<feed xmlns='http://www.w3.org/2005/Atom'>
<title>user/sven/linux.git/include, branch v5.10.6</title>
<subtitle>Linux Kernel
</subtitle>
<id>https://git.stealer.net/cgit.cgi/user/sven/linux.git/atom?h=v5.10.6</id>
<link rel='self' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/atom?h=v5.10.6'/>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/'/>
<updated>2021-01-09T12:46:24Z</updated>
<entry>
<title>exec: Transform exec_update_mutex into a rw_semaphore</title>
<updated>2021-01-09T12:46:24Z</updated>
<author>
<name>Eric W. Biederman</name>
<email>ebiederm@xmission.com</email>
</author>
<published>2020-12-03T20:12:00Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=ab7709b551de24e7bebf44946120e6740b1e28db'/>
<id>urn:sha1:ab7709b551de24e7bebf44946120e6740b1e28db</id>
<content type='text'>
[ Upstream commit f7cfd871ae0c5008d94b6f66834e7845caa93c15 ]

Recently syzbot reported[0] that there is a deadlock amongst the users
of exec_update_mutex.  The problematic lock ordering found by lockdep
was:

   perf_event_open  (exec_update_mutex -&gt; ovl_i_mutex)
   chown            (ovl_i_mutex       -&gt; sb_writes)
   sendfile         (sb_writes         -&gt; p-&gt;lock)
     by reading from a proc file and writing to overlayfs
   proc_pid_syscall (p-&gt;lock           -&gt; exec_update_mutex)

While looking at possible solutions it occured to me that all of the
users and possible users involved only wanted to state of the given
process to remain the same.  They are all readers.  The only writer is
exec.

There is no reason for readers to block on each other.  So fix
this deadlock by transforming exec_update_mutex into a rw_semaphore
named exec_update_lock that only exec takes for writing.

Cc: Jann Horn &lt;jannh@google.com&gt;
Cc: Vasiliy Kulikov &lt;segoon@openwall.com&gt;
Cc: Al Viro &lt;viro@zeniv.linux.org.uk&gt;
Cc: Bernd Edlinger &lt;bernd.edlinger@hotmail.de&gt;
Cc: Oleg Nesterov &lt;oleg@redhat.com&gt;
Cc: Christopher Yeoh &lt;cyeoh@au1.ibm.com&gt;
Cc: Cyrill Gorcunov &lt;gorcunov@gmail.com&gt;
Cc: Sargun Dhillon &lt;sargun@sargun.me&gt;
Cc: Christian Brauner &lt;christian.brauner@ubuntu.com&gt;
Cc: Arnd Bergmann &lt;arnd@arndb.de&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Ingo Molnar &lt;mingo@redhat.com&gt;
Cc: Arnaldo Carvalho de Melo &lt;acme@kernel.org&gt;
Fixes: eea9673250db ("exec: Add exec_update_mutex to replace cred_guard_mutex")
[0] https://lkml.kernel.org/r/00000000000063640c05ade8e3de@google.com
Reported-by: syzbot+db9cdf3dd1f64252c6ef@syzkaller.appspotmail.com
Link: https://lkml.kernel.org/r/87ft4mbqen.fsf@x220.int.ebiederm.org
Signed-off-by: Eric W. Biederman &lt;ebiederm@xmission.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>rwsem: Implement down_read_interruptible</title>
<updated>2021-01-09T12:46:24Z</updated>
<author>
<name>Eric W. Biederman</name>
<email>ebiederm@xmission.com</email>
</author>
<published>2020-12-03T20:11:13Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=933b7cc86068fe9c2b8ebb51606022a37a7f958a'/>
<id>urn:sha1:933b7cc86068fe9c2b8ebb51606022a37a7f958a</id>
<content type='text'>
[ Upstream commit 31784cff7ee073b34d6eddabb95e3be2880a425c ]

In preparation for converting exec_update_mutex to a rwsem so that
multiple readers can execute in parallel and not deadlock, add
down_read_interruptible.  This is needed for perf_event_open to be
converted (with no semantic changes) from working on a mutex to
wroking on a rwsem.

Signed-off-by: Eric W. Biederman &lt;ebiederm@xmission.com&gt;
Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Link: https://lkml.kernel.org/r/87k0tybqfy.fsf@x220.int.ebiederm.org
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>rwsem: Implement down_read_killable_nested</title>
<updated>2021-01-09T12:46:24Z</updated>
<author>
<name>Eric W. Biederman</name>
<email>ebiederm@xmission.com</email>
</author>
<published>2020-12-03T20:10:32Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=27bae39e4fc4f911eae970ed2a332a36a92d463d'/>
<id>urn:sha1:27bae39e4fc4f911eae970ed2a332a36a92d463d</id>
<content type='text'>
[ Upstream commit 0f9368b5bf6db0c04afc5454b1be79022a681615 ]

In preparation for converting exec_update_mutex to a rwsem so that
multiple readers can execute in parallel and not deadlock, add
down_read_killable_nested.  This is needed so that kcmp_lock
can be converted from working on a mutexes to working on rw_semaphores.

