<feed xmlns='http://www.w3.org/2005/Atom'>
<title>user/sven/linux.git/drivers/misc/mic, branch v4.19.135</title>
<subtitle>Linux Kernel
</subtitle>
<id>https://git.stealer.net/cgit.cgi/user/sven/linux.git/atom?h=v4.19.135</id>
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<updated>2020-01-27T13:51:02Z</updated>
<entry>
<title>mic: avoid statically declaring a 'struct device'.</title>
<updated>2020-01-27T13:51:02Z</updated>
<author>
<name>Arnd Bergmann</name>
<email>arnd@arndb.de</email>
</author>
<published>2019-07-12T09:24:09Z</published>
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<id>urn:sha1:ba5cc235ea6cc536d0255e773b700c7fe5f0bedc</id>
<content type='text'>
[ Upstream commit bc83f79bd2119230888fb8574639d5a51b38f903 ]

Generally, declaring a platform device as a static variable is
a bad idea and can cause all kinds of problems, in particular
with the DMA configuration and lifetime rules.

A specific problem we hit here is from a bug in clang that warns
about certain (otherwise valid) macros when used in static variables:

drivers/misc/mic/card/mic_x100.c:285:27: warning: shift count &gt;= width of type [-Wshift-count-overflow]
static u64 mic_dma_mask = DMA_BIT_MASK(64);
                          ^~~~~~~~~~~~~~~~
include/linux/dma-mapping.h:141:54: note: expanded from macro 'DMA_BIT_MASK'
 #define DMA_BIT_MASK(n) (((n) == 64) ? ~0ULL : ((1ULL&lt;&lt;(n))-1))
                                                     ^ ~~~

A slightly better way here is to create the platform device dynamically
and set the dma mask in the probe function.
This avoids the warning and some other problems, but is still not ideal
because the device creation should really be separated from the driver,
and the fact that the device has no parent means we have to force
the dma mask rather than having it set up from the bus that the device
is actually on.

Fixes: dd8d8d44df64 ("misc: mic: MIC card driver specific changes to enable SCIF")
Signed-off-by: Arnd Bergmann &lt;arnd@arndb.de&gt;
Link: https://lore.kernel.org/r/20190712092426.872625-1-arnd@arndb.de
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>misc: mic: fix a DMA pool free failure</title>
<updated>2019-12-01T08:16:22Z</updated>
<author>
<name>Wenwen Wang</name>
<email>wang6495@umn.edu</email>
</author>
<published>2018-10-10T23:38:28Z</published>
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<id>urn:sha1:d11d985d0a8285cc308a61c2464ad68e8e1f4ff8</id>
<content type='text'>
[ Upstream commit 6b995f4eec34745f6cb20d66d5277611f0b3c3fa ]

In _scif_prog_signal(), the boolean variable 'x100' is used to indicate
whether the MIC Coprocessor is X100. If 'x100' is true, the status
descriptor will be used to write the value to the destination. Otherwise, a
DMA pool will be allocated for this purpose. Specifically, if the DMA pool
is allocated successfully, two memory addresses will be returned. One is
for the CPU and the other is for the device to access the DMA pool. The
former is stored to the variable 'status' and the latter is stored to the
variable 'src'. After the allocation, the address in 'src' is saved to
'status-&gt;src_dma_addr', which is actually in the DMA pool, and 'src' is
then modified.

Later on, if an error occurs, the execution flow will transfer to the label
'dma_fail', which will check 'x100' and free up the allocated DMA pool if
'x100' is false. The point here is that 'status-&gt;src_dma_addr' is used for
freeing up the DMA pool. As mentioned before, 'status-&gt;src_dma_addr' is in
the DMA pool. And thus, the device is able to modify this data. This can
potentially cause failures when freeing up the DMA pool because of the
modified device address.

This patch avoids the above issue by using the variable 'src' (with
necessary calculation) to free up the DMA pool.

Signed-off-by: Wenwen Wang &lt;wang6495@umn.edu&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>mic: vop: Fix use-after-free on remove</title>
<updated>2019-02-15T07:10:12Z</updated>
<author>
<name>Vincent Whitchurch</name>
<email>vincent.whitchurch@axis.com</email>
</author>
<published>2019-02-01T09:03:12Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=1ce0fcebff24f3f06ec0e42e472c0250384e6d41'/>
<id>urn:sha1:1ce0fcebff24f3f06ec0e42e472c0250384e6d41</id>
<content type='text'>
commit 70ed7148dadb812f2f7c9927e98ef3cf4869dfa9 upstream.

KASAN detects a use-after-free when vop devices are removed.

