<feed xmlns='http://www.w3.org/2005/Atom'>
<title>user/sven/linux.git, branch v4.20.5</title>
<subtitle>Linux Kernel
</subtitle>
<id>https://git.stealer.net/cgit.cgi/user/sven/linux.git/atom?h=v4.20.5</id>
<link rel='self' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/atom?h=v4.20.5'/>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/'/>
<updated>2019-01-26T08:20:52Z</updated>
<entry>
<title>Linux 4.20.5</title>
<updated>2019-01-26T08:20:52Z</updated>
<author>
<name>Greg Kroah-Hartman</name>
<email>gregkh@linuxfoundation.org</email>
</author>
<published>2019-01-26T08:20:52Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=9f1a389a0b5b4004757759e26e2ff459016515ac'/>
<id>urn:sha1:9f1a389a0b5b4004757759e26e2ff459016515ac</id>
<content type='text'>
</content>
</entry>
<entry>
<title>ipmi:ssif: Fix handling of multi-part return messages</title>
<updated>2019-01-26T08:20:52Z</updated>
<author>
<name>Corey Minyard</name>
<email>cminyard@mvista.com</email>
</author>
<published>2018-11-16T15:59:21Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=cab266c86c34baf5176191d9d5f2bc3a1c1e22ce'/>
<id>urn:sha1:cab266c86c34baf5176191d9d5f2bc3a1c1e22ce</id>
<content type='text'>
commit 7d6380cd40f7993f75c4bde5b36f6019237e8719 upstream.

The block number was not being compared right, it was off by one
when checking the response.

Some statistics wouldn't be incremented properly in some cases.

Check to see if that middle-part messages always have 31 bytes of
data.

Signed-off-by: Corey Minyard &lt;cminyard@mvista.com&gt;
Cc: stable@vger.kernel.org # 4.4
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
<entry>
<title>ipmi: Prevent use-after-free in deliver_response</title>
<updated>2019-01-26T08:20:51Z</updated>
<author>
<name>Fred Klassen</name>
<email>fklassen@appneta.com</email>
</author>
<published>2019-01-19T22:28:18Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=0eef3c63df7840f14de154d5bdd55cba73f9068b'/>
<id>urn:sha1:0eef3c63df7840f14de154d5bdd55cba73f9068b</id>
<content type='text'>
commit 479d6b39b9e0d2de648ebf146f23a1e40962068f upstream.

Some IPMI modules (e.g. ibmpex_msg_handler()) will have ipmi_usr_hdlr
handlers that call ipmi_free_recv_msg() directly. This will essentially
kfree(msg), leading to use-after-free.

This does not happen in the ipmi_devintf module, which will queue the
message and run ipmi_free_recv_msg() later.

BUG: KASAN: use-after-free in deliver_response+0x12f/0x1b0
Read of size 8 at addr ffff888a7bf20018 by task ksoftirqd/3/27
CPU: 3 PID: 27 Comm: ksoftirqd/3 Tainted: G           O      4.19.11-amd64-ani99-debug #12.0.1.601133+pv
Hardware name: AppNeta r1000/X11SPW-TF, BIOS 2.1a-AP 09/17/2018
Call Trace:
dump_stack+0x92/0xeb
print_address_description+0x73/0x290
kasan_report+0x258/0x380
deliver_response+0x12f/0x1b0
? ipmi_free_recv_msg+0x50/0x50
deliver_local_response+0xe/0x50
handle_one_recv_msg+0x37a/0x21d0
handle_new_recv_msgs+0x1ce/0x440
...

Allocated by task 9885:
kasan_kmalloc+0xa0/0xd0
kmem_cache_alloc_trace+0x116/0x290
ipmi_alloc_recv_msg+0x28/0x70
i_ipmi_request+0xb4a/0x1640
ipmi_request_settime+0x1b8/0x1e0
...

