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path: root/drivers/net/netconsole.c
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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>
2024-12-04netcons: Add udp send fail statistics to netconsoleMaksym Kutsevol
Enhance observability of netconsole. Packet sends can fail. Start tracking at least two failure possibilities: ENOMEM and NET_XMIT_DROP for every target. Stats are exposed via an additional attribute in CONFIGFS. The exposed statistics allows easier debugging of cases when netconsole messages were not seen by receivers, eliminating the guesswork if the sender thinks that messages in question were sent out. Stats are not reset on enable/disable/change remote ip/etc, they belong to the netcons target itself. Reported-by: Breno Leitao <leitao@debian.org> Closes: https://lore.kernel.org/all/ZsWoUzyK5du9Ffl+@gmail.com/ Signed-off-by: Maksym Kutsevol <max@kutsevol.com> Link: https://patch.msgid.link/20241202-netcons-add-udp-send-fail-statistics-to-netconsole-v5-2-70e82239f922@kutsevol.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-10-22net: netconsole: split send_msg_fragmentedBreno Leitao
Refactor the send_msg_fragmented() function by extracting the logic for sending the message body into a new function called send_fragmented_body(). Now, send_msg_fragmented() handles appending the release and header, and then delegates the task of breaking up the body and sending the fragments to send_fragmented_body(). This is the final flow now: When send_ext_msg_udp() is called to send a message, it will: - call send_msg_no_fragmentation() if no fragmentation is needed or - call send_msg_fragmented() if fragmentation is needed * send_msg_fragmented() appends the header to the buffer, which is be persisted until the function returns * call send_fragmented_body() to iterate and populate the body of the message. It will not touch the header, and it will only replace the body, writing the msgbody and/or userdata. Also add some comment to make the code easier to review. Signed-off-by: Breno Leitao <leitao@debian.org> Reviewed-by: Simon Horman <horms@kernel.org> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2024-10-22net: netconsole: do not pass userdata up to the tailBreno Leitao
Do not pass userdata to send_msg_fragmented, since we can get it later. This will be more useful in the next patch, where send_msg_fragmented() will be split even more, and userdata is only necessary in the last function. Suggested-by: Simon Horman <horms@kernel.org> Signed-off-by: Breno Leitao <leitao@debian.org> Reviewed-by: Simon Horman <horms@kernel.org> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2024-10-22net: netconsole: extract release appending into separate functionBreno Leitao
Refactor the code by extracting the logic for appending the release into the buffer into a separate function. The goal is to reduce the size of send_msg_fragmented() and improve code readability. Signed-off-by: Breno Leitao <leitao@debian.org> Reviewed-by: Simon Horman <horms@kernel.org> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2024-10-22net: netconsole: track explicitly if msgbody was written to bufferBreno Leitao
The current check to determine if the message body was fully sent is difficult to follow. To improve clarity, introduce a variable that explicitly tracks whether the message body (msgbody) has been completely sent, indicating when it's time to begin sending userdata. Additionally, add comments to make the code more understandable for others who may work with it. Signed-off-by: Breno Leitao <leitao@debian.org> Reviewed-by: Simon Horman <horms@kernel.org> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2024-10-22net: netconsole: introduce variable to track body lengthBreno Leitao
This new variable tracks the total length of the data to be sent, encompassing both the message body (msgbody) and userdata, which is collectively called body. By explicitly defining body_len, the code becomes clearer and easier to reason about, simplifying offset calculations and improving overall readability of the function. Signed-off-by: Breno Leitao <leitao@debian.org> Reviewed-by: Simon Horman <horms@kernel.org> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2024-10-22net: netconsole: rename body to msg_bodyBreno Leitao
