<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/kernel/printk, branch master</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>Merge branch 'rework/prb-fixes' into for-linus</title>
<updated>2026-04-20T11:42:01+00:00</updated>
<author>
<name>Petr Mladek</name>
<email>pmladek@suse.com</email>
</author>
<published>2026-04-20T11:42:01+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=add9d911be9b141706ccf41d17b4043ed1bc12a1'/>
<id>add9d911be9b141706ccf41d17b4043ed1bc12a1</id>
<content type='text'>
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
</pre>
</div>
</content>
</entry>
<entry>
<title>printk: ringbuffer: fix errors in comments</title>
<updated>2026-03-31T15:40:23+00:00</updated>
<author>
<name>Loïc Grégoire</name>
<email>loicgre@gmail.com</email>
</author>
<published>2026-03-28T02:18:54+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=bf56987c111372a54ae877934a42f7fb0953a6ca'/>
<id>bf56987c111372a54ae877934a42f7fb0953a6ca</id>
<content type='text'>
The printk ringbuffer implementation is described in the comment as
using three ringbuffers, but the current implementation uses two (desc
and data). Update the comment so it matches the code.

Fix few more known issues in the comments.

Signed-off-by: Loïc Grégoire &lt;loicgre@gmail.com&gt;
Reviewed-by: John Ogness &lt;john.ogness@linutronix.de&gt;
Link: https://patch.msgid.link/20260328021855.53956-1-loicgre@gmail.com
[pmladek@suse.com: Fixed few more issues in the comments by John Ogness.]
Signed-off-by: John Ogness &lt;john.ogness@linutronix.de&gt;
Reviewed-by: Petr Mladek &lt;pmladek@suse.com&gt;
Signed-off-by: Petr Mladek &lt;pmladek@suse.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The printk ringbuffer implementation is described in the comment as
using three ringbuffers, but the current implementation uses two (desc
and data). Update the comment so it matches the code.

Fix few more known issues in the comments.

Signed-off-by: Loïc Grégoire &lt;loicgre@gmail.com&gt;
Reviewed-by: John Ogness &lt;john.ogness@linutronix.de&gt;
Link: https://patch.msgid.link/20260328021855.53956-1-loicgre@gmail.com
[pmladek@suse.com: Fixed few more issues in the comments by John Ogness.]
Signed-off-by: John Ogness &lt;john.ogness@linutronix.de&gt;
Reviewed-by: Petr Mladek &lt;pmladek@suse.com&gt;
Signed-off-by: Petr Mladek &lt;pmladek@suse.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>printk_ringbuffer: Add sanity check for 0-size data</title>
<updated>2026-03-27T16:12:37+00:00</updated>
<author>
<name>John Ogness</name>
<email>john.ogness@linutronix.de</email>
</author>
<published>2026-03-26T13:38:02+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=407f666db2b12c71744e5c897a74284768450578'/>
<id>407f666db2b12c71744e5c897a74284768450578</id>
<content type='text'>
get_data() has a sanity check for regular data blocks to ensure at
least space for the ID exists. But a regular block should also have
at least 1 byte of data (otherwise it would be data-less instead of
regular).

Expand the get_data() block size sanity check to additionally expect
at least 1 byte of data.

Signed-off-by: John Ogness &lt;john.ogness@linutronix.de&gt;
Reviewed-by: Petr Mladek &lt;pmladek@suse.com&gt;
Tested-by: Petr Mladek &lt;pmladek@suse.com&gt;
Link: https://patch.msgid.link/20260326133809.8045-2-john.ogness@linutronix.de
Signed-off-by: Petr Mladek &lt;pmladek@suse.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
get_data() has a sanity check for regular data blocks to ensure at
least space for the ID exists. But a regular block should also have
at least 1 byte of data (otherwise it would be data-less instead of
regular).

Expand the get_data() block size sanity check to additionally expect
at least 1 byte of data.

Signed-off-by: John Ogness &lt;john.ogness@linutronix.de&gt;
Reviewed-by: Petr Mladek &lt;pmladek@suse.com&gt;
Tested-by: Petr Mladek &lt;pmladek@suse.com&gt;
Link: https://patch.msgid.link/20260326133809.8045-2-john.ogness@linutronix.de
Signed-off-by: Petr Mladek &lt;pmladek@suse.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>printk_ringbuffer: Fix get_data() size sanity check</title>
<updated>2026-03-27T16:12:37+00:00</updated>
<author>
<name>John Ogness</name>
<email>john.ogness@linutronix.de</email>
</author>
<published>2026-03-26T13:38:01+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=8e81ecbf1cb46b8d2d13e772d5924b09bd60169a'/>
<id>8e81ecbf1cb46b8d2d13e772d5924b09bd60169a</id>
<content type='text'>
Commit cc3bad11de6e ("printk_ringbuffer: Fix check of valid data
size when blk_lpos overflows") added sanity checking to get_data()
to avoid returning data of illegal sizes (too large or too small).
It uses the helper function data_check_size() for the check.
However, data_check_size() expects the size of the data, not the
size of the data block. get_data() is providing the size of the
data block.  This means that if the data size (text_buf_size) is
at or near the maximum legal size:

sizeof(prb_data_block) + text_buf_size == DATA_SIZE(data_ring) / 2

data_check_size() will report failure because it adds
sizeof(prb_data_block) to the provided size. The sanity check in
get_data() is counting the data block header twice. The result is
that the reader fails to read the legal record.