This problem was introduced by commit 0063e8bbd2b62d136 ("virtio_vop:
don't kfree device on register failure").  That patch moved the freeing
of the struct _vop_vdev to the release function, but failed to ensure
that vop holds a reference to the device when it doesn't want it to go
away.  A kfree() was replaced with a put_device() in the unregistration
path, but the last reference to the device is already dropped in
unregister_virtio_device() so the struct is freed before vop is done
with it.

Fix it by holding a reference until cleanup is done.  This is similar to
the fix in virtio_pci in commit 2989be09a8a9d6 ("virtio_pci: fix use
after free on release").

 ==================================================================
 BUG: KASAN: use-after-free in vop_scan_devices+0xc6c/0xe50 [vop]
 Read of size 8 at addr ffff88800da18580 by task kworker/0:1/12

 CPU: 0 PID: 12 Comm: kworker/0:1 Not tainted 5.0.0-rc4+ #53
 Workqueue: events vop_hotplug_devices [vop]
 Call Trace:
  dump_stack+0x74/0xbb
  print_address_description+0x5d/0x2b0
  ? vop_scan_devices+0xc6c/0xe50 [vop]
  kasan_report+0x152/0x1aa
  ? vop_scan_devices+0xc6c/0xe50 [vop]
  ? vop_scan_devices+0xc6c/0xe50 [vop]
  vop_scan_devices+0xc6c/0xe50 [vop]
  ? vop_loopback_free_irq+0x160/0x160 [vop_loopback]
  process_one_work+0x7c0/0x14b0
  ? pwq_dec_nr_in_flight+0x2d0/0x2d0
  ? do_raw_spin_lock+0x120/0x280
  worker_thread+0x8f/0xbf0
  ? __kthread_parkme+0x78/0xf0
  ? process_one_work+0x14b0/0x14b0
  kthread+0x2ae/0x3a0
  ? kthread_park+0x120/0x120
  ret_from_fork+0x3a/0x50

 Allocated by task 12:
  kmem_cache_alloc_trace+0x13a/0x2a0
  vop_scan_devices+0x473/0xe50 [vop]
  process_one_work+0x7c0/0x14b0
  worker_thread+0x8f/0xbf0
  kthread+0x2ae/0x3a0
  ret_from_fork+0x3a/0x50

 Freed by task 12:
  kfree+0x104/0x310
  device_release+0x73/0x1d0
  kobject_put+0x14f/0x420
  unregister_virtio_device+0x32/0x50
  vop_scan_devices+0x19d/0xe50 [vop]
  process_one_work+0x7c0/0x14b0
  worker_thread+0x8f/0xbf0
  kthread+0x2ae/0x3a0
  ret_from_fork+0x3a/0x50

 The buggy address belongs to the object at ffff88800da18008
  which belongs to the cache kmalloc-2k of size 2048
 The buggy address is located 1400 bytes inside of
  2048-byte region [ffff88800da18008, ffff88800da18808)
 The buggy address belongs to the page:
 page:ffffea0000368600 count:1 mapcount:0 mapping:ffff88801440dbc0 index:0x0 compound_mapcount: 0
 flags: 0x4000000000010200(slab|head)
 raw: 4000000000010200 ffffea0000378608 ffffea000037a008 ffff88801440dbc0
 raw: 0000000000000000 00000000000d000d 00000001ffffffff 0000000000000000
 page dumped because: kasan: bad access detected

 Memory state around the buggy address:
  ffff88800da18480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
  ffff88800da18500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 &gt;ffff88800da18580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                    ^
  ffff88800da18600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
  ffff88800da18680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ==================================================================

Fixes: 0063e8bbd2b62d136 ("virtio_vop: don't kfree device on register failure")
Signed-off-by: Vincent Whitchurch &lt;vincent.whitchurch@axis.com&gt;
Cc: stable &lt;stable@vger.kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
<entry>
<title>misc: mic/scif: fix copy-paste error in scif_create_remote_lookup</title>
<updated>2018-12-05T18:32:14Z</updated>
<author>
<name>YueHaibing</name>
<email>yuehaibing@huawei.com</email>
</author>
<published>2018-11-14T01:57:03Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=842c4c22ea2b39688b868e6fead0b5b06f03f631'/>
<id>urn:sha1:842c4c22ea2b39688b868e6fead0b5b06f03f631</id>
<content type='text'>
commit 6484a677294aa5d08c0210f2f387ebb9be646115 upstream.

gcc '-Wunused-but-set-variable' warning:

drivers/misc/mic/scif/scif_rma.c: In function 'scif_create_remote_lookup':
drivers/misc/mic/scif/scif_rma.c:373:25: warning:
 variable 'vmalloc_num_pages' set but not used [-Wunused-but-set-variable]

'vmalloc_num_pages' should be used to determine if the address is
within the vmalloc range.

