<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/kernel/irq, branch linux-3.18.y</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>genirq: Prevent use-after-free and work list corruption</title>
<updated>2019-05-16T07:17:21+00:00</updated>
<author>
<name>Prasad Sodagudi</name>
<email>psodagud@codeaurora.org</email>
</author>
<published>2019-03-24T14:57:04+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=43dae3a4e492472a4770979405e9aee9b6dc2969'/>
<id>43dae3a4e492472a4770979405e9aee9b6dc2969</id>
<content type='text'>
[ Upstream commit 59c39840f5abf4a71e1810a8da71aaccd6c17d26 ]

When irq_set_affinity_notifier() replaces the notifier, then the
reference count on the old notifier is dropped which causes it to be
freed. But nothing ensures that the old notifier is not longer queued
in the work list. If it is queued this results in a use after free and
possibly in work list corruption.

Ensure that the work is canceled before the reference is dropped.

Signed-off-by: Prasad Sodagudi &lt;psodagud@codeaurora.org&gt;
Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: marc.zyngier@arm.com
Link: https://lkml.kernel.org/r/1553439424-6529-1-git-send-email-psodagud@codeaurora.org
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 59c39840f5abf4a71e1810a8da71aaccd6c17d26 ]

When irq_set_affinity_notifier() replaces the notifier, then the
reference count on the old notifier is dropped which causes it to be
freed. But nothing ensures that the old notifier is not longer queued
in the work list. If it is queued this results in a use after free and
possibly in work list corruption.

Ensure that the work is canceled before the reference is dropped.

Signed-off-by: Prasad Sodagudi &lt;psodagud@codeaurora.org&gt;
Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: marc.zyngier@arm.com
Link: https://lkml.kernel.org/r/1553439424-6529-1-git-send-email-psodagud@codeaurora.org
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Revert "genirq: Use irqd_get_trigger_type to compare the trigger type for shared IRQs"</title>
<updated>2018-04-08T09:49:42+00:00</updated>
<author>
<name>Greg Kroah-Hartman</name>
<email>gregkh@linuxfoundation.org</email>
</author>
<published>2018-03-30T08:56:51+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=6ab380698a5301fa8ccf995d946351cf4047ee52'/>
<id>6ab380698a5301fa8ccf995d946351cf4047ee52</id>
<content type='text'>
This reverts commit 093c265afffb0a91a7611c3bb74d0883731a807b which is
commit 382bd4de61827dbaaf5fb4fb7b1f4be4a86505e7 upstream.

It causes too many problems with the stable tree, and would require too
many other things to be backported, so just revert it.

Reported-by: Guenter Roeck &lt;linux@roeck-us.net&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: Hans de Goede &lt;hdegoede@redhat.com&gt;
Cc: Marc Zyngier &lt;marc.zyngier@arm.com&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: Sasha Levin &lt;alexander.levin@microsoft.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
This reverts commit 093c265afffb0a91a7611c3bb74d0883731a807b which is
commit 382bd4de61827dbaaf5fb4fb7b1f4be4a86505e7 upstream.

It causes too many problems with the stable tree, and would require too
many other things to be backported, so just revert it.

Reported-by: Guenter Roeck &lt;linux@roeck-us.net&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: Hans de Goede &lt;hdegoede@redhat.com&gt;
Cc: Marc Zyngier &lt;marc.zyngier@arm.com&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: Sasha Levin &lt;alexander.levin@microsoft.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>genirq: Use irqd_get_trigger_type to compare the trigger type for shared IRQs</title>
<updated>2018-03-24T09:57:32+00:00</updated>
<author>
<name>Hans de Goede</name>
<email>hdegoede@redhat.com</email>
</author>
<published>2017-04-15T10:08:31+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=093c265afffb0a91a7611c3bb74d0883731a807b'/>
<id>093c265afffb0a91a7611c3bb74d0883731a807b</id>
<content type='text'>
[ Upstream commit 382bd4de61827dbaaf5fb4fb7b1f4be4a86505e7 ]

When requesting a shared irq with IRQF_TRIGGER_NONE then the irqaction
flags get filled with the trigger type from the irq_data:

        if (!(new-&gt;flags &amp; IRQF_TRIGGER_MASK))
                new-&gt;flags |= irqd_get_trigger_type(&amp;desc-&gt;irq_data);

On the first setup_irq() the trigger type in irq_data is NONE when the
above code executes, then the irq is started up for the first time and
then the actual trigger type gets established, but that's too late to fix
up new-&gt;flags.