Since get_data() subtracts the data block header size before returning,
move the sanity check to after the subtraction.

Luckily printk() is not vulnerable to this problem because
truncate_msg() limits printk-messages to 1/4 of the ringbuffer.
Indeed, by adjusting the printk_ringbuffer KUnit test, which does not
use printk() and its truncate_msg() check, it is easy to see that the
reader fails and the WARN_ON is triggered.

Fixes: cc3bad11de6e ("printk_ringbuffer: Fix check of valid data size when blk_lpos overflows")
Signed-off-by: John Ogness &lt;john.ogness@linutronix.de&gt;
Reviewed-by: Petr Mladek &lt;pmladek@suse.com&gt;
Tested-by: Petr Mladek &lt;pmladek@suse.com&gt;
Link: https://patch.msgid.link/20260326133809.8045-1-john.ogness@linutronix.de
Signed-off-by: Petr Mladek &lt;pmladek@suse.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Commit cc3bad11de6e ("printk_ringbuffer: Fix check of valid data
size when blk_lpos overflows") added sanity checking to get_data()
to avoid returning data of illegal sizes (too large or too small).
It uses the helper function data_check_size() for the check.
However, data_check_size() expects the size of the data, not the
size of the data block. get_data() is providing the size of the
data block.  This means that if the data size (text_buf_size) is
at or near the maximum legal size:

sizeof(prb_data_block) + text_buf_size == DATA_SIZE(data_ring) / 2

data_check_size() will report failure because it adds
sizeof(prb_data_block) to the provided size. The sanity check in
get_data() is counting the data block header twice. The result is
that the reader fails to read the legal record.

Since get_data() subtracts the data block header size before returning,
move the sanity check to after the subtraction.

Luckily printk() is not vulnerable to this problem because
truncate_msg() limits printk-messages to 1/4 of the ringbuffer.
Indeed, by adjusting the printk_ringbuffer KUnit test, which does not
use printk() and its truncate_msg() check, it is easy to see that the
reader fails and the WARN_ON is triggered.

Fixes: cc3bad11de6e ("printk_ringbuffer: Fix check of valid data size when blk_lpos overflows")
Signed-off-by: John Ogness &lt;john.ogness@linutronix.de&gt;
Reviewed-by: Petr Mladek &lt;pmladek@suse.com&gt;
Tested-by: Petr Mladek &lt;pmladek@suse.com&gt;
Link: https://patch.msgid.link/20260326133809.8045-1-john.ogness@linutronix.de
Signed-off-by: Petr Mladek &lt;pmladek@suse.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>printk: Fix _DESCS_COUNT type for 64-bit systems</title>
<updated>2026-03-10T15:58:05+00:00</updated>
<author>
<name>feng.zhou</name>
<email>realsummitzhou@gmail.com</email>
</author>
<published>2026-02-02T09:41:40+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=9095f233c0258e9a05e958c7d822eb38681e7a5a'/>
<id>9095f233c0258e9a05e958c7d822eb38681e7a5a</id>
<content type='text'>
The _DESCS_COUNT macro currently uses 1U (32-bit unsigned) instead of
1UL (unsigned long), which breaks the intended overflow testing design
on 64-bit systems.

Problem Analysis:
----------------
The printk_ringbuffer uses a deliberate design choice to initialize
descriptor IDs near the maximum 62-bit value to trigger overflow early
in the system's lifetime. This is documented in printk_ringbuffer.h:

  "initial values are chosen that map to the correct initial array
   indexes, but will result in overflows soon."

The DESC0_ID macro calculates:
  DESC0_ID(ct_bits) = DESC_ID(-(_DESCS_COUNT(ct_bits) + 1))

On 64-bit systems with typical configuration (descbits=16):
- Current buggy behavior: DESC0_ID = 0xfffeffff
- Expected behavior:      DESC0_ID = 0x3ffffffffffeffff

The buggy version only uses 32 bits, which means:
1. The initial ID is nowhere near 2^62
2. It would take ~140 trillion wraps to trigger 62-bit overflow
3. The overflow handling code is never tested in practice

Root Cause:
----------
The issue is in this line:
  #define _DESCS_COUNT(ct_bits)    (1U &lt;&lt; (ct_bits))

When _DESCS_COUNT(16) is calculated:
  1U &lt;&lt; 16 = 0x10000 (32-bit value)
  -(0x10000 + 1) = -0x10001 = 0xFFFEFFFF (32-bit two's complement)

On 64-bit systems, this 32-bit value doesn't get extended to create
the intended 62-bit ID near the maximum value.

Impact:
------
While index calculations still work correctly in the short term, this
bug has several implications:

1. Violates the design intention documented in the code
2. Overflow handling code paths remain untested
3. ABA detection code doesn't get exercised under overflow conditions
4. In extreme long-term running scenarios (though unlikely), could
   potentially cause issues when ID actually reaches 2^62

Verification:
------------
Tested on ARM64 system with CONFIG_LOG_BUF_SHIFT=20 (descbits=15):
- Before fix: DESC0_ID(16) = 0xfffeffff
- After fix:  DESC0_ID(16) = 0x3fffffffffff7fff

The fix aligns _DESCS_COUNT with _DATA_SIZE, which already correctly
uses 1UL:
  #define _DATA_SIZE(sz_bits)    (1UL &lt;&lt; (sz_bits))

Signed-off-by: feng.zhou &lt;realsummitzhou@gmail.com&gt;
Reviewed-by: Petr Mladek &lt;pmladek@suse.com&gt;
Tested-by: Petr Mladek &lt;pmladek@suse.com&gt;
Link: https://patch.msgid.link/20260202094140.9518-1-realsummitzhou@gmail.com
Signed-off-by: Petr Mladek &lt;pmladek@suse.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The _DESCS_COUNT macro currently uses 1U (32-bit unsigned) instead of
1UL (unsigned long), which breaks the intended overflow testing design
on 64-bit systems.

