Commit Graph

161 Commits

Author SHA1 Message Date
Breno Leitao
5af6e8b549 netconsole: fix sysdata_release_enabled_show checking wrong flag
sysdata_release_enabled_show() checks SYSDATA_TASKNAME instead of
SYSDATA_RELEASE, causing the configfs release_enabled attribute to
reflect the taskname feature state rather than the release feature
state. This is a copy-paste error from the adjacent
sysdata_taskname_enabled_show() function.

The corresponding _store function already uses the correct
SYSDATA_RELEASE flag.

Fixes: 343f902270 ("netconsole: implement configfs for release_enabled")
Signed-off-by: Breno Leitao <leitao@debian.org>
Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/20260302-sysdata_release_fix-v1-1-e5090f677c7c@debian.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-03-03 17:23:50 -08:00
Linus Torvalds
b9c8fc2cae Merge tag 'net-7.0-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Pull networking fixes from Paolo Abeni:
 "Including fixes from IPsec, Bluetooth and netfilter

  Current release - regressions:

   - wifi: fix dev_alloc_name() return value check

   - rds: fix recursive lock in rds_tcp_conn_slots_available

  Current release - new code bugs:

   - vsock: lock down child_ns_mode as write-once

  Previous releases - regressions:

   - core:
      - do not pass flow_id to set_rps_cpu()
      - consume xmit errors of GSO frames

   - netconsole: avoid OOB reads, msg is not nul-terminated

   - netfilter: h323: fix OOB read in decode_choice()

   - tcp: re-enable acceptance of FIN packets when RWIN is 0

   - udplite: fix null-ptr-deref in __udp_enqueue_schedule_skb().

   - wifi: brcmfmac: fix potential kernel oops when probe fails

   - phy: register phy led_triggers during probe to avoid AB-BA deadlock

   - eth:
      - bnxt_en: fix deleting of Ntuple filters
      - wan: farsync: fix use-after-free bugs caused by unfinished tasklets
      - xscale: check for PTP support properly

  Previous releases - always broken:

   - tcp: fix potential race in tcp_v6_syn_recv_sock()

   - kcm: fix zero-frag skb in frag_list on partial sendmsg error

   - xfrm:
      - fix race condition in espintcp_close()
      - always flush state and policy upon NETDEV_UNREGISTER event

   - bluetooth:
      - purge error queues in socket destructors
      - fix response to L2CAP_ECRED_CONN_REQ

   - eth:
      - mlx5:
         - fix circular locking dependency in dump
         - fix "scheduling while atomic" in IPsec MAC address query
      - gve: fix incorrect buffer cleanup for QPL
      - team: avoid NETDEV_CHANGEMTU event when unregistering slave
      - usb: validate USB endpoints"

* tag 'net-7.0-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (72 commits)
  netfilter: nf_conntrack_h323: fix OOB read in decode_choice()
  dpaa2-switch: validate num_ifs to prevent out-of-bounds write
  net: consume xmit errors of GSO frames
  vsock: document write-once behavior of the child_ns_mode sysctl
  vsock: lock down child_ns_mode as write-once
  selftests/vsock: change tests to respect write-once child ns mode
  net/mlx5e: Fix "scheduling while atomic" in IPsec MAC address query
  net/mlx5: Fix missing devlink lock in SRIOV enable error path
  net/mlx5: E-switch, Clear legacy flag when moving to switchdev
  net/mlx5: LAG, disable MPESW in lag_disable_change()
  net/mlx5: DR, Fix circular locking dependency in dump
  selftests: team: Add a reference count leak test
  team: avoid NETDEV_CHANGEMTU event when unregistering slave
  net: mana: Fix double destroy_workqueue on service rescan PCI path
  MAINTAINERS: Update maintainer entry for QUALCOMM ETHQOS ETHERNET DRIVER
  dpll: zl3073x: Remove redundant cleanup in devm_dpll_init()
  selftests/net: packetdrill: Verify acceptance of FIN packets when RWIN is 0
  tcp: re-enable acceptance of FIN packets when RWIN is 0
  vsock: Use container_of() to get net namespace in sysctl handlers
  net: usb: kaweth: validate USB endpoints
  ...
2026-02-26 08:00:13 -08:00
Jakub Kicinski
82aec772fc netconsole: avoid OOB reads, msg is not nul-terminated
msg passed to netconsole from the console subsystem is not guaranteed
to be nul-terminated. Before recent
commit 7eab73b186 ("netconsole: convert to NBCON console infrastructure")
the message would be placed in printk_shared_pbufs, a static global
buffer, so KASAN had harder time catching OOB accesses. Now we see:

    printk: console [netcon_ext0] enabled
    BUG: KASAN: slab-out-of-bounds in string+0x1f7/0x240
    Read of size 1 at addr ffff88813b6d4c00 by task pr/netcon_ext0/594

    CPU: 65 UID: 0 PID: 594 Comm: pr/netcon_ext0 Not tainted 6.19.0-11754-g4246fd6547c9
    Call Trace:
     kasan_report+0xe4/0x120
     string+0x1f7/0x240
     vsnprintf+0x655/0xba0
     scnprintf+0xba/0x120
     netconsole_write+0x3fe/0xa10
     nbcon_emit_next_record+0x46e/0x860
     nbcon_kthread_func+0x623/0x750