When then a second user of the irq requests the irq with IRQF_TRIGGER_NONE
its irqaction's triggertype gets set to the actual trigger type and the
following check fails:

        if (!((old-&gt;flags ^ new-&gt;flags) &amp; IRQF_TRIGGER_MASK))

Resulting in the request_irq failing with -EBUSY even though both
users requested the irq with IRQF_SHARED | IRQF_TRIGGER_NONE

Fix this by comparing the new irqaction's trigger type to the trigger type
stored in the irq_data which correctly reflects the actual trigger type
being used for the irq.

Suggested-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Signed-off-by: Hans de Goede &lt;hdegoede@redhat.com&gt;
Acked-by: Marc Zyngier &lt;marc.zyngier@arm.com&gt;
Link: http://lkml.kernel.org/r/20170415100831.17073-1-hdegoede@redhat.com
Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Signed-off-by: Sasha Levin &lt;alexander.levin@microsoft.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 382bd4de61827dbaaf5fb4fb7b1f4be4a86505e7 ]

When requesting a shared irq with IRQF_TRIGGER_NONE then the irqaction
flags get filled with the trigger type from the irq_data:

        if (!(new-&gt;flags &amp; IRQF_TRIGGER_MASK))
                new-&gt;flags |= irqd_get_trigger_type(&amp;desc-&gt;irq_data);

On the first setup_irq() the trigger type in irq_data is NONE when the
above code executes, then the irq is started up for the first time and
then the actual trigger type gets established, but that's too late to fix
up new-&gt;flags.

When then a second user of the irq requests the irq with IRQF_TRIGGER_NONE
its irqaction's triggertype gets set to the actual trigger type and the
following check fails:

        if (!((old-&gt;flags ^ new-&gt;flags) &amp; IRQF_TRIGGER_MASK))

Resulting in the request_irq failing with -EBUSY even though both
users requested the irq with IRQF_SHARED | IRQF_TRIGGER_NONE

Fix this by comparing the new irqaction's trigger type to the trigger type
stored in the irq_data which correctly reflects the actual trigger type
being used for the irq.

Suggested-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Signed-off-by: Hans de Goede &lt;hdegoede@redhat.com&gt;
Acked-by: Marc Zyngier &lt;marc.zyngier@arm.com&gt;
Link: http://lkml.kernel.org/r/20170415100831.17073-1-hdegoede@redhat.com
Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Signed-off-by: Sasha Levin &lt;alexander.levin@microsoft.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>genirq: Release resources in __setup_irq() error path</title>
<updated>2017-06-26T05:10:53+00:00</updated>
<author>
<name>Heiner Kallweit</name>
<email>hkallweit1@gmail.com</email>
</author>
<published>2017-06-10T22:38:36+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=b773ff26285d2fd221e3674fcea0fd80b0852da8'/>
<id>b773ff26285d2fd221e3674fcea0fd80b0852da8</id>
<content type='text'>
commit fa07ab72cbb0d843429e61bf179308aed6cbe0dd upstream.

In case __irq_set_trigger() fails the resources requested via
irq_request_resources() are not released.

Add the missing release call into the error handling path.

Fixes: c1bacbae8192 ("genirq: Provide irq_request/release_resources chip callbacks")
Signed-off-by: Heiner Kallweit &lt;hkallweit1@gmail.com&gt;
Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Link: http://lkml.kernel.org/r/655538f5-cb20-a892-ff15-fbd2dd1fa4ec@gmail.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit fa07ab72cbb0d843429e61bf179308aed6cbe0dd upstream.

In case __irq_set_trigger() fails the resources requested via
irq_request_resources() are not released.

Add the missing release call into the error handling path.