Problem Analysis:
----------------
The printk_ringbuffer uses a deliberate design choice to initialize
descriptor IDs near the maximum 62-bit value to trigger overflow early
in the system's lifetime. This is documented in printk_ringbuffer.h:

  "initial values are chosen that map to the correct initial array
   indexes, but will result in overflows soon."

The DESC0_ID macro calculates:
  DESC0_ID(ct_bits) = DESC_ID(-(_DESCS_COUNT(ct_bits) + 1))

On 64-bit systems with typical configuration (descbits=16):
- Current buggy behavior: DESC0_ID = 0xfffeffff
- Expected behavior:      DESC0_ID = 0x3ffffffffffeffff

The buggy version only uses 32 bits, which means:
1. The initial ID is nowhere near 2^62
2. It would take ~140 trillion wraps to trigger 62-bit overflow
3. The overflow handling code is never tested in practice

Root Cause:
----------
The issue is in this line:
  #define _DESCS_COUNT(ct_bits)    (1U &lt;&lt; (ct_bits))

When _DESCS_COUNT(16) is calculated:
  1U &lt;&lt; 16 = 0x10000 (32-bit value)
  -(0x10000 + 1) = -0x10001 = 0xFFFEFFFF (32-bit two's complement)

On 64-bit systems, this 32-bit value doesn't get extended to create
the intended 62-bit ID near the maximum value.

Impact:
------
While index calculations still work correctly in the short term, this
bug has several implications:

1. Violates the design intention documented in the code
2. Overflow handling code paths remain untested
3. ABA detection code doesn't get exercised under overflow conditions
4. In extreme long-term running scenarios (though unlikely), could
   potentially cause issues when ID actually reaches 2^62

Verification:
------------
Tested on ARM64 system with CONFIG_LOG_BUF_SHIFT=20 (descbits=15):
- Before fix: DESC0_ID(16) = 0xfffeffff
- After fix:  DESC0_ID(16) = 0x3fffffffffff7fff

The fix aligns _DESCS_COUNT with _DATA_SIZE, which already correctly
uses 1UL:
  #define _DATA_SIZE(sz_bits)    (1UL &lt;&lt; (sz_bits))

Signed-off-by: feng.zhou &lt;realsummitzhou@gmail.com&gt;
Reviewed-by: Petr Mladek &lt;pmladek@suse.com&gt;
Tested-by: Petr Mladek &lt;pmladek@suse.com&gt;
Link: https://patch.msgid.link/20260202094140.9518-1-realsummitzhou@gmail.com
Signed-off-by: Petr Mladek &lt;pmladek@suse.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Convert 'alloc_obj' family to use the new default GFP_KERNEL argument</title>
<updated>2026-02-22T01:09:51+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2026-02-22T00:37:42+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=bf4afc53b77aeaa48b5409da5c8da6bb4eff7f43'/>
<id>bf4afc53b77aeaa48b5409da5c8da6bb4eff7f43</id>
<content type='text'>
This was done entirely with mindless brute force, using

    git grep -l '\&lt;k[vmz]*alloc_objs*(.*, GFP_KERNEL)' |
        xargs sed -i 's/\(alloc_objs*(.*\), GFP_KERNEL)/\1)/'

to convert the new alloc_obj() users that had a simple GFP_KERNEL
argument to just drop that argument.

Note that due to the extreme simplicity of the scripting, any slightly
more complex cases spread over multiple lines would not be triggered:
they definitely exist, but this covers the vast bulk of the cases, and
the resulting diff is also then easier to check automatically.

For the same reason the 'flex' versions will be done as a separate
conversion.

Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
This was done entirely with mindless brute force, using

    git grep -l '\&lt;k[vmz]*alloc_objs*(.*, GFP_KERNEL)' |
        xargs sed -i 's/\(alloc_objs*(.*\), GFP_KERNEL)/\1)/'

to convert the new alloc_obj() users that had a simple GFP_KERNEL
argument to just drop that argument.

Note that due to the extreme simplicity of the scripting, any slightly
more complex cases spread over multiple lines would not be triggered:
they definitely exist, but this covers the vast bulk of the cases, and
the resulting diff is also then easier to check automatically.

For the same reason the 'flex' versions will be done as a separate
conversion.

Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>treewide: Replace kmalloc with kmalloc_obj for non-scalar types</title>
<updated>2026-02-21T09:02:28+00:00</updated>
<author>
<name>Kees Cook</name>
<email>kees@kernel.org</email>
</author>
<published>2026-02-21T07:49:23+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=69050f8d6d075dc01af7a5f2f550a8067510366f'/>
<id>69050f8d6d075dc01af7a5f2f550a8067510366f</id>
<content type='text'>
This is the result of running the Coccinelle script from
scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to
avoid scalar types (which need careful case-by-case checking), and
instead replace kmalloc-family calls that allocate struct or union
object instances:

Single allocations:	kmalloc(sizeof(TYPE), ...)
are replaced with:	kmalloc_obj(TYPE, ...)

