<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux.git/kernel/printk/nbcon.c, branch v7.1</title>
<subtitle>Linux kernel source tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/'/>
<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.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.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 '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.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>
<entry>
<title>Merge branch 'for-6.20' into for-linus</title>
<updated>2026-02-11T09:14:35+00:00</updated>
<author>
<name>Petr Mladek</name>
<email>pmladek@suse.com</email>
</author>
<published>2026-02-11T09:14:35+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=9abbecf408cba09d73d14f044e1bc12ab7776da0'/>
<id>9abbecf408cba09d73d14f044e1bc12ab7776da0</id>
<content type='text'>
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
</pre>
</div>
</content>
</entry>
<entry>
<title>printk: Add execution context (task name/CPU) to printk_info</title>
<updated>2026-02-11T03:51:56+00:00</updated>
<author>
<name>Breno Leitao</name>
<email>leitao@debian.org</email>
</author>
<published>2026-02-06T12:45:29+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=60325c27d3cfe13466f6d6aa882b11bdd1c58cc8'/>
<id>60325c27d3cfe13466f6d6aa882b11bdd1c58cc8</id>
<content type='text'>
Extend struct printk_info to include the task name, pid, and CPU
number where printk messages originate. This information is captured
at vprintk_store() time and propagated through printk_message to
nbcon_write_context, making it available to nbcon console drivers.

This is useful for consoles like netconsole that want to include
execution context in their output, allowing correlation of messages
with specific tasks and CPUs regardless of where the console driver
actually runs.

The feature is controlled by CONFIG_PRINTK_EXECUTION_CTX, which is
automatically selected by CONFIG_NETCONSOLE_DYNAMIC. When disabled,
the helper functions compile to no-ops with no overhead.

Suggested-by: John Ogness &lt;john.ogness@linutronix.de&gt;
Signed-off-by: Petr Mladek &lt;pmladek@suse.com&gt;
Reviewed-by: Petr Mladek &lt;pmladek@suse.com&gt;
Signed-off-by: Breno Leitao &lt;leitao@debian.org&gt;
Reviewed-by: John Ogness &lt;john.ogness@linutronix.de&gt;
Link: https://patch.msgid.link/20260206-nbcon-v7-1-62bda69b1b41@debian.org
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Extend struct printk_info to include the task name, pid, and CPU
number where printk messages originate. This information is captured
at vprintk_store() time and propagated through printk_message to
nbcon_write_context, making it available to nbcon console drivers.

This is useful for consoles like netconsole that want to include
execution context in their output, allowing correlation of messages
with specific tasks and CPUs regardless of where the console driver
actually runs.

The feature is controlled by CONFIG_PRINTK_EXECUTION_CTX, which is
automatically selected by CONFIG_NETCONSOLE_DYNAMIC. When disabled,
the helper functions compile to no-ops with no overhead.

Suggested-by: John Ogness &lt;john.ogness@linutronix.de&gt;
Signed-off-by: Petr Mladek &lt;pmladek@suse.com&gt;
Reviewed-by: Petr Mladek &lt;pmladek@suse.com&gt;
Signed-off-by: Breno Leitao &lt;leitao@debian.org&gt;
Reviewed-by: John Ogness &lt;john.ogness@linutronix.de&gt;
Link: https://patch.msgid.link/20260206-nbcon-v7-1-62bda69b1b41@debian.org
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>printk/nbcon: Restore IRQ in atomic flush after each emitted record</title>
<updated>2025-12-15T15:18:41+00:00</updated>
<author>
<name>Petr Mladek</name>
<email>pmladek@suse.com</email>
</author>
<published>2025-12-12T12:45:20+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=9bd18e1262c0fec6d76ffe6e2eae2b5f6cc08e3e'/>
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The commit d5d399efff6577 ("printk/nbcon: Release nbcon consoles ownership
in atomic flush after each emitted record") prevented stall of a CPU
which lost nbcon console ownership because another CPU entered
an emergency flush.

But there is still the problem that the CPU doing the emergency flush
might cause a stall on its own.

Let's go even further and restore IRQ in the atomic flush after
each emitted record.