Fixes: c1bacbae8192 ("genirq: Provide irq_request/release_resources chip callbacks")
Signed-off-by: Heiner Kallweit &lt;hkallweit1@gmail.com&gt;
Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Link: http://lkml.kernel.org/r/655538f5-cb20-a892-ff15-fbd2dd1fa4ec@gmail.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>genirq: Generic chip: Change irq_reg_{readl,writel} arguments</title>
<updated>2016-10-06T02:40:20+00:00</updated>
<author>
<name>Kevin Cernekee</name>
<email>cernekee@gmail.com</email>
</author>
<published>2014-11-07T06:44:17+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=b5937a545309b73ec6deef5b5d19d664db6236a1'/>
<id>b5937a545309b73ec6deef5b5d19d664db6236a1</id>
<content type='text'>
[ Upstream commit 332fd7c4fef5f3b166e93decb07fd69eb24f7998 ]

Pass in the irq_chip_generic struct so we can use different readl/writel
settings for each irqchip driver, when appropriate.  Compute
(gc-&gt;reg_base + reg_offset) in the helper function because this is pretty
much what all callers want to do anyway.

Compile-tested using the following configurations:

    at91_dt_defconfig (CONFIG_ATMEL_AIC_IRQ=y)
    sama5_defconfig (CONFIG_ATMEL_AIC5_IRQ=y)
    sunxi_defconfig (CONFIG_ARCH_SUNXI=y)

tb10x (ARC) is untested.

Signed-off-by: Kevin Cernekee &lt;cernekee@gmail.com&gt;
Acked-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Acked-by: Acked-by: Arnd Bergmann &lt;arnd@arndb.de&gt;
Link: https://lkml.kernel.org/r/1415342669-30640-3-git-send-email-cernekee@gmail.com
Signed-off-by: Jason Cooper &lt;jason@lakedaemon.net&gt;
Signed-off-by: Sasha Levin &lt;alexander.levin@verizon.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 332fd7c4fef5f3b166e93decb07fd69eb24f7998 ]

Pass in the irq_chip_generic struct so we can use different readl/writel
settings for each irqchip driver, when appropriate.  Compute
(gc-&gt;reg_base + reg_offset) in the helper function because this is pretty
much what all callers want to do anyway.

Compile-tested using the following configurations:

    at91_dt_defconfig (CONFIG_ATMEL_AIC_IRQ=y)
    sama5_defconfig (CONFIG_ATMEL_AIC5_IRQ=y)
    sunxi_defconfig (CONFIG_ARCH_SUNXI=y)

tb10x (ARC) is untested.

Signed-off-by: Kevin Cernekee &lt;cernekee@gmail.com&gt;
Acked-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Acked-by: Acked-by: Arnd Bergmann &lt;arnd@arndb.de&gt;
Link: https://lkml.kernel.org/r/1415342669-30640-3-git-send-email-cernekee@gmail.com
Signed-off-by: Jason Cooper &lt;jason@lakedaemon.net&gt;
Signed-off-by: Sasha Levin &lt;alexander.levin@verizon.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>genirq: Fix race in register_irq_proc()</title>
<updated>2015-10-28T02:14:21+00:00</updated>
<author>
<name>Ben Hutchings</name>
<email>ben@decadent.org.uk</email>
</author>
<published>2015-09-26T11:23:56+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=4f3ab8579a28bac0fc5bd15cc82a852fd0a261ab'/>
<id>4f3ab8579a28bac0fc5bd15cc82a852fd0a261ab</id>
<content type='text'>
[ Upstream commit 95c2b17534654829db428f11bcf4297c059a2a7e ]

Per-IRQ directories in procfs are created only when a handler is first
added to the irqdesc, not when the irqdesc is created.  In the case of
a shared IRQ, multiple tasks can race to create a directory.  This
race condition seems to have been present forever, but is easier to
hit with async probing.

Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
Link: http://lkml.kernel.org/r/1443266636.2004.2.camel@decadent.org.uk
Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: stable@vger.kernel.org
Signed-off-by: Sasha Levin &lt;sasha.levin@oracle.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 95c2b17534654829db428f11bcf4297c059a2a7e ]

Per-IRQ directories in procfs are created only when a handler is first
added to the irqdesc, not when the irqdesc is created.  In the case of
a shared IRQ, multiple tasks can race to create a directory.  This
race condition seems to have been present forever, but is easier to
hit with async probing.

Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
Link: http://lkml.kernel.org/r/1443266636.2004.2.camel@decadent.org.uk
Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: stable@vger.kernel.org
Signed-off-by: Sasha Levin &lt;sasha.levin@oracle.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>genirq: Prevent resend to interrupts marked IRQ_NESTED_THREAD</title>
<updated>2015-08-27T17:25:40+00:00</updated>
<author>
<name>Thomas Gleixner</name>
<email>tglx@linutronix.de</email>
</author>
<published>2015-07-16T12:10:17+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=51871c2b908de6353bdafeeda28d52b51dedf306'/>
<id>51871c2b908de6353bdafeeda28d52b51dedf306</id>
<content type='text'>
[ Upstream commit 75a06189fc508a2acf470b0b12710362ffb2c4b1 ]

The resend mechanism happily calls the interrupt handler of interrupts
which are marked IRQ_NESTED_THREAD from softirq context. This can
result in crashes because the interrupt handler is not the proper way
to invoke the device handlers. They must be invoked via
handle_nested_irq.

Prevent the resend even if the interrupt has no valid parent irq
set. Its better to have a lost interrupt than a crashing machine.

Reported-by: Uwe Kleine-König &lt;u.kleine-koenig@pengutronix.de&gt;
Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: stable@vger.kernel.org
Signed-off-by: Sasha Levin &lt;sasha.levin@oracle.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 75a06189fc508a2acf470b0b12710362ffb2c4b1 ]

The resend mechanism happily calls the interrupt handler of interrupts
which are marked IRQ_NESTED_THREAD from softirq context. This can
result in crashes because the interrupt handler is not the proper way
to invoke the device handlers. They must be invoked via
handle_nested_irq.

Prevent the resend even if the interrupt has no valid parent irq
set. Its better to have a lost interrupt than a crashing machine.

Reported-by: Uwe Kleine-König &lt;u.kleine-koenig@pengutronix.de&gt;
Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: stable@vger.kernel.org
Signed-off-by: Sasha Levin &lt;sasha.levin@oracle.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>genirq: devres: Fix testing return value of request_any_context_irq()</title>
<updated>2015-07-04T03:02:16+00:00</updated>
<author>
<name>Axel Lin</name>
<email>axel.lin@ingics.com</email>
</author>
<published>2015-05-11T09:02:58+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=c1610d2cf12d7cab89cec2f1935e23f6ca0a5cb8'/>
<id>c1610d2cf12d7cab89cec2f1935e23f6ca0a5cb8</id>
<content type='text'>
[ Upstream commit 63781394c540dd9e666a6b21d70b64dd52bce76e ]

request_any_context_irq() returns a negative value on failure.
It returns either IRQC_IS_HARDIRQ or IRQC_IS_NESTED on success.
So fix testing return value of request_any_context_irq().

Also fixup the return value of devm_request_any_context_irq() to make it
consistent with request_any_context_irq().

Fixes: 0668d3065128 ("genirq: Add devm_request_any_context_irq()")
Signed-off-by: Axel Lin &lt;axel.lin@ingics.com&gt;
Reviewed-by: Stephen Boyd &lt;sboyd@codeaurora.org&gt;
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/1431334978.17783.4.camel@ingics.com
Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Signed-off-by: Sasha Levin &lt;sasha.levin@oracle.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 63781394c540dd9e666a6b21d70b64dd52bce76e ]

request_any_context_irq() returns a negative value on failure.
It returns either IRQC_IS_HARDIRQ or IRQC_IS_NESTED on success.
So fix testing return value of request_any_context_irq().

Also fixup the return value of devm_request_any_context_irq() to make it
consistent with request_any_context_irq().

Fixes: 0668d3065128 ("genirq: Add devm_request_any_context_irq()")
Signed-off-by: Axel Lin &lt;axel.lin@ingics.com&gt;
Reviewed-by: Stephen Boyd &lt;sboyd@codeaurora.org&gt;
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/1431334978.17783.4.camel@ingics.com
Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Signed-off-by: Sasha Levin &lt;sasha.levin@oracle.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>genirq: Prevent proc race against freeing of irq descriptors</title>
<updated>2015-01-27T16:29:37+00:00</updated>
<author>
<name>Thomas Gleixner</name>
<email>tglx@linutronix.de</email>
</author>
<published>2014-12-11T22:01:41+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=a27d8a2319e7abd65c41ed4fcddb7e55d4f64e42'/>
<id>a27d8a2319e7abd65c41ed4fcddb7e55d4f64e42</id>
<content type='text'>
commit c291ee622165cb2c8d4e7af63fffd499354a23be upstream.

