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* dump_stack: Do not get cpu_sync for panic CPUJohn Ogness2024-02-073-4/+15
| | | | | | | | | | | | | | | | | | | dump_stack() is called in panic(). If for some reason another CPU is holding the printk_cpu_sync and is unable to release it, the panic CPU will be unable to continue and print the stacktrace. Since non-panic CPUs are not allowed to store new printk messages anyway, there is no need to synchronize the stacktrace output in a panic situation. For the panic CPU, do not get the printk_cpu_sync because it is not needed and avoids a potential deadlock scenario in panic(). Link: https://lore.kernel.org/lkml/ZcIGKU8sxti38Kok@alley Signed-off-by: John Ogness <john.ogness@linutronix.de> Reviewed-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20240207134103.1357162-15-john.ogness@linutronix.de Signed-off-by: Petr Mladek <pmladek@suse.com>
* panic: Flush kernel log buffer at the endJohn Ogness2024-02-071-0/+8
| | | | | | | | | | | | | | | | | If the kernel crashes in a context where printk() calls always defer printing (such as in NMI or inside a printk_safe section) then the final panic messages will be deferred to irq_work. But if irq_work is not available, the messages will not get printed unless explicitly flushed. The result is that the final "end Kernel panic" banner does not get printed. Add one final flush after the last printk() call to make sure the final panic messages make it out as well. Signed-off-by: John Ogness <john.ogness@linutronix.de> Reviewed-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20240207134103.1357162-14-john.ogness@linutronix.de Signed-off-by: Petr Mladek <pmladek@suse.com>
* printk: Avoid non-panic CPUs writing to ringbufferJohn Ogness2024-02-071-20/+6
| | | | | | | | | | | | | | | | | | | | | | | Commit 13fb0f74d702 ("printk: Avoid livelock with heavy printk during panic") introduced a mechanism to silence non-panic CPUs if too many messages are being dropped. Aside from trying to workaround the livelock bugs of legacy consoles, it was also intended to avoid losing panic messages. However, if non-panic CPUs are writing to the ringbuffer, then reacting to dropped messages is too late. Another motivation is that non-finalized messages already might be skipped in panic(). In other words, random messages from non-panic CPUs might already get lost. It is better to ignore all to avoid confusion. To avoid losing panic CPU messages, silence non-panic CPUs immediately on panic. Signed-off-by: John Ogness <john.ogness@linutronix.de> Reviewed-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20240207134103.1357162-13-john.ogness@linutronix.de Signed-off-by: Petr Mladek <pmladek@suse.com>
* printk: Disable passing console lock owner completely during panic()Petr Mladek2024-02-071-0/+29
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The commit d51507098ff91 ("printk: disable optimistic spin during panic") added checks to avoid becoming a console waiter if a panic is in progress. However, the transition to panic can occur while there is already a waiter. The current owner should not pass the lock to the waiter because it might get stopped or blocked anytime. Also the panic context might pass the console lock owner to an already stopped waiter by mistake. It might happen when console_flush_on_panic() ignores the current lock owner, for example: CPU0 CPU1 ---- ---- console_lock_spinning_enable() console_trylock_spinning() [CPU1 now console waiter] NMI: panic() panic_other_cpus_shutdown() [stopped as console waiter] console_flush_on_panic() console_lock_spinning_enable() [print 1 record] console_lock_spinning_disable_and_check() [handover to stopped CPU1] This results in panic() not flushing the panic messages. Fix these problems by disabling all spinning operations completely during panic(). Another advantage is that it prevents possible deadlocks caused by "console_owner_lock". The panic() context does not need to take it any longer. The lockless checks are safe because the functions become NOPs when they see the panic in progress. All operations manipulating the state are still synchronized by the lock even when non-panic CPUs would notice the panic synchronously. The current owner might stay spinning. But non-panic() CPUs would get stopped anyway and the panic context will never start spinning. Fixes: dbdda842fe96 ("printk: Add console owner and waiter logic to load balance console writes") Signed-off-by: John Ogness <john.ogness@linutronix.de> Link: https://lore.kernel.org/r/20240207134103.1357162-12-john.ogness@linutronix.de Signed-off-by: Petr Mladek <pmladek@suse.com>
* printk: ringbuffer: Skip non-finalized records in panicJohn Ogness2024-02-071-2/+26
| | | | | | | | | | | | | | | | | | | Normally a reader will stop once reaching a non-finalized record. However, when a panic happens, writers from other CPUs (or an interrupted context on the panic CPU) may have been writing a record and were unable to finalize it. The panic CPU will reserve/commit/finalize its panic records, but these will be located after the non-finalized records. This results in panic() not flushing the panic messages. Extend _prb_read_valid() to skip over non-finalized records if on the panic CPU. Fixes: 896fbe20b4e2 ("printk: use the lockless ringbuffer") Signed-off-by: John Ogness <john.ogness@linutronix.de> Reviewed-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20240207134103.1357162-11-john.ogness@linutronix.de Signed-off-by: Petr Mladek <pmladek@suse.com>
* printk: Wait for all reserved records with pr_flush()John Ogness2024-02-073-1/+107
