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path: root/drivers/net/netconsole.c
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2026-02-12Merge tag 'mm-nonmm-stable-2026-02-12-10-48' of ↵Linus Torvalds
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 ...
2026-02-10netconsole: Use printk context for CPU and task informationBreno Leitao
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>
2026-02-10netconsole: convert to NBCON console infrastructureBreno Leitao
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>
2026-02-10netconsole: extract message fragmentation into send_msg_udp()Breno Leitao
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>
2026-01-21netconsole: resume previously deactivated targetAndre Carvalho
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>
2026-01-21netconsole: introduce helpers for dynamic_netconsole_mutex lock/unlockAndre Carvalho
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>
2026-01-21netconsole: clear dev_name for devices bound by macAndre Carvalho
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>
2026-01-21netconsole: add STATE_DEACTIVATED to track targets disabled by low levelBreno Leitao
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>
2026-01-21netconsole: convert 'enabled' flag to enum for clearer state managementAndre Carvalho
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>
2026-01-21netconsole: add target_state enumBreno Leitao
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>
2026-01-20kernel.h: drop hex.h and update all hex.h usersRandy Dunlap
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>
2025-11-20netconsole: Increase MAX_USERDATA_ITEMSGustavo Luiz Duarte
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>
2025-11-20netconsole: Dynamic allocation of userdata bufferGustavo Luiz Duarte
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>
2025-11-20netconsole: Split userdata and sysdataGustavo Luiz Duarte
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>
2025-11-20netconsole: Simplify send_fragmented_body()Gustavo Luiz Duarte
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>
2025-10-31netconsole: Acquire su_mutex before navigating configs hierarchyGustavo Luiz Duarte
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: df03f830d099 ("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>
2025-10-29netconsole: Fix race condition in between reader and writer of userdataGustavo Luiz Duarte
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: df03f830d099 ("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>
2025-08-12netconsole: use netpoll_parse_ip_addr in local_ip_storeBreno Leitao
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>
2025-08-12netconsole: use netpoll_parse_ip_addr in local_ip_storeBreno Leitao
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>
2025-08-12netconsole: add support for strings with new line in netpoll_parse_ip_addrBreno Leitao
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>
2025-08-12netconsole: move netpoll_parse_ip_addr() earlier for reuseBreno Leitao
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>
2025-06-18netconsole: append msgid to sysdataGustavo Luiz Duarte
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>
2025-06-18netconsole: implement configfs for msgid_enabledGustavo Luiz Duarte
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>
2025-06-18netconsole: introduce 'msgid' as a new sysdata fieldGustavo Luiz Duarte
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>
2025-06-16netconsole: improve code style in parser functionBreno Leitao
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>
2025-06-16netconsole: rename functions to better reflect their purposeBreno Leitao
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>
2025-06-16netpoll: move netpoll_print_options to netconsoleBreno Leitao
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>
2025-06-16netpoll: relocate netconsole-specific functions to netconsole moduleBreno Leitao
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>
2025-06-12Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski
Cross-merge networking fixes after downstream PR (net-6.16-rc2). No conflicts or adjacent changes. Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-06-10netconsole: fix appending sysdata when sysdata_fields == SYSDATA_RELEASEGustavo Luiz Duarte
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: cfcc9239e78a ("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>
2025-06-10netconsole: Add automatic console unregistration on target removalBreno Leitao
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>
2025-06-10netconsole: Only register console drivers when targets are configuredBreno Leitao
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: e2f15f9a79201 ("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>
2025-03-21netconsole: append release to sysdataBreno Leitao
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>
2025-03-21netconsole: add 'sysdata' suffix to related functionsBreno Leitao