    Allocated by task 1:
     nbcon_alloc+0x1ea/0x450
     register_console+0x26b/0xe10
     init_netconsole+0xbb0/0xda0

    The buggy address belongs to the object at ffff88813b6d4000
                which belongs to the cache kmalloc-4k of size 4096
    The buggy address is located 0 bytes to the right of
                allocated 3072-byte region [ffff88813b6d4000, ffff88813b6d4c00)

Fixes: c62c0a17f9 ("netconsole: Append kernel version to message")
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20260219195021.2099699-1-kuba@kernel.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-02-24 10:46:29 +01:00
Linus Torvalds
bf4afc53b7 Convert 'alloc_obj' family to use the new default GFP_KERNEL argument
This was done entirely with mindless brute force, using

    git grep -l '\<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 <torvalds@linux-foundation.org>
2026-02-21 17:09:51 -08:00
Kees Cook
69050f8d6d treewide: Replace kmalloc with kmalloc_obj for non-scalar types
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 <kees@kernel.org>
2026-02-21 01:02:28 -08:00
Linus Torvalds
136114e0ab Merge tag 'mm-nonmm-stable-2026-02-12-10-48' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull non-MM updates from Andrew Morton:

 - "ocfs2: give ocfs2 the ability to reclaim suballocator free bg" saves
   disk space by teaching ocfs2 to reclaim suballocator block group
   space (Heming Zhao)

 - "Add ARRAY_END(), and use it to fix off-by-one bugs" adds the
   ARRAY_END() macro and uses it in various places (Alejandro Colomar)

 - "vmcoreinfo: support VMCOREINFO_BYTES larger than PAGE_SIZE" makes
   the vmcore code future-safe, if VMCOREINFO_BYTES ever exceeds the
   page size (Pnina Feder)

 - "kallsyms: Prevent invalid access when showing module buildid" cleans
   up kallsyms code related to module buildid and fixes an invalid
   access crash when printing backtraces (Petr Mladek)

 - "Address page fault in ima_restore_measurement_list()" fixes a
   kexec-related crash that can occur when booting the second-stage
   kernel on x86 (Harshit Mogalapalli)

 - "kho: ABI headers and Documentation updates" updates the kexec
   handover ABI documentation (Mike Rapoport)

 - "Align atomic storage" adds the __aligned attribute to atomic_t and
   atomic64_t definitions to get natural alignment of both types on
   csky, m68k, microblaze, nios2, openrisc and sh (Finn Thain)

 - "kho: clean up page initialization logic" simplifies the page
   initialization logic in kho_restore_page() (Pratyush Yadav)

 - "Unload linux/kernel.h" moves several things out of kernel.h and into
   more appropriate places (Yury Norov)

 - "don't abuse task_struct.group_leader" removes the usage of
   ->group_leader when it is "obviously unnecessary" (Oleg Nesterov)

 - "list private v2 & luo flb" adds some infrastructure improvements to
   the live update orchestrator (Pasha Tatashin)

* tag 'mm-nonmm-stable-2026-02-12-10-48' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (107 commits)
  watchdog/hardlockup: simplify perf event probe and remove per-cpu dependency
  procfs: fix missing RCU protection when reading real_parent in do_task_stat()
  watchdog/softlockup: fix sample ring index wrap in need_counting_irqs()
  kcsan, compiler_types: avoid duplicate type issues in BPF Type Format
  kho: fix doc for kho_restore_pages()
  tests/liveupdate: add in-kernel liveupdate test
  liveupdate: luo_flb: introduce File-Lifecycle-Bound global state
  liveupdate: luo_file: Use private list
  list: add kunit test for private list primitives
  list: add primitives for private list manipulations
  delayacct: fix uapi timespec64 definition
  panic: add panic_force_cpu= parameter to redirect panic to a specific CPU
  netclassid: use thread_group_leader(p) in update_classid_task()
  RDMA/umem: don't abuse current->group_leader
  drm/pan*: don't abuse current->group_leader
  drm/amd: kill the outdated "Only the pthreads threading model is supported" checks
  drm/amdgpu: don't abuse current->group_leader
  android/binder: use same_thread_group(proc->tsk, current) in binder_mmap()
  android/binder: don't abuse current->group_leader
  kho: skip memoryless NUMA nodes when reserving scratch areas
  ...
2026-02-12 12:13:01 -08:00
Breno Leitao
79ba362b43 netconsole: Use printk context for CPU and task information
Use the CPU and task name captured at printk() time from
nbcon_write_context instead of querying the current execution context.
This provides accurate information about where the message originated,
rather than where netconsole happens to be running.

For CPU, use wctxt->cpu instead of raw_smp_processor_id().

For taskname, use wctxt->comm directly which contains the task
name captured at printk time.

This change ensures netconsole outputs reflect the actual context that
generated the log message, which is especially important when the
console driver runs asynchronously in a dedicated thread.

Reviewed-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Breno Leitao <leitao@debian.org>
Link: https://patch.msgid.link/20260206-nbcon-v7-4-62bda69b1b41@debian.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-02-10 19:51:57 -08:00
Breno Leitao
7eab73b186 netconsole: convert to NBCON console infrastructure
Convert netconsole from the legacy console API to the NBCON framework.
NBCON provides threaded printing which unblocks printk()s and flushes in
a thread, decoupling network TX from printk() when netconsole is
in use.