| | | | | | | | | | | | | | | | | | | | | Currently pr_flush() will only wait for records that were available to readers at the time of the call (using prb_next_seq()). But there may be more records (non-finalized) that have following finalized records. pr_flush() should wait for these to print as well. Particularly because any trailing finalized records may be the messages that the calling context wants to ensure are printed. Add a new ringbuffer function prb_next_reserve_seq() to return the sequence number following the most recently reserved record. This guarantees that pr_flush() will wait until all current printk() messages (completed or in progress) have been printed. Fixes: 3b604ca81202 ("printk: add pr_flush()") Signed-off-by: John Ogness <john.ogness@linutronix.de> Reviewed-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20240207134103.1357162-10-john.ogness@linutronix.de Signed-off-by: Petr Mladek <pmladek@suse.com>
* printk: ringbuffer: Cleanup reader terminologyJohn Ogness2024-02-071-7/+9
| | | | | | | | | | | | | | | | With the lockless ringbuffer, it is allowed that multiple CPUs/contexts write simultaneously into the buffer. This creates an ambiguity as some writers will finalize sooner. The documentation for the prb_read functions is not clear as it refers to "not yet written" and "no data available". Clarify the return values and language to be in terms of the reader: records available for reading. Signed-off-by: John Ogness <john.ogness@linutronix.de> Reviewed-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20240207134103.1357162-9-john.ogness@linutronix.de Signed-off-by: Petr Mladek <pmladek@suse.com>
* printk: Add this_cpu_in_panic()John Ogness2024-02-072-20/+24
| | | | | | | | | | | | | There is already panic_in_progress() and other_cpu_in_panic(), but checking if the current CPU is the panic CPU must still be open coded. Add this_cpu_in_panic() to complete the set. Signed-off-by: John Ogness <john.ogness@linutronix.de> Reviewed-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20240207134103.1357162-8-john.ogness@linutronix.de Signed-off-by: Petr Mladek <pmladek@suse.com>
* printk: For @suppress_panic_printk check for other CPU in panicJohn Ogness2024-02-071-2/+1
| | | | | | | | | | | | | | | | Currently @suppress_panic_printk is checked along with non-matching @panic_cpu and current CPU. This works because @suppress_panic_printk is only set when panic_in_progress() is true. Rather than relying on the @suppress_panic_printk semantics, use the concise helper function other_cpu_in_progress(). The helper function exists to avoid open coding such tests. Signed-off-by: John Ogness <john.ogness@linutronix.de> Reviewed-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20240207134103.1357162-7-john.ogness@linutronix.de Signed-off-by: Petr Mladek <pmladek@suse.com>
* printk: ringbuffer: Clarify special lpos valuesJohn Ogness2024-02-072-5/+31
| | | | | | | | | | | | | | | | | | | | | | For empty line records, no data blocks are created. Instead, these valid records are identified by special logical position values (in fields of @prb_desc.text_blk_lpos). Currently the macro NO_LPOS is used for empty line records. This name is confusing because it does not imply _why_ there is no data block. Rename NO_LPOS to EMPTY_LINE_LPOS so that it is clear why there is no data block. Also add comments explaining the use of EMPTY_LINE_LPOS as well as clarification to the values used to represent data-less blocks. Signed-off-by: John Ogness <john.ogness@linutronix.de> Reviewed-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20240207134103.1357162-6-john.ogness@linutronix.de Signed-off-by: Petr Mladek <pmladek@suse.com>
* printk: ringbuffer: Do not skip non-finalized records with prb_next_seq()John Ogness2024-02-072-41/+127
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit f244b4dc53e5 ("printk: ringbuffer: Improve prb_next_seq() performance") introduced an optimization for prb_next_seq() by using best-effort to track recently finalized records. However, the order of finalization does not necessarily match the order of the records. The optimization changed prb_next_seq() to return inconsistent results, possibly yielding sequence numbers that are not available to readers because they are preceded by non-finalized records or they are not yet visible to the reader CPU. Rather than simply best-effort tracking recently finalized records, force the committing writer to read records and increment the last "contiguous block" of finalized records. In order to do this, the sequence number instead of ID must be stored because ID's cannot be directly compared. A new memory barrier pair is introduced to guarantee that a reader can always read the records up until the sequence number returned by prb_next_seq() (unless the records have since been overwritten in the ringbuffer). This restores the original functionality of prb_next_seq() while also keeping the optimization. For 32bit systems, only the lower 32 bits of the sequence number are stored. When reading the value, it is expanded to the full 64bit sequence number using the 32bit seq macros, which fold in the value returned by prb_first_seq(). Fixes: f244b4dc53e5 ("printk: ringbuffer: Improve prb_next_seq() performance") Signed-off-by: John Ogness <john.ogness@linutronix.de> Reviewed-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20240207134103.1357162-5-john.ogness@linutronix.de Signed-off-by: Petr Mladek <pmladek@suse.com>
* printk: Use prb_first_seq() as base for 32bit seq macrosJohn Ogness2024-02-072-5/+5
| | | | | | | | | | | | | | | | | | | Note: This change only applies to 32bit architectures. On 64bit architectures the macros are NOPs. Currently prb_next_seq() is used as the base for the 32bit seq macros __u64seq_to_ulseq() and __ulseq_to_u64seq(). However, in a follow-up commit, prb_next_seq() will need to make use of the 32bit seq macros. Use prb_first_seq() as the base for the 32bit seq macros instead because it is guaranteed to return 64bit sequence numbers without relying on any 32bit seq macros. Signed-off-by: John Ogness <john.ogness@linutronix.de> Reviewed-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20240207134103.1357162-4-john.ogness@linutronix.de Signed-off-by: Petr Mladek <pmladek@suse.com>