Freed by task 27:
__kasan_slab_free+0x12e/0x180
kfree+0xe9/0x280
deliver_response+0x122/0x1b0
deliver_local_response+0xe/0x50
handle_one_recv_msg+0x37a/0x21d0
handle_new_recv_msgs+0x1ce/0x440
tasklet_action_common.isra.19+0xc4/0x250
__do_softirq+0x11f/0x51f

Fixes: e86ee2d44b44 ("ipmi: Rework locking and shutdown for hot remove")
Cc: stable@vger.kernel.org # 4.18
Signed-off-by: Fred Klassen &lt;fklassen@appneta.com&gt;
Signed-off-by: Corey Minyard &lt;cminyard@mvista.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
<entry>
<title>ipmi: msghandler: Fix potential Spectre v1 vulnerabilities</title>
<updated>2019-01-26T08:20:51Z</updated>
<author>
<name>Gustavo A. R. Silva</name>
<email>gustavo@embeddedor.com</email>
</author>
<published>2019-01-09T23:39:06Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=118ec2b2bd357fd07389652db7b00eb3387b7b9f'/>
<id>urn:sha1:118ec2b2bd357fd07389652db7b00eb3387b7b9f</id>
<content type='text'>
commit a7102c7461794a5bb31af24b08e9e0f50038897a upstream.

channel and addr-&gt;channel are indirectly controlled by user-space,
hence leading to a potential exploitation of the Spectre variant 1
vulnerability.

These issues were detected with the help of Smatch:

drivers/char/ipmi/ipmi_msghandler.c:1381 ipmi_set_my_address() warn: potential spectre issue 'user-&gt;intf-&gt;addrinfo' [w] (local cap)
drivers/char/ipmi/ipmi_msghandler.c:1401 ipmi_get_my_address() warn: potential spectre issue 'user-&gt;intf-&gt;addrinfo' [r] (local cap)
drivers/char/ipmi/ipmi_msghandler.c:1421 ipmi_set_my_LUN() warn: potential spectre issue 'user-&gt;intf-&gt;addrinfo' [w] (local cap)
drivers/char/ipmi/ipmi_msghandler.c:1441 ipmi_get_my_LUN() warn: potential spectre issue 'user-&gt;intf-&gt;addrinfo' [r] (local cap)
drivers/char/ipmi/ipmi_msghandler.c:2260 check_addr() warn: potential spectre issue 'intf-&gt;addrinfo' [r] (local cap)

Fix this by sanitizing channel and addr-&gt;channel before using them to
index user-&gt;intf-&gt;addrinfo and intf-&gt;addrinfo, correspondingly.

Notice that given that speculation windows are large, the policy is
to kill the speculation on the first load and not worry if it can be
completed with a dependent load/store [1].

[1] https://lore.kernel.org/lkml/20180423164740.GY17484@dhcp22.suse.cz/

Cc: stable@vger.kernel.org
Signed-off-by: Gustavo A. R. Silva &lt;gustavo@embeddedor.com&gt;
Signed-off-by: Corey Minyard &lt;cminyard@mvista.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
<entry>
<title>ipmi: Don't initialize anything in the core until something uses it</title>
<updated>2019-01-26T08:20:51Z</updated>
<author>
<name>Corey Minyard</name>
<email>cminyard@mvista.com</email>
</author>
<published>2018-12-20T22:50:23Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=fca9f9b4c97c948036740ba466dd9bef7d1f2a85'/>
<id>urn:sha1:fca9f9b4c97c948036740ba466dd9bef7d1f2a85</id>
<content type='text'>
commit 913a89f009d98c85a902d718cd54bb32ab11d167 upstream.

The IPMI driver was recently modified to use SRCU, but it turns out
this uses a chunk of percpu memory, even if IPMI is never used.

So modify thing to on initialize on the first use.  There was already
code to sort of handle this for handling init races, so piggy back
on top of that, and simplify it in the process.