With the introduction of the userdata concept, the term body has become ambiguous and less intuitive. To improve clarity, body is renamed to msg_body, making it clear that the body is not the only content following the header. In an upcoming patch, the term body_len will also be revised for further clarity. The current packet structure is as follows: release, header, body, [msg_body + userdata] Here, [msg_body + userdata] collectively forms what is currently referred to as "body." This renaming helps to distinguish and better understand each component of the packet. Signed-off-by: Breno Leitao <leitao@debian.org> Reviewed-by: Simon Horman <horms@kernel.org> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2024-10-22net: netconsole: separate fragmented message handling in send_ext_msgBreno Leitao
Following the previous change, where the non-fragmented case was moved to its own function, this update introduces a new function called send_msg_fragmented to specifically manage scenarios where message fragmentation is required. Signed-off-by: Breno Leitao <leitao@debian.org> Reviewed-by: Simon Horman <horms@kernel.org> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2024-10-22net: netconsole: split send_ext_msg_udp() functionBreno Leitao
The send_ext_msg_udp() function has become quite large, currently spanning 102 lines. Its complexity, along with extensive pointer and offset manipulation, makes it difficult to read and error-prone. The function has evolved over time, and it’s now due for a refactor. To improve readability and maintainability, isolate the case where no message fragmentation occurs into a separate function, into a new send_msg_no_fragmentation() function. This scenario covers about 95% of the messages. Signed-off-by: Breno Leitao <leitao@debian.org> Reviewed-by: Simon Horman <horms@kernel.org> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2024-10-22net: netconsole: remove msg_ready variableBreno Leitao
Variable msg_ready is useless, since it does not represent anything. Get rid of it, using buf directly instead. Signed-off-by: Breno Leitao <leitao@debian.org> Reviewed-by: Simon Horman <horms@kernel.org> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2024-10-09net: netconsole: fix wrong warningBreno Leitao
A warning is triggered when there is insufficient space in the buffer for userdata. However, this is not an issue since userdata will be sent in the next iteration. Current warning message: ------------[ cut here ]------------ WARNING: CPU: 13 PID: 3013042 at drivers/net/netconsole.c:1122 write_ext_msg+0x3b6/0x3d0 ? write_ext_msg+0x3b6/0x3d0 console_flush_all+0x1e9/0x330 The code incorrectly issues a warning when this_chunk is zero, which is a valid scenario. The warning should only be triggered when this_chunk is negative. Fixes: 1ec9daf95093 ("net: netconsole: append userdata to fragmented netconsole messages") Signed-off-by: Breno Leitao <leitao@debian.org> Reviewed-by: Simon Horman <horms@kernel.org> Link: https://patch.msgid.link/20241008094325.896208-1-leitao@debian.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-08-26net: netconsole: Populate dynamic entry even if netpoll failsBreno Leitao
Currently, netconsole discards targets that fail during initialization, causing two issues: 1) Inconsistency between target list and configfs entries * user pass cmdline0, cmdline1. If cmdline0 fails, then cmdline1 becomes cmdline0 in configfs. 2) Inability to manage failed targets from userspace * If user pass a target that fails with netpoll (interface not loaded at netcons initialization time, such as interface is a module), then the target will not exist in the configfs, so, user cannot re-enable or modify it from userspace. Failed targets are now added to the target list and configfs, but remain disabled until manually enabled or reconfigured. This change does not change the behaviour if CONFIG_NETCONSOLE_DYNAMIC is not set. CC: Aijay Adams <aijay@meta.com> Signed-off-by: Breno Leitao <leitao@debian.org> Link: https://patch.msgid.link/20240822111051.179850-3-leitao@debian.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-08-13net: netconsole: Constify struct config_item_typeChristophe JAILLET
'struct config_item_type' is not modified in this driver. This structure is only used with config_group_init_type_name() which takes a const struct config_item_type* as a 3rd argument. This also makes things consistent with 'netconsole_target_type' witch is already const. Constifying this structure moves some data to a read-only section, so increase overall security, especially when the structure holds some function pointers. On a x86_64, with allmodconfig: Before: ====== text data bss dec hex filename 33007 3952 1312 38271 957f drivers/net/netconsole.o After: ===== text data bss dec hex filename 33071 3888 1312 38271 957f drivers/net/netconsole.o Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr> Reviewed-by: Breno Leitao <leitao@debian.org> Link: https://patch.msgid.link/9c205b2b4bdb09fc9e9d2cb2f2936ec053da1b1b.1723325900.git.christophe.jaillet@wanadoo.fr Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-08-13net: netconsole: Defer netpoll cleanup to avoid lock release during list ↵Breno Leitao