Since the rework of the sparse interrupt code to actually free the
unused interrupt descriptors there exists a race between the /proc
interfaces to the irq subsystem and the code which frees the interrupt
descriptor.

CPU0				CPU1
				show_interrupts()
				  desc = irq_to_desc(X);
free_desc(desc)
  remove_from_radix_tree();
  kfree(desc);
				  raw_spinlock_irq(&amp;desc-&gt;lock);

/proc/interrupts is the only interface which can actively corrupt
kernel memory via the lock access. /proc/stat can only read from freed
memory. Extremly hard to trigger, but possible.

The interfaces in /proc/irq/N/ are not affected by this because the
removal of the proc file is serialized in procfs against concurrent
readers/writers. The removal happens before the descriptor is freed.

For architectures which have CONFIG_SPARSE_IRQ=n this is a non issue
as the descriptor is never freed. It's merely cleared out with the irq
descriptor lock held. So any concurrent proc access will either see
the old correct value or the cleared out ones.

Protect the lookup and access to the irq descriptor in
show_interrupts() with the sparse_irq_lock.

Provide kstat_irqs_usr() which is protecting the lookup and access
with sparse_irq_lock and switch /proc/stat to use it.

Document the existing kstat_irqs interfaces so it's clear that the
caller needs to take care about protection. The users of these
interfaces are either not affected due to SPARSE_IRQ=n or already
protected against removal.

Fixes: 1f5a5b87f78f "genirq: Implement a sane sparse_irq allocator"
Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit c291ee622165cb2c8d4e7af63fffd499354a23be upstream.

Since the rework of the sparse interrupt code to actually free the
unused interrupt descriptors there exists a race between the /proc
interfaces to the irq subsystem and the code which frees the interrupt
descriptor.

CPU0				CPU1
				show_interrupts()
				  desc = irq_to_desc(X);
free_desc(desc)
  remove_from_radix_tree();
  kfree(desc);
				  raw_spinlock_irq(&amp;desc-&gt;lock);

/proc/interrupts is the only interface which can actively corrupt
kernel memory via the lock access. /proc/stat can only read from freed
memory. Extremly hard to trigger, but possible.

The interfaces in /proc/irq/N/ are not affected by this because the
removal of the proc file is serialized in procfs against concurrent
readers/writers. The removal happens before the descriptor is freed.

For architectures which have CONFIG_SPARSE_IRQ=n this is a non issue
as the descriptor is never freed. It's merely cleared out with the irq
descriptor lock held. So any concurrent proc access will either see
the old correct value or the cleared out ones.

Protect the lookup and access to the irq descriptor in
show_interrupts() with the sparse_irq_lock.

Provide kstat_irqs_usr() which is protecting the lookup and access
with sparse_irq_lock and switch /proc/stat to use it.

Document the existing kstat_irqs interfaces so it's clear that the
caller needs to take care about protection. The users of these
interfaces are either not affected due to SPARSE_IRQ=n or already
protected against removal.

Fixes: 1f5a5b87f78f "genirq: Implement a sane sparse_irq allocator"
Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>Merge branch 'for-3.18-consistent-ops' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu</title>
<updated>2014-10-15T05:48:18+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2014-10-15T05:48:18+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=0429fbc0bdc297d64188483ba029a23773ae07b0'/>
<id>0429fbc0bdc297d64188483ba029a23773ae07b0</id>
<content type='text'>
Pull percpu consistent-ops changes from Tejun Heo:
 "Way back, before the current percpu allocator was implemented, static
  and dynamic percpu memory areas were allocated and handled separately
  and had their own accessors.  The distinction has been gone for many
  years now; however, the now duplicate two sets of accessors remained
  with the pointer based ones - this_cpu_*() - evolving various other
  operations over time.  During the process, we also accumulated other
  inconsistent operations.