* printk: Adjust mapping for 32bit seq macrosSebastian Andrzej Siewior2024-02-071-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Note: This change only applies to 32bit architectures. On 64bit architectures the macros are NOPs. __ulseq_to_u64seq() computes the upper 32 bits of the passed argument value (@ulseq). The upper bits are derived from a base value (@rb_next_seq) in a way that assumes @ulseq represents a 64bit number that is less than or equal to @rb_next_seq. Until now this mapping has been correct for all call sites. However, in a follow-up commit, values of @ulseq will be passed in that are higher than the base value. This requires a change to how the 32bit value is mapped to a 64bit sequence number. Rather than mapping @ulseq such that the base value is the end of a 32bit block, map @ulseq such that the base value is in the middle of a 32bit block. This allows supporting 31 bits before and after the base value, which is deemed acceptable for the console sequence number during runtime. Here is an example to illustrate the previous and new mappings. For a base value (@rb_next_seq) of 2 2000 0000... Before this change the range of possible return values was: 1 2000 0001 to 2 2000 0000 __ulseq_to_u64seq(1fff ffff) => 2 1fff ffff __ulseq_to_u64seq(2000 0000) => 2 2000 0000 __ulseq_to_u64seq(2000 0001) => 1 2000 0001 __ulseq_to_u64seq(9fff ffff) => 1 9fff ffff __ulseq_to_u64seq(a000 0000) => 1 a000 0000 __ulseq_to_u64seq(a000 0001) => 1 a000 0001 After this change the range of possible return values are: 1 a000 0001 to 2 a000 0000 __ulseq_to_u64seq(1fff ffff) => 2 1fff ffff __ulseq_to_u64seq(2000 0000) => 2 2000 0000 __ulseq_to_u64seq(2000 0001) => 2 2000 0001 __ulseq_to_u64seq(9fff ffff) => 2 9fff ffff __ulseq_to_u64seq(a000 0000) => 2 a000 0000 __ulseq_to_u64seq(a000 0001) => 1 a000 0001 [ john.ogness: Rewrite commit message. ] Reported-by: Francesco Dolcini <francesco@dolcini.it> Reported-by: kernel test robot <oliver.sang@intel.com> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: John Ogness <john.ogness@linutronix.de> Reviewed-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20240207134103.1357162-3-john.ogness@linutronix.de Signed-off-by: Petr Mladek <pmladek@suse.com>
* printk: nbcon: Relocate 32bit seq macrosJohn Ogness2024-02-072-37/+37
| | | | | | | | | | | | | | | | | | | | | | The macros __seq_to_nbcon_seq() and __nbcon_seq_to_seq() are used to provide support for atomic handling of sequence numbers on 32bit systems. Until now this was only used by nbcon.c, which is why they were located in nbcon.c and include nbcon in the name. In a follow-up commit this functionality is also needed by printk_ringbuffer. Rather than duplicating the functionality, relocate the macros to printk_ringbuffer.h. Also, since the macros will be no longer nbcon-specific, rename them to __u64seq_to_ulseq() and __ulseq_to_u64seq(). This does not result in any functional change. Signed-off-by: John Ogness <john.ogness@linutronix.de> Reviewed-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20240207134103.1357162-2-john.ogness@linutronix.de Signed-off-by: Petr Mladek <pmladek@suse.com>
* Merge tag 'printk-for-6.7' of ↵Linus Torvalds2023-11-036-78/+1288
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux Pull printk updates from Petr Mladek: - Another preparation step for introducing printk kthreads. The main piece is a per-console lock with several features: - Support three priorities: normal, emergency, and panic. They will be defined by a context where the lock is taken. A context with a higher priority is allowed to take over the lock from a context with a lower one. The plan is to use the emergency context for Oops and WARN() messages, and also by watchdogs. The panic() context will be used on panic CPU. - The owner might enter/exit regions where it is not safe to take over the lock. It allows the take over the lock a safe way in the middle of a message. For example, serial drivers emit characters one by one. And the serial port is in a safe state in between. Only the final console_flush_in_panic() will be allowed to take over the lock even in the unsafe state (last chance, pray, and hope). - A higher priority context might busy wait with a timeout. The current owner is informed about the waiter and releases the lock on exit from the unsafe state. - The new lock is safe even in atomic contexts, including NMI. Another change is a safe manipulation of per-console sequence number counter under the new lock. - simple_strntoull() micro-optimization - Reduce pr_flush() pooling time. - Calm down false warning about possible buffer invalid access to console buffers when CONFIG_PRINTK is disabled. [ .. and Thomas Gleixner wants to point out that while several of the commits are attributed to him, he only authored the early versions of said commits, and that John Ogness and Petr Mladek have been the ones who sorted out the details and really should be those who get the credit - Linus ] * tag 'printk-for-6.7' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux: vsprintf: uninline simple_strntoull(), reorder arguments printk: printk: Remove unnecessary statements＇len = 0;＇ printk: Reduce pr_flush() pooling time printk: fix illegal pbufs access for !CONFIG_PRINTK printk: nbcon: Allow drivers to mark unsafe regions and check state printk: nbcon: Add emit function and callback function for atomic printing printk: nbcon: Add sequence handling printk: nbcon: Add ownership state functions printk: nbcon: Add buffer management printk: Make static printk buffers available to nbcon printk: nbcon: Add acquire/release logic printk: Add non-BKL (nbcon) console basic infrastructure
| * Merge branch 'rework/nbcon-base' into for-linusPetr Mladek2023-11-025-50/+1263