Array allocations:	kmalloc_array(COUNT, sizeof(TYPE), ...)
are replaced with:	kmalloc_objs(TYPE, COUNT, ...)

Flex array allocations:	kmalloc(struct_size(PTR, FAM, COUNT), ...)
are replaced with:	kmalloc_flex(*PTR, FAM, COUNT, ...)

(where TYPE may also be *VAR)

The resulting allocations no longer return "void *", instead returning
"TYPE *".

Signed-off-by: Kees Cook &lt;kees@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
This is the result of running the Coccinelle script from
scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to
avoid scalar types (which need careful case-by-case checking), and
instead replace kmalloc-family calls that allocate struct or union
object instances:

Single allocations:	kmalloc(sizeof(TYPE), ...)
are replaced with:	kmalloc_obj(TYPE, ...)

Array allocations:	kmalloc_array(COUNT, sizeof(TYPE), ...)
are replaced with:	kmalloc_objs(TYPE, COUNT, ...)

Flex array allocations:	kmalloc(struct_size(PTR, FAM, COUNT), ...)
are replaced with:	kmalloc_flex(*PTR, FAM, COUNT, ...)

(where TYPE may also be *VAR)

The resulting allocations no longer return "void *", instead returning
"TYPE *".

Signed-off-by: Kees Cook &lt;kees@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'sysctl-7.00-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/sysctl/sysctl</title>
<updated>2026-02-18T18:45:36+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2026-02-18T18:45:36+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=23b0f90ba871f096474e1c27c3d14f455189d2d9'/>
<id>23b0f90ba871f096474e1c27c3d14f455189d2d9</id>
<content type='text'>
Pull sysctl updates from Joel Granados:

 - Remove macros from proc handler converters

   Replace the proc converter macros with "regular" functions. Though it
   is more verbose than the macro version, it helps when debugging and
   better aligns with coding-style.rst.

 - General cleanup

   Remove superfluous ctl_table forward declarations. Const qualify the
   memory_allocation_profiling_sysctl and loadpin_sysctl_table arrays.
   Add missing kernel doc to proc_dointvec_conv.

 - Testing

   This series was run through sysctl selftests/kunit test suite in
   x86_64. And went into linux-next after rc4, giving it a good 3 weeks
   of testing

* tag 'sysctl-7.00-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/sysctl/sysctl:
  sysctl: replace SYSCTL_INT_CONV_CUSTOM macro with functions
  sysctl: Replace unidirectional INT converter macros with functions
  sysctl: Add kernel doc to proc_douintvec_conv
  sysctl: Replace UINT converter macros with functions
  sysctl: Add CONFIG_PROC_SYSCTL guards for converter macros
  sysctl: clarify proc_douintvec_minmax doc
  sysctl: Return -ENOSYS from proc_douintvec_conv when CONFIG_PROC_SYSCTL=n
  sysctl: Remove unused ctl_table forward declarations
  loadpin: Implement custom proc_handler for enforce
  alloc_tag: move memory_allocation_profiling_sysctls into .rodata
  sysctl: Add missing kernel-doc for proc_dointvec_conv
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull sysctl updates from Joel Granados:

 - Remove macros from proc handler converters

   Replace the proc converter macros with "regular" functions. Though it
   is more verbose than the macro version, it helps when debugging and
   better aligns with coding-style.rst.

 - General cleanup

   Remove superfluous ctl_table forward declarations. Const qualify the
   memory_allocation_profiling_sysctl and loadpin_sysctl_table arrays.
   Add missing kernel doc to proc_dointvec_conv.

 - Testing

   This series was run through sysctl selftests/kunit test suite in
   x86_64. And went into linux-next after rc4, giving it a good 3 weeks
   of testing

* tag 'sysctl-7.00-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/sysctl/sysctl:
  sysctl: replace SYSCTL_INT_CONV_CUSTOM macro with functions
  sysctl: Replace unidirectional INT converter macros with functions
  sysctl: Add kernel doc to proc_douintvec_conv
  sysctl: Replace UINT converter macros with functions
  sysctl: Add CONFIG_PROC_SYSCTL guards for converter macros
  sysctl: clarify proc_douintvec_minmax doc
  sysctl: Return -ENOSYS from proc_douintvec_conv when CONFIG_PROC_SYSCTL=n
  sysctl: Remove unused ctl_table forward declarations
  loadpin: Implement custom proc_handler for enforce
  alloc_tag: move memory_allocation_profiling_sysctls into .rodata
  sysctl: Add missing kernel-doc for proc_dointvec_conv
</pre>
</div>
</content>
</entry>
<entry>
<title>printk, vt, fbcon: Remove console_conditional_schedule()</title>
<updated>2026-02-14T10:09:47+00:00</updated>
<author>
<name>Sebastian Andrzej Siewior</name>
<email>bigeasy@linutronix.de</email>
</author>
<published>2026-01-26T18:08:36+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=8e9bf8b9e8c0a3e1ef16dd48260a113f65ed01d2'/>
<id>8e9bf8b9e8c0a3e1ef16dd48260a113f65ed01d2</id>
<content type='text'>
do_con_write(), fbcon_redraw.*() invoke console_conditional_schedule()
which is a conditional scheduling point based on printk's internal
variables console_may_schedule. It may only be used if the console lock
is acquired for instance via console_lock() or console_trylock().

Prinkt sets the internal variable to 1 (and allows to schedule)
if the console lock has been acquired via console_lock(). The trylock
does not allow it.

