<feed xmlns='http://www.w3.org/2005/Atom'>
<title>BMC/Intel-BMC/linux.git/include, branch v5.1.8</title>
<subtitle>Intel OpenBMC Linux kernel source tree (mirror)</subtitle>
<id>https://git.radix-linux.su/BMC/Intel-BMC/linux.git/atom?h=v5.1.8</id>
<link rel='self' href='https://git.radix-linux.su/BMC/Intel-BMC/linux.git/atom?h=v5.1.8'/>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/BMC/Intel-BMC/linux.git/'/>
<updated>2019-06-09T07:16:13+00:00</updated>
<entry>
<title>memcg: make it work on sparse non-0-node systems</title>
<updated>2019-06-09T07:16:13+00:00</updated>
<author>
<name>Jiri Slaby</name>
<email>jslaby@suse.cz</email>
</author>
<published>2019-06-01T05:30:26+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/BMC/Intel-BMC/linux.git/commit/?id=770368348c84c613aef82d81d68208db733b54f0'/>
<id>urn:sha1:770368348c84c613aef82d81d68208db733b54f0</id>
<content type='text'>
commit 3e8589963773a5c23e2f1fe4bcad0e9a90b7f471 upstream.

We have a single node system with node 0 disabled:
  Scanning NUMA topology in Northbridge 24
  Number of physical nodes 2
  Skipping disabled node 0
  Node 1 MemBase 0000000000000000 Limit 00000000fbff0000
  NODE_DATA(1) allocated [mem 0xfbfda000-0xfbfeffff]

This causes crashes in memcg when system boots:
  BUG: unable to handle kernel NULL pointer dereference at 0000000000000008
  #PF error: [normal kernel read fault]
...
  RIP: 0010:list_lru_add+0x94/0x170
...
  Call Trace:
   d_lru_add+0x44/0x50
   dput.part.34+0xfc/0x110
   __fput+0x108/0x230
   task_work_run+0x9f/0xc0
   exit_to_usermode_loop+0xf5/0x100

It is reproducible as far as 4.12.  I did not try older kernels.  You have
to have a new enough systemd, e.g.  241 (the reason is unknown -- was not
investigated).  Cannot be reproduced with systemd 234.

The system crashes because the size of lru array is never updated in
memcg_update_all_list_lrus and the reads are past the zero-sized array,
causing dereferences of random memory.

The root cause are list_lru_memcg_aware checks in the list_lru code.  The
test in list_lru_memcg_aware is broken: it assumes node 0 is always
present, but it is not true on some systems as can be seen above.

So fix this by avoiding checks on node 0.  Remember the memcg-awareness by
a bool flag in struct list_lru.

Link: http://lkml.kernel.org/r/20190522091940.3615-1-jslaby@suse.cz
Fixes: 60d3fd32a7a9 ("list_lru: introduce per-memcg lists")
Signed-off-by: Jiri Slaby &lt;jslaby@suse.cz&gt;
Acked-by: Michal Hocko &lt;mhocko@suse.com&gt;
Suggested-by: Vladimir Davydov &lt;vdavydov.dev@gmail.com&gt;
Acked-by: Vladimir Davydov &lt;vdavydov.dev@gmail.com&gt;
Reviewed-by: Shakeel Butt &lt;shakeelb@google.com&gt;
Cc: Johannes Weiner &lt;hannes@cmpxchg.org&gt;
Cc: Raghavendra K T &lt;raghavendra.kt@linux.vnet.ibm.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>mm, memcg: consider subtrees in memory.events</title>
<updated>2019-06-09T07:16:13+00:00</updated>
<author>
<name>Chris Down</name>
<email>chris@chrisdown.name</email>
</author>
<published>2019-06-01T05:30:22+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/BMC/Intel-BMC/linux.git/commit/?id=f96109988a8edd15c668d521af49f51797e4621e'/>
<id>urn:sha1:f96109988a8edd15c668d521af49f51797e4621e</id>
<content type='text'>
commit 9852ae3fe5293264f01c49f2571ef7688f7823ce upstream.

memory.stat and other files already consider subtrees in their output, and
we should too in order to not present an inconsistent interface.