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>
2025-03-21netconsole: implement configfs for release_enabledBreno Leitao
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>
2025-03-21netconsole: introduce 'release' as a new sysdata fieldBreno Leitao
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>
2025-03-19net, treewide: define and use MAC_ADDR_STR_LENUday Shankar
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>
2025-03-04netconsole: add task name to extra data fieldsBreno Leitao
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>
2025-03-04netconsole: add configfs controls for taskname sysdata featureBreno Leitao
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>
2025-03-04netconsole: add taskname to extradata entry countBreno Leitao
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>
2025-03-04netconsole: refactor CPU number formatting into separate functionBreno Leitao
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>
2025-03-04netconsole: Make boolean comparison consistentBreno Leitao
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>
2025-03-04netconsole: prefix CPU_NR sysdata feature with SYSDATA_Breno Leitao
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>
2025-02-10netconsole: add support for sysdata and CPU populationBreno Leitao
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>
2025-02-10netconsole: Include sysdata in extradata entry countBreno Leitao
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>
2025-02-10netconsole: Introduce configfs helpers for sysdata featuresBreno Leitao
This patch introduces a bitfield to store sysdata features in the netconsole_target struct. It also adds configfs helpers to enable or disable the CPU_NR feature, which populates the CPU number in sysdata. The patch provides the necessary infrastructure to set or unset the CPU_NR feature, but does not modify the message itself. Signed-off-by: Breno Leitao <leitao@debian.org> Reviewed-by: Simon Horman <horms@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2025-02-10netconsole: Helper to count number of used entriesBreno Leitao
Add a helper function nr_extradata_entries() to count the number of used extradata entries in a netconsole target. This refactors the duplicate code for counting entries into a single function, which will be reused by upcoming CPU sysdata changes. The helper uses list_count_nodes() to count the number of children in the userdata group configfs hierarchy. Signed-off-by: Breno Leitao <leitao@debian.org> Reviewed-by: Simon Horman <horms@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2025-02-10netconsole: Rename userdata to extradataBreno Leitao
Rename "userdata" to "extradata" since this structure will hold both user and system data in future patches. Keep "userdata" term only for data that comes from userspace (configfs), while "extradata" encompasses both userdata and future kerneldata. These are the rules of the design 1. extradata_complete will hold userdata and sysdata (coming) 2. sysdata will come after userdata_length 3. extradata_complete[userdata_length] string will be replaced at every message 5. userdata is replaced when configfs changes (update_userdata()) 6. sysdata is replaced at every message Example: extradata_complete = "userkey=uservalue cpu=42" userdata_length = 17 sysdata_length = 7 (space (" ") is part of sysdata) Since sysdata is still not available, you will see the following in the send functions: extradata_len = nt->userdata_length; The upcoming patches will, which will add support for sysdata, will change it to: extradata_len = nt->userdata_length + sysdata_len; Signed-off-by: Breno Leitao <leitao@debian.org> Reviewed-by: Simon Horman <horms@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2025-02-10netconsole: consolidate send buffers into netconsole_target structBreno Leitao
Move the static buffers from send_msg_no_fragmentation() and send_msg_fragmented() into the netconsole_target structure. This simplifies the code by: - Eliminating redundant static buffers - Centralizing buffer management in the target structure - Reducing memory usage by 1KB (one buffer instead of two) The buffer in netconsole_target is protected by target_list_lock, maintaining the same synchronization semantics as the original code. Suggested-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Breno Leitao <leitao@debian.org> Reviewed-by: Simon Horman <horms@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2025-01-09netconsole: Warn if MAX_USERDATA_ITEMS limit is exceededBreno Leitao
netconsole configfs helpers doesn't allow the creation of more than MAX_USERDATA_ITEMS items. Add a warning when netconsole userdata update function attempts sees more than MAX_USERDATA_ITEMS entries. Replace silent ignore mechanism with WARN_ON_ONCE() to highlight potential misuse during development and debugging. Signed-off-by: Breno Leitao <leitao@debian.org> Reviewed-by: Simon Horman <horms@kernel.org> Link: https://patch.msgid.link/20250108-netcons_overflow_test-v3-1-3d85eb091bec@debian.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>