The console_conditional_schedule() invocation in do_con_write() is
invoked shortly before console_unlock().
The console_conditional_schedule() invocation in fbcon_redraw.*()
original from fbcon_scroll() / vt's con_scroll() which originate from a
line feed.

In console_unlock() the variable is set to 0 (forbids to schedule) and
it tries to schedule while making progress printing. This is brand new
compared to when console_conditional_schedule() was added in v2.4.9.11.

In v2.6.38-rc3, console_unlock() (started its existence) iterated over
all consoles and flushed them with disabled interrupts. A scheduling
attempt here was not possible, it relied that a long print scheduled
before console_unlock().

Since commit 8d91f8b15361d ("printk: do cond_resched() between lines
while outputting to consoles"), which appeared in v4.5-rc1,
console_unlock() attempts to schedule if it was allowed to schedule
while during console_lock(). Each record is idealy one line so after
every line feed.

This console_conditional_schedule() is also only relevant on
PREEMPT_NONE and PREEMPT_VOLUNTARY builds. In other configurations
cond_resched() becomes a nop and has no impact.

I'm bringing this all up just proof that it is not required anymore. It
becomes a problem on a PREEMPT_RT build with debug code enabled because
that might_sleep() in cond_resched() remains and triggers a warnings.
This is due to

 legacy_kthread_func-&gt; console_flush_one_record -&gt;  vt_console_print-&gt; lf
   -&gt; con_scroll -&gt; fbcon_scroll

and vt_console_print() acquires a spinlock_t which does not allow a
voluntary schedule. There is no need to fb_scroll() to schedule since
console_flush_one_record() attempts to schedule after each line.
!PREEMPT_RT is not affected because the legacy printing thread is only
enabled on PREEMPT_RT builds.

Therefore I suggest to remove console_conditional_schedule().

Cc: Simona Vetter &lt;simona@ffwll.ch&gt;
Cc: Helge Deller &lt;deller@gmx.de&gt;
Cc: linux-fbdev@vger.kernel.org
Cc: dri-devel@lists.freedesktop.org
Fixes: 5f53ca3ff83b4 ("printk: Implement legacy printer kthread for PREEMPT_RT")
Signed-off-by: Sebastian Andrzej Siewior &lt;bigeasy@linutronix.de&gt;
Acked-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Acked-by: Petr Mladek &lt;pmladek@suse.com&gt; # from printk() POV
Signed-off-by: Helge Deller &lt;deller@gmx.de&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
do_con_write(), fbcon_redraw.*() invoke console_conditional_schedule()
which is a conditional scheduling point based on printk's internal
variables console_may_schedule. It may only be used if the console lock
is acquired for instance via console_lock() or console_trylock().

Prinkt sets the internal variable to 1 (and allows to schedule)
if the console lock has been acquired via console_lock(). The trylock
does not allow it.

The console_conditional_schedule() invocation in do_con_write() is
invoked shortly before console_unlock().
The console_conditional_schedule() invocation in fbcon_redraw.*()
original from fbcon_scroll() / vt's con_scroll() which originate from a
line feed.

In console_unlock() the variable is set to 0 (forbids to schedule) and
it tries to schedule while making progress printing. This is brand new
compared to when console_conditional_schedule() was added in v2.4.9.11.

In v2.6.38-rc3, console_unlock() (started its existence) iterated over
all consoles and flushed them with disabled interrupts. A scheduling
attempt here was not possible, it relied that a long print scheduled
before console_unlock().

Since commit 8d91f8b15361d ("printk: do cond_resched() between lines
while outputting to consoles"), which appeared in v4.5-rc1,
console_unlock() attempts to schedule if it was allowed to schedule
while during console_lock(). Each record is idealy one line so after
every line feed.

This console_conditional_schedule() is also only relevant on
PREEMPT_NONE and PREEMPT_VOLUNTARY builds. In other configurations
cond_resched() becomes a nop and has no impact.

I'm bringing this all up just proof that it is not required anymore. It
becomes a problem on a PREEMPT_RT build with debug code enabled because
that might_sleep() in cond_resched() remains and triggers a warnings.
This is due to

 legacy_kthread_func-&gt; console_flush_one_record -&gt;  vt_console_print-&gt; lf
   -&gt; con_scroll -&gt; fbcon_scroll

and vt_console_print() acquires a spinlock_t which does not allow a
voluntary schedule. There is no need to fb_scroll() to schedule since
console_flush_one_record() attempts to schedule after each line.
!PREEMPT_RT is not affected because the legacy printing thread is only
enabled on PREEMPT_RT builds.

Therefore I suggest to remove console_conditional_schedule().

Cc: Simona Vetter &lt;simona@ffwll.ch&gt;
Cc: Helge Deller &lt;deller@gmx.de&gt;
Cc: linux-fbdev@vger.kernel.org
Cc: dri-devel@lists.freedesktop.org
Fixes: 5f53ca3ff83b4 ("printk: Implement legacy printer kthread for PREEMPT_RT")
Signed-off-by: Sebastian Andrzej Siewior &lt;bigeasy@linutronix.de&gt;
Acked-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Acked-by: Petr Mladek &lt;pmladek@suse.com&gt; # from printk() POV
Signed-off-by: Helge Deller &lt;deller@gmx.de&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'net-next-7.0' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next</title>
<updated>2026-02-12T03:31:52+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2026-02-12T03:31:52+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=37a93dd5c49b5fda807fd204edf2547c3493319c'/>
<id>37a93dd5c49b5fda807fd204edf2547c3493319c</id>
<content type='text'>
Pull networking updates from Paolo Abeni:
 "Core &amp; protocols:

   - A significant effort all around the stack to guide the compiler to
     make the right choice when inlining code, to avoid unneeded calls
     for small helper and stack canary overhead in the fast-path.