The current situation is fairly confusing, because people interacting with
cgroups expect hierarchical behaviour in the vein of memory.stat,
cgroup.events, and other files.  For example, this causes confusion when
debugging reclaim events under low, as currently these always read "0" at
non-leaf memcg nodes, which frequently causes people to misdiagnose breach
behaviour.  The same confusion applies to other counters in this file when
debugging issues.

Aggregation is done at write time instead of at read-time since these
counters aren't hot (unlike memory.stat which is per-page, so it does it
at read time), and it makes sense to bundle this with the file
notifications.

After this patch, events are propagated up the hierarchy:

    [root@ktst ~]# cat /sys/fs/cgroup/system.slice/memory.events
    low 0
    high 0
    max 0
    oom 0
    oom_kill 0
    [root@ktst ~]# systemd-run -p MemoryMax=1 true
    Running as unit: run-r251162a189fb4562b9dabfdc9b0422f5.service
    [root@ktst ~]# cat /sys/fs/cgroup/system.slice/memory.events
    low 0
    high 0
    max 7
    oom 1
    oom_kill 1

As this is a change in behaviour, this can be reverted to the old
behaviour by mounting with the `memory_localevents' flag set.  However, we
use the new behaviour by default as there's a lack of evidence that there
are any current users of memory.events that would find this change
undesirable.

akpm: this is a behaviour change, so Cc:stable.  THis is so that
forthcoming distros which use cgroup v2 are more likely to pick up the
revised behaviour.

Link: http://lkml.kernel.org/r/20190208224419.GA24772@chrisdown.name
Signed-off-by: Chris Down &lt;chris@chrisdown.name&gt;
Acked-by: Johannes Weiner &lt;hannes@cmpxchg.org&gt;
Reviewed-by: Shakeel Butt &lt;shakeelb@google.com&gt;
Cc: Michal Hocko &lt;mhocko@kernel.org&gt;
Cc: Tejun Heo &lt;tj@kernel.org&gt;
Cc: Roman Gushchin &lt;guro@fb.com&gt;
Cc: Dennis Zhou &lt;dennis@kernel.org&gt;
Cc: Suren Baghdasaryan &lt;surenb@google.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>include/linux/bitops.h: sanitize rotate primitives</title>
<updated>2019-06-09T07:16:06+00:00</updated>
<author>
<name>Rasmus Villemoes</name>
<email>linux@rasmusvillemoes.dk</email>
</author>
<published>2019-05-14T22:43:27+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/BMC/Intel-BMC/linux.git/commit/?id=a40d0bd2fd4e38fb66fd058cf294947036310d1a'/>
<id>urn:sha1:a40d0bd2fd4e38fb66fd058cf294947036310d1a</id>
<content type='text'>
commit ef4d6f6b275c498f8e5626c99dbeefdc5027f843 upstream.

The ror32 implementation (word &gt;&gt; shift) | (word &lt;&lt; (32 - shift) has
undefined behaviour if shift is outside the [1, 31] range.  Similarly
for the 64 bit variants.  Most callers pass a compile-time constant
(naturally in that range), but there's an UBSAN report that these may
actually be called with a shift count of 0.

Instead of special-casing that, we can make them DTRT for all values of
shift while also avoiding UB.  For some reason, this was already partly
done for rol32 (which was well-defined for [0, 31]).  gcc 8 recognizes
these patterns as rotates, so for example

  __u32 rol32(__u32 word, unsigned int shift)
  {
	return (word &lt;&lt; (shift &amp; 31)) | (word &gt;&gt; ((-shift) &amp; 31));
  }

compiles to

0000000000000020 &lt;rol32&gt;:
  20:   89 f8                   mov    %edi,%eax
  22:   89 f1                   mov    %esi,%ecx
  24:   d3 c0                   rol    %cl,%eax
  26:   c3                      retq

Older compilers unfortunately do not do as well, but this only affects
the small minority of users that don't pass constants.

Due to integer promotions, ro[lr]8 were already well-defined for shifts
in [0, 8], and ro[lr]16 were mostly well-defined for shifts in [0, 16]
(only mostly - u16 gets promoted to _signed_ int, so if bit 15 is set,
word &lt;&lt; 16 is undefined).  For consistency, update those as well.