It is not a complete solution. The interrupts and/or scheduling might
still be blocked when the emergency atomic flush was called with
IRQs and/or scheduling disabled. But it should remove the following
lockup:

  mlx5_core 0000:03:00.0: Shutdown was called
  kvm: exiting hardware virtualization
  arm-smmu-v3 arm-smmu-v3.10.auto: CMD_SYNC timeout at 0x00000103 [hwprod 0x00000104, hwcons 0x00000102]
  smp: csd: Detected non-responsive CSD lock (#1) on CPU#4, waiting 5000000032 ns for CPU#00 do_nothing (kernel/smp.c:1057)
  smp:     csd: CSD lock (#1) unresponsive.
  [...]
  Call trace:
  pl011_console_write_atomic (./arch/arm64/include/asm/vdso/processor.h:12 drivers/tty/serial/amba-pl011.c:2540) (P)
  nbcon_emit_next_record (kernel/printk/nbcon.c:1049)
  __nbcon_atomic_flush_pending_con (kernel/printk/nbcon.c:1517)
  __nbcon_atomic_flush_pending.llvm.15488114865160659019 (./arch/arm64/include/asm/alternative-macros.h:254 ./arch/arm64/include/asm/cpufeature.h:808 ./arch/arm64/include/asm/irqflags.h:192 kernel/printk/nbcon.c:1562 kernel/printk/nbcon.c:1612)
  nbcon_atomic_flush_pending (kernel/printk/nbcon.c:1629)
  printk_kthreads_shutdown (kernel/printk/printk.c:?)
  syscore_shutdown (drivers/base/syscore.c:120)
  kernel_kexec (kernel/kexec_core.c:1045)
  __arm64_sys_reboot (kernel/reboot.c:794 kernel/reboot.c:722 kernel/reboot.c:722)
  invoke_syscall (arch/arm64/kernel/syscall.c:50)
  el0_svc_common.llvm.14158405452757855239 (arch/arm64/kernel/syscall.c:?)
  do_el0_svc (arch/arm64/kernel/syscall.c:152)
  el0_svc (./arch/arm64/include/asm/alternative-macros.h:254 ./arch/arm64/include/asm/cpufeature.h:808 ./arch/arm64/include/asm/irqflags.h:73 arch/arm64/kernel/entry-common.c:169 arch/arm64/kernel/entry-common.c:182 arch/arm64/kernel/entry-common.c:749)
  el0t_64_sync_handler (arch/arm64/kernel/entry-common.c:820)
  el0t_64_sync (arch/arm64/kernel/entry.S:600)

In this case, nbcon_atomic_flush_pending() is called from
printk_kthreads_shutdown() with IRQs and scheduling enabled.

Note that __nbcon_atomic_flush_pending_con() is directly called also from
nbcon_device_release() where the disabled IRQs might break PREEMPT_RT
guarantees. But the atomic flush is called only in emergency or panic
situations where the latencies are irrelevant anyway.

An ultimate solution would be a touching of watchdogs. But it would hide
all problems. Let's do it later when anyone reports a stall which does
not have a better solution.

Closes: https://lore.kernel.org/r/sqwajvt7utnt463tzxgwu2yctyn5m6bjwrslsnupfexeml6hkd@v6sqmpbu3vvu
Tested-by: Breno Leitao &lt;leitao@debian.org&gt;
Reviewed-by: John Ogness &lt;john.ogness@linutronix.de&gt;
Link: https://patch.msgid.link/20251212124520.244483-1-pmladek@suse.com
Signed-off-by: Petr Mladek &lt;pmladek@suse.com&gt;
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<pre>
The commit d5d399efff6577 ("printk/nbcon: Release nbcon consoles ownership
in atomic flush after each emitted record") prevented stall of a CPU
which lost nbcon console ownership because another CPU entered
an emergency flush.

But there is still the problem that the CPU doing the emergency flush
might cause a stall on its own.

Let's go even further and restore IRQ in the atomic flush after
each emitted record.

It is not a complete solution. The interrupts and/or scheduling might
still be blocked when the emergency atomic flush was called with
IRQs and/or scheduling disabled. But it should remove the following
lockup:

