<feed xmlns='http://www.w3.org/2005/Atom'>
<title>kernel/linux.git/include, branch v4.19.315</title>
<subtitle>Linux kernel stable tree (mirror)</subtitle>
<id>https://git.radix-linux.su/kernel/linux.git/atom?h=v4.19.315</id>
<link rel='self' href='https://git.radix-linux.su/kernel/linux.git/atom?h=v4.19.315'/>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/'/>
<updated>2024-05-25T14:16:19+00:00</updated>
<entry>
<title>string.h: Add str_has_prefix() helper function</title>
<updated>2024-05-25T14:16:19+00:00</updated>
<author>
<name>Steven Rostedt (VMware)</name>
<email>rostedt@goodmis.org</email>
</author>
<published>2024-05-09T02:29:24+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=1415e7a48bb2a4418495fa2c6d94bbcb0b23ff33'/>
<id>urn:sha1:1415e7a48bb2a4418495fa2c6d94bbcb0b23ff33</id>
<content type='text'>
commit 72921427d46bf9731a1ab7864adc64c43dfae29f upstream.

A discussion came up in the trace triggers thread about converting a
bunch of:

 strncmp(str, "const", sizeof("const") - 1)

use cases into a helper macro. It started with:

	strncmp(str, const, sizeof(const) - 1)

But then Joe Perches mentioned that if a const is not used, the
sizeof() will be the size of a pointer, which can be bad. And that
gcc will optimize strlen("const") into "sizeof("const") - 1".

Thinking about this more, a quick grep in the kernel tree found several
(thousands!) of cases that use this construct. A quick grep also
revealed that there's probably several bugs in that use case. Some are
that people forgot the "- 1" (which I found) and others could be that
the constant for the sizeof is different than the constant (although, I
haven't found any of those, but I also didn't look hard).

I figured the best thing to do is to create a helper macro and place it
into include/linux/string.h. And go around and fix all the open coded
versions of it later.

Note, gcc appears to optimize this when we make it into an always_inline
static function, which removes a lot of issues that a macro produces.

Link: http://lkml.kernel.org/r/e3e754f2bd18e56eaa8baf79bee619316ebf4cfc.1545161087.git.tom.zanussi@linux.intel.com
Link: http://lkml.kernel.org/r/20181219211615.2298e781@gandalf.local.home
Link: http://lkml.kernel.org/r/CAHk-=wg_sR-UEC1ggmkZpypOUYanL5CMX4R7ceuaV4QMf5jBtg@mail.gmail.com

Cc: Tom Zanussi &lt;zanussi@kernel.org&gt;
Cc: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Acked-by: Namhyung Kim &lt;namhyung@kernel.org&gt;
Suggestions-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Suggestions-by: Joe Perches &lt;joe@perches.com&gt;
Suggestions-by: Andreas Schwab &lt;schwab@linux-m68k.org&gt;
Signed-off-by: Steven Rostedt (VMware) &lt;rostedt@goodmis.org&gt;
Signed-off-by: George Guo &lt;guodongtai@kylinos.cn&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>tracing: Consolidate trace_add/remove_event_call back to the nolock functions</title>
<updated>2024-05-25T14:16:19+00:00</updated>
<author>
<name>Steven Rostedt (VMware)</name>
<email>rostedt@goodmis.org</email>
</author>
<published>2024-05-09T02:29:23+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=13b957b785b0c58b99608c8b677368ed14e973ce'/>
<id>urn:sha1:13b957b785b0c58b99608c8b677368ed14e973ce</id>
<content type='text'>
commit 7e1413edd6194a9807aa5f3ac0378b9b4b9da879 upstream.

The trace_add/remove_event_call_nolock() functions were added to allow
the tace_add/remove_event_call() code be called when the event_mutex
lock was already taken. Now that all callers are done within the
event_mutex, there's no reason to have two different interfaces.

Remove the current wrapper trace_add/remove_event_call()s and rename the
_nolock versions back to the original names.

Link: http://lkml.kernel.org/r/154140866955.17322.2081425494660638846.stgit@devbox

Acked-by: Masami Hiramatsu &lt;mhiramat@kernel.org&gt;
Signed-off-by: Steven Rostedt (VMware) &lt;rostedt@goodmis.org&gt;
Signed-off-by: George Guo &lt;guodongtai@kylinos.cn&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>af_unix: Suppress false-positive lockdep splat for spin_lock() in __unix_gc().</title>
<updated>2024-05-17T09:42:43+00:00</updated>
<author>
<name>Kuniyuki Iwashima</name>
<email>kuniyu@amazon.com</email>
</author>
<published>2024-04-24T17:04:43+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=b29dcdd0582c00cd6ee0bd7c958d3639aa9db27f'/>
<id>urn:sha1:b29dcdd0582c00cd6ee0bd7c958d3639aa9db27f</id>
<content type='text'>
commit 1971d13ffa84a551d29a81fdf5b5ec5be166ac83 upstream.

syzbot reported a lockdep splat regarding unix_gc_lock and
unix_state_lock().