traversal Current issue: - The `target_list_lock` spinlock is held while iterating over target_list() entries. - Mid-loop, the lock is released to call __netpoll_cleanup(), then reacquired. - This practice compromises the protection provided by `target_list_lock`. Reason for current design: 1. __netpoll_cleanup() may sleep, incompatible with holding a spinlock. 2. target_list_lock must be a spinlock because write_msg() cannot sleep. (See commit b5427c27173e ("[NET] netconsole: Support multiple logging targets")) Defer the cleanup of the netpoll structure to outside the target_list_lock() protected area. Create another list (target_cleanup_list) to hold the entries that need to be cleaned up, and clean them using a mutex (target_cleanup_list_lock). Signed-off-by: Breno Leitao <leitao@debian.org> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2024-08-13net: netconsole: Unify Function Return PathsBreno Leitao
The return flow in netconsole's dynamic functions is currently inconsistent. This patch aims to streamline and standardize the process by ensuring that the mutex is unlocked before returning the ret value. Additionally, this update includes a minor functional change where certain strnlen() operations are performed with the dynamic_netconsole_mutex locked. This adjustment is not anticipated to cause any issues, however, it is crucial to document this change for clarity. Signed-off-by: Breno Leitao <leitao@debian.org> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2024-08-13net: netconsole: Standardize variable namingBreno Leitao
Update variable names from err to ret in cases where the variable may return non-error values. This change facilitates a forthcoming patch that relies on ret being used consistently to handle return values, regardless of whether they indicate an error or not. Signed-off-by: Breno Leitao <leitao@debian.org> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2024-08-13net: netconsole: Correct mismatched return typesBreno Leitao
netconsole incorrectly mixes int and ssize_t types by using int for return variables in functions that should return ssize_t. This is fixed by updating the return variables to the appropriate ssize_t type, ensuring consistency across the function definitions. Signed-off-by: Breno Leitao <leitao@debian.org> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2024-08-05net: netconsole: Fix MODULE_AUTHOR formatBreno Leitao
Update the MODULE_AUTHOR for netconsole, according to the format, as stated in module.h: use "Name <email>" or just "Name" Suggested-by: Stephen Hemminger <stephen@networkplumber.org> Signed-off-by: Breno Leitao <leitao@debian.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2024-07-15Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski
Merge in late fixes to prepare for the 6.11 net-next PR. Conflicts: 93c3a96c301f ("net: pse-pd: Do not return EOPNOSUPP if config is null") 4cddb0f15ea9 ("net: ethtool: pse-pd: Fix possible null-deref") 30d7b6727724 ("net: ethtool: Add new power limit get and set features") https://lore.kernel.org/20240715123204.623520bb@canb.auug.org.au/ Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-07-14net: netconsole: Disable target before netpoll cleanupBreno Leitao
Currently, netconsole cleans up the netpoll structure before disabling the target. This approach can lead to race conditions, as message senders (write_ext_msg() and write_msg()) check if the target is enabled before using netpoll. The sender can validate that the target is enabled, but, the netpoll might be de-allocated already, causing undesired behaviours. This patch reverses the order of operations: 1. Disable the target 2. Clean up the netpoll structure This change eliminates the potential race condition, ensuring that no messages are sent through a partially cleaned-up netpoll structure. Fixes: 2382b15bcc39 ("netconsole: take care of NETDEV_UNREGISTER event") Cc: stable@vger.kernel.org Signed-off-by: Breno Leitao <leitao@debian.org> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20240712143415.1141039-1-leitao@debian.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-07-11net: netconsole: Eliminate redundant setting of enabled fieldBreno Leitao