Since netconsole relies on the network stack which cannot safely operate
from all atomic contexts, mark both consoles with
CON_NBCON_ATOMIC_UNSAFE. (See discussion in [1])

CON_NBCON_ATOMIC_UNSAFE restricts write_atomic() usage to emergency
scenarios (panic) where regular messages are sent in threaded mode.

Implementation changes:
- Unify write_ext_msg() and write_msg() into netconsole_write()
- Add device_lock/device_unlock callbacks to manage target_list_lock
- Use nbcon_enter_unsafe()/nbcon_exit_unsafe() around network
  operations.
  - If nbcon_enter_unsafe() fails, just return given netconsole lost
    the ownership of the console.
- Set write_thread and write_atomic callbacks (both use same function)

Link: https://lore.kernel.org/all/b2qps3uywhmjaym4mht2wpxul4yqtuuayeoq4iv4k3zf5wdgh3@tocu6c7mj4lt/ [1]
Reviewed-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Breno Leitao <leitao@debian.org>
Link: https://patch.msgid.link/20260206-nbcon-v7-3-62bda69b1b41@debian.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-02-10 19:51:57 -08:00
Breno Leitao
eaf35bc63b netconsole: extract message fragmentation into send_msg_udp()
Extract the message fragmentation logic from write_msg() into a
dedicated send_msg_udp() function. This improves code readability
and prepares for future enhancements.

The new send_msg_udp() function handles splitting messages that
exceed MAX_PRINT_CHUNK into smaller fragments and sending them
sequentially. This function is placed before send_ext_msg_udp()
to maintain a logical ordering of related functions.

No functional changes - this is purely a refactoring commit.

Reviewed-by: Petr Mladek <pmladek@suse.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Reviewed-by: John Ogness <john.ogness@linutronix.de>
Signed-off-by: Breno Leitao <leitao@debian.org>
Link: https://patch.msgid.link/20260206-nbcon-v7-2-62bda69b1b41@debian.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-02-10 19:51:56 -08:00
Andre Carvalho
220dbe3c76 netconsole: resume previously deactivated target
Attempt to resume a previously deactivated target when the associated
interface comes back (NETDEV_REGISTER) or when it changes name
(NETDEV_CHANGENAME) by calling netpoll_setup on the device.

Depending on how the target was setup (by mac or interface name), the
corresponding field is compared with the device being brought up. Targets
that match the incoming device, are scheduled for resume on a workqueue.

Resuming happens on a workqueue as we can't execute netpoll_setup in the
context of the netdev event. A standalone workqueue (as opposed to the
global one) is used to allow for proper cleanup process during
netconsole module cleanup as we need to be able to flush all pending
work before traversing the target list given that targets are temporarily
removed from the list during resume_target.

Target transitions to STATE_DISABLED in case of failures resuming it to
avoid retrying the same target indefinitely.

Signed-off-by: Andre Carvalho <asantostc@gmail.com>
Reviewed-by: Breno Leitao <leitao@debian.org>
Tested-by: Breno Leitao <leitao@debian.org>
Link: https://patch.msgid.link/20260118-netcons-retrigger-v11-6-4de36aebcf48@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-01-21 19:09:11 -08:00
Andre Carvalho
c52861e566 netconsole: introduce helpers for dynamic_netconsole_mutex lock/unlock
This commit introduces two helper functions to perform lock/unlock on
dynamic_netconsole_mutex providing no-op stub versions when compiled
without CONFIG_NETCONSOLE_DYNAMIC and refactors existing call sites to
use the new helpers.

This is done following kernel coding style guidelines, in preparation
for an upcoming change. It avoids the need for preprocessor conditionals
in the call site and keeps the logic easier to follow.

Signed-off-by: Andre Carvalho <asantostc@gmail.com>
Reviewed-by: Breno Leitao <leitao@debian.org>
Tested-by: Breno Leitao <leitao@debian.org>
Link: https://patch.msgid.link/20260118-netcons-retrigger-v11-5-4de36aebcf48@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-01-21 19:09:11 -08:00
Andre Carvalho
5b11408743 netconsole: clear dev_name for devices bound by mac
This patch makes sure netconsole clears dev_name for devices bound by mac
in order to allow calling setup_netpoll on targets that have previously
been cleaned up (in order to support resuming deactivated targets).

This is required as netpoll_setup populates dev_name even when devices are
matched via mac address. The cleanup is done inside netconsole as bound
by mac is a netconsole concept.

Signed-off-by: Andre Carvalho <asantostc@gmail.com>
Reviewed-by: Breno Leitao <leitao@debian.org>
Tested-by: Breno Leitao <leitao@debian.org>
Link: https://patch.msgid.link/20260118-netcons-retrigger-v11-4-4de36aebcf48@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-01-21 19:09:11 -08:00
Breno Leitao
e8f4005ab2 netconsole: add STATE_DEACTIVATED to track targets disabled by low level
When the low level interface brings a netconsole target down, record this
using a new STATE_DEACTIVATED state. This allows netconsole to distinguish
between targets explicitly disabled by users and those deactivated due to
interface state changes.

It also enables automatic recovery and re-enabling of targets if the
underlying low-level interfaces come back online.

From a code perspective, anything that is not STATE_ENABLED is disabled.

Devices (de)enslaving are marked STATE_DISABLED to prevent automatically
resuming as enslaved interfaces cannot have netconsole enabled.