Link: http://lkml.kernel.org/r/20190410211906.2190-1-linux@rasmusvillemoes.dk
Signed-off-by: Rasmus Villemoes &lt;linux@rasmusvillemoes.dk&gt;
Reported-by: Ido Schimmel &lt;idosch@mellanox.com&gt;
Tested-by: Ido Schimmel &lt;idosch@mellanox.com&gt;
Reviewed-by: Will Deacon &lt;will.deacon@arm.com&gt;
Cc: Vadim Pasternak &lt;vadimp@mellanox.com&gt;
Cc: Andrey Ryabinin &lt;aryabinin@virtuozzo.com&gt;
Cc: Jacek Anaszewski &lt;jacek.anaszewski@gmail.com&gt;
Cc: Pavel Machek &lt;pavel@ucw.cz&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>tipc: Avoid copying bytes beyond the supplied data</title>
<updated>2019-06-04T05:59:43+00:00</updated>
<author>
<name>Chris Packham</name>
<email>chris.packham@alliedtelesis.co.nz</email>
</author>
<published>2019-05-20T03:45:36+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/BMC/Intel-BMC/linux.git/commit/?id=b78931285473f7258ce7657b4feeff6ff6397b83'/>
<id>urn:sha1:b78931285473f7258ce7657b4feeff6ff6397b83</id>
<content type='text'>
TLV_SET is called with a data pointer and a len parameter that tells us
how many bytes are pointed to by data. When invoking memcpy() we need
to careful to only copy len bytes.

Previously we would copy TLV_LENGTH(len) bytes which would copy an extra
4 bytes past the end of the data pointer which newer GCC versions
complain about.

 In file included from test.c:17:
 In function 'TLV_SET',
     inlined from 'test' at test.c:186:5:
 /usr/include/linux/tipc_config.h:317:3:
 warning: 'memcpy' forming offset [33, 36] is out of the bounds [0, 32]
 of object 'bearer_name' with type 'char[32]' [-Warray-bounds]
     memcpy(TLV_DATA(tlv_ptr), data, tlv_len);
     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 test.c: In function 'test':
 test.c::161:10: note:
 'bearer_name' declared here
     char bearer_name[TIPC_MAX_BEARER_NAME];
          ^~~~~~~~~~~

We still want to ensure any padding bytes at the end are initialised, do
this with a explicit memset() rather than copy bytes past the end of
data. Apply the same logic to TCM_SET.

Signed-off-by: Chris Packham &lt;chris.packham@alliedtelesis.co.nz&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>inet: switch IP ID generator to siphash</title>
<updated>2019-06-04T05:59:40+00:00</updated>
<author>
<name>Eric Dumazet</name>
<email>edumazet@google.com</email>
</author>
<published>2019-03-27T19:40:33+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/BMC/Intel-BMC/linux.git/commit/?id=f2a11618d82a1ccb98a734b7d55f34f1ad404aac'/>
<id>urn:sha1:f2a11618d82a1ccb98a734b7d55f34f1ad404aac</id>
<content type='text'>
[ Upstream commit df453700e8d81b1bdafdf684365ee2b9431fb702 ]

According to Amit Klein and Benny Pinkas, IP ID generation is too weak
and might be used by attackers.

Even with recent net_hash_mix() fix (netns: provide pure entropy for net_hash_mix())
having 64bit key and Jenkins hash is risky.

It is time to switch to siphash and its 128bit keys.

Signed-off-by: Eric Dumazet &lt;edumazet@google.com&gt;
Reported-by: Amit Klein &lt;aksecurity@gmail.com&gt;
Reported-by: Benny Pinkas &lt;benny@pinkas.net&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>tinydrm/mipi-dbi: Use dma-safe buffers for all SPI transfers</title>
<updated>2019-05-31T13:43:51+00:00</updated>
<author>
<name>Noralf Trønnes</name>
<email>noralf@tronnes.org</email>
</author>
<published>2019-02-22T12:43:29+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/BMC/Intel-BMC/linux.git/commit/?id=14edc56d71ca33cf9effadb490de5bc5a35be1b8'/>
<id>urn:sha1:14edc56d71ca33cf9effadb490de5bc5a35be1b8</id>
<content type='text'>
[ Upstream commit a89bfc5d9a0732d84b4de311e27133daa0586316 ]

Buffers passed to spi_sync() must be dma-safe even for tiny buffers since
some SPI controllers use DMA for all transfers.