One is called from recvmsg() for a connected socket, and another
is called from GC for TCP_LISTEN socket.

So, the splat is false-positive.

Let's add a dedicated lock class for the latter to suppress the splat.

Note that this change is not necessary for net-next.git as the issue
is only applied to the old GC impl.

[0]:
WARNING: possible circular locking dependency detected
6.9.0-rc5-syzkaller-00007-g4d2008430ce8 #0 Not tainted
 -----------------------------------------------------
kworker/u8:1/11 is trying to acquire lock:
ffff88807cea4e70 (&amp;u-&gt;lock){+.+.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline]
ffff88807cea4e70 (&amp;u-&gt;lock){+.+.}-{2:2}, at: __unix_gc+0x40e/0xf70 net/unix/garbage.c:302

but task is already holding lock:
ffffffff8f6ab638 (unix_gc_lock){+.+.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline]
ffffffff8f6ab638 (unix_gc_lock){+.+.}-{2:2}, at: __unix_gc+0x117/0xf70 net/unix/garbage.c:261

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

 -&gt; #1 (unix_gc_lock){+.+.}-{2:2}:
       lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5754
       __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
       _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154
       spin_lock include/linux/spinlock.h:351 [inline]
       unix_notinflight+0x13d/0x390 net/unix/garbage.c:140
       unix_detach_fds net/unix/af_unix.c:1819 [inline]
       unix_destruct_scm+0x221/0x350 net/unix/af_unix.c:1876
       skb_release_head_state+0x100/0x250 net/core/skbuff.c:1188
       skb_release_all net/core/skbuff.c:1200 [inline]
       __kfree_skb net/core/skbuff.c:1216 [inline]
       kfree_skb_reason+0x16d/0x3b0 net/core/skbuff.c:1252
       kfree_skb include/linux/skbuff.h:1262 [inline]
       manage_oob net/unix/af_unix.c:2672 [inline]
       unix_stream_read_generic+0x1125/0x2700 net/unix/af_unix.c:2749
       unix_stream_splice_read+0x239/0x320 net/unix/af_unix.c:2981
       do_splice_read fs/splice.c:985 [inline]
       splice_file_to_pipe+0x299/0x500 fs/splice.c:1295
       do_splice+0xf2d/0x1880 fs/splice.c:1379
       __do_splice fs/splice.c:1436 [inline]
       __do_sys_splice fs/splice.c:1652 [inline]
       __se_sys_splice+0x331/0x4a0 fs/splice.c:1634
       do_syscall_x64 arch/x86/entry/common.c:52 [inline]
       do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

 -&gt; #0 (&amp;u-&gt;lock){+.+.}-{2:2}:
       check_prev_add kernel/locking/lockdep.c:3134 [inline]
       check_prevs_add kernel/locking/lockdep.c:3253 [inline]
       validate_chain+0x18cb/0x58e0 kernel/locking/lockdep.c:3869
       __lock_acquire+0x1346/0x1fd0 kernel/locking/lockdep.c:5137
       lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5754
       __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
       _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154
       spin_lock include/linux/spinlock.h:351 [inline]
       __unix_gc+0x40e/0xf70 net/unix/garbage.c:302
       process_one_work kernel/workqueue.c:3254 [inline]
       process_scheduled_works+0xa10/0x17c0 kernel/workqueue.c:3335
       worker_thread+0x86d/0xd70 kernel/workqueue.c:3416
       kthread+0x2f0/0x390 kernel/kthread.c:388
       ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
       ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

other info that might help us debug this:

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(unix_gc_lock);
                               lock(&amp;u-&gt;lock);
                               lock(unix_gc_lock);
  lock(&amp;u-&gt;lock);

