<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/include/linux, branch v5.4.28</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>futex: Fix inode life-time issue</title>
<updated>2020-03-25T07:25:58+00:00</updated>
<author>
<name>Peter Zijlstra</name>
<email>peterz@infradead.org</email>
</author>
<published>2020-03-04T10:28:31+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=553d46b07dc4813e1d8e6a3b3d6eb8603b4dda74'/>
<id>553d46b07dc4813e1d8e6a3b3d6eb8603b4dda74</id>
<content type='text'>
commit 8019ad13ef7f64be44d4f892af9c840179009254 upstream.

As reported by Jann, ihold() does not in fact guarantee inode
persistence. And instead of making it so, replace the usage of inode
pointers with a per boot, machine wide, unique inode identifier.

This sequence number is global, but shared (file backed) futexes are
rare enough that this should not become a performance issue.

Reported-by: Jann Horn &lt;jannh@google.com&gt;
Suggested-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&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 8019ad13ef7f64be44d4f892af9c840179009254 upstream.

As reported by Jann, ihold() does not in fact guarantee inode
persistence. And instead of making it so, replace the usage of inode
pointers with a per boot, machine wide, unique inode identifier.

This sequence number is global, but shared (file backed) futexes are
rare enough that this should not become a performance issue.

Reported-by: Jann Horn &lt;jannh@google.com&gt;
Suggested-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>x86/mm: split vmalloc_sync_all()</title>
<updated>2020-03-25T07:25:58+00:00</updated>
<author>
<name>Joerg Roedel</name>
<email>jroedel@suse.de</email>
</author>
<published>2020-03-22T01:22:41+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=66f28e110565595800d6253938befef3fa88625b'/>
<id>66f28e110565595800d6253938befef3fa88625b</id>
<content type='text'>
commit 763802b53a427ed3cbd419dbba255c414fdd9e7c upstream.

Commit 3f8fd02b1bf1 ("mm/vmalloc: Sync unmappings in
__purge_vmap_area_lazy()") introduced a call to vmalloc_sync_all() in
the vunmap() code-path.  While this change was necessary to maintain
correctness on x86-32-pae kernels, it also adds additional cycles for
architectures that don't need it.

Specifically on x86-64 with CONFIG_VMAP_STACK=y some people reported
severe performance regressions in micro-benchmarks because it now also
calls the x86-64 implementation of vmalloc_sync_all() on vunmap().  But
the vmalloc_sync_all() implementation on x86-64 is only needed for newly
created mappings.

To avoid the unnecessary work on x86-64 and to gain the performance
back, split up vmalloc_sync_all() into two functions:

	* vmalloc_sync_mappings(), and
	* vmalloc_sync_unmappings()

Most call-sites to vmalloc_sync_all() only care about new mappings being
synchronized.  The only exception is the new call-site added in the
above mentioned commit.

Shile Zhang directed us to a report of an 80% regression in reaim
throughput.

Fixes: 3f8fd02b1bf1 ("mm/vmalloc: Sync unmappings in __purge_vmap_area_lazy()")
Reported-by: kernel test robot &lt;oliver.sang@intel.com&gt;
Reported-by: Shile Zhang &lt;shile.zhang@linux.alibaba.com&gt;
Signed-off-by: Joerg Roedel &lt;jroedel@suse.de&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Tested-by: Borislav Petkov &lt;bp@suse.de&gt;
Acked-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;	[GHES]
Cc: Dave Hansen &lt;dave.hansen@linux.intel.com&gt;
Cc: Andy Lutomirski &lt;luto@kernel.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: Ingo Molnar &lt;mingo@redhat.com&gt;
Cc: &lt;stable@vger.kernel.org&gt;
Link: http://lkml.kernel.org/r/20191009124418.8286-1-joro@8bytes.org
Link: https://lists.01.org/hyperkitty/list/lkp@lists.01.org/thread/4D3JPPHBNOSPFK2KEPC6KGKS6J25AIDB/
Link: http://lkml.kernel.org/r/20191113095530.228959-1-shile.zhang@linux.alibaba.com
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&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 763802b53a427ed3cbd419dbba255c414fdd9e7c upstream.

Commit 3f8fd02b1bf1 ("mm/vmalloc: Sync unmappings in
__purge_vmap_area_lazy()") introduced a call to vmalloc_sync_all() in
the vunmap() code-path.  While this change was necessary to maintain
correctness on x86-32-pae kernels, it also adds additional cycles for
architectures that don't need it.

Specifically on x86-64 with CONFIG_VMAP_STACK=y some people reported
severe performance regressions in micro-benchmarks because it now also
calls the x86-64 implementation of vmalloc_sync_all() on vunmap().  But
the vmalloc_sync_all() implementation on x86-64 is only needed for newly
created mappings.

