<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/kernel/power/snapshot.c, branch v4.14.331</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>PM: hibernate: Clean up sync_read handling in snapshot_write_next()</title>
<updated>2023-11-28T16:45:45+00:00</updated>
<author>
<name>Brian Geffon</name>
<email>bgeffon@google.com</email>
</author>
<published>2023-09-22T16:07:04+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=d437f97a25dec1771ce674ddc75e09aa34225074'/>
<id>d437f97a25dec1771ce674ddc75e09aa34225074</id>
<content type='text'>
commit d08970df1980476f27936e24d452550f3e9e92e1 upstream.

In snapshot_write_next(), sync_read is set and unset in three different
spots unnecessiarly. As a result there is a subtle bug where the first
page after the meta data has been loaded unconditionally sets sync_read
to 0. If this first PFN was actually a highmem page, then the returned
buffer will be the global "buffer," and the page needs to be loaded
synchronously.

That is, I'm not sure we can always assume the following to be safe:

	handle-&gt;buffer = get_buffer(&amp;orig_bm, &amp;ca);
	handle-&gt;sync_read = 0;

Because get_buffer() can call get_highmem_page_buffer() which can
return 'buffer'.

The easiest way to address this is just set sync_read before
snapshot_write_next() returns if handle-&gt;buffer == buffer.

Signed-off-by: Brian Geffon &lt;bgeffon@google.com&gt;
Fixes: 8357376d3df2 ("[PATCH] swsusp: Improve handling of highmem")
Cc: All applicable &lt;stable@vger.kernel.org&gt;
[ rjw: Subject and changelog edits ]
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.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>
commit d08970df1980476f27936e24d452550f3e9e92e1 upstream.

In snapshot_write_next(), sync_read is set and unset in three different
spots unnecessiarly. As a result there is a subtle bug where the first
page after the meta data has been loaded unconditionally sets sync_read
to 0. If this first PFN was actually a highmem page, then the returned
buffer will be the global "buffer," and the page needs to be loaded
synchronously.

That is, I'm not sure we can always assume the following to be safe:

	handle-&gt;buffer = get_buffer(&amp;orig_bm, &amp;ca);
	handle-&gt;sync_read = 0;

Because get_buffer() can call get_highmem_page_buffer() which can
return 'buffer'.

The easiest way to address this is just set sync_read before
snapshot_write_next() returns if handle-&gt;buffer == buffer.

Signed-off-by: Brian Geffon &lt;bgeffon@google.com&gt;
Fixes: 8357376d3df2 ("[PATCH] swsusp: Improve handling of highmem")
Cc: All applicable &lt;stable@vger.kernel.org&gt;
[ rjw: Subject and changelog edits ]
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>PM: hibernate: Use __get_safe_page() rather than touching the list</title>
<updated>2023-11-28T16:45:44+00:00</updated>
<author>
<name>Brian Geffon</name>
<email>bgeffon@google.com</email>
</author>
<published>2023-09-21T17:00:45+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=960ff6f5e6b18dc52c409457f7895967b156be02'/>
<id>960ff6f5e6b18dc52c409457f7895967b156be02</id>
<content type='text'>
commit f0c7183008b41e92fa676406d87f18773724b48b upstream.

We found at least one situation where the safe pages list was empty and
get_buffer() would gladly try to use a NULL pointer.

Signed-off-by: Brian Geffon &lt;bgeffon@google.com&gt;
Fixes: 8357376d3df2 ("[PATCH] swsusp: Improve handling of highmem")
Cc: All applicable &lt;stable@vger.kernel.org&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.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>
commit f0c7183008b41e92fa676406d87f18773724b48b upstream.

We found at least one situation where the safe pages list was empty and
get_buffer() would gladly try to use a NULL pointer.

Signed-off-by: Brian Geffon &lt;bgeffon@google.com&gt;
Fixes: 8357376d3df2 ("[PATCH] swsusp: Improve handling of highmem")
Cc: All applicable &lt;stable@vger.kernel.org&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>PM: hibernate: Fix mistake in kerneldoc comment</title>
<updated>2023-01-18T08:26:09+00:00</updated>
<author>
<name>xiongxin</name>
<email>xiongxin@kylinos.cn</email>
</author>
<published>2022-11-01T02:28:39+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=6117eab9559e7dac021e19df11f7442d4d8a570d'/>
<id>6117eab9559e7dac021e19df11f7442d4d8a570d</id>
<content type='text'>
[ Upstream commit 6e5d7300cbe7c3541bc31f16db3e9266e6027b4b ]

The actual maximum image size formula in hibernate_preallocate_memory()
is as follows:

max_size = (count - (size + PAGES_FOR_IO)) / 2
	    - 2 * DIV_ROUND_UP(reserved_size, PAGE_SIZE);

but the one in the kerneldoc comment of the function is different and
incorrect.

