gregkh@linuxfoundation.org writes:
This is a note to let you know that I've just added the patch titled
powerpc/pseries: Make RAS IRQ explicitly dependent on DLPAR WQto the 4.14-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...
The filename of the patch is: powerpc-pseries-make-ras-irq-explicitly-dependent-on-dlpar-wq.patch and it can be found in the queue-4.14 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.
Did someone request this one?
I didn't Cc it to stable because I wasn't confident of the testing it'd had, and in fact we found another related bug recently.
So if you take this you probably also want:
c9dccf1d074a ("powerpc/pseries: Enable RAS hotplug events later")
But note that commit is only ~2-3 weeks old, so again I can't vouch 100% for it's bullet-proof-ness.
cheers
From foo@baz Wed Feb 28 16:23:28 CET 2018 From: Michael Ellerman mpe@ellerman.id.au Date: Mon, 8 Jan 2018 14:54:32 +1100 Subject: powerpc/pseries: Make RAS IRQ explicitly dependent on DLPAR WQ
From: Michael Ellerman mpe@ellerman.id.au
[ 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=mem1,size=10G (qemu) device_add pc-dimm,id=dimm1,memdev=mem1 Unable to handle kernel paging request for data at address 0xf94d03007c421378 Faulting instruction address: 0xc00000000012d744 Oops: Kernel access of bad area, sig: 11 [#1] LE SMP NR_CPUS=2048 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 <SF,EE,ME,IR,DR,RI,LE> CR: 28088042 XER: 20040000 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 mdeng@redhat.com Reported-by: Daniel Henrique Barboza danielhb@linux.vnet.ibm.com Tested-by: Jose Ricardo Ziviani joserz@linux.vnet.ibm.com Signed-off-by: Michael Ellerman mpe@ellerman.id.au Reviewed-by: David Gibson david@gibson.dropbear.id.au Signed-off-by: Sasha Levin alexander.levin@verizon.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
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(-)
--- 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 * static CLASS_ATTR_RW(dlpar); -static int __init pseries_dlpar_init(void) +int __init dlpar_workqueue_init(void) {
- if (pseries_hp_wq)
return 0;- pseries_hp_wq = 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 = 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); --- 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 return CMO_PageSize; } +int dlpar_workqueue_init(void);
#endif /* _PSERIES_PSERIES_H */ --- 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 = of_find_node_by_path("/event-sources/hot-plug-events"); if (np != NULL) {
request_event_sources_irqs(np, ras_hotplug_interrupt,
if (dlpar_workqueue_init() == 0)request_event_sources_irqs(np, ras_hotplug_interrupt, "RAS_HOTPLUG");Patches currently in stable-queue which might be from mpe@ellerman.id.au are
queue-4.14/powerpc-pseries-make-ras-irq-explicitly-dependent-on-dlpar-wq.patch