To avoid the unnecessary work on x86-64 and to gain the performance
back, split up vmalloc_sync_all() into two functions:

	* vmalloc_sync_mappings(), and
	* vmalloc_sync_unmappings()

Most call-sites to vmalloc_sync_all() only care about new mappings being
synchronized.  The only exception is the new call-site added in the
above mentioned commit.

Shile Zhang directed us to a report of an 80% regression in reaim
throughput.

Fixes: 3f8fd02b1bf1 ("mm/vmalloc: Sync unmappings in __purge_vmap_area_lazy()")
Reported-by: kernel test robot &lt;oliver.sang@intel.com&gt;
Reported-by: Shile Zhang &lt;shile.zhang@linux.alibaba.com&gt;
Signed-off-by: Joerg Roedel &lt;jroedel@suse.de&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Tested-by: Borislav Petkov &lt;bp@suse.de&gt;
Acked-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;	[GHES]
Cc: Dave Hansen &lt;dave.hansen@linux.intel.com&gt;
Cc: Andy Lutomirski &lt;luto@kernel.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: Ingo Molnar &lt;mingo@redhat.com&gt;
Cc: &lt;stable@vger.kernel.org&gt;
Link: http://lkml.kernel.org/r/20191009124418.8286-1-joro@8bytes.org
Link: https://lists.01.org/hyperkitty/list/lkp@lists.01.org/thread/4D3JPPHBNOSPFK2KEPC6KGKS6J25AIDB/
Link: http://lkml.kernel.org/r/20191113095530.228959-1-shile.zhang@linux.alibaba.com
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>page-flags: fix a crash at SetPageError(THP_SWAP)</title>
<updated>2020-03-25T07:25:58+00:00</updated>
<author>
<name>Qian Cai</name>
<email>cai@lca.pw</email>
</author>
<published>2020-03-22T01:22:17+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=9dfed456e1ebe2dc8383102cb043df09ed47b96b'/>
<id>9dfed456e1ebe2dc8383102cb043df09ed47b96b</id>
<content type='text'>
commit d72520ad004a8ce18a6ba6cde317f0081b27365a upstream.

Commit bd4c82c22c36 ("mm, THP, swap: delay splitting THP after swapped
out") supported writing THP to a swap device but forgot to upgrade an
older commit df8c94d13c7e ("page-flags: define behavior of FS/IO-related
flags on compound pages") which could trigger a crash during THP
swapping out with DEBUG_VM_PGFLAGS=y,

  kernel BUG at include/linux/page-flags.h:317!

  page dumped because: VM_BUG_ON_PAGE(1 &amp;&amp; PageCompound(page))
  page:fffff3b2ec3a8000 refcount:512 mapcount:0 mapping:000000009eb0338c index:0x7f6e58200 head:fffff3b2ec3a8000 order:9 compound_mapcount:0 compound_pincount:0
  anon flags: 0x45fffe0000d8454(uptodate|lru|workingset|owner_priv_1|writeback|head|reclaim|swapbacked)

  end_swap_bio_write()
    SetPageError(page)
      VM_BUG_ON_PAGE(1 &amp;&amp; PageCompound(page))

  &lt;IRQ&gt;
  bio_endio+0x297/0x560
  dec_pending+0x218/0x430 [dm_mod]
  clone_endio+0xe4/0x2c0 [dm_mod]
  bio_endio+0x297/0x560
  blk_update_request+0x201/0x920
  scsi_end_request+0x6b/0x4b0
  scsi_io_completion+0x509/0x7e0
  scsi_finish_command+0x1ed/0x2a0
  scsi_softirq_done+0x1c9/0x1d0
  __blk_mqnterrupt+0xf/0x20
  &lt;/IRQ&gt;

Fix by checking PF_NO_TAIL in those places instead.

Fixes: bd4c82c22c36 ("mm, THP, swap: delay splitting THP after swapped out")
Signed-off-by: Qian Cai &lt;cai@lca.pw&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Reviewed-by: David Hildenbrand &lt;david@redhat.com&gt;
Acked-by: "Huang, Ying" &lt;ying.huang@intel.com&gt;
Acked-by: Rafael Aquini &lt;aquini@redhat.com&gt;
Cc: &lt;stable@vger.kernel.org&gt;
Link: http://lkml.kernel.org/r/20200310235846.1319-1-cai@lca.pw
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&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 d72520ad004a8ce18a6ba6cde317f0081b27365a upstream.