Fixes: ba612aa8b487 ("misc: mic: SCIF memory registration and unregistration")
Signed-off-by: YueHaibing &lt;yuehaibing@huawei.com&gt;
Cc: stable &lt;stable@vger.kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
<entry>
<title>mm, oom: distinguish blockable mode for mmu notifiers</title>
<updated>2018-08-22T17:52:44Z</updated>
<author>
<name>Michal Hocko</name>
<email>mhocko@suse.com</email>
</author>
<published>2018-08-22T04:52:33Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=93065ac753e4443840a057bfef4be71ec766fde9'/>
<id>urn:sha1:93065ac753e4443840a057bfef4be71ec766fde9</id>
<content type='text'>
There are several blockable mmu notifiers which might sleep in
mmu_notifier_invalidate_range_start and that is a problem for the
oom_reaper because it needs to guarantee a forward progress so it cannot
depend on any sleepable locks.

Currently we simply back off and mark an oom victim with blockable mmu
notifiers as done after a short sleep.  That can result in selecting a new
oom victim prematurely because the previous one still hasn't torn its
memory down yet.

We can do much better though.  Even if mmu notifiers use sleepable locks
there is no reason to automatically assume those locks are held.  Moreover
majority of notifiers only care about a portion of the address space and
there is absolutely zero reason to fail when we are unmapping an unrelated
range.  Many notifiers do really block and wait for HW which is harder to
handle and we have to bail out though.

This patch handles the low hanging fruit.
__mmu_notifier_invalidate_range_start gets a blockable flag and callbacks
are not allowed to sleep if the flag is set to false.  This is achieved by
using trylock instead of the sleepable lock for most callbacks and
continue as long as we do not block down the call chain.

I think we can improve that even further because there is a common pattern
to do a range lookup first and then do something about that.  The first
part can be done without a sleeping lock in most cases AFAICS.

The oom_reaper end then simply retries if there is at least one notifier
which couldn't make any progress in !blockable mode.  A retry loop is
already implemented to wait for the mmap_sem and this is basically the
same thing.

The simplest way for driver developers to test this code path is to wrap
userspace code which uses these notifiers into a memcg and set the hard
limit to hit the oom.  This can be done e.g.  after the test faults in all
the mmu notifier managed memory and set the hard limit to something really
small.  Then we are looking for a proper process tear down.

[akpm@linux-foundation.org: coding style fixes]
[akpm@linux-foundation.org: minor code simplification]
Link: http://lkml.kernel.org/r/20180716115058.5559-1-mhocko@kernel.org
Signed-off-by: Michal Hocko &lt;mhocko@suse.com&gt;
Acked-by: Christian König &lt;christian.koenig@amd.com&gt; # AMD notifiers
Acked-by: Leon Romanovsky &lt;leonro@mellanox.com&gt; # mlx and umem_odp
Reported-by: David Rientjes &lt;rientjes@google.com&gt;
Cc: "David (ChunMing) Zhou" &lt;David1.Zhou@amd.com&gt;
Cc: Paolo Bonzini &lt;pbonzini@redhat.com&gt;
Cc: Alex Deucher &lt;alexander.deucher@amd.com&gt;
Cc: David Airlie &lt;airlied@linux.ie&gt;
Cc: Jani Nikula &lt;jani.nikula@linux.intel.com&gt;
Cc: Joonas Lahtinen &lt;joonas.lahtinen@linux.intel.com&gt;
Cc: Rodrigo Vivi &lt;rodrigo.vivi@intel.com&gt;
Cc: Doug Ledford &lt;dledford@redhat.com&gt;
Cc: Jason Gunthorpe &lt;jgg@ziepe.ca&gt;
Cc: Mike Marciniszyn &lt;mike.marciniszyn@intel.com&gt;
Cc: Dennis Dalessandro &lt;dennis.dalessandro@intel.com&gt;
Cc: Sudeep Dutt &lt;sudeep.dutt@intel.com&gt;
Cc: Ashutosh Dixit &lt;ashutosh.dixit@intel.com&gt;
Cc: Dimitri Sivanich &lt;sivanich@sgi.com&gt;
Cc: Boris Ostrovsky &lt;boris.ostrovsky@oracle.com&gt;
Cc: Juergen Gross &lt;jgross@suse.com&gt;
Cc: "Jérôme Glisse" &lt;jglisse@redhat.com&gt;
Cc: Andrea Arcangeli &lt;aarcange@redhat.com&gt;
Cc: Felix Kuehling &lt;felix.kuehling@amd.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
</entry>
<entry>
<title>misc: mic: SCIF Fix scif_get_new_port() error handling</title>
<updated>2018-08-05T14:29:11Z</updated>
<author>
<name>Dan Carpenter</name>
<email>dan.carpenter@oracle.com</email>
</author>
<published>2018-08-02T08:42:22Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=a39284ae9d2ad09975c8ae33f1bd0f05fbfbf6ee'/>
<id>urn:sha1:a39284ae9d2ad09975c8ae33f1bd0f05fbfbf6ee</id>
<content type='text'>
There are only 2 callers of scif_get_new_port() and both appear to get
the error handling wrong.  Both treat zero returns as error, but it
actually returns negative error codes and &gt;= 0 on success.