When disabling a netconsole target, enabled_store() is called with enabled=false. Currently, this results in updating the nt->enabled field twice: 1. Inside the if/else block, with the target_list_lock spinlock held 2. Later, without the target_list_lock This patch eliminates the redundancy by setting the field only once, improving efficiency and reducing potential race conditions. Signed-off-by: Breno Leitao <leitao@debian.org> Link: https://patch.msgid.link/20240709144403.544099-3-leitao@debian.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-07-11net: netconsole: Remove unnecessary cast from boolBreno Leitao
The 'enabled' variable is already a bool, so casting it to its value is redundant. Remove the superfluous cast, improving code clarity without changing functionality. Signed-off-by: Breno Leitao <leitao@debian.org> Link: https://patch.msgid.link/20240709144403.544099-2-leitao@debian.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-05-29netconsole: Do not shutdown dynamic configuration if cmdline is invalidBreno Leitao
If a user provides an invalid netconsole configuration during boot time (e.g., specifying an invalid ethX interface), netconsole will be entirely disabled. Consequently, the user won't be able to create new entries in /sys/kernel/config/netconsole/ as that directory does not exist. Apart from misconfiguration, another issue arises when ethX is loaded as a module and the netconsole= line in the command line points to ethX, resulting in an obvious failure. This renders netconsole unusable, as /sys/kernel/config/netconsole/ will never appear. This is more annoying since users reconfigure (or just toggle) the configuratin later (see commit 5fbd6cdbe304b ("netconsole: Attach cmdline target to dynamic target")) Create /sys/kernel/config/netconsole/ even if the command line arguments are invalid, so, users can create dynamic entries in netconsole. Reported-by: Aijay Adams <aijay@meta.com> Signed-off-by: Breno Leitao <leitao@debian.org> Link: https://lore.kernel.org/r/20240528084225.3215853-1-leitao@debian.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-03-11net: netconsole: Add continuation line prefix to userdata messagesMatthew Wood
Add a space (' ') prefix to every userdata line to match docs for dev-kmsg. To account for this extra character in each userdata entry, reduce userdata entry names (directory name) from 54 characters to 53. According to the dev-kmsg docs, a space is used for subsequent lines to mark them as continuation lines. > A line starting with ' ', is a continuation line, adding > key/value pairs to the log message, which provide the machine > readable context of the message, for reliable processing in > userspace. Testing for this patch:: cd /sys/kernel/config/netconsole && mkdir cmdline0 cd cmdline0 mkdir userdata/test && echo "hello" > userdata/test/value mkdir userdata/test2 && echo "hello2" > userdata/test2/value echo "message" > /dev/kmsg Outputs:: 6.8.0-rc5-virtme,12,493,231373579,-;message test=hello test2=hello2 And I confirmed all testing works as expected from the original patchset Fixes: df03f830d099 ("net: netconsole: cache userdata formatted string in netconsole_target") Signed-off-by: Matthew Wood <thepacketgeek@gmail.com> Reviewed-by: Breno Leitao <leitao@debian.org> Link: https://lore.kernel.org/r/20240308002525.248672-1-thepacketgeek@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-02-09net: netconsole: append userdata to fragmented netconsole messagesMatthew Wood
Regardless of whether the original message body or formatted userdata exceeds the MAX_PRINT_CHUNK, append userdata to the netconsole message starting with the first chunk that has available space after writing the body. Co-developed-by: Breno Leitao <leitao@debian.org> Signed-off-by: Breno Leitao <leitao@debian.org> Signed-off-by: Matthew Wood <thepacketgeek@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2024-02-09net: netconsole: append userdata to netconsole messagesMatthew Wood
Append userdata to outgoing unfragmented (<1000 bytes) netconsole messages. When sending messages the userdata string is already formatted and stored in netconsole_target->userdata_complete. Always write the outgoing message to buf, so userdata can be appended in a standard fashion. This is a change from only using buf when the release needs to be prepended to the message. Co-developed-by: Breno Leitao <leitao@debian.org> Signed-off-by: Breno Leitao <leitao@debian.org> Signed-off-by: Matthew Wood <thepacketgeek@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2024-02-09net: netconsole: cache userdata formatted string in netconsole_targetMatthew Wood