 *** DEADLOCK ***

3 locks held by kworker/u8:1/11:
 #0: ffff888015089148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3229 [inline]
 #0: ffff888015089148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x8e0/0x17c0 kernel/workqueue.c:3335
 #1: ffffc90000107d00 (unix_gc_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3230 [inline]
 #1: ffffc90000107d00 (unix_gc_work){+.+.}-{0:0}, at: process_scheduled_works+0x91b/0x17c0 kernel/workqueue.c:3335
 #2: ffffffff8f6ab638 (unix_gc_lock){+.+.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline]
 #2: ffffffff8f6ab638 (unix_gc_lock){+.+.}-{2:2}, at: __unix_gc+0x117/0xf70 net/unix/garbage.c:261

stack backtrace:
CPU: 0 PID: 11 Comm: kworker/u8:1 Not tainted 6.9.0-rc5-syzkaller-00007-g4d2008430ce8 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
Workqueue: events_unbound __unix_gc
Call Trace:
 &lt;TASK&gt;
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114
 check_noncircular+0x36a/0x4a0 kernel/locking/lockdep.c:2187
 check_prev_add kernel/locking/lockdep.c:3134 [inline]
 check_prevs_add kernel/locking/lockdep.c:3253 [inline]
 validate_chain+0x18cb/0x58e0 kernel/locking/lockdep.c:3869
 __lock_acquire+0x1346/0x1fd0 kernel/locking/lockdep.c:5137
 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5754
 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
 _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154
 spin_lock include/linux/spinlock.h:351 [inline]
 __unix_gc+0x40e/0xf70 net/unix/garbage.c:302
 process_one_work kernel/workqueue.c:3254 [inline]
 process_scheduled_works+0xa10/0x17c0 kernel/workqueue.c:3335
 worker_thread+0x86d/0xd70 kernel/workqueue.c:3416
 kthread+0x2f0/0x390 kernel/kthread.c:388
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 &lt;/TASK&gt;

Fixes: 47d8ac011fe1 ("af_unix: Fix garbage collector racing against connect()")
Reported-and-tested-by: syzbot+fa379358c28cc87cc307@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=fa379358c28cc87cc307
Signed-off-by: Kuniyuki Iwashima &lt;kuniyu@amazon.com&gt;
Link: https://lore.kernel.org/r/20240424170443.9832-1-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>af_unix: Do not use atomic ops for unix_sk(sk)-&gt;inflight.</title>
<updated>2024-05-17T09:42:42+00:00</updated>
<author>
<name>Kuniyuki Iwashima</name>
<email>kuniyu@amazon.com</email>
</author>
<published>2024-01-23T17:08:53+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=c8a2b1f7208b0ea0a4ad4355e0510d84f508a9ff'/>
<id>urn:sha1:c8a2b1f7208b0ea0a4ad4355e0510d84f508a9ff</id>
<content type='text'>
[ Upstream commit 97af84a6bba2ab2b9c704c08e67de3b5ea551bb2 ]

When touching unix_sk(sk)-&gt;inflight, we are always under
spin_lock(&amp;unix_gc_lock).

Let's convert unix_sk(sk)-&gt;inflight to the normal unsigned long.

Signed-off-by: Kuniyuki Iwashima &lt;kuniyu@amazon.com&gt;
Reviewed-by: Simon Horman &lt;horms@kernel.org&gt;
Link: https://lore.kernel.org/r/20240123170856.41348-3-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>ethernet: Add helper for assigning packet type when dest address does not match device address</title>
<updated>2024-05-17T09:42:37+00:00</updated>
<author>
<name>Rahul Rameshbabu</name>
<email>rrameshbabu@nvidia.com</email>
</author>
<published>2024-04-23T18:13:03+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=3d63a6c77b51c1a7cef2987a7f70ec9d91b04d95'/>
<id>urn:sha1:3d63a6c77b51c1a7cef2987a7f70ec9d91b04d95</id>
<content type='text'>
[ Upstream commit 6e159fd653d7ebf6290358e0330a0cb8a75cf73b ]

Enable reuse of logic in eth_type_trans for determining packet type.

Suggested-by: Sabrina Dubroca &lt;sd@queasysnail.net&gt;
Cc: stable@vger.kernel.org
Signed-off-by: Rahul Rameshbabu &lt;rrameshbabu@nvidia.com&gt;
Reviewed-by: Sabrina Dubroca &lt;sd@queasysnail.net&gt;
Link: https://lore.kernel.org/r/20240423181319.115860-3-rrameshbabu@nvidia.com
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>ethernet: add a helper for assigning port addresses</title>
<updated>2024-05-17T09:42:37+00:00</updated>
<author>
<name>Jakub Kicinski</name>
<email>kuba@kernel.org</email>
</author>
<published>2021-10-18T21:10:02+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=51fcea1b7c52abc3ff5af354e199731582a34ebf'/>
<id>urn:sha1:51fcea1b7c52abc3ff5af354e199731582a34ebf</id>
<content type='text'>
[ Upstream commit e80094a473eefad9d856ce3ab0d7afdbb64800c4 ]

We have 5 drivers which offset base MAC addr by port id.
Create a helper for them.