  mlx5_core 0000:03:00.0: Shutdown was called
  kvm: exiting hardware virtualization
  arm-smmu-v3 arm-smmu-v3.10.auto: CMD_SYNC timeout at 0x00000103 [hwprod 0x00000104, hwcons 0x00000102]
  smp: csd: Detected non-responsive CSD lock (#1) on CPU#4, waiting 5000000032 ns for CPU#00 do_nothing (kernel/smp.c:1057)
  smp:     csd: CSD lock (#1) unresponsive.
  [...]
  Call trace:
  pl011_console_write_atomic (./arch/arm64/include/asm/vdso/processor.h:12 drivers/tty/serial/amba-pl011.c:2540) (P)
  nbcon_emit_next_record (kernel/printk/nbcon.c:1049)
  __nbcon_atomic_flush_pending_con (kernel/printk/nbcon.c:1517)
  __nbcon_atomic_flush_pending.llvm.15488114865160659019 (./arch/arm64/include/asm/alternative-macros.h:254 ./arch/arm64/include/asm/cpufeature.h:808 ./arch/arm64/include/asm/irqflags.h:192 kernel/printk/nbcon.c:1562 kernel/printk/nbcon.c:1612)
  nbcon_atomic_flush_pending (kernel/printk/nbcon.c:1629)
  printk_kthreads_shutdown (kernel/printk/printk.c:?)
  syscore_shutdown (drivers/base/syscore.c:120)
  kernel_kexec (kernel/kexec_core.c:1045)
  __arm64_sys_reboot (kernel/reboot.c:794 kernel/reboot.c:722 kernel/reboot.c:722)
  invoke_syscall (arch/arm64/kernel/syscall.c:50)
  el0_svc_common.llvm.14158405452757855239 (arch/arm64/kernel/syscall.c:?)
  do_el0_svc (arch/arm64/kernel/syscall.c:152)
  el0_svc (./arch/arm64/include/asm/alternative-macros.h:254 ./arch/arm64/include/asm/cpufeature.h:808 ./arch/arm64/include/asm/irqflags.h:73 arch/arm64/kernel/entry-common.c:169 arch/arm64/kernel/entry-common.c:182 arch/arm64/kernel/entry-common.c:749)
  el0t_64_sync_handler (arch/arm64/kernel/entry-common.c:820)
  el0t_64_sync (arch/arm64/kernel/entry.S:600)

In this case, nbcon_atomic_flush_pending() is called from
printk_kthreads_shutdown() with IRQs and scheduling enabled.

Note that __nbcon_atomic_flush_pending_con() is directly called also from
nbcon_device_release() where the disabled IRQs might break PREEMPT_RT
guarantees. But the atomic flush is called only in emergency or panic
situations where the latencies are irrelevant anyway.

An ultimate solution would be a touching of watchdogs. But it would hide
all problems. Let's do it later when anyone reports a stall which does
not have a better solution.

Closes: https://lore.kernel.org/r/sqwajvt7utnt463tzxgwu2yctyn5m6bjwrslsnupfexeml6hkd@v6sqmpbu3vvu
Tested-by: Breno Leitao &lt;leitao@debian.org&gt;
Reviewed-by: John Ogness &lt;john.ogness@linutronix.de&gt;
Link: https://patch.msgid.link/20251212124520.244483-1-pmladek@suse.com
Signed-off-by: Petr Mladek &lt;pmladek@suse.com&gt;
</pre>
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</content>
</entry>
<entry>
<title>printk: nbcon: Check for device_{lock,unlock} callbacks</title>
<updated>2025-12-15T14:10:33+00:00</updated>
<author>
<name>Marcos Paulo de Souza</name>
<email>mpdesouza@suse.com</email>
</author>
<published>2025-12-08T14:06:16+00:00</published>
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<id>bdfcca65e7a681f7511a5c15501a01dd855f6d23</id>
<content type='text'>
These callbacks are necessary to synchronize -&gt;write_thread callback
against other operations using the same device.

Signed-off-by: Marcos Paulo de Souza &lt;mpdesouza@suse.com&gt;
Reviewed-by: John Ogness &lt;john.ogness@linutronix.de&gt;
Link: https://patch.msgid.link/20251208-nbcon-device-cb-fix-v2-1-36be8d195123@suse.com
Signed-off-by: Petr Mladek &lt;pmladek@suse.com&gt;
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<pre>
These callbacks are necessary to synchronize -&gt;write_thread callback
against other operations using the same device.

Signed-off-by: Marcos Paulo de Souza &lt;mpdesouza@suse.com&gt;
Reviewed-by: John Ogness &lt;john.ogness@linutronix.de&gt;
Link: https://patch.msgid.link/20251208-nbcon-device-cb-fix-v2-1-36be8d195123@suse.com
Signed-off-by: Petr Mladek &lt;pmladek@suse.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge branch 'rework/write_atomic-unsafe' into for-linus</title>
<updated>2025-12-01T13:17:04+00:00</updated>
<author>
<name>Petr Mladek</name>
<email>pmladek@suse.com</email>
</author>
<published>2025-12-01T13:17:04+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=5cae92e622300d04ff23cc721dc67d8f5788e51c'/>
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</entry>
<entry>
<title>Merge branch 'rework/suspend-fixes' into for-linus</title>
<updated>2025-12-01T13:16:28+00:00</updated>
<author>
<name>Petr Mladek</name>
<email>pmladek@suse.com</email>
</author>
<published>2025-12-01T13:16:28+00:00</published>
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<entry>
<title>Merge branch 'rework/nbcon-in-kdb' into for-linus</title>
<updated>2025-12-01T13:15:43+00:00</updated>
<author>
<name>Petr Mladek</name>
<email>pmladek@suse.com</email>
</author>
<published>2025-12-01T13:15:43+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=2d786a5b80a715dab2ef570fefbca8ef0753c7ed'/>
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