Example splat with CONFIG_DMA_API_DEBUG enabled:

[   23.750467] DMA-API: dw_dmac_pci 0000:00:15.0: device driver maps memory from stack [probable addr=000000001e49185d]
[   23.750529] WARNING: CPU: 1 PID: 1296 at kernel/dma/debug.c:1161 check_for_stack+0xb7/0x190
[   23.750533] Modules linked in: mmc_block(+) spi_pxa2xx_platform(+) pwm_lpss_pci pwm_lpss spi_pxa2xx_pci sdhci_pci cqhci intel_mrfld_pwrbtn extcon_intel_mrfld sdhci intel_mrfld_adc led_class mmc_core ili9341 mipi_dbi tinydrm backlight ti_ads7950 industrialio_triggered_buffer kfifo_buf intel_soc_pmic_mrfld hci_uart btbcm
[   23.750599] CPU: 1 PID: 1296 Comm: modprobe Not tainted 5.0.0-rc7+ #236
[   23.750605] Hardware name: Intel Corporation Merrifield/BODEGA BAY, BIOS 542 2015.01.21:18.19.48
[   23.750620] RIP: 0010:check_for_stack+0xb7/0x190
[   23.750630] Code: 8b 6d 50 4d 85 ed 75 04 4c 8b 6d 10 48 89 ef e8 2f 8b 44 00 48 89 c6 4a 8d 0c 23 4c 89 ea 48 c7 c7 88 d0 82 b4 e8 40 7c f9 ff &lt;0f&gt; 0b 8b 05 79 00 4b 01 85 c0 74 07 5b 5d 41 5c 41 5d c3 8b 05 54
[   23.750637] RSP: 0000:ffff97bbc0292fa0 EFLAGS: 00010286
[   23.750646] RAX: 0000000000000000 RBX: ffff97bbc0290000 RCX: 0000000000000006
[   23.750652] RDX: 0000000000000007 RSI: 0000000000000002 RDI: ffff94b33e115450
[   23.750658] RBP: ffff94b33c8578b0 R08: 0000000000000002 R09: 00000000000201c0
[   23.750664] R10: 00000006ecb0ccc6 R11: 0000000000034f38 R12: 000000000000316c
[   23.750670] R13: ffff94b33c84b250 R14: ffff94b33dedd5a0 R15: 0000000000000001
[   23.750679] FS:  0000000000000000(0000) GS:ffff94b33e100000(0063) knlGS:00000000f7faf690
[   23.750686] CS:  0010 DS: 002b ES: 002b CR0: 0000000080050033
[   23.750691] CR2: 00000000f7f54faf CR3: 000000000722c000 CR4: 00000000001006e0
[   23.750696] Call Trace:
[   23.750713]  debug_dma_map_sg+0x100/0x340
[   23.750727]  ? dma_direct_map_sg+0x3b/0xb0
[   23.750739]  spi_map_buf+0x25a/0x300
[   23.750751]  __spi_pump_messages+0x2a4/0x680
[   23.750762]  __spi_sync+0x1dd/0x1f0
[   23.750773]  spi_sync+0x26/0x40
[   23.750790]  mipi_dbi_typec3_command_read+0x14d/0x240 [mipi_dbi]
[   23.750802]  ? spi_finalize_current_transfer+0x10/0x10
[   23.750821]  mipi_dbi_typec3_command+0x1bc/0x1d0 [mipi_dbi]

Reported-by: Andy Shevchenko &lt;andriy.shevchenko@linux.intel.com&gt;
Signed-off-by: Noralf Trønnes &lt;noralf@tronnes.org&gt;
Tested-by: Andy Shevchenko &lt;andriy.shevchenko@linux.intel.com&gt;
Acked-by: Andy Shevchenko &lt;andriy.shevchenko@linux.intel.com&gt;
Link: https://patchwork.freedesktop.org/patch/msgid/20190222124329.23046-1-noralf@tronnes.org
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>regulator: add regulator_get_linear_step() stub helper</title>
<updated>2019-05-31T13:43:50+00:00</updated>
<author>
<name>Arnd Bergmann</name>
<email>arnd@arndb.de</email>
</author>
<published>2019-03-04T19:38:29+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/BMC/Intel-BMC/linux.git/commit/?id=13b91576a59adaeacf348cddfa0108888e65d2fa'/>
<id>urn:sha1:13b91576a59adaeacf348cddfa0108888e65d2fa</id>
<content type='text'>
[ Upstream commit 7287275b4301e230be9e4569431c7dacb67ebc13 ]