  This pull request contains Christoph's patches to clean up the
  duplicate accessor situation.  __get_cpu_var() uses are replaced with
  with this_cpu_ptr() and __this_cpu_ptr() with raw_cpu_ptr().

  Unfortunately, the former sometimes is tricky thanks to C being a bit
  messy with the distinction between lvalues and pointers, which led to
  a rather ugly solution for cpumask_var_t involving the introduction of
  this_cpu_cpumask_var_ptr().

  This converts most of the uses but not all.  Christoph will follow up
  with the remaining conversions in this merge window and hopefully
  remove the obsolete accessors"

* 'for-3.18-consistent-ops' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu: (38 commits)
  irqchip: Properly fetch the per cpu offset
  percpu: Resolve ambiguities in __get_cpu_var/cpumask_var_t -fix
  ia64: sn_nodepda cannot be assigned to after this_cpu conversion. Use __this_cpu_write.
  percpu: Resolve ambiguities in __get_cpu_var/cpumask_var_t
  Revert "powerpc: Replace __get_cpu_var uses"
  percpu: Remove __this_cpu_ptr
  clocksource: Replace __this_cpu_ptr with raw_cpu_ptr
  sparc: Replace __get_cpu_var uses
  avr32: Replace __get_cpu_var with __this_cpu_write
  blackfin: Replace __get_cpu_var uses
  tile: Use this_cpu_ptr() for hardware counters
  tile: Replace __get_cpu_var uses
  powerpc: Replace __get_cpu_var uses
  alpha: Replace __get_cpu_var
  ia64: Replace __get_cpu_var uses
  s390: cio driver &amp;__get_cpu_var replacements
  s390: Replace __get_cpu_var uses
  mips: Replace __get_cpu_var uses
  MIPS: Replace __get_cpu_var uses in FPU emulator.
  arm: Replace __this_cpu_ptr with raw_cpu_ptr
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull percpu consistent-ops changes from Tejun Heo:
 "Way back, before the current percpu allocator was implemented, static
  and dynamic percpu memory areas were allocated and handled separately
  and had their own accessors.  The distinction has been gone for many
  years now; however, the now duplicate two sets of accessors remained
  with the pointer based ones - this_cpu_*() - evolving various other
  operations over time.  During the process, we also accumulated other
  inconsistent operations.

  This pull request contains Christoph's patches to clean up the
  duplicate accessor situation.  __get_cpu_var() uses are replaced with
  with this_cpu_ptr() and __this_cpu_ptr() with raw_cpu_ptr().

  Unfortunately, the former sometimes is tricky thanks to C being a bit
  messy with the distinction between lvalues and pointers, which led to
  a rather ugly solution for cpumask_var_t involving the introduction of
  this_cpu_cpumask_var_ptr().

  This converts most of the uses but not all.  Christoph will follow up
  with the remaining conversions in this merge window and hopefully
  remove the obsolete accessors"

* 'for-3.18-consistent-ops' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu: (38 commits)
  irqchip: Properly fetch the per cpu offset
  percpu: Resolve ambiguities in __get_cpu_var/cpumask_var_t -fix
  ia64: sn_nodepda cannot be assigned to after this_cpu conversion. Use __this_cpu_write.
  percpu: Resolve ambiguities in __get_cpu_var/cpumask_var_t
  Revert "powerpc: Replace __get_cpu_var uses"
  percpu: Remove __this_cpu_ptr
  clocksource: Replace __this_cpu_ptr with raw_cpu_ptr
  sparc: Replace __get_cpu_var uses
  avr32: Replace __get_cpu_var with __this_cpu_write
  blackfin: Replace __get_cpu_var uses
  tile: Use this_cpu_ptr() for hardware counters
  tile: Replace __get_cpu_var uses
  powerpc: Replace __get_cpu_var uses
  alpha: Replace __get_cpu_var
  ia64: Replace __get_cpu_var uses
  s390: cio driver &amp;__get_cpu_var replacements
  s390: Replace __get_cpu_var uses
  mips: Replace __get_cpu_var uses
  MIPS: Replace __get_cpu_var uses in FPU emulator.
  arm: Replace __this_cpu_ptr with raw_cpu_ptr
  ...
</pre>
</div>
</content>
</entry>
</feed>