Signed-off-by: Corey Minyard &lt;cminyard@mvista.com&gt;
Reported-by: Tejun Heo &lt;tj@kernel.org&gt;
Cc: Paul E. McKenney &lt;paulmck@linux.vnet.ibm.com&gt;
Reviewed-by: Paul E. McKenney &lt;paulmck@linux.vnet.ibm.com&gt;
Cc: stable@vger.kernel.org # 4.18
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
<entry>
<title>ipmi: fix use-after-free of user-&gt;release_barrier.rda</title>
<updated>2019-01-26T08:20:51Z</updated>
<author>
<name>Yang Yingliang</name>
<email>yangyingliang@huawei.com</email>
</author>
<published>2019-01-16T05:33:22Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=542ee863f15ecc8d6e1dfc561e3432da6a8daef8'/>
<id>urn:sha1:542ee863f15ecc8d6e1dfc561e3432da6a8daef8</id>
<content type='text'>
commit 77f8269606bf95fcb232ee86f6da80886f1dfae8 upstream.

When we do the following test, we got oops in ipmi_msghandler driver
while((1))
do
	service ipmievd restart &amp; service ipmievd restart
done

---------------------------------------------------------------
[  294.230186] Unable to handle kernel paging request at virtual address 0000803fea6ea008
[  294.230188] Mem abort info:
[  294.230190]   ESR = 0x96000004
[  294.230191]   Exception class = DABT (current EL), IL = 32 bits
[  294.230193]   SET = 0, FnV = 0
[  294.230194]   EA = 0, S1PTW = 0
[  294.230195] Data abort info:
[  294.230196]   ISV = 0, ISS = 0x00000004
[  294.230197]   CM = 0, WnR = 0
[  294.230199] user pgtable: 4k pages, 48-bit VAs, pgdp = 00000000a1c1b75a
[  294.230201] [0000803fea6ea008] pgd=0000000000000000
[  294.230204] Internal error: Oops: 96000004 [#1] SMP
[  294.235211] Modules linked in: nls_utf8 isofs rpcrdma ib_iser ib_srpt target_core_mod ib_srp scsi_transport_srp ib_ipoib rdma_ucm ib_umad rdma_cm ib_cm iw_cm dm_mirror dm_region_hash dm_log dm_mod aes_ce_blk crypto_simd cryptd aes_ce_cipher ghash_ce sha2_ce ses sha256_arm64 sha1_ce hibmc_drm hisi_sas_v2_hw enclosure sg hisi_sas_main sbsa_gwdt ip_tables mlx5_ib ib_uverbs marvell ib_core mlx5_core ixgbe ipmi_si mdio hns_dsaf ipmi_devintf ipmi_msghandler hns_enet_drv hns_mdio
[  294.277745] CPU: 3 PID: 0 Comm: swapper/3 Kdump: loaded Not tainted 5.0.0-rc2+ #113
[  294.285511] Hardware name: Huawei TaiShan 2280 /BC11SPCD, BIOS 1.37 11/21/2017
[  294.292835] pstate: 80000005 (Nzcv daif -PAN -UAO)
[  294.297695] pc : __srcu_read_lock+0x38/0x58
[  294.301940] lr : acquire_ipmi_user+0x2c/0x70 [ipmi_msghandler]
[  294.307853] sp : ffff00001001bc80
[  294.311208] x29: ffff00001001bc80 x28: ffff0000117e5000
[  294.316594] x27: 0000000000000000 x26: dead000000000100
[  294.321980] x25: dead000000000200 x24: ffff803f6bd06800
[  294.327366] x23: 0000000000000000 x22: 0000000000000000
[  294.332752] x21: ffff00001001bd04 x20: ffff80df33d19018
[  294.338137] x19: ffff80df33d19018 x18: 0000000000000000
[  294.343523] x17: 0000000000000000 x16: 0000000000000000
[  294.348908] x15: 0000000000000000 x14: 0000000000000002
[  294.354293] x13: 0000000000000000 x12: 0000000000000000
[  294.359679] x11: 0000000000000000 x10: 0000000000100000
[  294.365065] x9 : 0000000000000000 x8 : 0000000000000004
[  294.370451] x7 : 0000000000000000 x6 : ffff80df34558678
[  294.375836] x5 : 000000000000000c x4 : 0000000000000000
[  294.381221] x3 : 0000000000000001 x2 : 0000803fea6ea000
[  294.386607] x1 : 0000803fea6ea008 x0 : 0000000000000001
[  294.391994] Process swapper/3 (pid: 0, stack limit = 0x0000000083087293)
[  294.398791] Call trace:
[  294.401266]  __srcu_read_lock+0x38/0x58
[  294.405154]  acquire_ipmi_user+0x2c/0x70 [ipmi_msghandler]
[  294.410716]  deliver_response+0x80/0xf8 [ipmi_msghandler]
[  294.416189]  deliver_local_response+0x28/0x68 [ipmi_msghandler]
[  294.422193]  handle_one_recv_msg+0x158/0xcf8 [ipmi_msghandler]
[  294.432050]  handle_new_recv_msgs+0xc0/0x210 [ipmi_msghandler]
[  294.441984]  smi_recv_tasklet+0x8c/0x158 [ipmi_msghandler]
[  294.451618]  tasklet_action_common.isra.5+0x88/0x138
[  294.460661]  tasklet_action+0x2c/0x38
[  294.468191]  __do_softirq+0x120/0x2f8
[  294.475561]  irq_exit+0x134/0x140
[  294.482445]  __handle_domain_irq+0x6c/0xc0
[  294.489954]  gic_handle_irq+0xb8/0x178
[  294.497037]  el1_irq+0xb0/0x140
[  294.503381]  arch_cpu_idle+0x34/0x1a8
[  294.510096]  do_idle+0x1d4/0x290
[  294.516322]  cpu_startup_entry+0x28/0x30
[  294.523230]  secondary_start_kernel+0x184/0x1d0
[  294.530657] Code: d538d082 d2800023 8b010c81 8b020021 (c85f7c25)
[  294.539746] ---[ end trace 8a7a880dee570b29 ]---
[  294.547341] Kernel panic - not syncing: Fatal exception in interrupt
[  294.556837] SMP: stopping secondary CPUs
[  294.563996] Kernel Offset: disabled
[  294.570515] CPU features: 0x002,21006008
[  294.577638] Memory Limit: none
[  294.587178] Starting crashdump kernel...
[  294.594314] Bye!