Commit bd4c82c22c36 ("mm, THP, swap: delay splitting THP after swapped
out") supported writing THP to a swap device but forgot to upgrade an
older commit df8c94d13c7e ("page-flags: define behavior of FS/IO-related
flags on compound pages") which could trigger a crash during THP
swapping out with DEBUG_VM_PGFLAGS=y,

  kernel BUG at include/linux/page-flags.h:317!

  page dumped because: VM_BUG_ON_PAGE(1 &amp;&amp; PageCompound(page))
  page:fffff3b2ec3a8000 refcount:512 mapcount:0 mapping:000000009eb0338c index:0x7f6e58200 head:fffff3b2ec3a8000 order:9 compound_mapcount:0 compound_pincount:0
  anon flags: 0x45fffe0000d8454(uptodate|lru|workingset|owner_priv_1|writeback|head|reclaim|swapbacked)

  end_swap_bio_write()
    SetPageError(page)
      VM_BUG_ON_PAGE(1 &amp;&amp; PageCompound(page))

  &lt;IRQ&gt;
  bio_endio+0x297/0x560
  dec_pending+0x218/0x430 [dm_mod]
  clone_endio+0xe4/0x2c0 [dm_mod]
  bio_endio+0x297/0x560
  blk_update_request+0x201/0x920
  scsi_end_request+0x6b/0x4b0
  scsi_io_completion+0x509/0x7e0
  scsi_finish_command+0x1ed/0x2a0
  scsi_softirq_done+0x1c9/0x1d0
  __blk_mqnterrupt+0xf/0x20
  &lt;/IRQ&gt;

Fix by checking PF_NO_TAIL in those places instead.

Fixes: bd4c82c22c36 ("mm, THP, swap: delay splitting THP after swapped out")
Signed-off-by: Qian Cai &lt;cai@lca.pw&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Reviewed-by: David Hildenbrand &lt;david@redhat.com&gt;
Acked-by: "Huang, Ying" &lt;ying.huang@intel.com&gt;
Acked-by: Rafael Aquini &lt;aquini@redhat.com&gt;
Cc: &lt;stable@vger.kernel.org&gt;
Link: http://lkml.kernel.org/r/20200310235846.1319-1-cai@lca.pw
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>driver code: clarify and fix platform device DMA mask allocation</title>
<updated>2020-03-18T06:17:56+00:00</updated>
<author>
<name>Christoph Hellwig</name>
<email>hch@lst.de</email>
</author>
<published>2020-03-11T16:07:10+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=b8c3cbca80e86c703ecf8aea629cbac9399837a7'/>
<id>b8c3cbca80e86c703ecf8aea629cbac9399837a7</id>
<content type='text'>
commit e3a36eb6dfaeea8175c05d5915dcf0b939be6dab upstream.

This does three inter-related things to clarify the usage of the
platform device dma_mask field. In the process, fix the bug introduced
by cdfee5623290 ("driver core: initialize a default DMA mask for
platform device") that caused Artem Tashkinov's laptop to not boot with
newer Fedora kernels.

This does:

 - First off, rename the field to "platform_dma_mask" to make it
   greppable.

   We have way too many different random fields called "dma_mask" in
   various data structures, where some of them are actual masks, and
   some of them are just pointers to the mask. And the structures all
   have pointers to each other, or embed each other inside themselves,
   and "pdev" sometimes means "platform device" and sometimes it means
   "PCI device".

   So to make it clear in the code when you actually use this new field,
   give it a unique name (it really should be something even more unique
   like "platform_device_dma_mask", since it's per platform device, not
   per platform, but that gets old really fast, and this is unique
   enough in context).

   To further clarify when the field gets used, initialize it when we
   actually start using it with the default value.

 - Then, use this field instead of the random one-off allocation in
   platform_device_register_full() that is now unnecessary since we now
   already have a perfectly fine allocation for it in the platform
   device structure.

 - The above then allows us to fix the actual bug, where the error path
   of platform_device_register_full() would unconditionally free the
   platform device DMA allocation with 'kfree()'.

   That kfree() was dont regardless of whether the allocation had been
   done earlier with the (now removed) kmalloc, or whether
   setup_pdev_dma_masks() had already been used and the dma_mask pointer
   pointed to the mask that was part of the platform device.

It seems most people never triggered the error path, or only triggered
it from a call chain that set an explicit pdevinfo-&gt;dma_mask value (and
thus caused the unnecessary allocation that was "cleaned up" in the
error path) before calling platform_device_register_full().

Robin Murphy points out that in Artem's case the wdat_wdt driver failed
in platform_device_add(), and that was the one that had called
platform_device_register_full() with pdevinfo.dma_mask = 0, and would
have caused that kfree() of pdev.dma_mask corrupting the heap.

A later unrelated kmalloc() then oopsed due to the heap corruption.

Fixes: cdfee5623290 ("driver core: initialize a default DMA mask for platform device")
Reported-bisected-and-tested-by:  Artem S. Tashkinov &lt;aros@gmx.com&gt;
Reviewed-by: Robin Murphy &lt;robin.murphy@arm.com&gt;
Cc: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Signed-off-by: Christoph Hellwig &lt;hch@lst.de&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&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 e3a36eb6dfaeea8175c05d5915dcf0b939be6dab upstream.