     This generates better and faster code with very small or no text
     size increases, as in many cases the call generated more code than
     the actual inlined helper.

   - Extend AccECN implementation so that is now functionally complete,
     also allow the user-space enabling it on a per network namespace
     basis.

   - Add support for memory providers with large (above 4K) rx buffer.
     Paired with hw-gro, larger rx buffer sizes reduce the number of
     buffers traversing the stack, dincreasing single stream CPU usage
     by up to ~30%.

   - Do not add HBH header to Big TCP GSO packets. This simplifies the
     RX path, the TX path and the NIC drivers, and is possible because
     user-space taps can now interpret correctly such packets without
     the HBH hint.

   - Allow IPv6 routes to be configured with a gateway address that is
     resolved out of a different interface than the one specified,
     aligning IPv6 to IPv4 behavior.

   - Multi-queue aware sch_cake. This makes it possible to scale the
     rate shaper of sch_cake across multiple CPUs, while still enforcing
     a single global rate on the interface.

   - Add support for the nbcon (new buffer console) infrastructure to
     netconsole, enabling lock-free, priority-based console operations
     that are safer in crash scenarios.

   - Improve the TCP ipv6 output path to cache the flow information,
     saving cpu cycles, reducing cache line misses and stack use.

   - Improve netfilter packet tracker to resolve clashes for most
     protocols, avoiding unneeded drops on rare occasions.

   - Add IP6IP6 tunneling acceleration to the flowtable infrastructure.

   - Reduce tcp socket size by one cache line.

   - Notify neighbour changes atomically, avoiding inconsistencies
     between the notification sequence and the actual states sequence.

   - Add vsock namespace support, allowing complete isolation of vsocks
     across different network namespaces.

   - Improve xsk generic performances with cache-alignment-oriented
     optimizations.

   - Support netconsole automatic target recovery, allowing netconsole
     to reestablish targets when underlying low-level interface comes
     back online.

  Driver API:

   - Support for switching the working mode (automatic vs manual) of a
     DPLL device via netlink.

   - Introduce PHY ports representation to expose multiple front-facing
     media ports over a single MAC.

   - Introduce "rx-polarity" and "tx-polarity" device tree properties,
     to generalize polarity inversion requirements for differential
     signaling.

   - Add helper to create, prepare and enable managed clocks.

  Device drivers:

   - Add Huawei hinic3 PF etherner driver.

   - Add DWMAC glue driver for Motorcomm YT6801 PCIe ethernet
     controller.

   - Add ethernet driver for MaxLinear MxL862xx switches

   - Remove parallel-port Ethernet driver.

   - Convert existing driver timestamp configuration reporting to
     hwtstamp_get and remove legacy ioctl().

   - Convert existing drivers to .get_rx_ring_count(), simplifing the RX
     ring count retrieval. Also remove the legacy fallback path.

   - Ethernet high-speed NICs:
      - Broadcom (bnxt, bng):
         - bnxt: add FW interface update to support FEC stats histogram
           and NVRAM defragmentation
         - bng: add TSO and H/W GRO support
      - nVidia/Mellanox (mlx5):
         - improve latency of channel restart operations, reducing the
           used H/W resources
         - add TSO support for UDP over GRE over VLAN
         - add flow counters support for hardware steering (HWS) rules
         - use a static memory area to store headers for H/W GRO,
           leading to 12% RX tput improvement
      - Intel (100G, ice, idpf):
         - ice: reorganizes layout of Tx and Rx rings for cacheline
           locality and utilizes __cacheline_group* macros on the new
           layouts
         - ice: introduces Synchronous Ethernet (SyncE) support
      - Meta (fbnic):
         - adds debugfs for firmware mailbox and tx/rx rings vectors

   - Ethernet virtual:
      - geneve: introduce GRO/GSO support for double UDP encapsulation

   - Ethernet NICs consumer, and embedded:
      - Synopsys (stmmac):
         - some code refactoring and cleanups
      - RealTek (r8169):
         - add support for RTL8127ATF (10G Fiber SFP)
         - add dash and LTR support
      - Airoha:
         - AN8811HB 2.5 Gbps phy support
      - Freescale (fec):
         - add XDP zero-copy support
      - Thunderbolt:
         - add get link setting support to allow bonding
      - Renesas:
         - add support for RZ/G3L GBETH SoC

   - Ethernet switches:
      - Maxlinear:
         - support R(G)MII slow rate configuration
         - add support for Intel GSW150
      - Motorcomm (yt921x):
         - add DCB/QoS support
      - TI:
         - icssm-prueth: support bridging (STP/RSTP) via the switchdev
           framework

   - Ethernet PHYs:
      - Realtek:
         - enable SGMII and 2500Base-X in-band auto-negotiation
         - simplify and reunify C22/C45 drivers
      - Micrel: convert bindings to DT schema

   - CAN:
      - move skb headroom content into skb extensions, making CAN
        metadata access more robust

   - CAN drivers:
      - rcar_canfd:
         - add support for FD-only mode
         - add support for the RZ/T2H SoC
      - sja1000: cleanup the CAN state handling