The regulator header has empty inline functions for most interfaces,
but not regulator_get_linear_step(), which has just grown a user
that does not depend on regulators otherwise:

drivers/clk/tegra/clk-tegra124-dfll-fcpu.c: In function 'get_alignment_from_regulator':
drivers/clk/tegra/clk-tegra124-dfll-fcpu.c:555:19: error: implicit declaration of function 'regulator_get_linear_step'; did you mean 'regulator_get_drvdata'? [-Werror=implicit-function-declaration]
  align-&gt;step_uv = regulator_get_linear_step(reg);
                   ^~~~~~~~~~~~~~~~~~~~~~~~~
                   regulator_get_drvdata
cc1: all warnings being treated as errors
scripts/Makefile.build:278: recipe for target 'drivers/clk/tegra/clk-tegra124-dfll-fcpu.o' failed

Add the missing stub along the others.

Fixes: b3cf8d069505 ("clk: tegra: dfll: CVB calculation alignment with the regulator")
Signed-off-by: Arnd Bergmann &lt;arnd@arndb.de&gt;
Signed-off-by: Mark Brown &lt;broonie@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>rcu: Do a single rhp-&gt;func read in rcu_head_after_call_rcu()</title>
<updated>2019-05-31T13:43:48+00:00</updated>
<author>
<name>Neeraj Upadhyay</name>
<email>neeraju@codeaurora.org</email>
</author>
<published>2019-03-11T11:58:03+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/BMC/Intel-BMC/linux.git/commit/?id=e8cfc3265cdce02a8c26b734b1b2d6b1368f04ba'/>
<id>urn:sha1:e8cfc3265cdce02a8c26b734b1b2d6b1368f04ba</id>
<content type='text'>
[ Upstream commit b699cce1604e828f19c39845252626eb78cdf38a ]

The rcu_head_after_call_rcu() function reads the rhp-&gt;func pointer twice,
which can result in a false-positive WARN_ON_ONCE() if the callback
were passed to call_rcu() between the two reads.  Although racing
rcu_head_after_call_rcu() with call_rcu() is to be a dubious use case
(the return value is not reliable in that case), intermittent and
irreproducible warnings are also quite dubious.  This commit therefore
uses a single READ_ONCE() to pick up the value of rhp-&gt;func once, then
tests that value twice, thus guaranteeing consistent processing within
rcu_head_after_call_rcu()().

Neverthless, racing rcu_head_after_call_rcu() with call_rcu() is still
a dubious use case.

Signed-off-by: Neeraj Upadhyay &lt;neeraju@codeaurora.org&gt;
[ paulmck: Add blank line after declaration per checkpatch.pl. ]
Signed-off-by: Paul E. McKenney &lt;paulmck@linux.ibm.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>overflow: Fix -Wtype-limits compilation warnings</title>
<updated>2019-05-31T13:43:47+00:00</updated>
<author>
<name>Leon Romanovsky</name>
<email>leonro@mellanox.com</email>
</author>
<published>2019-03-17T10:11:14+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/BMC/Intel-BMC/linux.git/commit/?id=a3d4afffaac1087bd6562e6cbe511ce6923e2f7a'/>
<id>urn:sha1:a3d4afffaac1087bd6562e6cbe511ce6923e2f7a</id>
<content type='text'>
[ Upstream commit dc7fe518b0493faa0af0568d6d8c2a33c00f58d0 ]

Attempt to use check_shl_overflow() with inputs of unsigned type
produces the following compilation warnings.

