linux-kernel - Re: [PATCH v4 3/5] acpi_processor: do not mark present at boot but not onlined CPU as onlined

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20140415080032.787580b9@nial.usersys.redhat.com>
Date:	Tue, 15 Apr 2014 08:00:32 +0200
From:	Igor Mammedov <imammedo@...hat.com>
To:	"Rafael J. Wysocki" <rjw@...ysocki.net>
Cc:	linux-kernel@...r.kernel.org, tglx@...utronix.de, mingo@...hat.com,
	hpa@...or.com, x86@...nel.org, bp@...e.de,
	paul.gortmaker@...driver.com, JBeulich@...e.com, prarit@...hat.com,
	drjones@...hat.com, toshi.kani@...com, riel@...hat.com,
	gong.chen@...ux.intel.com, andi@...stfloor.org, lenb@...nel.org,
	linux-acpi@...r.kernel.org
Subject: Re: [PATCH v4 3/5] acpi_processor: do not mark present at boot but
 not onlined CPU as onlined

On Tue, 15 Apr 2014 07:48:30 +0200
"Rafael J. Wysocki" <rjw@...ysocki.net> wrote:

> On Monday, April 14, 2014 05:11:15 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@...hat.com>
> > ---
> > v2:
> >  - fix regression in v1 leading to NULL pointer dereference
> >    on CPU unplug, do not remove "pr->dev = dev;"
> 
> Yeah.
> 
> Does this patch depend on any other patches in the series?
> 
> I don't think so, but just asking.
> 
> If it doesn't, why is it part of this series at all?
It's doesn't depend on any other patches in here, it was just
convenient to post it as a part of fixes found in CPU hotplug
code and nothing more.

> 
> > ---
> >  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 c29c2c3..42d66f8 100644
> > --- a/drivers/acpi/acpi_processor.c
> > +++ b/drivers/acpi/acpi_processor.c
> > @@ -404,7 +404,6 @@ 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)
> > 
> 

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/