Signed-off-by: Eric W. Biederman &lt;ebiederm@xmission.com&gt;
Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Link: https://lkml.kernel.org/r/87o8jabqh3.fsf@x220.int.ebiederm.org
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>RDMA/core: remove use of dma_virt_ops</title>
<updated>2021-01-09T12:46:24Z</updated>
<author>
<name>Christoph Hellwig</name>
<email>hch@lst.de</email>
</author>
<published>2020-11-06T18:19:38Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=404fa093741e15e16fd522cc76cd9f86e9ef81d2'/>
<id>urn:sha1:404fa093741e15e16fd522cc76cd9f86e9ef81d2</id>
<content type='text'>
[ Upstream commit 5a7a9e038b032137ae9c45d5429f18a2ffdf7d42 ]

Use the ib_dma_* helpers to skip the DMA translation instead.  This
removes the last user if dma_virt_ops and keeps the weird layering
violation inside the RDMA core instead of burderning the DMA mapping
subsystems with it.  This also means the software RDMA drivers now don't
have to mess with DMA parameters that are not relevant to them at all, and
that in the future we can use PCI P2P transfers even for software RDMA, as
there is no first fake layer of DMA mapping that the P2P DMA support.

Link: https://lore.kernel.org/r/20201106181941.1878556-8-hch@lst.de
Signed-off-by: Christoph Hellwig &lt;hch@lst.de&gt;
Tested-by: Mike Marciniszyn &lt;mike.marciniszyn@cornelisnetworks.com&gt;
Signed-off-by: Jason Gunthorpe &lt;jgg@nvidia.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>kdev_t: always inline major/minor helper functions</title>
<updated>2021-01-09T12:46:23Z</updated>
<author>
<name>Josh Poimboeuf</name>
<email>jpoimboe@redhat.com</email>
</author>
<published>2020-12-29T23:14:55Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=3e073508920aeafa8c6896a8897ee71e8b864559'/>
<id>urn:sha1:3e073508920aeafa8c6896a8897ee71e8b864559</id>
<content type='text'>
commit aa8c7db494d0a83ecae583aa193f1134ef25d506 upstream.

Silly GCC doesn't always inline these trivial functions.

Fixes the following warning:

  arch/x86/kernel/sys_ia32.o: warning: objtool: cp_stat64()+0xd8: call to new_encode_dev() with UACCESS enabled

Link: https://lkml.kernel.org/r/984353b44a4484d86ba9f73884b7306232e25e30.1608737428.git.jpoimboe@redhat.com
Signed-off-by: Josh Poimboeuf &lt;jpoimboe@redhat.com&gt;
Reported-by: Randy Dunlap &lt;rdunlap@infradead.org&gt;
Acked-by: Randy Dunlap &lt;rdunlap@infradead.org&gt;	[build-tested]
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
<entry>
<title>uapi: move constants from &lt;linux/kernel.h&gt; to &lt;linux/const.h&gt;</title>
<updated>2021-01-06T13:56:51Z</updated>
<author>
<name>Petr Vorel</name>
<email>petr.vorel@gmail.com</email>
</author>
<published>2020-12-15T03:03:21Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=e8afbbac2f687e4134b5626168792f3c6d448073'/>
<id>urn:sha1:e8afbbac2f687e4134b5626168792f3c6d448073</id>
<content type='text'>
commit a85cbe6159ffc973e5702f70a3bd5185f8f3c38d upstream.

and include &lt;linux/const.h&gt; in UAPI headers instead of &lt;linux/kernel.h&gt;.

The reason is to avoid indirect &lt;linux/sysinfo.h&gt; include when using
some network headers: &lt;linux/netlink.h&gt; or others -&gt; &lt;linux/kernel.h&gt;
-&gt; &lt;linux/sysinfo.h&gt;.