This does three inter-related things to clarify the usage of the
platform device dma_mask field. In the process, fix the bug introduced
by cdfee5623290 ("driver core: initialize a default DMA mask for
platform device") that caused Artem Tashkinov's laptop to not boot with
newer Fedora kernels.

This does:

 - First off, rename the field to "platform_dma_mask" to make it
   greppable.

   We have way too many different random fields called "dma_mask" in
   various data structures, where some of them are actual masks, and
   some of them are just pointers to the mask. And the structures all
   have pointers to each other, or embed each other inside themselves,
   and "pdev" sometimes means "platform device" and sometimes it means
   "PCI device".

   So to make it clear in the code when you actually use this new field,
   give it a unique name (it really should be something even more unique
   like "platform_device_dma_mask", since it's per platform device, not
   per platform, but that gets old really fast, and this is unique
   enough in context).

   To further clarify when the field gets used, initialize it when we
   actually start using it with the default value.

 - Then, use this field instead of the random one-off allocation in
   platform_device_register_full() that is now unnecessary since we now
   already have a perfectly fine allocation for it in the platform
   device structure.

 - The above then allows us to fix the actual bug, where the error path
   of platform_device_register_full() would unconditionally free the
   platform device DMA allocation with 'kfree()'.

   That kfree() was dont regardless of whether the allocation had been
   done earlier with the (now removed) kmalloc, or whether
   setup_pdev_dma_masks() had already been used and the dma_mask pointer
   pointed to the mask that was part of the platform device.

It seems most people never triggered the error path, or only triggered
it from a call chain that set an explicit pdevinfo-&gt;dma_mask value (and
thus caused the unnecessary allocation that was "cleaned up" in the
error path) before calling platform_device_register_full().

Robin Murphy points out that in Artem's case the wdat_wdt driver failed
in platform_device_add(), and that was the one that had called
platform_device_register_full() with pdevinfo.dma_mask = 0, and would
have caused that kfree() of pdev.dma_mask corrupting the heap.

A later unrelated kmalloc() then oopsed due to the heap corruption.

Fixes: cdfee5623290 ("driver core: initialize a default DMA mask for platform device")
Reported-bisected-and-tested-by:  Artem S. Tashkinov &lt;aros@gmx.com&gt;
Reviewed-by: Robin Murphy &lt;robin.murphy@arm.com&gt;
Cc: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Signed-off-by: Christoph Hellwig &lt;hch@lst.de&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>iommu/vt-d: Fix RCU list debugging warnings</title>
<updated>2020-03-18T06:17:54+00:00</updated>
<author>
<name>Amol Grover</name>
<email>frextrite@gmail.com</email>
</author>
<published>2020-02-23T16:55:39+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=28ffabf65e42c26b2d7be385ef1941930346d9f9'/>
<id>28ffabf65e42c26b2d7be385ef1941930346d9f9</id>
<content type='text'>
commit 02d715b4a8182f4887d82df82a7b83aced647760 upstream.

dmar_drhd_units is traversed using list_for_each_entry_rcu()
outside of an RCU read side critical section but under the
protection of dmar_global_lock. Hence add corresponding lockdep
expression to silence the following false-positive warnings:

[    1.603975] =============================
[    1.603976] WARNING: suspicious RCU usage
[    1.603977] 5.5.4-stable #17 Not tainted
[    1.603978] -----------------------------
[    1.603980] drivers/iommu/intel-iommu.c:4769 RCU-list traversed in non-reader section!!

[    1.603869] =============================
[    1.603870] WARNING: suspicious RCU usage
[    1.603872] 5.5.4-stable #17 Not tainted
[    1.603874] -----------------------------
[    1.603875] drivers/iommu/dmar.c:293 RCU-list traversed in non-reader section!!

Tested-by: Madhuparna Bhowmik &lt;madhuparnabhowmik10@gmail.com&gt;
Signed-off-by: Amol Grover &lt;frextrite@gmail.com&gt;
Cc: stable@vger.kernel.org
Acked-by: Lu Baolu &lt;baolu.lu@linux.intel.com&gt;
Signed-off-by: Joerg Roedel &lt;jroedel@suse.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 02d715b4a8182f4887d82df82a7b83aced647760 upstream.

dmar_drhd_units is traversed using list_for_each_entry_rcu()
outside of an RCU read side critical section but under the
protection of dmar_global_lock. Hence add corresponding lockdep
expression to silence the following false-positive warnings:

[    1.603975] =============================
[    1.603976] WARNING: suspicious RCU usage
[    1.603977] 5.5.4-stable #17 Not tainted
[    1.603978] -----------------------------
[    1.603980] drivers/iommu/intel-iommu.c:4769 RCU-list traversed in non-reader section!!

