloc_workqueue("pseries hotplug workqueue", - WQ_UNBOUND, 1); + WQ_UNBOUND, 1); + + return pseries_hp_wq ? 0 : -ENOMEM; +} + +static int __init dlpar_sysfs_init(void) +{ + int rc; + + rc =3D dlpar_workqueue_init(); + if (rc) + return rc; + return sysfs_create_file(kernel_kobj, &class_attr_dlpar.attr); } -machine_device_initcall(pseries, pseries_dlpar_init); +machine_device_initcall(pseries, dlpar_sysfs_init); =20 diff --git a/arch/powerpc/platforms/pseries/pseries.h b/arch/powerpc/platfo= rms/pseries/pseries.h index 4470a3194311..1ae1d9f4dbe9 100644 --- a/arch/powerpc/platforms/pseries/pseries.h +++ b/arch/powerpc/platforms/pseries/pseries.h @@ -98,4 +98,6 @@ static inline unsigned long cmo_get_page_size(void) return CMO_PageSize; } =20 +int dlpar_workqueue_init(void); + #endif /* _PSERIES_PSERIES_H */ diff --git a/arch/powerpc/platforms/pseries/ras.c b/arch/powerpc/platforms/= pseries/ras.c index 4923ffe230cf..81d8614e7379 100644 --- a/arch/powerpc/platforms/pseries/ras.c +++ b/arch/powerpc/platforms/pseries/ras.c @@ -69,7 +69,8 @@ static int __init init_ras_IRQ(void) /* Hotplug Events */ np =3D of_find_node_by_path("/event-sources/hot-plug-events"); if (np !=3D NULL) { - request_event_sources_irqs(np, ras_hotplug_interrupt, + if (dlpar_workqueue_init() =3D=3D 0) + request_event_sources_irqs(np, ras_hotplug_interrupt, "RAS_HOTPLUG"); of_node_put(np); } --=20 2.11.0