This indirect include causes on MUSL redefinition of struct sysinfo when
included both &lt;sys/sysinfo.h&gt; and some of UAPI headers:

    In file included from x86_64-buildroot-linux-musl/sysroot/usr/include/linux/kernel.h:5,
                     from x86_64-buildroot-linux-musl/sysroot/usr/include/linux/netlink.h:5,
                     from ../include/tst_netlink.h:14,
                     from tst_crypto.c:13:
    x86_64-buildroot-linux-musl/sysroot/usr/include/linux/sysinfo.h:8:8: error: redefinition of `struct sysinfo'
     struct sysinfo {
            ^~~~~~~
    In file included from ../include/tst_safe_macros.h:15,
                     from ../include/tst_test.h:93,
                     from tst_crypto.c:11:
    x86_64-buildroot-linux-musl/sysroot/usr/include/sys/sysinfo.h:10:8: note: originally defined here

Link: https://lkml.kernel.org/r/20201015190013.8901-1-petr.vorel@gmail.com
Signed-off-by: Petr Vorel &lt;petr.vorel@gmail.com&gt;
Suggested-by: Rich Felker &lt;dalias@aerifal.cx&gt;
Acked-by: Rich Felker &lt;dalias@libc.org&gt;
Cc: Peter Korsgaard &lt;peter@korsgaard.com&gt;
Cc: Baruch Siach &lt;baruch@tkos.co.il&gt;
Cc: Florian Weimer &lt;fweimer@redhat.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
<entry>
<title>mm: memmap defer init doesn't work as expected</title>
<updated>2021-01-06T13:56:50Z</updated>
<author>
<name>Baoquan He</name>
<email>bhe@redhat.com</email>
</author>
<published>2020-12-29T23:14:37Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=98b57685c26d8f41040ecf71e190250fb2eb2a0c'/>
<id>urn:sha1:98b57685c26d8f41040ecf71e190250fb2eb2a0c</id>
<content type='text'>
commit dc2da7b45ffe954a0090f5d0310ed7b0b37d2bd2 upstream.

VMware observed a performance regression during memmap init on their
platform, and bisected to commit 73a6e474cb376 ("mm: memmap_init:
iterate over memblock regions rather that check each PFN") causing it.

Before the commit:

  [0.033176] Normal zone: 1445888 pages used for memmap
  [0.033176] Normal zone: 89391104 pages, LIFO batch:63
  [0.035851] ACPI: PM-Timer IO Port: 0x448

With commit

  [0.026874] Normal zone: 1445888 pages used for memmap
  [0.026875] Normal zone: 89391104 pages, LIFO batch:63
  [2.028450] ACPI: PM-Timer IO Port: 0x448

The root cause is the current memmap defer init doesn't work as expected.

Before, memmap_init_zone() was used to do memmap init of one whole zone,
to initialize all low zones of one numa node, but defer memmap init of
the last zone in that numa node.  However, since commit 73a6e474cb376,
function memmap_init() is adapted to iterater over memblock regions
inside one zone, then call memmap_init_zone() to do memmap init for each
region.

E.g, on VMware's system, the memory layout is as below, there are two
memory regions in node 2.  The current code will mistakenly initialize the
whole 1st region [mem 0xab00000000-0xfcffffffff], then do memmap defer to
iniatialize only one memmory section on the 2nd region [mem
0x10000000000-0x1033fffffff].  In fact, we only expect to see that there's
only one memory section's memmap initialized.  That's why more time is
costed at the time.

[    0.008842] ACPI: SRAT: Node 0 PXM 0 [mem 0x00000000-0x0009ffff]
[    0.008842] ACPI: SRAT: Node 0 PXM 0 [mem 0x00100000-0xbfffffff]
[    0.008843] ACPI: SRAT: Node 0 PXM 0 [mem 0x100000000-0x55ffffffff]
[    0.008844] ACPI: SRAT: Node 1 PXM 1 [mem 0x5600000000-0xaaffffffff]
[    0.008844] ACPI: SRAT: Node 2 PXM 2 [mem 0xab00000000-0xfcffffffff]
[    0.008845] ACPI: SRAT: Node 2 PXM 2 [mem 0x10000000000-0x1033fffffff]

Now, let's add a parameter 'zone_end_pfn' to memmap_init_zone() to pass
down the real zone end pfn so that defer_init() can use it to judge
whether defer need be taken in zone wide.

Link: https://lkml.kernel.org/r/20201223080811.16211-1-bhe@redhat.com
Link: https://lkml.kernel.org/r/20201223080811.16211-2-bhe@redhat.com
Fixes: commit 73a6e474cb376 ("mm: memmap_init: iterate over memblock regions rather that check each PFN")
Signed-off-by: Baoquan He &lt;bhe@redhat.com&gt;
Reported-by: Rahul Gopakumar &lt;gopakumarr@vmware.com&gt;
Reviewed-by: Mike Rapoport &lt;rppt@linux.ibm.com&gt;
Cc: David Hildenbrand &lt;david@redhat.com&gt;
Cc: &lt;stable@vger.kernel.org&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
<entry>
<title>of: fix linker-section match-table corruption</title>
<updated>2020-12-30T10:54:28Z</updated>
<author>
<name>Johan Hovold</name>
<email>johan@kernel.org</email>
</author>
<published>2020-11-23T10:23:12Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=94bc6f5e2c14309e536f61e815521975eb0c62d0'/>
<id>urn:sha1:94bc6f5e2c14309e536f61e815521975eb0c62d0</id>
<content type='text'>
commit 5812b32e01c6d86ba7a84110702b46d8a8531fe9 upstream.