[    1.603869] =============================
[    1.603870] WARNING: suspicious RCU usage
[    1.603872] 5.5.4-stable #17 Not tainted
[    1.603874] -----------------------------
[    1.603875] drivers/iommu/dmar.c:293 RCU-list traversed in non-reader section!!

Tested-by: Madhuparna Bhowmik &lt;madhuparnabhowmik10@gmail.com&gt;
Signed-off-by: Amol Grover &lt;frextrite@gmail.com&gt;
Cc: stable@vger.kernel.org
Acked-by: Lu Baolu &lt;baolu.lu@linux.intel.com&gt;
Signed-off-by: Joerg Roedel &lt;jroedel@suse.de&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>cgroup: Iterate tasks that did not finish do_exit()</title>
<updated>2020-03-18T06:17:48+00:00</updated>
<author>
<name>Michal Koutný</name>
<email>mkoutny@suse.com</email>
</author>
<published>2020-01-24T11:40:15+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=72655d84263678ac3edf434a7272fd36a5049a51'/>
<id>72655d84263678ac3edf434a7272fd36a5049a51</id>
<content type='text'>
commit 9c974c77246460fa6a92c18554c3311c8c83c160 upstream.

PF_EXITING is set earlier than actual removal from css_set when a task
is exitting. This can confuse cgroup.procs readers who see no PF_EXITING
tasks, however, rmdir is checking against css_set membership so it can
transitionally fail with EBUSY.

Fix this by listing tasks that weren't unlinked from css_set active
lists.
It may happen that other users of the task iterator (without
CSS_TASK_ITER_PROCS) spot a PF_EXITING task before cgroup_exit(). This
is equal to the state before commit c03cd7738a83 ("cgroup: Include dying
leaders with live threads in PROCS iterations") but it may be reviewed
later.

Reported-by: Suren Baghdasaryan &lt;surenb@google.com&gt;
Fixes: c03cd7738a83 ("cgroup: Include dying leaders with live threads in PROCS iterations")
Signed-off-by: Michal Koutný &lt;mkoutny@suse.com&gt;
Signed-off-by: Tejun Heo &lt;tj@kernel.org&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 9c974c77246460fa6a92c18554c3311c8c83c160 upstream.

PF_EXITING is set earlier than actual removal from css_set when a task
is exitting. This can confuse cgroup.procs readers who see no PF_EXITING
tasks, however, rmdir is checking against css_set membership so it can
transitionally fail with EBUSY.

Fix this by listing tasks that weren't unlinked from css_set active
lists.
It may happen that other users of the task iterator (without
CSS_TASK_ITER_PROCS) spot a PF_EXITING task before cgroup_exit(). This
is equal to the state before commit c03cd7738a83 ("cgroup: Include dying
leaders with live threads in PROCS iterations") but it may be reviewed
later.

Reported-by: Suren Baghdasaryan &lt;surenb@google.com&gt;
Fixes: c03cd7738a83 ("cgroup: Include dying leaders with live threads in PROCS iterations")
Signed-off-by: Michal Koutný &lt;mkoutny@suse.com&gt;
Signed-off-by: Tejun Heo &lt;tj@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>net: phy: fix MDIO bus PM PHY resuming</title>
<updated>2020-03-18T06:17:46+00:00</updated>
<author>
<name>Heiner Kallweit</name>
<email>hkallweit1@gmail.com</email>
</author>
<published>2020-03-12T21:25:20+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=886345d9305afd6781a18d2b563afbb274e58596'/>
<id>886345d9305afd6781a18d2b563afbb274e58596</id>
<content type='text'>
[ Upstream commit 611d779af7cad2b87487ff58e4931a90c20b113c ]

So far we have the unfortunate situation that mdio_bus_phy_may_suspend()
is called in suspend AND resume path, assuming that function result is
the same. After the original change this is no longer the case,
resulting in broken resume as reported by Geert.

To fix this call mdio_bus_phy_may_suspend() in the suspend path only,
and let the phy_device store the info whether it was suspended by
MDIO bus PM.

Fixes: 503ba7c69610 ("net: phy: Avoid multiple suspends")
Reported-by: Geert Uytterhoeven &lt;geert@linux-m68k.org&gt;
Tested-by: Geert Uytterhoeven &lt;geert@linux-m68k.org&gt;
Signed-off-by: Heiner Kallweit &lt;hkallweit1@gmail.com&gt;
Reviewed-by: Florian Fainelli &lt;f.fainelli@gmail.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&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 611d779af7cad2b87487ff58e4931a90c20b113c ]

So far we have the unfortunate situation that mdio_bus_phy_may_suspend()
is called in suspend AND resume path, assuming that function result is
the same. After the original change this is no longer the case,
resulting in broken resume as reported by Geert.