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| | * printk: fix illegal pbufs access for !CONFIG_PRINTKJohn Ogness2023-09-211-26/+18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When CONFIG_PRINTK is not set, PRINTK_MESSAGE_MAX is 0. This leads to a zero-sized array @outbuf in @printk_shared_pbufs. In console_flush_all() a pointer to the first element of the array is assigned with: char *outbuf = &printk_shared_pbufs.outbuf[0]; For !CONFIG_PRINTK this leads to a compiler warning: warning: array subscript 0 is outside array bounds of 'char[0]' [-Warray-bounds] This is not really dangerous because printk_get_next_message() always returns false for !CONFIG_PRINTK, which leads to @outbuf never being used. However, it makes no sense to even compile these functions for !CONFIG_PRINTK. Extend the existing '#ifdef CONFIG_PRINTK' block to contain the formatting and emitting functions since these have no purpose in !CONFIG_PRINTK. This also allows removing several more !CONFIG_PRINTK dummies as well as moving @suppress_panic_printk into a CONFIG_PRINTK block. Reported-by: kernel test robot <lkp@intel.com> Closes: https://lore.kernel.org/oe-kbuild-all/202309201724.M9BMAQIh-lkp@intel.com/ Signed-off-by: John Ogness <john.ogness@linutronix.de> Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org> Signed-off-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20230920155238.670439-1-john.ogness@linutronix.de
| | * printk: nbcon: Allow drivers to mark unsafe regions and check stateThomas Gleixner2023-09-182-0/+85
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | For the write_atomic callback, the console driver may have unsafe regions that need to be appropriately marked. Provide functions that accept the nbcon_write_context struct to allow for the driver to enter and exit unsafe regions. Also provide a function for drivers to check if they are still the owner of the console. Co-developed-by: John Ogness <john.ogness@linutronix.de> Signed-off-by: John Ogness <john.ogness@linutronix.de> Signed-off-by: Thomas Gleixner (Intel) <tglx@linutronix.de> Reviewed-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20230916192007.608398-9-john.ogness@linutronix.de
| | * printk: nbcon: Add emit function and callback function for atomic printingThomas Gleixner2023-09-184-8/+134
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Implement an emit function for nbcon consoles to output printk messages. It utilizes the lockless printk_get_next_message() and console_prepend_dropped() functions to retrieve/build the output message. The emit function includes the required safety points to check for handover/takeover and calls a new write_atomic callback of the console driver to output the message. It also includes proper handling for updating the nbcon console sequence number. A new nbcon_write_context struct is introduced. This is provided to the write_atomic callback and includes only the information necessary for performing atomic writes. Co-developed-by: John Ogness <john.ogness@linutronix.de> Signed-off-by: John Ogness <john.ogness@linutronix.de> Signed-off-by: Thomas Gleixner (Intel) <tglx@linutronix.de> Reviewed-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20230916192007.608398-8-john.ogness@linutronix.de
| | * printk: nbcon: Add sequence handlingThomas Gleixner2023-09-184-7/+136
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add an atomic_long_t field @nbcon_seq to the console struct to store the sequence number for nbcon consoles. For nbcon consoles this will be used instead of the non-atomic @seq field. The new field allows for safe atomic sequence number updates without requiring any locking. On 64bit systems the new field stores the full sequence number. On 32bit systems the new field stores the lower 32 bits of the sequence number, which are expanded to 64bit as needed by folding the values based on the sequence numbers available in the ringbuffer. For 32bit systems, having a 32bit representation in the console is sufficient. If a console ever gets more than 2^31 records behind the ringbuffer then this is the least of the problems. Co-developed-by: John Ogness <john.ogness@linutronix.de> Signed-off-by: John Ogness <john.ogness@linutronix.de> Signed-off-by: Thomas Gleixner (Intel) <tglx@linutronix.de> Signed-off-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20230916192007.608398-7-john.ogness@linutronix.de
| | * printk: nbcon: Add ownership state functionsThomas Gleixner2023-09-181-1/+122
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Provide functions that are related to the safe handover mechanism and allow console drivers to dynamically specify unsafe regions: - nbcon_context_can_proceed() Invoked by a console owner to check whether a handover request is pending or whether the console has been taken over by another context. If a handover request is pending, this function will also perform the handover, thus cancelling its own ownership. - nbcon_context_enter_unsafe()/nbcon_context_exit_unsafe() Invoked by a console owner to denote that the driver is about to enter or leave a critical region where a take over is unsafe. The exit variant is the point where the current owner releases the lock for a higher priority context which asked for the friendly handover. The unsafe state is stored in the console state and allows a new context to make informed decisions whether to attempt a takeover of such a console. The unsafe state is also available to the driver so that it can make informed decisions about the required actions and possibly take a special emergency path. Co-developed-by: John Ogness <john.ogness@linutronix.de> Signed-off-by: John Ogness <john.ogness@linutronix.de> Signed-off-by: Thomas Gleixner (Intel) <tglx@linutronix.de> Reviewed-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20230916192007.608398-6-john.ogness@linutronix.de
| | * printk: nbcon: Add buffer managementThomas Gleixner2023-09-184-15/+99