Specify type alignment when declaring linker-section match-table entries
to prevent gcc from increasing alignment and corrupting the various
tables with padding (e.g. timers, irqchips, clocks, reserved memory).

This is specifically needed on x86 where gcc (typically) aligns larger
objects like struct of_device_id with static extent on 32-byte
boundaries which at best prevents matching on anything but the first
entry. Specifying alignment when declaring variables suppresses this
optimisation.

Here's a 64-bit example where all entries are corrupt as 16 bytes of
padding has been inserted before the first entry:

	ffffffff8266b4b0 D __clk_of_table
	ffffffff8266b4c0 d __of_table_fixed_factor_clk
	ffffffff8266b5a0 d __of_table_fixed_clk
	ffffffff8266b680 d __clk_of_table_sentinel

And here's a 32-bit example where the 8-byte-aligned table happens to be
placed on a 32-byte boundary so that all but the first entry are corrupt
due to the 28 bytes of padding inserted between entries:

	812b3ec0 D __irqchip_of_table
	812b3ec0 d __of_table_irqchip1
	812b3fa0 d __of_table_irqchip2
	812b4080 d __of_table_irqchip3
	812b4160 d irqchip_of_match_end

Verified on x86 using gcc-9.3 and gcc-4.9 (which uses 64-byte
alignment), and on arm using gcc-7.2.

Note that there are no in-tree users of these tables on x86 currently
(even if they are included in the image).

Fixes: 54196ccbe0ba ("of: consolidate linker section OF match table declarations")
Fixes: f6e916b82022 ("irqchip: add basic infrastructure")
Cc: stable &lt;stable@vger.kernel.org&gt;     # 3.9
Signed-off-by: Johan Hovold &lt;johan@kernel.org&gt;
Link: https://lore.kernel.org/r/20201123102319.8090-2-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>xen/xenbus: Count pending messages for each watch</title>
<updated>2020-12-30T10:54:27Z</updated>
<author>
<name>SeongJae Park</name>
<email>sjpark@amazon.de</email>
</author>
<published>2020-12-14T09:07:13Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=1a72241aabcbb19b52be6f009423e5782b87a09e'/>
<id>urn:sha1:1a72241aabcbb19b52be6f009423e5782b87a09e</id>
<content type='text'>
commit 3dc86ca6b4c8cfcba9da7996189d1b5a358a94fc upstream.

This commit adds a counter of pending messages for each watch in the
struct.  It is used to skip unnecessary pending messages lookup in
'unregister_xenbus_watch()'.  It could also be used in 'will_handle'
callback.

This is part of XSA-349

Cc: stable@vger.kernel.org
Signed-off-by: SeongJae Park &lt;sjpark@amazon.de&gt;
Reported-by: Michael Kurth &lt;mku@amazon.de&gt;
Reported-by: Pawel Wieczorkiewicz &lt;wipawel@amazon.de&gt;
Reviewed-by: Juergen Gross &lt;jgross@suse.com&gt;
Signed-off-by: Juergen Gross &lt;jgross@suse.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
<entry>
<title>xen/xenbus: Add 'will_handle' callback support in xenbus_watch_path()</title>
<updated>2020-12-30T10:54:26Z</updated>
<author>
<name>SeongJae Park</name>
<email>sjpark@amazon.de</email>
</author>
<published>2020-12-14T09:04:18Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=9ae6d2f4ca8aa871cbb9c2ab78e1848177c5641c'/>
<id>urn:sha1:9ae6d2f4ca8aa871cbb9c2ab78e1848177c5641c</id>
<content type='text'>
commit 2e85d32b1c865bec703ce0c962221a5e955c52c2 upstream.

Some code does not directly make 'xenbus_watch' object and call
'register_xenbus_watch()' but use 'xenbus_watch_path()' instead.  This
commit adds support of 'will_handle' callback in the
'xenbus_watch_path()' and it's wrapper, 'xenbus_watch_pathfmt()'.

This is part of XSA-349

Cc: stable@vger.kernel.org
Signed-off-by: SeongJae Park &lt;sjpark@amazon.de&gt;
Reported-by: Michael Kurth &lt;mku@amazon.de&gt;
Reported-by: Pawel Wieczorkiewicz &lt;wipawel@amazon.de&gt;
Reviewed-by: Juergen Gross &lt;jgross@suse.com&gt;
Signed-off-by: Juergen Gross &lt;jgross@suse.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
</feed>