This helper takes care of overflows, which some drivers
did not do, please complain if that's going to break
anything!

Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
Reviewed-by: Vladimir Oltean &lt;vladimir.oltean@nxp.com&gt;
Reviewed-by: Shannon Nelson &lt;snelson@pensando.io&gt;
Reviewed-by: Ido Schimmel &lt;idosch@nvidia.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Stable-dep-of: 6e159fd653d7 ("ethernet: Add helper for assigning packet type when dest address does not match device address")
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>serial: core: fix kernel-doc for uart_port_unlock_irqrestore()</title>
<updated>2024-05-02T14:17:14+00:00</updated>
<author>
<name>Randy Dunlap</name>
<email>rdunlap@infradead.org</email>
</author>
<published>2023-09-27T04:41:28+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=6e5937b23a13ce6bbe8bf17319efa34598f1650a'/>
<id>urn:sha1:6e5937b23a13ce6bbe8bf17319efa34598f1650a</id>
<content type='text'>
commit 29bff582b74ed0bdb7e6986482ad9e6799ea4d2f upstream.

Fix the function name to avoid a kernel-doc warning:

include/linux/serial_core.h:666: warning: expecting prototype for uart_port_lock_irqrestore(). Prototype was for uart_port_unlock_irqrestore() instead

Fixes: b0af4bcb4946 ("serial: core: Provide port lock wrappers")
Signed-off-by: Randy Dunlap &lt;rdunlap@infradead.org&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: John Ogness &lt;john.ogness@linutronix.de&gt;
Cc: linux-serial@vger.kernel.org
Cc: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Cc: Jiri Slaby &lt;jirislaby@kernel.org&gt;
Reviewed-by: John Ogness &lt;john.ogness@linutronix.de&gt;
Link: https://lore.kernel.org/r/20230927044128.4748-1-rdunlap@infradead.org
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>Revert "y2038: rusage: use __kernel_old_timeval"</title>
<updated>2024-05-02T14:17:14+00:00</updated>
<author>
<name>Ben Hutchings</name>
<email>ben@decadent.org.uk</email>
</author>
<published>2024-04-29T21:44:50+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=271b53d629d6329f1d99177b0590dce7c3cbf28b'/>
<id>urn:sha1:271b53d629d6329f1d99177b0590dce7c3cbf28b</id>
<content type='text'>
This reverts commit d5e38d6b84d6d21a4f8a4f555a0908b6d9ffe224, which
was commit bdd565f817a74b9e30edec108f7cb1dbc762b8a6 upstream.  It
broke the build for alpha and that can't be fixed without backporting
other more intrusive y2038 changes.

This was not a completely clean revert as the affected code in
getrusage() was moved by subsequent changes.

Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>tracing: Increase PERF_MAX_TRACE_SIZE to handle Sentinel1 and docker together</title>
<updated>2024-05-02T14:17:13+00:00</updated>
<author>
<name>Robin H. Johnson</name>
<email>robbat2@gentoo.org</email>
</author>
<published>2021-08-31T04:37:23+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=c8d5402dcd1834747bb3dbd9b6fe51defd3d636b'/>
<id>urn:sha1:c8d5402dcd1834747bb3dbd9b6fe51defd3d636b</id>
<content type='text'>
commit e531e90b5ab0f7ce5ff298e165214c1aec6ed187 upstream.

Running endpoint security solutions like Sentinel1 that use perf-based
tracing heavily lead to this repeated dump complaining about dockerd.
The default value of 2048 is nowhere near not large enough.

Using the prior patch "tracing: show size of requested buffer", we get
"perf buffer not large enough, wanted 6644, have 6144", after repeated
up-sizing (I did 2/4/6/8K). With 8K, the problem doesn't occur at all,
so below is the trace for 6K.