drivers/infiniband/hw/mlx5/qp.c: In function _set_user_rq_size_:
./include/linux/overflow.h:230:6: warning: comparison of unsigned
expression &gt;= 0 is always true [-Wtype-limits]
   _s &gt;= 0 &amp;&amp; _s &lt; 8 * sizeof(*d) ? _s : 0;  \
      ^~
drivers/infiniband/hw/mlx5/qp.c:5820:6: note: in expansion of macro _check_shl_overflow_
  if (check_shl_overflow(rwq-&gt;wqe_count, rwq-&gt;wqe_shift,
&amp;rwq-&gt;buf_size))
      ^~~~~~~~~~~~~~~~~~
./include/linux/overflow.h:232:26: warning: comparison of unsigned expression &lt; 0 is always false [-Wtype-limits]
  (_to_shift != _s || *_d &lt; 0 || _a &lt; 0 ||   \
                          ^
drivers/infiniband/hw/mlx5/qp.c:5820:6: note: in expansion of macro _check_shl_overflow_
  if (check_shl_overflow(rwq-&gt;wqe_count, rwq-&gt;wqe_shift, &amp;rwq-&gt;buf_size))
      ^~~~~~~~~~~~~~~~~~
./include/linux/overflow.h:232:36: warning: comparison of unsigned expression &lt; 0 is always false [-Wtype-limits]
  (_to_shift != _s || *_d &lt; 0 || _a &lt; 0 ||   \
                                    ^
drivers/infiniband/hw/mlx5/qp.c:5820:6: note: in expansion of macro _check_shl_overflow_
  if (check_shl_overflow(rwq-&gt;wqe_count, rwq-&gt;wqe_shift,&amp;rwq-&gt;buf_size))
      ^~~~~~~~~~~~~~~~~~

Fixes: 0c66847793d1 ("overflow.h: Add arithmetic shift helper")
Reviewed-by: Bart Van Assche &lt;bvanassche@acm.org&gt;
Acked-by: Kees Cook &lt;keescook@chromium.org&gt;
Signed-off-by: Leon Romanovsky &lt;leonro@mellanox.com&gt;
Signed-off-by: Jason Gunthorpe &lt;jgg@mellanox.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>timekeeping: Force upper bound for setting CLOCK_REALTIME</title>
<updated>2019-05-31T13:43:46+00:00</updated>
<author>
<name>Thomas Gleixner</name>
<email>tglx@linutronix.de</email>
</author>
<published>2019-03-23T10:36:19+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/BMC/Intel-BMC/linux.git/commit/?id=5e04fcbab4b417ac1110ec917f653d7eb38fd056'/>
<id>urn:sha1:5e04fcbab4b417ac1110ec917f653d7eb38fd056</id>
<content type='text'>
[ Upstream commit 7a8e61f8478639072d402a26789055a4a4de8f77 ]

Several people reported testing failures after setting CLOCK_REALTIME close
to the limits of the kernel internal representation in nanoseconds,
i.e. year 2262.

The failures are exposed in subsequent operations, i.e. when arming timers
or when the advancing CLOCK_MONOTONIC makes the calculation of
CLOCK_REALTIME overflow into negative space.

Now people start to paper over the underlying problem by clamping
calculations to the valid range, but that's just wrong because such
workarounds will prevent detection of real issues as well.

It is reasonable to force an upper bound for the various methods of setting
CLOCK_REALTIME. Year 2262 is the absolute upper bound. Assume a maximum
uptime of 30 years which is plenty enough even for esoteric embedded
systems. That results in an upper bound of year 2232 for setting the time.

Once that limit is reached in reality this limit is only a small part of
the problem space. But until then this stops people from trying to paper
over the problem at the wrong places.

Reported-by: Xiongfeng Wang &lt;wangxiongfeng2@huawei.com&gt;
Reported-by: Hongbo Yao &lt;yaohongbo@huawei.com&gt;
Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: John Stultz &lt;john.stultz@linaro.org&gt;
Cc: Stephen Boyd &lt;sboyd@kernel.org&gt;
Cc: Miroslav Lichvar &lt;mlichvar@redhat.com&gt;
Cc: Arnd Bergmann &lt;arnd@arndb.de&gt;
Cc: Richard Cochran &lt;richardcochran@gmail.com&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Link: https://lkml.kernel.org/r/alpine.DEB.2.21.1903231125480.2157@nanos.tec.linutronix.de
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
</feed>