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In case of hostile takeovers it must be ensured that the previous owner cannot scribble over the output buffer of the emergency/panic context. This is achieved by: - Adding a global output buffer instance for the panic context. This is the only situation where hostile takeovers can occur and there is always at most 1 panic context. - Allocating an output buffer per non-boot console upon console registration. This buffer is used by the console owner when not in panic context. (For boot consoles, the existing shared global legacy output buffer is used instead. Boot console printing will be synchronized with legacy console printing.) - Choosing the appropriate buffer is handled in the acquire/release functions. Co-developed-by: John Ogness <john.ogness@linutronix.de> Signed-off-by: John Ogness <john.ogness@linutronix.de> Signed-off-by: Thomas Gleixner (Intel) <tglx@linutronix.de> Reviewed-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20230916192007.608398-5-john.ogness@linutronix.de
| | * printk: Make static printk buffers available to nbconJohn Ogness2023-09-182-4/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The nbcon boot consoles also need printk buffers that are available very early. Since the nbcon boot consoles will also be serialized by the console_lock, they can use the same static printk buffers that the legacy consoles are using. Make the legacy static printk buffers available outside of printk.c so they can be used by nbcon.c. Signed-off-by: John Ogness <john.ogness@linutronix.de> Reviewed-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20230916192007.608398-4-john.ogness@linutronix.de
| | * printk: nbcon: Add acquire/release logicThomas Gleixner2023-09-182-0/+553
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add per console acquire/release functionality. The state of the console is maintained in the "nbcon_state" atomic variable. The console is locked when: - The 'prio' field contains the priority of the context that owns the console. Only higher priority contexts are allowed to take over the lock. A value of 0 (NBCON_PRIO_NONE) means the console is not locked. - The 'cpu' field denotes on which CPU the console is locked. It is used to prevent busy waiting on the same CPU. Also it informs the lock owner that it has lost the lock in a more complex scenario when the lock was taken over by a higher priority context, released, and taken on another CPU with the same priority as the interrupted owner. The acquire mechanism uses a few more fields: - The 'req_prio' field is used by the handover approach to make the current owner aware that there is a context with a higher priority waiting for the friendly handover. - The 'unsafe' field allows to take over the console in a safe way in the middle of emitting a message. The field is set only when accessing some shared resources or when the console device is manipulated. It can be cleared, for example, after emitting one character when the console device is in a consistent state. - The 'unsafe_takeover' field is set when a hostile takeover took the console in an unsafe state. The console will stay in the unsafe state until re-initialized. The acquire mechanism uses three approaches: 1) Direct acquire when the console is not owned or is owned by a lower priority context and is in a safe state. 2) Friendly handover mechanism uses a request/grant handshake. It is used when the current owner has lower priority and the console is in an unsafe state. The requesting context: a) Sets its priority into the 'req_prio' field. b) Waits (with a timeout) for the owning context to unlock the console. c) Takes the lock and clears the 'req_prio' field. The owning context: a) Observes the 'req_prio' field set on exit from the unsafe console state. b) Gives up console ownership by clearing the 'prio' field. 3) Unsafe hostile takeover allows to take over the lock even when the console is an unsafe state. It is used only in panic() by the final attempt to flush consoles in a try and hope mode. Note that separate record buffers are used in panic(). As a result, the messages can be read and formatted without any risk even after using the hostile takeover in unsafe state. The release function simply clears the 'prio' field. All operations on @console::nbcon_state are atomic cmpxchg based to handle concurrency. The acquire/release functions implement only minimal policies: - Preference for higher priority contexts. - Protection of the panic CPU. All other policy decisions must be made at the call sites: - What is marked as an unsafe section. - Whether to spin-wait if there is already an owner and the console is in an unsafe state. - Whether to attempt an unsafe hostile takeover. The design allows to implement the well known: acquire() output_one_printk_record() release() The output of one printk record might be interrupted with a higher priority context. The new owner is supposed to reprint the entire interrupted record from scratch. Co-developed-by: John Ogness <john.ogness@linutronix.de> Signed-off-by: John Ogness <john.ogness@linutronix.de> Signed-off-by: Thomas Gleixner (Intel) <tglx@linutronix.de> Signed-off-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20230916192007.608398-3-john.ogness@linutronix.de
| | * printk: Add non-BKL (nbcon) console basic infrastructureThomas Gleixner2023-09-185-4/+120