To fix this call mdio_bus_phy_may_suspend() in the suspend path only,
and let the phy_device store the info whether it was suspended by
MDIO bus PM.

Fixes: 503ba7c69610 ("net: phy: Avoid multiple suspends")
Reported-by: Geert Uytterhoeven &lt;geert@linux-m68k.org&gt;
Tested-by: Geert Uytterhoeven &lt;geert@linux-m68k.org&gt;
Signed-off-by: Heiner Kallweit &lt;hkallweit1@gmail.com&gt;
Reviewed-by: Florian Fainelli &lt;f.fainelli@gmail.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>net: phy: avoid clearing PHY interrupts twice in irq handler</title>
<updated>2020-03-18T06:17:46+00:00</updated>
<author>
<name>Heiner Kallweit</name>
<email>hkallweit1@gmail.com</email>
</author>
<published>2020-03-01T20:36:09+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=4d365c7b4747379bc489c126727431994c908796'/>
<id>4d365c7b4747379bc489c126727431994c908796</id>
<content type='text'>
[ Upstream commit 249bc9744e165abe74ae326f43e9d70bad54c3b7 ]

On all PHY drivers that implement did_interrupt() reading the interrupt
status bits clears them. This means we may loose an interrupt that
is triggered between calling did_interrupt() and phy_clear_interrupt().
As part of the fix make it a requirement that did_interrupt() clears
the interrupt.

The Fixes tag refers to the first commit where the patch applies
cleanly.

Fixes: 49644e68f472 ("net: phy: add callback for custom interrupt handler to struct phy_driver")
Reported-by: Michael Walle &lt;michael@walle.cc&gt;
Signed-off-by: Heiner Kallweit &lt;hkallweit1@gmail.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&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 249bc9744e165abe74ae326f43e9d70bad54c3b7 ]

On all PHY drivers that implement did_interrupt() reading the interrupt
status bits clears them. This means we may loose an interrupt that
is triggered between calling did_interrupt() and phy_clear_interrupt().
As part of the fix make it a requirement that did_interrupt() clears
the interrupt.

The Fixes tag refers to the first commit where the patch applies
cleanly.

Fixes: 49644e68f472 ("net: phy: add callback for custom interrupt handler to struct phy_driver")
Reported-by: Michael Walle &lt;michael@walle.cc&gt;
Signed-off-by: Heiner Kallweit &lt;hkallweit1@gmail.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>inet_diag: return classid for all socket types</title>
<updated>2020-03-18T06:17:38+00:00</updated>
<author>
<name>Dmitry Yakunin</name>
<email>zeil@yandex-team.ru</email>
</author>
<published>2020-03-05T12:33:12+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=8be8c4555431c7c46883a2b29aef05763554cfbe'/>
<id>8be8c4555431c7c46883a2b29aef05763554cfbe</id>
<content type='text'>
[ Upstream commit 83f73c5bb7b9a9135173f0ba2b1aa00c06664ff9 ]

In commit 1ec17dbd90f8 ("inet_diag: fix reporting cgroup classid and
fallback to priority") croup classid reporting was fixed. But this works
only for TCP sockets because for other socket types icsk parameter can
be NULL and classid code path is skipped. This change moves classid
handling to inet_diag_msg_attrs_fill() function.

Also inet_diag_msg_attrs_size() helper was added and addends in
nlmsg_new() were reordered to save order from inet_sk_diag_fill().

Fixes: 1ec17dbd90f8 ("inet_diag: fix reporting cgroup classid and fallback to priority")
Signed-off-by: Dmitry Yakunin &lt;zeil@yandex-team.ru&gt;
Reviewed-by: Konstantin Khlebnikov &lt;khlebnikov@yandex-team.ru&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&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 83f73c5bb7b9a9135173f0ba2b1aa00c06664ff9 ]

In commit 1ec17dbd90f8 ("inet_diag: fix reporting cgroup classid and
fallback to priority") croup classid reporting was fixed. But this works
only for TCP sockets because for other socket types icsk parameter can
be NULL and classid code path is skipped. This change moves classid
handling to inet_diag_msg_attrs_fill() function.

Also inet_diag_msg_attrs_size() helper was added and addends in
nlmsg_new() were reordered to save order from inet_sk_diag_fill().

Fixes: 1ec17dbd90f8 ("inet_diag: fix reporting cgroup classid and fallback to priority")
Signed-off-by: Dmitry Yakunin &lt;zeil@yandex-team.ru&gt;
Reviewed-by: Konstantin Khlebnikov &lt;khlebnikov@yandex-team.ru&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>mm, hotplug: fix page online with DEBUG_PAGEALLOC compiled but not enabled</title>
<updated>2020-03-12T12:00:19+00:00</updated>
<author>
<name>Vlastimil Babka</name>
<email>vbabka@suse.cz</email>
</author>
<published>2020-03-06T06:28:42+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=d467fbc93cdbb851427d7553876a67974e4a419a'/>
<id>d467fbc93cdbb851427d7553876a67974e4a419a</id>
<content type='text'>
commit c87cbc1f007c4b46165f05ceca04e1973cda0b9c upstream.