Because the user-&gt;release_barrier.rda is freed in ipmi_destroy_user(), but
the refcount is not zero, when acquire_ipmi_user() uses user-&gt;release_barrier.rda
in __srcu_read_lock(), it causes oops.
Fix this by calling cleanup_srcu_struct() when the refcount is zero.

Fixes: e86ee2d44b44 ("ipmi: Rework locking and shutdown for hot remove")
Cc: stable@vger.kernel.org # 4.18
Signed-off-by: Yang Yingliang &lt;yangyingliang@huawei.com&gt;
Signed-off-by: Corey Minyard &lt;cminyard@mvista.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
<entry>
<title>Bluetooth: Fix unnecessary error message for HCI request completion</title>
<updated>2019-01-26T08:20:51Z</updated>
<author>
<name>Johan Hedberg</name>
<email>johan.hedberg@intel.com</email>
</author>
<published>2018-11-27T09:37:46Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=062134e8fda0582d70eaf5a54b3fd5013005a0e3'/>
<id>urn:sha1:062134e8fda0582d70eaf5a54b3fd5013005a0e3</id>
<content type='text'>
commit 1629db9c75342325868243d6bca5853017d91cf8 upstream.

In case a command which completes in Command Status was sent using the
hci_cmd_send-family of APIs there would be a misleading error in the
hci_get_cmd_complete function, since the code would be trying to fetch
the Command Complete parameters when there are none.

Avoid the misleading error and silently bail out from the function in
case the received event is a command status.

Signed-off-by: Johan Hedberg &lt;johan.hedberg@intel.com&gt;
Acked-by: Luiz Augusto von Dentz &lt;luiz.von.dentz@intel.com&gt;
Signed-off-by: Marcel Holtmann &lt;marcel@holtmann.org&gt;
Tested-by Adam Ford &lt;aford173@gmail.com&gt; #4.19.16
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
<entry>
<title>drm/amd/display: Fix disabled cursor on top screen edge</title>
<updated>2019-01-26T08:20:51Z</updated>
<author>
<name>Nicholas Kazlauskas</name>
<email>nicholas.kazlauskas@amd.com</email>
</author>
<published>2018-12-11T17:35:56Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=a42242c709f6f2dec69a0ba960a24c0b92d4ef32'/>
<id>urn:sha1:a42242c709f6f2dec69a0ba960a24c0b92d4ef32</id>
<content type='text'>
commit ae1cf20df7a9c60ff5ef41c3315c33c1a5fafd77 upstream.