Signed-off-by: Breno Leitao <leitao@debian.org>
Signed-off-by: Andre Carvalho <asantostc@gmail.com>
Tested-by: Breno Leitao <leitao@debian.org>
Link: https://patch.msgid.link/20260118-netcons-retrigger-v11-3-4de36aebcf48@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-01-21 19:09:11 -08:00
Andre Carvalho
a46bb0103c netconsole: convert 'enabled' flag to enum for clearer state management
This patch refactors the netconsole driver's target enabled state from a
simple boolean to an explicit enum (`target_state`).

This allow the states to be expanded to a new state in the upcoming
change.

Co-developed-by: Breno Leitao <leitao@debian.org>
Signed-off-by: Breno Leitao <leitao@debian.org>
Reviewed-by: Breno Leitao <leitao@debian.org>
Signed-off-by: Andre Carvalho <asantostc@gmail.com>
Tested-by: Breno Leitao <leitao@debian.org>
Link: https://patch.msgid.link/20260118-netcons-retrigger-v11-2-4de36aebcf48@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-01-21 19:09:10 -08:00
Breno Leitao
d793db4aa0 netconsole: add target_state enum
Introduces a enum to track netconsole target state which is going to
replace the enabled boolean.

Signed-off-by: Breno Leitao <leitao@debian.org>
Signed-off-by: Andre Carvalho <asantostc@gmail.com>
Tested-by: Breno Leitao <leitao@debian.org>
Link: https://patch.msgid.link/20260118-netcons-retrigger-v11-1-4de36aebcf48@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-01-21 19:09:10 -08:00
Randy Dunlap
24c776355f kernel.h: drop hex.h and update all hex.h users
Remove <linux/hex.h> from <linux/kernel.h> and update all users/callers of
hex.h interfaces to directly #include <linux/hex.h> as part of the process
of putting kernel.h on a diet.

Removing hex.h from kernel.h means that 36K C source files don't have to
pay the price of parsing hex.h for the roughly 120 C source files that
need it.

This change has been build-tested with allmodconfig on most ARCHes.  Also,
all users/callers of <linux/hex.h> in the entire source tree have been
updated if needed (if not already #included).

Link: https://lkml.kernel.org/r/20251215005206.2362276-1-rdunlap@infradead.org
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@intel.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Yury Norov (NVIDIA) <yury.norov@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-01-20 19:44:19 -08:00
Gustavo Luiz Duarte
5ad9945341 netconsole: Increase MAX_USERDATA_ITEMS
Increase MAX_USERDATA_ITEMS from 16 to 256 entries now that the userdata
buffer is allocated dynamically.

The previous limit of 16 was necessary because the buffer was statically
allocated for all targets. With dynamic allocation, we can support more
entries without wasting memory on targets that don't use userdata.

This allows users to attach more metadata to their netconsole messages,
which is useful for complex debugging and logging scenarios.

Also update the testcase accordingly.

Signed-off-by: Gustavo Luiz Duarte <gustavold@gmail.com>
Reviewed-by: Breno Leitao <leitao@debian.org>
Link: https://patch.msgid.link/20251119-netconsole_dynamic_extradata-v3-4-497ac3191707@meta.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-11-20 18:47:18 -08:00
Gustavo Luiz Duarte
eb83801af2 netconsole: Dynamic allocation of userdata buffer
The userdata buffer in struct netconsole_target is currently statically
allocated with a size of MAX_USERDATA_ITEMS * MAX_EXTRADATA_ENTRY_LEN
(16 * 256 = 4096 bytes). This wastes memory when userdata entries are
not used or when only a few entries are configured, which is common in
typical usage scenarios. It also forces us to keep MAX_USERDATA_ITEMS
small to limit the memory wasted.

Change the userdata buffer from a static array to a dynamically
allocated pointer. The buffer is now allocated on-demand in
update_userdata() whenever userdata entries are added, modified, or
removed via configfs. The implementation calculates the exact size
needed for all current userdata entries, allocates a new buffer of that
size, formats the entries into it, and atomically swaps it with the old
buffer.

This approach provides several benefits:
- Memory efficiency: Targets with no userdata use zero bytes instead of
  4KB, and targets with userdata only allocate what they need;
- Scalability: Makes it practical to increase MAX_USERDATA_ITEMS to a
  much larger value without imposing a fixed memory cost on every
  target;
- No hot-path overhead: Allocation occurs during configuration (write to
  configfs), not during message transmission

If memory allocation fails during userdata update, -ENOMEM is returned
to userspace through the configfs attribute write operation.

The sysdata buffer remains statically allocated since it has a smaller
fixed size (MAX_SYSDATA_ITEMS * MAX_EXTRADATA_ENTRY_LEN = 4 * 256 = 1024
bytes) and its content length is less predictable.

Signed-off-by: Gustavo Luiz Duarte <gustavold@gmail.com>
Reviewed-by: Breno Leitao <leitao@debian.org>
Link: https://patch.msgid.link/20251119-netconsole_dynamic_extradata-v3-3-497ac3191707@meta.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-11-20 18:47:18 -08:00
Gustavo Luiz Duarte
9dc10f50c4 netconsole: Split userdata and sysdata
Separate userdata and sysdata into distinct buffers to enable independent
management. Previously, both were stored in a single extradata_complete
buffer with a fixed size that accommodated both types of data.