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The current console/printk subsystem is protected by a Big Kernel Lock, (aka console_lock) which has ill defined semantics and is more or less stateless. This puts severe limitations on the console subsystem and makes forced takeover and output in emergency and panic situations a fragile endeavour that is based on try and pray. The goal of non-BKL (nbcon) consoles is to break out of the console lock jail and to provide a new infrastructure that avoids the pitfalls and also allows console drivers to be gradually converted over. The proposed infrastructure aims for the following properties: - Per console locking instead of global locking - Per console state that allows to make informed decisions - Stateful handover and takeover As a first step, state is added to struct console. The per console state is an atomic_t using a 32bit bit field. Reserve state bits, which will be populated later in the series. Wire it up into the console register/unregister functionality. It was decided to use a bitfield because using a plain u32 with mask/shift operations resulted in uncomprehensible code. Co-developed-by: John Ogness <john.ogness@linutronix.de> Signed-off-by: John Ogness <john.ogness@linutronix.de> Signed-off-by: Thomas Gleixner (Intel) <tglx@linutronix.de> Reviewed-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20230916192007.608398-2-john.ogness@linutronix.de
| * | Merge branch 'rework/misc-cleanups' into for-linusPetr Mladek2023-11-021-13/+13
| |\ \
| | * | printk: Reduce pr_flush() pooling timePetr Mladek2023-10-111-13/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | pr_flush() does not guarantee that all messages would really get flushed to the console. The best it could do is to wait with a given timeout.[*] The current interval 100ms for checking the progress might seem too long in some situations. For example, such delays are not appreciated during suspend and resume especially when the consoles have been flushed "long" time before the check. On the other hand, the sleeping wait might be useful in other situations. Especially, it would allow flushing the messages using printk kthreads on the same CPU[*]. Use msleep(1) as a compromise. Also measure the time using jiffies. msleep() does not guarantee precise wakeup after the given delay. It might be much longer, especially for times < 20s. See Documentation/timers/timers-howto.rst for more details. Note that msecs_to_jiffies() already translates a negative value into an infinite timeout. [*] console_unlock() does not guarantee flushing the consoles since the commit dbdda842fe96f893 ("printk: Add console owner and waiter logic to load balance console writes"). It would be possible to guarantee it another way. For example, the spinning might be enabled only when the console_lock has been taken via console_trylock(). But the load balancing is helpful. And more importantly, the flush with a timeout has been added as a preparation step for introducing printk kthreads. Signed-off-by: Petr Mladek <pmladek@suse.com> Reviewed-by: John Ogness <john.ogness@linutronix.de> Link: https://lore.kernel.org/r/20231006082151.6969-3-pmladek@suse.com
| * | | Merge branch 'for-6.7' into for-linusPetr Mladek2023-11-022-15/+12
| |\ \ \
| | * | | vsprintf: uninline simple_strntoull(), reorder argumentsAlexey Dobriyan2023-11-011-13/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * uninline simple_strntoull(), gcc overinlines and this function is not performance critical * reorder arguments, so that appending INT_MAX as 4th argument generates very efficient tail call Space savings: add/remove: 1/0 grow/shrink: 0/3 up/down: 27/-179 (-152) Function old new delta simple_strntoll - 27 +27 simple_strtoull 15 10 -5 simple_strtoll 41 7 -34 vsscanf 1930 1790 -140 Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/all/82a2af6e-9b6c-4a09-89d7-ca90cc1cdad1@p183/
| | * | | printk: printk: Remove unnecessary statements＇len = 0;＇Li kunyu2023-10-241-2/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In the following two functions, len has already been assigned a value of 0 when defining the variable, so remove 'len=0;'. Signed-off-by: Li kunyu <kunyu@nfschina.com> Reviewed-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20231023062359.130633-1-kunyu@nfschina.com
* | | | | Merge tag 'livepatching-for-6.7' of ↵Linus Torvalds2023-11-031-1/+1
|\ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/livepatching/livepatching Pull livepatching update from Petr Mladek: - Add missing newline character to avoid waiting for a continuous message * tag 'livepatching-for-6.7' of git://git.kernel.org/pub/scm/linux/kernel/git/livepatching/livepatching: livepatch: Fix missing newline character in klp_resolve_symbols()
| * | | | | livepatch: Fix missing newline character in klp_resolve_symbols()Zheng Yejian2023-09-201-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Without the newline character, the log may not be printed immediately after the error occurs. Fixes: ca376a937486 ("livepatch: Prevent module-specific KLP rela sections from referencing vmlinux symbols") Signed-off-by: Zheng Yejian <zhengyejian1@huawei.com> Reviewed-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20230914072644.4098857-1-zhengyejian1@huawei.com
* | | | | | Merge tag 'bitmap-for-6.7' of https://github.com/norov/linuxLinus Torvalds2023-11-0310-754/+700
|\ \ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull bitmap updates from Yury Norov: "This includes the 'bitmap: cleanup bitmap_*_region() implementation' series, and scattered cleanup patches" * tag 'bitmap-for-6.7' of https://github.com/norov/linux: buildid: reduce header file dependencies for module bitmap: move bitmap_*_region() functions to bitmap.h bitmap: drop _reg_op() function bitmap: replace _reg_op(REG_OP_ISFREE) with find_next_bit() bitmap: replace _reg_op(REG_OP_RELEASE) with bitmap_clear() bitmap: replace _reg_op(REG_OP_ALLOC) with bitmap_set() bitmap: fix opencoded bitmap_allocate_region() bitmap: add test for bitmap_*_region() functions bitmap: align __reg_op() wrappers with modern coding style lib/bitmap: split-out string-related operations to a separate files bitmap: Remove dead code, i.e. bitmap_copy_le() bitmap: Fix a typo ("identify map") cpumask: kernel-doc cleanups and additions