[Why]
The cursor vanishes when touching the top of edge of the screen for
Raven on Linux.

This occurs because the cursor height is not taken into account when
deciding to disable the cursor.

[How]
Factor in the cursor height into the cursor calculations - and mimic
the existing x position calculations.

Fixes: 94a4ffd1d40b ("drm/amd/display: fix PIP bugs on Dal3")

Signed-off-by: Nicholas Kazlauskas &lt;nicholas.kazlauskas@amd.com&gt;
Reviewed-by: Harry Wentland &lt;Harry.Wentland@amd.com&gt;
Acked-by: Leo Li &lt;sunpeng.li@amd.com&gt;
Signed-off-by: Alex Deucher &lt;alexander.deucher@amd.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
<entry>
<title>mm/memblock.c: skip kmemleak for kasan_init()</title>
<updated>2019-01-26T08:20:51Z</updated>
<author>
<name>Qian Cai</name>
<email>cai@gmx.us</email>
</author>
<published>2018-12-28T08:36:29Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=051b746c13773d29f4e8064f2769004a2d0e8c15'/>
<id>urn:sha1:051b746c13773d29f4e8064f2769004a2d0e8c15</id>
<content type='text'>
[ Upstream commit fed84c78527009d4f799a3ed9a566502fa026d82 ]

Kmemleak does not play well with KASAN (tested on both HPE Apollo 70 and
Huawei TaiShan 2280 aarch64 servers).

After calling start_kernel()-&gt;setup_arch()-&gt;kasan_init(), kmemleak early
log buffer went from something like 280 to 260000 which caused kmemleak
disabled and crash dump memory reservation failed.  The multitude of
kmemleak_alloc() calls is from nested loops while KASAN is setting up full
memory mappings, so let early kmemleak allocations skip those
memblock_alloc_internal() calls came from kasan_init() given that those
early KASAN memory mappings should not reference to other memory.  Hence,
no kmemleak false positives.

kasan_init
  kasan_map_populate [1]
    kasan_pgd_populate [2]
      kasan_pud_populate [3]
        kasan_pmd_populate [4]
          kasan_pte_populate [5]
            kasan_alloc_zeroed_page
              memblock_alloc_try_nid
                memblock_alloc_internal
                  kmemleak_alloc

[1] for_each_memblock(memory, reg)
[2] while (pgdp++, addr = next, addr != end)
[3] while (pudp++, addr = next, addr != end &amp;&amp; pud_none(READ_ONCE(*pudp)))
[4] while (pmdp++, addr = next, addr != end &amp;&amp; pmd_none(READ_ONCE(*pmdp)))
[5] while (ptep++, addr = next, addr != end &amp;&amp; pte_none(READ_ONCE(*ptep)))

Link: http://lkml.kernel.org/r/1543442925-17794-1-git-send-email-cai@gmx.us
Signed-off-by: Qian Cai &lt;cai@gmx.us&gt;
Acked-by: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
Cc: Michal Hocko &lt;mhocko@suse.com&gt;
Cc: Mike Rapoport &lt;rppt@linux.vnet.ibm.com&gt;
Cc: Alexander Potapenko &lt;glider@google.com&gt;
Cc: Dmitry Vyukov &lt;dvyukov@google.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: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>mm, proc: be more verbose about unstable VMA flags in /proc/&lt;pid&gt;/smaps</title>
<updated>2019-01-26T08:20:51Z</updated>
<author>
<name>Michal Hocko</name>
<email>mhocko@suse.com</email>
</author>
<published>2018-12-28T08:38:17Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=3e38d0057afb6c0cd990c90a1a92d539a93c36fb'/>
<id>urn:sha1:3e38d0057afb6c0cd990c90a1a92d539a93c36fb</id>
<content type='text'>
[ Upstream commit 7550c6079846a24f30d15ac75a941c8515dbedfb ]

Patch series "THP eligibility reporting via proc".