This separation allows:
- userdata to grow dynamically (in subsequent patch)
- sysdata to remain in a small static buffer
- removal of complex entry counting logic that tracked both types together

The split also simplifies the code by eliminating the need to check total
entry count across both userdata and sysdata when enabling features,
which allows to drop holding su_mutex on sysdata_*_enabled_store().

No functional change in this patch, just structural preparation for
dynamic userdata allocation.

Signed-off-by: Gustavo Luiz Duarte <gustavold@gmail.com>
Reviewed-by: Breno Leitao <leitao@debian.org>
Link: https://patch.msgid.link/20251119-netconsole_dynamic_extradata-v3-2-497ac3191707@meta.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-11-20 18:47:18 -08:00
Gustavo Luiz Duarte
7279b718b4 netconsole: Simplify send_fragmented_body()
Refactor send_fragmented_body() to use separate offset tracking for
msgbody, and extradata instead of complex conditional logic.
The previous implementation used boolean flags and calculated offsets
which made the code harder to follow.

The new implementation maintains independent offset counters
(msgbody_offset, extradata_offset) and processes each section
sequentially, making the data flow more straightforward and the code
easier to maintain.

This is a preparatory refactoring with no functional changes, which will
allow easily splitting extradata_complete into separate userdata and
sysdata buffers in the next patch.

Signed-off-by: Gustavo Luiz Duarte <gustavold@gmail.com>
Reviewed-by: Breno Leitao <leitao@debian.org>
Link: https://patch.msgid.link/20251119-netconsole_dynamic_extradata-v3-1-497ac3191707@meta.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-11-20 18:47:18 -08:00
Gustavo Luiz Duarte
d7d2fcf7ae netconsole: Acquire su_mutex before navigating configs hierarchy
There is a race between operations that iterate over the userdata
cg_children list and concurrent add/remove of userdata items through
configfs. The update_userdata() function iterates over the
nt->userdata_group.cg_children list, and count_extradata_entries() also
iterates over this same list to count nodes.

Quoting from Documentation/filesystems/configfs.rst:
> A subsystem can navigate the cg_children list and the ci_parent pointer
> to see the tree created by the subsystem.  This can race with configfs'
> management of the hierarchy, so configfs uses the subsystem mutex to
> protect modifications.  Whenever a subsystem wants to navigate the
> hierarchy, it must do so under the protection of the subsystem
> mutex.

Without proper locking, if a userdata item is added or removed
concurrently while these functions are iterating, the list can be
accessed in an inconsistent state. For example, the list_for_each() loop
can reach a node that is being removed from the list by list_del_init()
which sets the nodes' .next pointer to point to itself, so the loop will
never end (or reach the WARN_ON_ONCE in update_userdata() ).

Fix this by holding the configfs subsystem mutex (su_mutex) during all
operations that iterate over cg_children.
This includes:
- userdatum_value_store() which calls update_userdata() to iterate over
  cg_children
- All sysdata_*_enabled_store() functions which call
  count_extradata_entries() to iterate over cg_children

The su_mutex must be acquired before dynamic_netconsole_mutex to avoid
potential lock ordering issues, as configfs operations may already hold
su_mutex when calling into our code.

Fixes: df03f830d0 ("net: netconsole: cache userdata formatted string in netconsole_target")
Signed-off-by: Gustavo Luiz Duarte <gustavold@gmail.com>
Link: https://patch.msgid.link/20251029-netconsole-fix-warn-v1-1-0d0dd4622f48@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-10-31 17:45:06 -07:00
Gustavo Luiz Duarte
00764aa5c9 netconsole: Fix race condition in between reader and writer of userdata
The update_userdata() function constructs the complete userdata string
in nt->extradata_complete and updates nt->userdata_length. This data
is then read by write_msg() and write_ext_msg() when sending netconsole
messages. However, update_userdata() was not holding target_list_lock
during this process, allowing concurrent message transmission to read
partially updated userdata.

This race condition could result in netconsole messages containing
incomplete or inconsistent userdata - for example, reading the old
userdata_length with new extradata_complete content, or vice versa,
leading to truncated or corrupted output.

Fix this by acquiring target_list_lock with spin_lock_irqsave() before
updating extradata_complete and userdata_length, and releasing it after
both fields are fully updated. This ensures that readers see a
consistent view of the userdata, preventing corruption during concurrent
access.

The fix aligns with the existing locking pattern used throughout the
netconsole code, where target_list_lock protects access to target
fields including buf[] and msgcounter that are accessed during message
transmission.

Also get rid of the unnecessary variable complete_idx, which makes it
easier to bail out of update_userdata().

Fixes: df03f830d0 ("net: netconsole: cache userdata formatted string in netconsole_target")
Signed-off-by: Gustavo Luiz Duarte <gustavold@gmail.com>
Link: https://patch.msgid.link/20251028-netconsole-fix-race-v4-1-63560b0ae1a0@meta.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-10-29 17:41:00 -07:00
Breno Leitao
4aeb452c23 netconsole: use netpoll_parse_ip_addr in local_ip_store
Replace manual IP address parsing with a call to netpoll_parse_ip_addr
in remote_ip_store(), simplifying the code and reducing the chance of
errors.

The error message got removed, since it is not a good practice to
pr_err() if used pass a wrong value in configfs.