Commit cd02cf1aceea ("mm/hotplug: fix an imbalance with DEBUG_PAGEALLOC")
fixed memory hotplug with debug_pagealloc enabled, where onlining a page
goes through page freeing, which removes the direct mapping.  Some arches
don't like when the page is not mapped in the first place, so
generic_online_page() maps it first.  This is somewhat wasteful, but
better than special casing page freeing fast paths.

The commit however missed that DEBUG_PAGEALLOC configured doesn't mean
it's actually enabled.  One has to test debug_pagealloc_enabled() since
031bc5743f15 ("mm/debug-pagealloc: make debug-pagealloc boottime
configurable"), or alternatively debug_pagealloc_enabled_static() since
8e57f8acbbd1 ("mm, debug_pagealloc: don't rely on static keys too early"),
but this is not done.

As a result, a s390 kernel with DEBUG_PAGEALLOC configured but not enabled
will crash:

Unable to handle kernel pointer dereference in virtual kernel address space
Failing address: 0000000000000000 TEID: 0000000000000483
Fault in home space mode while using kernel ASCE.
AS:0000001ece13400b R2:000003fff7fd000b R3:000003fff7fcc007 S:000003fff7fd7000 P:000000000000013d
Oops: 0004 ilc:2 [#1] SMP
CPU: 1 PID: 26015 Comm: chmem Kdump: loaded Tainted: GX 5.3.18-5-default #1 SLE15-SP2 (unreleased)
Krnl PSW : 0704e00180000000 0000001ecd281b9e (__kernel_map_pages+0x166/0x188)
R:0 T:1 IO:1 EX:1 Key:0 M:1 W:0 P:0 AS:3 CC:2 PM:0 RI:0 EA:3
Krnl GPRS: 0000000000000000 0000000000000800 0000400b00000000 0000000000000100
0000000000000001 0000000000000000 0000000000000002 0000000000000100
0000001ece139230 0000001ecdd98d40 0000400b00000100 0000000000000000
000003ffa17e4000 001fffe0114f7d08 0000001ecd4d93ea 001fffe0114f7b20
Krnl Code: 0000001ecd281b8e: ec17ffff00d8 ahik %r1,%r7,-1
0000001ecd281b94: ec111dbc0355 risbg %r1,%r1,29,188,3
&gt;0000001ecd281b9e: 94fb5006 ni 6(%r5),251
0000001ecd281ba2: 41505008 la %r5,8(%r5)
0000001ecd281ba6: ec51fffc6064 cgrj %r5,%r1,6,1ecd281b9e
0000001ecd281bac: 1a07 ar %r0,%r7
0000001ecd281bae: ec03ff584076 crj %r0,%r3,4,1ecd281a5e
Call Trace:
[&lt;0000001ecd281b9e&gt;] __kernel_map_pages+0x166/0x188
[&lt;0000001ecd4d9516&gt;] online_pages_range+0xf6/0x128
[&lt;0000001ecd2a8186&gt;] walk_system_ram_range+0x7e/0xd8
[&lt;0000001ecda28aae&gt;] online_pages+0x2fe/0x3f0
[&lt;0000001ecd7d02a6&gt;] memory_subsys_online+0x8e/0xc0
[&lt;0000001ecd7add42&gt;] device_online+0x5a/0xc8
[&lt;0000001ecd7d0430&gt;] state_store+0x88/0x118
[&lt;0000001ecd5b9f62&gt;] kernfs_fop_write+0xc2/0x200
[&lt;0000001ecd5064b6&gt;] vfs_write+0x176/0x1e0
[&lt;0000001ecd50676a&gt;] ksys_write+0xa2/0x100
[&lt;0000001ecda315d4&gt;] system_call+0xd8/0x2c8

Fix this by checking debug_pagealloc_enabled_static() before calling
kernel_map_pages(). Backports for kernel before 5.5 should use
debug_pagealloc_enabled() instead. Also add comments.

Fixes: cd02cf1aceea ("mm/hotplug: fix an imbalance with DEBUG_PAGEALLOC")
Reported-by: Gerald Schaefer &lt;gerald.schaefer@de.ibm.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Vlastimil Babka &lt;vbabka@suse.cz&gt;
Reviewed-by: David Hildenbrand &lt;david@redhat.com&gt;
Cc: &lt;stable@vger.kernel.org&gt;
Cc: Joonsoo Kim &lt;iamjoonsoo.kim@lge.com&gt;
Cc: Qian Cai &lt;cai@lca.pw&gt;
Link: http://lkml.kernel.org/r/20200224094651.18257-1-vbabka@suse.cz
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&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 c87cbc1f007c4b46165f05ceca04e1973cda0b9c upstream.