I'm wondering if this value should be selectable at boot time, but this
is a good starting point.

```
------------[ cut here ]------------
perf buffer not large enough, wanted 6644, have 6144
WARNING: CPU: 1 PID: 4997 at kernel/trace/trace_event_perf.c:402 perf_trace_buf_alloc+0x8c/0xa0
Modules linked in: [..]
CPU: 1 PID: 4997 Comm: sh Tainted: G                T 5.13.13-x86_64-00039-gb3959163488e #63
Hardware name: LENOVO 20KH002JUS/20KH002JUS, BIOS N23ET66W (1.41 ) 09/02/2019
RIP: 0010:perf_trace_buf_alloc+0x8c/0xa0
Code: 80 3d 43 97 d0 01 00 74 07 31 c0 5b 5d 41 5c c3 ba 00 18 00 00 89 ee 48 c7 c7 00 82 7d 91 c6 05 25 97 d0 01 01 e8 22 ee bc 00 &lt;0f&gt; 0b 31 c0 eb db 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 55 89
RSP: 0018:ffffb922026b7d58 EFLAGS: 00010282
RAX: 0000000000000000 RBX: ffff9da5ee012000 RCX: 0000000000000027
RDX: ffff9da881657828 RSI: 0000000000000001 RDI: ffff9da881657820
RBP: 00000000000019f4 R08: 0000000000000000 R09: ffffb922026b7b80
R10: ffffb922026b7b78 R11: ffffffff91dda688 R12: 000000000000000f
R13: ffff9da5ee012108 R14: ffff9da8816570a0 R15: ffffb922026b7e30
FS:  00007f420db1a080(0000) GS:ffff9da881640000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000060 CR3: 00000002504a8006 CR4: 00000000003706e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 kprobe_perf_func+0x11e/0x270
 ? do_execveat_common.isra.0+0x1/0x1c0
 ? do_execveat_common.isra.0+0x5/0x1c0
 kprobe_ftrace_handler+0x10e/0x1d0
 0xffffffffc03aa0c8
 ? do_execveat_common.isra.0+0x1/0x1c0
 do_execveat_common.isra.0+0x5/0x1c0
 __x64_sys_execve+0x33/0x40
 do_syscall_64+0x6b/0xc0
 ? do_syscall_64+0x11/0xc0
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7f420dc1db37
Code: ff ff 76 e7 f7 d8 64 41 89 00 eb df 0f 1f 80 00 00 00 00 f7 d8 64 41 89 00 eb dc 0f 1f 84 00 00 00 00 00 b8 3b 00 00 00 0f 05 &lt;48&gt; 3d 01 f0 ff ff 73 01 c3 48 8b 0d 01 43 0f 00 f7 d8 64 89 01 48
RSP: 002b:00007ffd4e8b4e38 EFLAGS: 00000246 ORIG_RAX: 000000000000003b
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f420dc1db37
RDX: 0000564338d1e740 RSI: 0000564338d32d50 RDI: 0000564338d28f00
RBP: 0000564338d28f00 R08: 0000564338d32d50 R09: 0000000000000020
R10: 00000000000001b6 R11: 0000000000000246 R12: 0000564338d28f00
R13: 0000564338d32d50 R14: 0000564338d1e740 R15: 0000564338d28c60
---[ end trace 83ab3e8e16275e49 ]---
```

Link: https://lkml.kernel.org/r/20210831043723.13481-2-robbat2@gentoo.org

Signed-off-by: Robin H. Johnson &lt;robbat2@gentoo.org&gt;
Signed-off-by: Steven Rostedt (VMware) &lt;rostedt@goodmis.org&gt;
Signed-off-by: Thadeu Lima de Souza Cascardo &lt;cascardo@igalia.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>serial: core: Provide port lock wrappers</title>
<updated>2024-05-02T14:17:12+00:00</updated>
<author>
<name>Thomas Gleixner</name>
<email>tglx@linutronix.de</email>
</author>
<published>2023-09-14T18:37:18+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=dcc8ed283f841e217ad23a65453f7b8c6068d6c5'/>
<id>urn:sha1:dcc8ed283f841e217ad23a65453f7b8c6068d6c5</id>
<content type='text'>
[ Upstream commit b0af4bcb49464c221ad5f95d40f2b1b252ceedcc ]

When a serial port is used for kernel console output, then all
modifications to the UART registers which are done from other contexts,
e.g. getty, termios, are interference points for the kernel console.

So far this has been ignored and the printk output is based on the
principle of hope. The rework of the console infrastructure which aims to
support threaded and atomic consoles, requires to mark sections which
modify the UART registers as unsafe. This allows the atomic write function
to make informed decisions and eventually to restore operational state. It
also allows to prevent the regular UART code from modifying UART registers
while printk output is in progress.

All modifications of UART registers are guarded by the UART port lock,
which provides an obvious synchronization point with the console
infrastructure.

Provide wrapper functions for spin_[un]lock*(port-&gt;lock) invocations so
that the console mechanics can be applied later on at a single place and
does not require to copy the same logic all over the drivers.

Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Reviewed-by: Ilpo Järvinen &lt;ilpo.jarvinen@linux.intel.com&gt;
Signed-off-by: John Ogness &lt;john.ogness@linutronix.de&gt;
Link: https://lore.kernel.org/r/20230914183831.587273-2-john.ogness@linutronix.de
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Stable-dep-of: 54c4ec5f8c47 ("serial: mxs-auart: add spinlock around changing cts state")
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
</feed>