Signed-off-by: Breno Leitao <leitao@debian.org>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-08-12 17:32:42 -07:00
Breno Leitao
60cb692141 netconsole: use netpoll_parse_ip_addr in local_ip_store
Replace manual IP address parsing with a call to netpoll_parse_ip_addr
in local_ip_store(), simplifying the code and reducing the chance of
errors.

Also, remove the pr_err() if the user enters an invalid value in
configfs entries. pr_err() is not the best way to alert user that the
configuration is invalid.

Signed-off-by: Breno Leitao <leitao@debian.org>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-08-12 17:32:42 -07:00
Breno Leitao
364213b736 netconsole: add support for strings with new line in netpoll_parse_ip_addr
The current IP address parsing logic fails when the input string
contains a trailing newline character. This can occur when IP
addresses are provided through configfs, which contains newlines in
a const buffer.

Teach netpoll_parse_ip_addr() how to ignore newlines at the end of the
IPs. Also, simplify the code by:

 * No need to check for separators. Try to parse ipv4, if it fails try
   ipv6 similarly to ceph_pton()
 * If ipv6 is not supported, don't call in6_pton() at all.

Signed-off-by: Breno Leitao <leitao@debian.org>
Link: https://patch.msgid.link/20250811-netconsole_ref-v4-2-9c510d8713a2@debian.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-08-12 17:32:42 -07:00
Breno Leitao
fa38524ca5 netconsole: move netpoll_parse_ip_addr() earlier for reuse
Move netpoll_parse_ip_addr() earlier in the file to be reused in
other functions, such as local_ip_store(). This avoids duplicate
address parsing logic and centralizes validation for both IPv4
and IPv6 string input.

No functional changes intended.

Signed-off-by: Breno Leitao <leitao@debian.org>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20250811-netconsole_ref-v4-1-9c510d8713a2@debian.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-08-12 17:32:42 -07:00
Gustavo Luiz Duarte
c5efaabd45 netconsole: append msgid to sysdata
Add msgcounter to the netconsole_target struct to generate message IDs.
If the msgid_enabled attribute is true, increment msgcounter and append
msgid=<msgcounter> to sysdata buffer before sending the message.

Signed-off-by: Gustavo Luiz Duarte <gustavold@gmail.com>
Reviewed-by: Breno Leitao <leitao@debian.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2025-06-18 10:46:10 +01:00
Gustavo Luiz Duarte
53def0c4c8 netconsole: implement configfs for msgid_enabled
Implement the _show and _store functions for the msgid_enabled configfs
attribute under userdata.
Set the sysdata_fields bit accordingly.

Reviewed-by: Breno Leitao <leitao@debian.org>
Signed-off-by: Gustavo Luiz Duarte <gustavold@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2025-06-18 10:46:10 +01:00
Gustavo Luiz Duarte
15b3c930a2 netconsole: introduce 'msgid' as a new sysdata field
This adds a new sysdata field to enable assigning a per-target unique id
to each message sent to that target. This id can later be appended as
part of sysdata, allowing targets to detect dropped netconsole messages.
Update count_extradata_entries() to take the new field into account.

Reviewed-by: Breno Leitao <leitao@debian.org>
Signed-off-by: Gustavo Luiz Duarte <gustavold@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2025-06-18 10:46:10 +01:00
Breno Leitao
d79206451f netconsole: improve code style in parser function
Split assignment from conditional checks and use preferred null pointer
check style (!delim instead of == NULL) in netconsole_parser_cmdline().
This improves code readability and follows kernel coding style
conventions.

Signed-off-by: Breno Leitao <leitao@debian.org>
Link: https://patch.msgid.link/20250613-rework-v3-6-0752bf2e6912@debian.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-06-16 15:18:34 -07:00
Breno Leitao
abebef96aa netconsole: rename functions to better reflect their purpose
Rename netpoll_parse_options() to netconsole_parser_cmdline() and
netpoll_print_options() to netconsole_print_banner() to better
describe what these functions actually do within the netconsole
context.

Also fix minor code style issues including variable declaration
ordering and spacing.

These functions are specific to netconsole functionality rather
than general netpoll operations, so the new names better reflect
their actual purpose.

Signed-off-by: Breno Leitao <leitao@debian.org>
Link: https://patch.msgid.link/20250613-rework-v3-5-0752bf2e6912@debian.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-06-16 15:18:33 -07:00
Breno Leitao
ccc7edf0ad netpoll: move netpoll_print_options to netconsole
Move netpoll_print_options() from net/core/netpoll.c to
drivers/net/netconsole.c and make it static. This function is only used
by netconsole, so there's no need to export it or keep it in the public
netpoll API.

This reduces the netpoll API surface and improves code locality
by keeping netconsole-specific functionality within the netconsole
driver.

Signed-off-by: Breno Leitao <leitao@debian.org>
Link: https://patch.msgid.link/20250613-rework-v3-4-0752bf2e6912@debian.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-06-16 15:18:33 -07:00
Breno Leitao
5a34c9a853 netpoll: relocate netconsole-specific functions to netconsole module
Move netpoll_parse_ip_addr() and netpoll_parse_options() from the generic
netpoll module to the netconsole module where they are actually used.