This series of three patches aims at making THP eligibility reporting much
more robust and long term sustainable.  The trigger for the change is a
regression report [2] and the long follow up discussion.  In short the
specific application didn't have good API to query whether a particular
mapping can be backed by THP so it has used VMA flags to workaround that.
These flags represent a deep internal state of VMAs and as such they
should be used by userspace with a great deal of caution.

A similar has happened for [3] when users complained that VM_MIXEDMAP is
no longer set on DAX mappings.  Again a lack of a proper API led to an
abuse.

The first patch in the series tries to emphasise that that the semantic of
flags might change and any application consuming those should be really
careful.

The remaining two patches provide a more suitable interface to address [2]
and provide a consistent API to query the THP status both for each VMA and
process wide as well.  [1]

http://lkml.kernel.org/r/20181120103515.25280-1-mhocko@kernel.org [2]
http://lkml.kernel.org/r/http://lkml.kernel.org/r/alpine.DEB.2.21.1809241054050.224429@chino.kir.corp.google.com
[3] http://lkml.kernel.org/r/20181002100531.GC4135@quack2.suse.cz

This patch (of 3):

Even though vma flags exported via /proc/&lt;pid&gt;/smaps are explicitly
documented to be not guaranteed for future compatibility the warning
doesn't go far enough because it doesn't mention semantic changes to those
flags.  And they are important as well because these flags are a deep
implementation internal to the MM code and the semantic might change at
any time.

Let's consider two recent examples:
http://lkml.kernel.org/r/20181002100531.GC4135@quack2.suse.cz
: commit e1fb4a086495 "dax: remove VM_MIXEDMAP for fsdax and device dax" has
: removed VM_MIXEDMAP flag from DAX VMAs. Now our testing shows that in the
: mean time certain customer of ours started poking into /proc/&lt;pid&gt;/smaps
: and looks at VMA flags there and if VM_MIXEDMAP is missing among the VMA
: flags, the application just fails to start complaining that DAX support is
: missing in the kernel.

http://lkml.kernel.org/r/alpine.DEB.2.21.1809241054050.224429@chino.kir.corp.google.com
: Commit 1860033237d4 ("mm: make PR_SET_THP_DISABLE immediately active")
: introduced a regression in that userspace cannot always determine the set
: of vmas where thp is ineligible.
: Userspace relies on the "nh" flag being emitted as part of /proc/pid/smaps
: to determine if a vma is eligible to be backed by hugepages.
: Previous to this commit, prctl(PR_SET_THP_DISABLE, 1) would cause thp to
: be disabled and emit "nh" as a flag for the corresponding vmas as part of
: /proc/pid/smaps.  After the commit, thp is disabled by means of an mm
: flag and "nh" is not emitted.
: This causes smaps parsing libraries to assume a vma is eligible for thp
: and ends up puzzling the user on why its memory is not backed by thp.

In both cases userspace was relying on a semantic of a specific VMA flag.
The primary reason why that happened is a lack of a proper interface.
While this has been worked on and it will be fixed properly, it seems that
our wording could see some refinement and be more vocal about semantic
aspect of these flags as well.

Link: http://lkml.kernel.org/r/20181211143641.3503-2-mhocko@kernel.org
Signed-off-by: Michal Hocko &lt;mhocko@suse.com&gt;
Acked-by: Jan Kara &lt;jack@suse.cz&gt;
Acked-by: Dan Williams &lt;dan.j.williams@intel.com&gt;
Acked-by: David Rientjes &lt;rientjes@google.com&gt;
Acked-by: Mike Rapoport &lt;rppt@linux.ibm.com&gt;
Acked-by: Vlastimil Babka &lt;vbabka@suse.cz&gt;
Cc: Dan Williams &lt;dan.j.williams@intel.com&gt;
Cc: David Rientjes &lt;rientjes@google.com&gt;
Cc: Paul Oppenheimer &lt;bepvte@gmail.com&gt;
Cc: William Kucharski &lt;william.kucharski@oracle.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: Sasha Levin &lt;sashal@kernel.org&gt;
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