Fixes: ddeb64870810 ("PM / Hibernate: Add sysfs knob to control size of memory for drivers")
Signed-off-by: xiongxin &lt;xiongxin@kylinos.cn&gt;
[ rjw: Subject and changelog rewrite ]
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
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 6e5d7300cbe7c3541bc31f16db3e9266e6027b4b ]

The actual maximum image size formula in hibernate_preallocate_memory()
is as follows:

max_size = (count - (size + PAGES_FOR_IO)) / 2
	    - 2 * DIV_ROUND_UP(reserved_size, PAGE_SIZE);

but the one in the kerneldoc comment of the function is different and
incorrect.

Fixes: ddeb64870810 ("PM / Hibernate: Add sysfs knob to control size of memory for drivers")
Signed-off-by: xiongxin &lt;xiongxin@kylinos.cn&gt;
[ rjw: Subject and changelog rewrite ]
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>PM / hibernate: memory_bm_find_bit(): Tighten node optimisation</title>
<updated>2020-01-09T09:17:53+00:00</updated>
<author>
<name>Andy Whitcroft</name>
<email>apw@canonical.com</email>
</author>
<published>2019-09-25T14:39:12+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=c0fb3b1b499391d4afe4cbc805ecfaaf495e2124'/>
<id>c0fb3b1b499391d4afe4cbc805ecfaaf495e2124</id>
<content type='text'>
[ Upstream commit da6043fe85eb5ec621e34a92540735dcebbea134 ]

When looking for a bit by number we make use of the cached result from the
preceding lookup to speed up operation.  Firstly we check if the requested
pfn is within the cached zone and if not lookup the new zone.  We then
check if the offset for that pfn falls within the existing cached node.
This happens regardless of whether the node is within the zone we are
now scanning.  With certain memory layouts it is possible for this to
false trigger creating a temporary alias for the pfn to a different bit.
This leads the hibernation code to free memory which it was never allocated
with the expected fallout.

Ensure the zone we are scanning matches the cached zone before considering
the cached node.

Deep thanks go to Andrea for many, many, many hours of hacking and testing
that went into cornering this bug.

Reported-by: Andrea Righi &lt;andrea.righi@canonical.com&gt;
Tested-by: Andrea Righi &lt;andrea.righi@canonical.com&gt;
Signed-off-by: Andy Whitcroft &lt;apw@canonical.com&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
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 da6043fe85eb5ec621e34a92540735dcebbea134 ]

When looking for a bit by number we make use of the cached result from the
preceding lookup to speed up operation.  Firstly we check if the requested
pfn is within the cached zone and if not lookup the new zone.  We then
check if the offset for that pfn falls within the existing cached node.
This happens regardless of whether the node is within the zone we are
now scanning.  With certain memory layouts it is possible for this to
false trigger creating a temporary alias for the pfn to a different bit.
This leads the hibernation code to free memory which it was never allocated
with the expected fallout.

Ensure the zone we are scanning matches the cached zone before considering
the cached node.

Deep thanks go to Andrea for many, many, many hours of hacking and testing
that went into cornering this bug.

Reported-by: Andrea Righi &lt;andrea.righi@canonical.com&gt;
Tested-by: Andrea Righi &lt;andrea.righi@canonical.com&gt;
Signed-off-by: Andy Whitcroft &lt;apw@canonical.com&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>mm: fix global NR_SLAB_.*CLAIMABLE counter reads</title>
<updated>2017-08-10T22:54:06+00:00</updated>
<author>
<name>Johannes Weiner</name>
<email>hannes@cmpxchg.org</email>
</author>
<published>2017-08-10T22:23:31+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=d507e2ebd2c7be9138e5cf5c0cb1931c90c42ab1'/>
<id>d507e2ebd2c7be9138e5cf5c0cb1931c90c42ab1</id>
<content type='text'>
As Tetsuo points out:
 "Commit 385386cff4c6 ("mm: vmstat: move slab statistics from zone to
  node counters") broke "Slab:" field of /proc/meminfo . It shows nearly
  0kB"

In addition to /proc/meminfo, this problem also affects the slab
counters OOM/allocation failure info dumps, can cause early -ENOMEM from
overcommit protection, and miscalculate image size requirements during
suspend-to-disk.