   - WiFi:
      - implement EPPKE/802.1X over auth frames support
      - split up drop reasons better, removing generic RX_DROP
      - additional FTM capabilities: 6 GHz support, supported number of
        spatial streams and supported number of LTF repetitions
      - better mac80211 iterators to enumerate resources
      - initial UHR (Wi-Fi 8) support for cfg80211/mac80211

   - WiFi drivers:
      - Qualcomm/Atheros:
         - ath11k: support for Channel Frequency Response measurement
         - ath12k: a significant driver refactor to support multi-wiphy
           devices and and pave the way for future device support in the
           same driver (rather than splitting to ath13k)
         - ath12k: support for the QCC2072 chipset
      - Intel:
         - iwlwifi: partial Neighbor Awareness Networking (NAN) support
         - iwlwifi: initial support for U-NII-9 and IEEE 802.11bn
      - RealTek (rtw89):
         - preparations for RTL8922DE support

   - Bluetooth:
      - implement setsockopt(BT_PHY) to set the connection packet type/PHY
      - set link_policy on incoming ACL connections

   - Bluetooth drivers:
      - btusb: add support for MediaTek7920, Realtek RTL8761BU and 8851BE
      - btqca: add WCN6855 firmware priority selection feature"

* tag 'net-next-7.0' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1254 commits)
  bnge/bng_re: Add a new HSI
  net: macb: Fix tx/rx malfunction after phy link down and up
  af_unix: Fix memleak of newsk in unix_stream_connect().
  net: ti: icssg-prueth: Add optional dependency on HSR
  net: dsa: add basic initial driver for MxL862xx switches
  net: mdio: add unlocked mdiodev C45 bus accessors
  net: dsa: add tag format for MxL862xx switches
  dt-bindings: net: dsa: add MaxLinear MxL862xx
  selftests: drivers: net: hw: Modify toeplitz.c to poll for packets
  octeontx2-pf: Unregister devlink on probe failure
  net: renesas: rswitch: fix forwarding offload statemachine
  ionic: Rate limit unknown xcvr type messages
  tcp: inet6_csk_xmit() optimization
  tcp: populate inet-&gt;cork.fl.u.ip6 in tcp_v6_syn_recv_sock()
  tcp: populate inet-&gt;cork.fl.u.ip6 in tcp_v6_connect()
  ipv6: inet6_csk_xmit() and inet6_csk_update_pmtu() use inet-&gt;cork.fl.u.ip6
  ipv6: use inet-&gt;cork.fl.u.ip6 and np-&gt;final in ip6_datagram_dst_update()
  ipv6: use np-&gt;final in inet6_sk_rebuild_header()
  ipv6: add daddr/final storage in struct ipv6_pinfo
  net: stmmac: qcom-ethqos: fix qcom_ethqos_serdes_powerup()
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull networking updates from Paolo Abeni:
 "Core &amp; protocols:

   - A significant effort all around the stack to guide the compiler to
     make the right choice when inlining code, to avoid unneeded calls
     for small helper and stack canary overhead in the fast-path.

     This generates better and faster code with very small or no text
     size increases, as in many cases the call generated more code than
     the actual inlined helper.

   - Extend AccECN implementation so that is now functionally complete,
     also allow the user-space enabling it on a per network namespace
     basis.

   - Add support for memory providers with large (above 4K) rx buffer.
     Paired with hw-gro, larger rx buffer sizes reduce the number of
     buffers traversing the stack, dincreasing single stream CPU usage
     by up to ~30%.

   - Do not add HBH header to Big TCP GSO packets. This simplifies the
     RX path, the TX path and the NIC drivers, and is possible because
     user-space taps can now interpret correctly such packets without
     the HBH hint.

   - Allow IPv6 routes to be configured with a gateway address that is
     resolved out of a different interface than the one specified,
     aligning IPv6 to IPv4 behavior.

   - Multi-queue aware sch_cake. This makes it possible to scale the
     rate shaper of sch_cake across multiple CPUs, while still enforcing
     a single global rate on the interface.

   - Add support for the nbcon (new buffer console) infrastructure to
     netconsole, enabling lock-free, priority-based console operations
     that are safer in crash scenarios.

   - Improve the TCP ipv6 output path to cache the flow information,
     saving cpu cycles, reducing cache line misses and stack use.

   - Improve netfilter packet tracker to resolve clashes for most
     protocols, avoiding unneeded drops on rare occasions.

   - Add IP6IP6 tunneling acceleration to the flowtable infrastructure.

   - Reduce tcp socket size by one cache line.

   - Notify neighbour changes atomically, avoiding inconsistencies
     between the notification sequence and the actual states sequence.

   - Add vsock namespace support, allowing complete isolation of vsocks
     across different network namespaces.

   - Improve xsk generic performances with cache-alignment-oriented
     optimizations.

   - Support netconsole automatic target recovery, allowing netconsole
     to reestablish targets when underlying low-level interface comes
     back online.

  Driver API:

   - Support for switching the working mode (automatic vs manual) of a
     DPLL device via netlink.

   - Introduce PHY ports representation to expose multiple front-facing
     media ports over a single MAC.

   - Introduce "rx-polarity" and "tx-polarity" device tree properties,
     to generalize polarity inversion requirements for differential
     signaling.

   - Add helper to create, prepare and enable managed clocks.

  Device drivers:

   - Add Huawei hinic3 PF etherner driver.

   - Add DWMAC glue driver for Motorcomm YT6801 PCIe ethernet
     controller.