Commit cd02cf1aceea ("mm/hotplug: fix an imbalance with DEBUG_PAGEALLOC")
fixed memory hotplug with debug_pagealloc enabled, where onlining a page
goes through page freeing, which removes the direct mapping.  Some arches
don't like when the page is not mapped in the first place, so
generic_online_page() maps it first.  This is somewhat wasteful, but
better than special casing page freeing fast paths.

The commit however missed that DEBUG_PAGEALLOC configured doesn't mean
it's actually enabled.  One has to test debug_pagealloc_enabled() since
031bc5743f15 ("mm/debug-pagealloc: make debug-pagealloc boottime
configurable"), or alternatively debug_pagealloc_enabled_static() since
8e57f8acbbd1 ("mm, debug_pagealloc: don't rely on static keys too early"),
but this is not done.

As a result, a s390 kernel with DEBUG_PAGEALLOC configured but not enabled
will crash:

Unable to handle kernel pointer dereference in virtual kernel address space
Failing address: 0000000000000000 TEID: 0000000000000483
Fault in home space mode while using kernel ASCE.
AS:0000001ece13400b R2:000003fff7fd000b R3:000003fff7fcc007 S:000003fff7fd7000 P:000000000000013d
Oops: 0004 ilc:2 [#1] SMP
CPU: 1 PID: 26015 Comm: chmem Kdump: loaded Tainted: GX 5.3.18-5-default #1 SLE15-SP2 (unreleased)
Krnl PSW : 0704e00180000000 0000001ecd281b9e (__kernel_map_pages+0x166/0x188)
R:0 T:1 IO:1 EX:1 Key:0 M:1 W:0 P:0 AS:3 CC:2 PM:0 RI:0 EA:3
Krnl GPRS: 0000000000000000 0000000000000800 0000400b00000000 0000000000000100
0000000000000001 0000000000000000 0000000000000002 0000000000000100
0000001ece139230 0000001ecdd98d40 0000400b00000100 0000000000000000
000003ffa17e4000 001fffe0114f7d08 0000001ecd4d93ea 001fffe0114f7b20
Krnl Code: 0000001ecd281b8e: ec17ffff00d8 ahik %r1,%r7,-1
0000001ecd281b94: ec111dbc0355 risbg %r1,%r1,29,188,3
&gt;0000001ecd281b9e: 94fb5006 ni 6(%r5),251
0000001ecd281ba2: 41505008 la %r5,8(%r5)
0000001ecd281ba6: ec51fffc6064 cgrj %r5,%r1,6,1ecd281b9e
0000001ecd281bac: 1a07 ar %r0,%r7
0000001ecd281bae: ec03ff584076 crj %r0,%r3,4,1ecd281a5e
Call Trace:
[&lt;0000001ecd281b9e&gt;] __kernel_map_pages+0x166/0x188
[&lt;0000001ecd4d9516&gt;] online_pages_range+0xf6/0x128
[&lt;0000001ecd2a8186&gt;] walk_system_ram_range+0x7e/0xd8
[&lt;0000001ecda28aae&gt;] online_pages+0x2fe/0x3f0
[&lt;0000001ecd7d02a6&gt;] memory_subsys_online+0x8e/0xc0
[&lt;0000001ecd7add42&gt;] device_online+0x5a/0xc8
[&lt;0000001ecd7d0430&gt;] state_store+0x88/0x118
[&lt;0000001ecd5b9f62&gt;] kernfs_fop_write+0xc2/0x200
[&lt;0000001ecd5064b6&gt;] vfs_write+0x176/0x1e0
[&lt;0000001ecd50676a&gt;] ksys_write+0xa2/0x100
[&lt;0000001ecda315d4&gt;] system_call+0xd8/0x2c8

Fix this by checking debug_pagealloc_enabled_static() before calling
kernel_map_pages(). Backports for kernel before 5.5 should use
debug_pagealloc_enabled() instead. Also add comments.

Fixes: cd02cf1aceea ("mm/hotplug: fix an imbalance with DEBUG_PAGEALLOC")
Reported-by: Gerald Schaefer &lt;gerald.schaefer@de.ibm.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Vlastimil Babka &lt;vbabka@suse.cz&gt;
Reviewed-by: David Hildenbrand &lt;david@redhat.com&gt;
Cc: &lt;stable@vger.kernel.org&gt;
Cc: Joonsoo Kim &lt;iamjoonsoo.kim@lge.com&gt;
Cc: Qian Cai &lt;cai@lca.pw&gt;
Link: http://lkml.kernel.org/r/20200224094651.18257-1-vbabka@suse.cz
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
</feed>