| * | | | | | buildid: reduce header file dependencies for moduleArnd Bergmann2023-10-181-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The vmlinux decompressor code intentionally has only a limited set of included header files, but this started running into a build failure because of the bitmap logic needing linux/errno.h: In file included from include/linux/cpumask.h:12, from include/linux/mm_types_task.h:14, from include/linux/mm_types.h:5, from include/linux/buildid.h:5, from include/linux/module.h:14, from arch/arm/boot/compressed/../../../../lib/lz4/lz4_decompress.c:39, from arch/arm/boot/compressed/../../../../lib/decompress_unlz4.c:10, from arch/arm/boot/compressed/decompress.c:60: include/linux/bitmap.h: In function 'bitmap_allocate_region': include/linux/bitmap.h:527:25: error: 'EBUSY' undeclared (first use in this function) 527 | return -EBUSY; | ^~~~~ include/linux/bitmap.h:527:25: note: each undeclared identifier is reported only once for each function it appears in include/linux/bitmap.h: In function 'bitmap_find_free_region': include/linux/bitmap.h:554:17: error: 'ENOMEM' undeclared (first use in this function) 554 | return -ENOMEM; | ^~~~~~ This is easily avoided by changing linux/buildid.h to no longer depend on linux/mm_types.h, a header that pulls in a huge number of indirect dependencies. Fixes: b9c957f554442 ("bitmap: move bitmap_*_region() functions to bitmap.h") Fixes: bd7525dacd7e2 ("bpf: Move stack_map_get_build_id into lib") Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Yury Norov <yury.norov@gmail.com>
| * | | | | | bitmap: move bitmap_*_region() functions to bitmap.hYury Norov2023-10-162-67/+61
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Now that bitmap_*_region() functions are implemented as thin wrappers around others, it's worth to move them to the header, as it opens room for compile-time optimizations. CC: Andy Shevchenko <andriy.shevchenko@linux.intel.com> CC: Rasmus Villemoes <linux@rasmusvillemoes.dk> CC: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Yury Norov <yury.norov@gmail.com>
| * | | | | | bitmap: drop _reg_op() functionYury Norov2023-10-141-76/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Now that all _reg_op() users are switched to alternative functions, _reg_op() machinery is not needed anymore. CC: Andy Shevchenko <andriy.shevchenko@linux.intel.com> CC: Rasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by: Yury Norov <yury.norov@gmail.com>
| * | | | | | bitmap: replace _reg_op(REG_OP_ISFREE) with find_next_bit()Yury Norov2023-10-141-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | _reg_op(REG_OP_ISFREE) can be trivially replaced with find_next_bit(). Doing that opens room for potential small_const_nbits() optimization. CC: Andy Shevchenko <andriy.shevchenko@linux.intel.com> CC: Rasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by: Yury Norov <yury.norov@gmail.com>
| * | | | | | bitmap: replace _reg_op(REG_OP_RELEASE) with bitmap_clear()Yury Norov2023-10-141-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | _reg_op(REG_OP_RELEASE) duplicates bitmap_clear(). CC: Andy Shevchenko <andriy.shevchenko@linux.intel.com> CC: Rasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by: Yury Norov <yury.norov@gmail.com>
| * | | | | | bitmap: replace _reg_op(REG_OP_ALLOC) with bitmap_set()Yury Norov2023-10-141-1/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | _reg_op(REG_OP_ALLOC) duplicates bitmap_set(). CC: Andy Shevchenko <andriy.shevchenko@linux.intel.com> CC: Rasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by: Yury Norov <yury.norov@gmail.com>
| * | | | | | bitmap: fix opencoded bitmap_allocate_region()Yury Norov2023-10-141-4/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | bitmap_find_region() opencodes bitmap_allocate_region(). CC: Andy Shevchenko <andriy.shevchenko@linux.intel.com> CC: Rasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by: Yury Norov <yury.norov@gmail.com>
| * | | | | | bitmap: add test for bitmap_*_region() functionsYury Norov2023-10-141-0/+24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Test basic functionality of bitmap_{allocate,release,find_free}_region() functions. CC: Rasmus Villemoes <linux@rasmusvillemoes.dk> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Yury Norov <yury.norov@gmail.com>
| * | | | | | bitmap: align __reg_op() wrappers with modern coding styleYury Norov2023-10-141-7/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Fix comments so that scripts/kernel-doc doesn't warn, and fix for-loop stype in bitmap_find_free_region(). CC: Rasmus Villemoes <linux@rasmusvillemoes.dk> Suggested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Yury Norov <yury.norov@gmail.com>
| * | | | | | lib/bitmap: split-out string-related operations to a separate filesYury Norov2023-10-146-530/+530
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | lib/bitmap.c and corresponding include/linux/bitmap.h are intended to hold functions related to operations on bitmaps, like bitmap_shift or bitmap_set. Historically, some string-related operations like bitmap_parse are also reside in lib/bitmap.c. Now that the subsystem evolves, string-related bitmap operations became a significant part of the file. Because they are quite different from the other bitmap functions by nature, it's worth to split them to a separate source/header files. CC: Andrew Morton <akpm@linux-foundation.org> CC: Andy Shevchenko <andriy.shevchenko@linux.intel.com> CC: Rasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by: Yury Norov <yury.norov@gmail.com>
| * | | | | | bitmap: Remove dead code, i.e. bitmap_copy_le()Andy Shevchenko2023-10-142-28/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Besides the fact it's not used anywhere it should be implemented differently, i.e. via helpers from linux/byteorder/generic.h. Yet the helpers themselves need to be introduced first. Also note, the function lacks of the test cases, they must be provided. Hence, drop the current dead code for good. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Yury Norov <yury.norov@gmail.com>