Store a formatted string for userdata that will be appended to netconsole messages. The string has a capacity of 4KB, as calculated by the userdatum entry length of 256 bytes and a max of 16 userdata entries. Update the stored netconsole_target->userdata_complete string with the new formatted userdata values when a userdatum is created, edited, or removed. Each userdata entry contains a trailing newline, which will be formatted as such in netconsole messages:: 6.7.0-rc8-virtme,12,500,1646292204,-;test release=foo something=bar 6.7.0-rc8-virtme,12,500,1646292204,-;another test release=foo something=bar Enforcement of MAX_USERDATA_ITEMS is done in userdatum_make_item; update_userdata will not check for this case but will skip any userdata children over the limit of MAX_USERDATA_ITEMs. If a userdata entry/dir is created but no value is provided, that entry will be skipped. This is in part because update_userdata() can't be called in userdatum_make_item() since the item will not have been added to the userdata config_group children yet. To preserve the experience of adding an empty userdata that doesn't show up in the netconsole messages, purposefully skip empty userdata items even when update_userdata() can be called. Co-developed-by: Breno Leitao <leitao@debian.org> Signed-off-by: Breno Leitao <leitao@debian.org> Signed-off-by: Matthew Wood <thepacketgeek@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2024-02-09net: netconsole: add a userdata config_group member to netconsole_targetMatthew Wood
Create configfs machinery for netconsole userdata appending, which depends on CONFIG_NETCONSOLE_DYNAMIC (for configfs interface). Add a userdata config_group to netconsole_target for managing userdata entries as a tree under the netconsole configfs subsystem. Directory names created under the userdata directory become userdatum keys; the userdatum value is the content of the value file. Include the minimum-viable-changes for userdata configfs config_group. init_target_config_group() ties in the complete configfs machinery to avoid unused func/variable errors during build. Initializing the netconsole_target->group is moved to init_target_config_group, which will also init and add the userdata config_group. Each userdatum entry has a limit of 256 bytes (54 for the key/directory, 200 for the value, and 2 for '=' and '\n' characters), which is enforced by the configfs functions for updating the userdata config_group. When a new netconsole_target is created, initialize the userdata config_group and add it as a default group for netconsole_target config_group, allowing the userdata configfs sub-tree to be presented in the netconsole configfs tree under the userdata directory. Co-developed-by: Breno Leitao <leitao@debian.org> Signed-off-by: Breno Leitao <leitao@debian.org> Signed-off-by: Matthew Wood <thepacketgeek@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2024-02-09net: netconsole: move newline trimming to functionMatthew Wood
Move newline trimming logic from `dev_name_store()` to a new function (trim_newline()) for shared use in netconsole.c Signed-off-by: Matthew Wood <thepacketgeek@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2024-02-09net: netconsole: move netconsole_target config_item to config_groupMatthew Wood
In order to support a nested userdata config_group in later patches, use a config_group for netconsole_target instead of a config_item. It's a no-op functionality-wise, since config_group maintains all features of a config_item via the cg_item member. Signed-off-by: Matthew Wood <thepacketgeek@gmail.com> Reviewed-by: Breno Leitao <leitao@debian.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2024-02-09net: netconsole: cleanup formatting lintsMatthew Wood
Address checkpatch lint suggestions in preparation for later changes Signed-off-by: Matthew Wood <thepacketgeek@gmail.com> Reviewed-by: Breno Leitao <leitao@debian.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-10-13netconsole: Attach cmdline target to dynamic targetBreno Leitao
Enable the attachment of a dynamic target to the target created during boot time. The boot-time targets are named as "cmdline\d", where "\d" is a number starting at 0. If the user creates a dynamic target named "cmdline0", it will attach to the first target created at boot time (as defined in the `netconsole=...` command line argument). `cmdline1` will attach to the second target and so forth. If there is no netconsole target created at boot time, then, the target name could be reused. Relevant design discussion: https://lore.kernel.org/all/ZRWRal5bW93px4km@gmail.com/ Suggested-by: Joel Becker <jlbec@evilplan.org> Signed-off-by: Breno Leitao <leitao@debian.org> Link: https://lore.kernel.org/r/20231012111401.333798-4-leitao@debian.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>