   - Add ethernet driver for MaxLinear MxL862xx switches

   - Remove parallel-port Ethernet driver.

   - Convert existing driver timestamp configuration reporting to
     hwtstamp_get and remove legacy ioctl().

   - Convert existing drivers to .get_rx_ring_count(), simplifing the RX
     ring count retrieval. Also remove the legacy fallback path.

   - Ethernet high-speed NICs:
      - Broadcom (bnxt, bng):
         - bnxt: add FW interface update to support FEC stats histogram
           and NVRAM defragmentation
         - bng: add TSO and H/W GRO support
      - nVidia/Mellanox (mlx5):
         - improve latency of channel restart operations, reducing the
           used H/W resources
         - add TSO support for UDP over GRE over VLAN
         - add flow counters support for hardware steering (HWS) rules
         - use a static memory area to store headers for H/W GRO,
           leading to 12% RX tput improvement
      - Intel (100G, ice, idpf):
         - ice: reorganizes layout of Tx and Rx rings for cacheline
           locality and utilizes __cacheline_group* macros on the new
           layouts
         - ice: introduces Synchronous Ethernet (SyncE) support
      - Meta (fbnic):
         - adds debugfs for firmware mailbox and tx/rx rings vectors

   - Ethernet virtual:
      - geneve: introduce GRO/GSO support for double UDP encapsulation

   - Ethernet NICs consumer, and embedded:
      - Synopsys (stmmac):
         - some code refactoring and cleanups
      - RealTek (r8169):
         - add support for RTL8127ATF (10G Fiber SFP)
         - add dash and LTR support
      - Airoha:
         - AN8811HB 2.5 Gbps phy support
      - Freescale (fec):
         - add XDP zero-copy support
      - Thunderbolt:
         - add get link setting support to allow bonding
      - Renesas:
         - add support for RZ/G3L GBETH SoC

   - Ethernet switches:
      - Maxlinear:
         - support R(G)MII slow rate configuration
         - add support for Intel GSW150
      - Motorcomm (yt921x):
         - add DCB/QoS support
      - TI:
         - icssm-prueth: support bridging (STP/RSTP) via the switchdev
           framework

   - Ethernet PHYs:
      - Realtek:
         - enable SGMII and 2500Base-X in-band auto-negotiation
         - simplify and reunify C22/C45 drivers
      - Micrel: convert bindings to DT schema

   - CAN:
      - move skb headroom content into skb extensions, making CAN
        metadata access more robust

   - CAN drivers:
      - rcar_canfd:
         - add support for FD-only mode
         - add support for the RZ/T2H SoC
      - sja1000: cleanup the CAN state handling

   - WiFi:
      - implement EPPKE/802.1X over auth frames support
      - split up drop reasons better, removing generic RX_DROP
      - additional FTM capabilities: 6 GHz support, supported number of
        spatial streams and supported number of LTF repetitions
      - better mac80211 iterators to enumerate resources
      - initial UHR (Wi-Fi 8) support for cfg80211/mac80211

   - WiFi drivers:
      - Qualcomm/Atheros:
         - ath11k: support for Channel Frequency Response measurement
         - ath12k: a significant driver refactor to support multi-wiphy
           devices and and pave the way for future device support in the
           same driver (rather than splitting to ath13k)
         - ath12k: support for the QCC2072 chipset
      - Intel:
         - iwlwifi: partial Neighbor Awareness Networking (NAN) support
         - iwlwifi: initial support for U-NII-9 and IEEE 802.11bn
      - RealTek (rtw89):
         - preparations for RTL8922DE support

   - Bluetooth:
      - implement setsockopt(BT_PHY) to set the connection packet type/PHY
      - set link_policy on incoming ACL connections

   - Bluetooth drivers:
      - btusb: add support for MediaTek7920, Realtek RTL8761BU and 8851BE
      - btqca: add WCN6855 firmware priority selection feature"

* tag 'net-next-7.0' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1254 commits)
  bnge/bng_re: Add a new HSI
  net: macb: Fix tx/rx malfunction after phy link down and up
  af_unix: Fix memleak of newsk in unix_stream_connect().
  net: ti: icssg-prueth: Add optional dependency on HSR
  net: dsa: add basic initial driver for MxL862xx switches
  net: mdio: add unlocked mdiodev C45 bus accessors
  net: dsa: add tag format for MxL862xx switches
  dt-bindings: net: dsa: add MaxLinear MxL862xx
  selftests: drivers: net: hw: Modify toeplitz.c to poll for packets
  octeontx2-pf: Unregister devlink on probe failure
  net: renesas: rswitch: fix forwarding offload statemachine
  ionic: Rate limit unknown xcvr type messages
  tcp: inet6_csk_xmit() optimization
  tcp: populate inet-&gt;cork.fl.u.ip6 in tcp_v6_syn_recv_sock()
  tcp: populate inet-&gt;cork.fl.u.ip6 in tcp_v6_connect()
  ipv6: inet6_csk_xmit() and inet6_csk_update_pmtu() use inet-&gt;cork.fl.u.ip6
  ipv6: use inet-&gt;cork.fl.u.ip6 and np-&gt;final in ip6_datagram_dst_update()
  ipv6: use np-&gt;final in inet6_sk_rebuild_header()
  ipv6: add daddr/final storage in struct ipv6_pinfo
  net: stmmac: qcom-ethqos: fix qcom_ethqos_serdes_powerup()
  ...
</pre>
</div>
</content>
</entry>
</feed>