Fixes: e9089f43c9a7 ("misc: mic: SCIF open close bind and listen APIs")
Signed-off-by: Dan Carpenter &lt;dan.carpenter@oracle.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>misc: mic: fix passing the current time</title>
<updated>2018-07-07T15:44:52Z</updated>
<author>
<name>Arnd Bergmann</name>
<email>arnd@arndb.de</email>
</author>
<published>2018-06-18T14:25:51Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=6051e79bbfa6111c3a56a86fa8c6ff9a248e30a6'/>
<id>urn:sha1:6051e79bbfa6111c3a56a86fa8c6ff9a248e30a6</id>
<content type='text'>
I noticed that the mic driver passes a 'struct timespec64' as part of
a message into an attached device, where it is used to set the current
system time.

This won't actually work if one of the two sides runs a 32-bit kernel and
the other runs a 64-bit kernel, since the structure layout is different
between the two.

I found this while replacing calls to the deprecated do_settimeofday64()
interface with the modern ktime_get_real_ts() variant, but it seems
appropriate to address both at the same time here.

To make sure we have a sane structure, let's define our own structure
using the layout of the 64-bit kernel.

Signed-off-by: Arnd Bergmann &lt;arnd@arndb.de&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>misc: mic: mark expected switch fall-through</title>
<updated>2018-07-07T15:38:57Z</updated>
<author>
<name>Gustavo A. R. Silva</name>
<email>gustavo@embeddedor.com</email>
</author>
<published>2018-07-03T22:36:29Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=bcde98fcf9cf084f6ed6c1751d2ef68877a87c20'/>
<id>urn:sha1:bcde98fcf9cf084f6ed6c1751d2ef68877a87c20</id>
<content type='text'>
In preparation to enabling -Wimplicit-fallthrough, mark switch cases
where we are expecting to fall through.

Signed-off-by: Gustavo A. R. Silva &lt;gustavo@embeddedor.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>misc: mic: Release reference count and memory for VOP device</title>
<updated>2018-03-15T17:12:01Z</updated>
<author>
<name>Arvind Yadav</name>
<email>arvind.yadav.cs@gmail.com</email>
</author>
<published>2018-03-12T11:36:52Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=5fbe9f35dfcd83d94ec9bf4f68a9e0d7cc0550b5'/>
<id>urn:sha1:5fbe9f35dfcd83d94ec9bf4f68a9e0d7cc0550b5</id>
<content type='text'>
Never directly free @dev after calling device_register(),
even if it returned an error! Always use put_device() to
give up the reference initialized.
Release allocated memory for vop device in vop_release_dev().

Signed-off-by: Arvind Yadav &lt;arvind.yadav.cs@gmail.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>vfs: do bulk POLL* -&gt; EPOLL* replacement</title>
<updated>2018-02-11T22:34:03Z</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2018-02-11T22:34:03Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=a9a08845e9acbd224e4ee466f5c1275ed50054e8'/>
<id>urn:sha1:a9a08845e9acbd224e4ee466f5c1275ed50054e8</id>
<content type='text'>
This is the mindless scripted replacement of kernel use of POLL*
variables as described by Al, done by this script:

    for V in IN OUT PRI ERR RDNORM RDBAND WRNORM WRBAND HUP RDHUP NVAL MSG; do
        L=`git grep -l -w POLL$V | grep -v '^t' | grep -v /um/ | grep -v '^sa' | grep -v '/poll.h$'|grep -v '^D'`
        for f in $L; do sed -i "-es/^\([^\"]*\)\(\&lt;POLL$V\&gt;\)/\\1E\\2/" $f; done
    done

with de-mangling cleanups yet to come.

NOTE! On almost all architectures, the EPOLL* constants have the same
values as the POLL* constants do.  But they keyword here is "almost".
For various bad reasons they aren't the same, and epoll() doesn't
actually work quite correctly in some cases due to this on Sparc et al.

The next patch from Al will sort out the final differences, and we
should be all done.

Scripted-by: Al Viro &lt;viro@zeniv.linux.org.uk&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
</entry>
</feed>