This is because the patch in question switched the slab counters from
the zone level to the node level, but forgot to update the global
accessor functions to read the aggregate node data instead of the
aggregate zone data.

Use global_node_page_state() to access the global slab counters.

Fixes: 385386cff4c6 ("mm: vmstat: move slab statistics from zone to node counters")
Link: http://lkml.kernel.org/r/20170801134256.5400-1-hannes@cmpxchg.org
Signed-off-by: Johannes Weiner &lt;hannes@cmpxchg.org&gt;
Reported-by: Tetsuo Handa &lt;penguin-kernel@i-love.sakura.ne.jp&gt;
Acked-by: Michal Hocko &lt;mhocko@suse.com&gt;
Cc: Josef Bacik &lt;josef@toxicpanda.com&gt;
Cc: Vladimir Davydov &lt;vdavydov.dev@gmail.com&gt;
Cc: Stefan Agner &lt;stefan@agner.ch&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
As Tetsuo points out:
 "Commit 385386cff4c6 ("mm: vmstat: move slab statistics from zone to
  node counters") broke "Slab:" field of /proc/meminfo . It shows nearly
  0kB"

In addition to /proc/meminfo, this problem also affects the slab
counters OOM/allocation failure info dumps, can cause early -ENOMEM from
overcommit protection, and miscalculate image size requirements during
suspend-to-disk.

This is because the patch in question switched the slab counters from
the zone level to the node level, but forgot to update the global
accessor functions to read the aggregate node data instead of the
aggregate zone data.

Use global_node_page_state() to access the global slab counters.

Fixes: 385386cff4c6 ("mm: vmstat: move slab statistics from zone to node counters")
Link: http://lkml.kernel.org/r/20170801134256.5400-1-hannes@cmpxchg.org
Signed-off-by: Johannes Weiner &lt;hannes@cmpxchg.org&gt;
Reported-by: Tetsuo Handa &lt;penguin-kernel@i-love.sakura.ne.jp&gt;
Acked-by: Michal Hocko &lt;mhocko@suse.com&gt;
Cc: Josef Bacik &lt;josef@toxicpanda.com&gt;
Cc: Vladimir Davydov &lt;vdavydov.dev@gmail.com&gt;
Cc: Stefan Agner &lt;stefan@agner.ch&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>kernel/power/snapshot.c: use linux/set_memory.h</title>
<updated>2017-07-06T23:24:30+00:00</updated>
<author>
<name>Michael Ellerman</name>
<email>mpe@ellerman.id.au</email>
</author>
<published>2017-07-06T22:35:55+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=61f6d09a931c3ab216f43e00505073088d387d05'/>
<id>61f6d09a931c3ab216f43e00505073088d387d05</id>
<content type='text'>
This header always exists, so doesn't require an ifdef around its
inclusion.  When CONFIG_ARCH_HAS_SET_MEMORY=y it includes the asm
header, otherwise it provides empty versions of the set_memory_xx()
routines.

Link: http://lkml.kernel.org/r/1498717781-29151-2-git-send-email-mpe@ellerman.id.au
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Acked-by: Kees Cook &lt;keescook@chromium.org&gt;
Acked-by: Laura Abbott &lt;labbott@redhat.com&gt;
Cc: Daniel Borkmann &lt;daniel@iogearbox.net&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
This header always exists, so doesn't require an ifdef around its
inclusion.  When CONFIG_ARCH_HAS_SET_MEMORY=y it includes the asm
header, otherwise it provides empty versions of the set_memory_xx()
routines.

Link: http://lkml.kernel.org/r/1498717781-29151-2-git-send-email-mpe@ellerman.id.au
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Acked-by: Kees Cook &lt;keescook@chromium.org&gt;
Acked-by: Laura Abbott &lt;labbott@redhat.com&gt;
Cc: Daniel Borkmann &lt;daniel@iogearbox.net&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>PM / hibernate: Drop redundant parameter of swsusp_alloc()</title>
<updated>2017-06-27T00:10:44+00:00</updated>
<author>
<name>BaoJun Luo</name>
<email>baojun.luo@samsung.com</email>
</author>
<published>2017-06-27T00:10:44+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=eba74c294467d55c697e2199c37dfaf8126fe396'/>
<id>eba74c294467d55c697e2199c37dfaf8126fe396</id>
<content type='text'>
The first parameter of swsusp_alloc is not used, so drop it.