These functions were originally placed in netpoll but are only consumed by
netconsole. This refactoring improves code organization by:

 - Removing unnecessary exported symbols from netpoll
 - Making netpoll_parse_options() static (no longer needs global visibility)
 - Reducing coupling between netpoll and netconsole modules

The functions remain functionally identical - this is purely a code
reorganization to better reflect their actual usage patterns. Here are
the changes:

 1) Move both functions from netpoll to netconsole
 2) Add static to netpoll_parse_options()
 3) Removed the EXPORT_SYMBOL()

PS: This diff does not change the function format, so, it is easy to
review, but, checkpatch will not be happy. A follow-up patch will
address the current issues reported by checkpatch.

Signed-off-by: Breno Leitao <leitao@debian.org>
Link: https://patch.msgid.link/20250613-rework-v3-3-0752bf2e6912@debian.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-06-16 15:18:33 -07:00
Jakub Kicinski
535de52801 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Cross-merge networking fixes after downstream PR (net-6.16-rc2).

No conflicts or adjacent changes.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-06-12 10:09:10 -07:00
Gustavo Luiz Duarte
c85bf19751 netconsole: fix appending sysdata when sysdata_fields == SYSDATA_RELEASE
Before appending sysdata, prepare_extradata() checks if any feature is
enabled in sysdata_fields (and exits early if none is enabled).

When SYSDATA_RELEASE was introduced, we missed adding it to the list of
features being checked against sysdata_fields in prepare_extradata().
The result was that, if only SYSDATA_RELEASE is enabled in
sysdata_fields, we incorreclty exit early and fail to append the
release.

Instead of checking specific bits in sysdata_fields, check if
sysdata_fields has ALL bit zeroed and exit early if true. This fixes
case when only SYSDATA_RELEASE enabled and makes the code more general /
less error prone in future feature implementation.

Signed-off-by: Gustavo Luiz Duarte <gustavold@gmail.com>
Reviewed-by: Breno Leitao <leitao@debian.org>
Fixes: cfcc9239e7 ("netconsole: append release to sysdata")
Link: https://patch.msgid.link/20250609-netconsole-fix-v1-1-17543611ae31@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-06-10 15:52:08 -07:00
Breno Leitao
e99d938f86 netconsole: Add automatic console unregistration on target removal
Add unregister_netcons_consoles() function to automatically unregister
console handlers when no targets of the corresponding type remain active.

The function iterates through the target list to determine which console
types (basic vs extended) are still needed, and unregisters any console
handlers that are no longer required. This prevents having registered
console handlers without corresponding active targets.

The function is called when a target is disabled and moved to the cleanup
list, ensuring proper cleanup of unused console registrations.

Signed-off-by: Breno Leitao <leitao@debian.org>
Link: https://patch.msgid.link/20250609-netcons_ext-v3-2-5336fa670326@debian.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-06-10 14:21:53 -07:00
Breno Leitao
bc0cb64db1 netconsole: Only register console drivers when targets are configured
The netconsole driver currently registers the basic console driver
unconditionally during initialization, even when only extended targets
are configured. This results in unnecessary console registration and
performance overhead, as the write_msg() callback is invoked for every
log message only to return early when no matching targets are found.

Optimize the driver by conditionally registering console drivers based
on the actual target configuration. The basic console driver is now
registered only when non-extended targets exist, same as the extended
console. The implementation also handles dynamic target creation through
the configfs interface.

This change eliminates unnecessary console driver registrations,
redundant write_msg() callbacks for unused console types, and associated
lock contention and target list iterations. The optimization is
particularly beneficial for systems using only the most common extended
console type.

Fixes: e2f15f9a79 ("netconsole: implement extended console support")
Signed-off-by: Breno Leitao <leitao@debian.org>
Link: https://patch.msgid.link/20250609-netcons_ext-v3-1-5336fa670326@debian.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-06-10 14:21:53 -07:00
Breno Leitao
cfcc9239e7 netconsole: append release to sysdata
Append the init_utsname()->release to sysdata buffer before sending the
message in case the feature is set.

Signed-off-by: Breno Leitao <leitao@debian.org>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20250314-netcons_release-v1-4-07979c4b86af@debian.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-03-21 18:59:25 +01:00
Breno Leitao
b92c6fc43f netconsole: add 'sysdata' suffix to related functions
This commit appends a common "sysdata" suffix to functions responsible
for appending data to sysdata.

This change enhances code clarity and prevents naming conflicts with
other "append" functions, particularly in anticipation of the upcoming
inclusion of the `release` field in the next patch.

Signed-off-by: Breno Leitao <leitao@debian.org>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20250314-netcons_release-v1-3-07979c4b86af@debian.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-03-21 18:59:24 +01:00
Breno Leitao
343f902270 netconsole: implement configfs for release_enabled
Implement the configfs helpers to show and set release_enabled configfs
directories under userdata.

When enabled, set the feature bit in netconsole_target->sysdata_fields.

Signed-off-by: Breno Leitao <leitao@debian.org>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20250314-netcons_release-v1-2-07979c4b86af@debian.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-03-21 18:59:24 +01:00
Breno Leitao
42211e3107 netconsole: introduce 'release' as a new sysdata field
This commit adds a new feature to the sysdata structure, allowing the
kernel release/version to be appended as part of sysdata. Additionally,
it updates the logic to count this new field as a used entry when
enabled.