| * | | | | | bitmap: Fix a typo ("identify map")Jonathan Neuschäfer2023-10-141-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | A map in which each element is mapped to itself is called an "identity map". Signed-off-by: Jonathan Neuschäfer <j.neuschaefer@gmx.net> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Yury Norov <yury.norov@gmail.com>
| * | | | | | cpumask: kernel-doc cleanups and additionsRandy Dunlap2023-10-142-49/+81
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Clean up some punctutation and abbreviations. Add kernel-doc notation for one function and function return value for 39 functions. cpumask.h: Fix some punctuation (plural vs. possessive). Fix some abbreviations (ie. -> i.e., id -> ID). Fix 35 warnings like this: include/linux/cpumask.h:161: warning: No description found for return value of 'cpumask_first' cpumask.c: Add Return: value for 4 functions. Add kernel-doc for cpumask_any_distribute(). Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Yury Norov <yury.norov@gmail.com>
* | | | | | | Merge tag 'mm-nonmm-stable-2023-11-02-14-08' of ↵Linus Torvalds2023-11-02106-1000/+894
|\ \ \ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull non-MM updates from Andrew Morton: "As usual, lots of singleton and doubleton patches all over the tree and there's little I can say which isn't in the individual changelogs. The lengthier patch series are - 'kdump: use generic functions to simplify crashkernel reservation in arch', from Baoquan He. This is mainly cleanups and consolidation of the 'crashkernel=' kernel parameter handling - After much discussion, David Laight's 'minmax: Relax type checks in min() and max()' is here. Hopefully reduces some typecasting and the use of min_t() and max_t() - A group of patches from Oleg Nesterov which clean up and slightly fix our handling of reads from /proc/PID/task/... and which remove task_struct.thread_group" * tag 'mm-nonmm-stable-2023-11-02-14-08' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (64 commits) scripts/gdb/vmalloc: disable on no-MMU scripts/gdb: fix usage of MOD_TEXT not defined when CONFIG_MODULES=n .mailmap: add address mapping for Tomeu Vizoso mailmap: update email address for Claudiu Beznea tools/testing/selftests/mm/run_vmtests.sh: lower the ptrace permissions .mailmap: map Benjamin Poirier's address scripts/gdb: add lx_current support for riscv ocfs2: fix a spelling typo in comment proc: test ProtectionKey in proc-empty-vm test proc: fix proc-empty-vm test with vsyscall fs/proc/base.c: remove unneeded semicolon do_io_accounting: use sig->stats_lock do_io_accounting: use __for_each_thread() ocfs2: replace BUG_ON() at ocfs2_num_free_extents() with ocfs2_error() ocfs2: fix a typo in a comment scripts/show_delta: add __main__ judgement before main code treewide: mark stuff as __ro_after_init fs: ocfs2: check status values proc: test /proc/${pid}/statm compiler.h: move __is_constexpr() to compiler.h ...
| * | | | | | | scripts/gdb/vmalloc: disable on no-MMUBen Wolsieffer2023-11-012-2/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | vmap_area does not exist on no-MMU, therefore the GDB scripts fail to load: Traceback (most recent call last): File "<...>/vmlinux-gdb.py", line 51, in <module> import linux.vmalloc File "<...>/scripts/gdb/linux/vmalloc.py", line 14, in <module> vmap_area_ptr_type = vmap_area_type.get_type().pointer() ^^^^^^^^^^^^^^^^^^^^^^^^^ File "<...>/scripts/gdb/linux/utils.py", line 28, in get_type self._type = gdb.lookup_type(self._name) ^^^^^^^^^^^^^^^^^^^^^^^^^^^ gdb.error: No struct type named vmap_area. To fix this, disable the command and add an informative error message if CONFIG_MMU is not defined, following the example of lx-slabinfo. Link: https://lkml.kernel.org/r/20231031202235.2655333-2-ben.wolsieffer@hefring.com Fixes: 852622bf3616 ("scripts/gdb/vmalloc: add vmallocinfo support") Signed-off-by: Ben Wolsieffer <ben.wolsieffer@hefring.com> Cc: Jan Kiszka <jan.kiszka@siemens.com> Cc: Kieran Bingham <kbingham@kernel.org> Cc: Kuan-Ying Lee <Kuan-Ying.Lee@mediatek.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| * | | | | | | scripts/gdb: fix usage of MOD_TEXT not defined when CONFIG_MODULES=nClément Léger2023-11-011-4/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | MOD_TEXT is only defined if CONFIG_MODULES=y which lead to loading failure of the gdb scripts when kernel is built without CONFIG_MODULES=y: Reading symbols from vmlinux... Traceback (most recent call last): File "/foo/vmlinux-gdb.py", line 25, in <module> import linux.constants File "/foo/scripts/gdb/linux/constants.py", line 14, in <module> LX_MOD_TEXT = gdb.parse_and_eval("MOD_TEXT") ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ gdb.error: No symbol "MOD_TEXT" in current context. Add a conditional check on CONFIG_MODULES to fix this error. Link: https://lkml.kernel.org/r/20231031134848.119391-1-da.gomez@samsung.com Fixes: b4aff7513df3 ("scripts/gdb: use mem instead of core_layout to get the module address") Signed-off-by: Clément Léger <cleger@rivosinc.com> Tested-by: Daniel Gomez <da.gomez@samsung.com> Signed-off-by: Daniel Gomez <da.gomez@samsung.com> Cc: Jan Kiszka <jan.kiszka@siemens.com> Cc: Kieran Bingham <kbingham@kernel.org> Cc: Luis Chamberlain <mcgrof@kernel.org> Cc: Pankaj Raghav <p.raghav@samsung.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| * | | | | | | .mailmap: add address mapping for Tomeu VizosoBagas Sanjaya2023-11-011-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | He's no longer working in Collabora (and his email address there bounces). Map it to his personal address. Link: https://lkml.kernel.org/r/20231031014009.22765-2-bagasdotme@gmail.com Signed-off-by: Bagas Sanjaya <bagasdotme@gmail.com> Acked-by: Tomeu Vizoso <tomeu@tomeuvizoso.net> Cc: Bjorn Andersson <quic_bjorande@quicinc.com> Cc: Heiko Stuebner <heiko@sntech.de> Cc: Jakub Kicinski <kuba@kernel.org> Cc: Jens Axboe <axboe@kernel.dk> Cc: Konrad Dybcio <konrad.dybcio@linaro.org> Cc: Stephen Hemminger <stephen@networkplumber.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-15 21:25:46 +0000