Signed-off-by: BaoJun Luo &lt;baojun.luo@samsung.com&gt;
[ rjw: Subject &amp; changelog ]
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The first parameter of swsusp_alloc is not used, so drop it.

Signed-off-by: BaoJun Luo &lt;baojun.luo@samsung.com&gt;
[ rjw: Subject &amp; changelog ]
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>PM / hibernate: Use CONFIG_HAVE_SET_MEMORY for include condition</title>
<updated>2017-06-27T00:05:28+00:00</updated>
<author>
<name>Balbir Singh</name>
<email>bsingharora@gmail.com</email>
</author>
<published>2017-06-03T10:52:32+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=49368a47f6dc1b256e3b83813da5c9b0731fe268'/>
<id>49368a47f6dc1b256e3b83813da5c9b0731fe268</id>
<content type='text'>
Kbuild reported a build failure when CONFIG_STRICT_KERNEL_RWX was
enabled on powerpc. We don't yet have ARCH_HAS_SET_MEMORY and ppc32
saw a build failure.

I've only done a basic compile test with a config that has
hibernation enabled.

Fixes: 50327ddfbc92 (kernel/power/snapshot.c: use set_memory.h header)
Reported-by: Christophe Leroy &lt;christophe.leroy@c-s.fr&gt;
Signed-off-by: Balbir Singh &lt;bsingharora@gmail.com&gt;
Acked-by: Pavel Machek &lt;pavel@ucw.cz&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Kbuild reported a build failure when CONFIG_STRICT_KERNEL_RWX was
enabled on powerpc. We don't yet have ARCH_HAS_SET_MEMORY and ppc32
saw a build failure.

I've only done a basic compile test with a config that has
hibernation enabled.

Fixes: 50327ddfbc92 (kernel/power/snapshot.c: use set_memory.h header)
Reported-by: Christophe Leroy &lt;christophe.leroy@c-s.fr&gt;
Signed-off-by: Balbir Singh &lt;bsingharora@gmail.com&gt;
Acked-by: Pavel Machek &lt;pavel@ucw.cz&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge branches 'pm-sleep' and 'powercap'</title>
<updated>2017-05-22T18:32:05+00:00</updated>
<author>
<name>Rafael J. Wysocki</name>
<email>rafael.j.wysocki@intel.com</email>
</author>
<published>2017-05-22T18:32:05+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=bb47e964175e5fb4c163066e4373fac055fe5da0'/>
<id>bb47e964175e5fb4c163066e4373fac055fe5da0</id>
<content type='text'>
* pm-sleep:
  PM / hibernate: Declare variables as static
  RTC: rtc-cmos: Fix wakeup from suspend-to-idle
  PM / wakeup: Fix up wakeup_source_report_event()

* powercap:
  PowerCap: Fix an error code in powercap_register_zone()
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
* pm-sleep:
  PM / hibernate: Declare variables as static
  RTC: rtc-cmos: Fix wakeup from suspend-to-idle
  PM / wakeup: Fix up wakeup_source_report_event()

* powercap:
  PowerCap: Fix an error code in powercap_register_zone()
</pre>
</div>
</content>
</entry>
<entry>
<title>PM / hibernate: Declare variables as static</title>
<updated>2017-05-14T11:33:24+00:00</updated>
<author>
<name>Pushkar Jambhlekar</name>
<email>pushkar.iit@gmail.com</email>
</author>
<published>2017-05-11T05:01:24+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=0bae5fd3330be0517fba697e6b228601d421fade'/>
<id>0bae5fd3330be0517fba697e6b228601d421fade</id>
<content type='text'>
Fixing sparse warnings: 'symbol not declared. Should it be static?'

Signed-off-by: Pushkar Jambhlekar &lt;pushkar.iit@gmail.com&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Fixing sparse warnings: 'symbol not declared. Should it be static?'

Signed-off-by: Pushkar Jambhlekar &lt;pushkar.iit@gmail.com&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
</pre>
</div>
</content>
</entry>
</feed>