Signed-off-by: Breno Leitao <leitao@debian.org>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20250314-netcons_release-v1-1-07979c4b86af@debian.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-03-21 18:59:24 +01:00
Uday Shankar
6d6c1ba782 net, treewide: define and use MAC_ADDR_STR_LEN
There are a few places in the tree which compute the length of the
string representation of a MAC address as 3 * ETH_ALEN - 1. Define a
constant for this and use it where relevant. No functionality changes
are expected.

Signed-off-by: Uday Shankar <ushankar@purestorage.com>
Reviewed-by: Michal Swiatkowski <michal.swiatkowski@linux.intel.com>
Acked-by: Johannes Berg <johannes@sipsolutions.net>
Reviewed-by: Breno Leitao <leitao@debian.org>
Reviewed-by: Simon Horman <horms@verge.net.au>
Link: https://patch.msgid.link/20250312-netconsole-v6-1-3437933e79b8@purestorage.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-03-19 19:17:58 +01:00
Breno Leitao
dd30ae5332 netconsole: add task name to extra data fields
This is the core patch for this whole patchset. Add support for
including the current task's name in netconsole's extra data output.
This adds a new append_taskname() function that writes the task name
(from current->comm) into the target's extradata buffer, similar to how
CPU numbers are handled.

The task name is included when the SYSDATA_TASKNAME field is set,
appearing in the format "taskname=<name>" in the output. This additional
context can help with debugging by showing which task generated each
console message.

Signed-off-by: Breno Leitao <leitao@debian.org>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-03-04 15:28:28 +01:00
Breno Leitao
09e877590b netconsole: add configfs controls for taskname sysdata feature
Add configfs interface to enable/disable the taskname sysdata feature.
This adds the following functionality:

The implementation follows the same pattern as the existing CPU number
feature, ensuring consistent behavior and error handling across sysdata
features.

Signed-off-by: Breno Leitao <leitao@debian.org>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-03-04 15:28:28 +01:00
Breno Leitao
33e4b29f2b netconsole: add taskname to extradata entry count
New SYSDATA_TASKNAME feature flag to track when taskname append is enabled.

Additional check in count_extradata_entries() to include taskname in
total, counting it as an entry in extradata. This function is used to
check if we are not overflowing the number of extradata items.

Signed-off-by: Breno Leitao <leitao@debian.org>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-03-04 15:28:28 +01:00
Breno Leitao
4d989521a9 netconsole: refactor CPU number formatting into separate function
Extract CPU number formatting logic from prepare_extradata() into a new
append_cpu_nr() function.

This refactoring improves code organization by isolating CPU number
formatting into its own function while reducing the complexity of
prepare_extradata().

The change prepares the codebase for the upcoming taskname feature by
establishing a consistent pattern for handling sysdata features.

The CPU number formatting logic itself remains unchanged; only its
location has moved to improve maintainability.

Signed-off-by: Breno Leitao <leitao@debian.org>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-03-04 15:28:27 +01:00
Breno Leitao
efb878fbe8 netconsole: Make boolean comparison consistent
Convert the current state assignment to use explicit boolean conversion,
making the code more robust and easier to read. This change adds a
double-negation operator to ensure consistent boolean conversion as
suggested by Paolo[1].

This approach aligns with the existing pattern used in
sysdata_cpu_nr_enabled_show().

Link: https://lore.kernel.org/all/7309e760-63b0-4b58-ad33-2fb8db361141@redhat.com/ [1]
Signed-off-by: Breno Leitao <leitao@debian.org>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-03-04 15:28:27 +01:00
Breno Leitao
8a683295c2 netconsole: prefix CPU_NR sysdata feature with SYSDATA_
Rename the CPU_NR enum value to SYSDATA_CPU_NR to establish a consistent
naming convention for sysdata features. This change prepares for
upcoming additions to the sysdata feature set by clearly grouping
related features under the SYSDATA prefix.

This change is purely cosmetic and does not modify any functionality.

Signed-off-by: Breno Leitao <leitao@debian.org>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-03-04 15:28:27 +01:00
Breno Leitao
ec15bc46c6 netconsole: add support for sysdata and CPU population
Add infrastructure to automatically append kernel-generated data (sysdata)
to netconsole messages. As the first use case, implement CPU number
population, which adds the CPU that sent the message.

This change introduces three distinct data types:
- extradata: The complete set of appended data (sysdata + userdata)
- userdata: User-provided key-value pairs from userspace
- sysdata: Kernel-populated data (e.g. cpu=XX)

The implementation adds a new configfs attribute 'cpu_nr' to control CPU
number population per target. When enabled, each message is tagged with
its originating CPU. The sysdata is dynamically updated at message time
and appended after any existing userdata.

The CPU number is formatted as "cpu=XX" and is added to the extradata
buffer, respecting the existing size limits.

Signed-off-by: Breno Leitao <leitao@debian.org>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2025-02-10 15:04:18 +00:00
Breno Leitao
2bae25b16a netconsole: Include sysdata in extradata entry count
Modify count_extradata_entries() to include sysdata fields when
calculating the total number of extradata entries. This change ensures
that the sysdata feature, specifically the CPU number field, is
correctly counted against the MAX_EXTRADATA_ITEMS limit.

The modification adds a simple check for the CPU_NR flag in the
sysdata_fields, incrementing the entry count accordingly.

Signed-off-by: Breno Leitao <leitao@debian.org>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2025-02-10 15:04:18 +00:00