| Message ID | 1399322991-19329-3-git-send-email-imammedo@redhat.com (mailing list archive) |
|---|---|
| State | Accepted, archived |
| Headers | show |
On Monday, May 05, 2014 10:49:49 PM Igor Mammedov wrote: > acpi_processor_add() assumes that present at boot CPUs > are always onlined, it is not so if a CPU failed to become > onlined. As result acpi_processor_add() will mark such CPU > device as onlined in sysfs and following attempts to > online/offline it using /sys/device/system/cpu/cpuX/online > attribute will fail. > > Do not poke into device internals in acpi_processor_add() > and touch "struct device { .offline }" attribute, since > for CPUs onlined at boot it's set by: > topology_init() -> arch_register_cpu() -> register_cpu() > before ACPI device tree is parsed, and for hotplugged > CPUs it's set when userspace onlines CPU via sysfs. > > Signed-off-by: Igor Mammedov <imammedo@redhat.com> > Acked-by: Toshi Kani <toshi.kani@hp.com> Would there be a problem if I applied this separately from the rest of the series? > --- > v2: > - fix regression in v1 leading to NULL pointer dereference > on CPU unplug, do not remove "pr->dev = dev;" > --- > drivers/acpi/acpi_processor.c | 1 - > 1 files changed, 0 insertions(+), 1 deletions(-) > > diff --git a/drivers/acpi/acpi_processor.c b/drivers/acpi/acpi_processor.c > index b06f5f5..52c81c4 100644 > --- a/drivers/acpi/acpi_processor.c > +++ b/drivers/acpi/acpi_processor.c > @@ -405,7 +405,6 @@ static int acpi_processor_add(struct acpi_device *device, > goto err; > > pr->dev = dev; > - dev->offline = pr->flags.need_hotplug_init; > > /* Trigger the processor driver's .probe() if present. */ > if (device_attach(dev) >= 0) >
* Rafael J. Wysocki <rjw@rjwysocki.net> wrote: > On Monday, May 05, 2014 10:49:49 PM Igor Mammedov wrote: > > acpi_processor_add() assumes that present at boot CPUs > > are always onlined, it is not so if a CPU failed to become > > onlined. As result acpi_processor_add() will mark such CPU > > device as onlined in sysfs and following attempts to > > online/offline it using /sys/device/system/cpu/cpuX/online > > attribute will fail. > > > > Do not poke into device internals in acpi_processor_add() > > and touch "struct device { .offline }" attribute, since > > for CPUs onlined at boot it's set by: > > topology_init() -> arch_register_cpu() -> register_cpu() > > before ACPI device tree is parsed, and for hotplugged > > CPUs it's set when userspace onlines CPU via sysfs. > > > > Signed-off-by: Igor Mammedov <imammedo@redhat.com> > > Acked-by: Toshi Kani <toshi.kani@hp.com> > > Would there be a problem if I applied this separately from the rest > of the series? If you push the fix upstream for v3.15 then it would be fine and I could base the other patches on top of your (soon to be upstream) commit. Thanks, Ingo -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
* Rafael J. Wysocki <rjw@rjwysocki.net> wrote: > On Thursday, May 08, 2014 08:09:35 AM Ingo Molnar wrote: > > > > * Rafael J. Wysocki <rjw@rjwysocki.net> wrote: > > > > > On Monday, May 05, 2014 10:49:49 PM Igor Mammedov wrote: > > > > acpi_processor_add() assumes that present at boot CPUs > > > > are always onlined, it is not so if a CPU failed to become > > > > onlined. As result acpi_processor_add() will mark such CPU > > > > device as onlined in sysfs and following attempts to > > > > online/offline it using /sys/device/system/cpu/cpuX/online > > > > attribute will fail. > > > > > > > > Do not poke into device internals in acpi_processor_add() > > > > and touch "struct device { .offline }" attribute, since > > > > for CPUs onlined at boot it's set by: > > > > topology_init() -> arch_register_cpu() -> register_cpu() > > > > before ACPI device tree is parsed, and for hotplugged > > > > CPUs it's set when userspace onlines CPU via sysfs. > > > > > > > > Signed-off-by: Igor Mammedov <imammedo@redhat.com> > > > > Acked-by: Toshi Kani <toshi.kani@hp.com> > > > > > > Would there be a problem if I applied this separately from the rest > > > of the series? > > > > If you push the fix upstream for v3.15 then it would be fine and I > > could base the other patches on top of your (soon to be upstream) > > commit. > > OK, I can do that. > > We also seem to need this in -stable, right? Yeah, agreed. Thanks, Ingo -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Thursday, May 08, 2014 08:09:35 AM Ingo Molnar wrote: > > * Rafael J. Wysocki <rjw@rjwysocki.net> wrote: > > > On Monday, May 05, 2014 10:49:49 PM Igor Mammedov wrote: > > > acpi_processor_add() assumes that present at boot CPUs > > > are always onlined, it is not so if a CPU failed to become > > > onlined. As result acpi_processor_add() will mark such CPU > > > device as onlined in sysfs and following attempts to > > > online/offline it using /sys/device/system/cpu/cpuX/online > > > attribute will fail. > > > > > > Do not poke into device internals in acpi_processor_add() > > > and touch "struct device { .offline }" attribute, since > > > for CPUs onlined at boot it's set by: > > > topology_init() -> arch_register_cpu() -> register_cpu() > > > before ACPI device tree is parsed, and for hotplugged > > > CPUs it's set when userspace onlines CPU via sysfs. > > > > > > Signed-off-by: Igor Mammedov <imammedo@redhat.com> > > > Acked-by: Toshi Kani <toshi.kani@hp.com> > > > > Would there be a problem if I applied this separately from the rest > > of the series? > > If you push the fix upstream for v3.15 then it would be fine and I > could base the other patches on top of your (soon to be upstream) > commit. OK, I can do that. We also seem to need this in -stable, right?
diff --git a/drivers/acpi/acpi_processor.c b/drivers/acpi/acpi_processor.c index b06f5f5..52c81c4 100644 --- a/drivers/acpi/acpi_processor.c +++ b/drivers/acpi/acpi_processor.c @@ -405,7 +405,6 @@ static int acpi_processor_add(struct acpi_device *device, goto err; pr->dev = dev; - dev->offline = pr->flags.need_hotplug_init; /* Trigger the processor driver's .probe() if present. */ if (device_attach(dev) >= 0)
acpi_processor_add() assumes that present at boot CPUs are always onlined, it is not so if a CPU failed to become onlined. As result acpi_processor_add() will mark such CPU device as onlined in sysfs and following attempts to online/offline it using /sys/device/system/cpu/cpuX/online attribute will fail. Do not poke into device internals in acpi_processor_add() and touch "struct device { .offline }" attribute, since for CPUs onlined at boot it's set by: topology_init() -> arch_register_cpu() -> register_cpu() before ACPI device tree is parsed, and for hotplugged CPUs it's set when userspace onlines CPU via sysfs. Signed-off-by: Igor Mammedov <imammedo@redhat.com> Acked-by: Toshi Kani <toshi.kani@hp.com> --- v2: - fix regression in v1 leading to NULL pointer dereference on CPU unplug, do not remove "pr->dev = dev;" --- drivers/acpi/acpi_processor.c | 1 - 1 files changed, 0 insertions(+), 1 deletions(-)