kernel.git/include/linux/rcupdate.h, branch linux-6.11.y

Rename .data.unlikely to .data..unlikely

2024-12-05T12:54:31Z

[ Upstream commit bb43a59944f45e89aa158740b8a16ba8f0b0fa2b ] Commit 7ccaba5314ca ("consolidate WARN_...ONCE() static variables") was intended to collect all .data.unlikely sections into one chunk. However, this has not worked when CONFIG_LD_DEAD_CODE_DATA_ELIMINATION or CONFIG_LTO_CLANG is enabled, because .data.unlikely matches the .data.[0-9a-zA-Z_]* pattern in the DATA_MAIN macro. Commit cb87481ee89d ("kbuild: linker script do not match C names unless LD_DEAD_CODE_DATA_ELIMINATION is configured") was introduced to suppress the issue for the default CONFIG_LD_DEAD_CODE_DATA_ELIMINATION=n case, providing a minimal fix for stable backporting. We were aware this did not address the issue for CONFIG_LD_DEAD_CODE_DATA_ELIMINATION=y. The plan was to apply correct fixes and then revert cb87481ee89d. [1] Seven years have passed since then, yet the #ifdef workaround remains in place. Using a ".." separator in the section name fixes the issue for CONFIG_LD_DEAD_CODE_DATA_ELIMINATION and CONFIG_LTO_CLANG. [1]: https://lore.kernel.org/linux-kbuild/CAK7LNASck6BfdLnESxXUeECYL26yUDm0cwRZuM4gmaWUkxjL5g@mail.gmail.com/ Fixes: cb87481ee89d ("kbuild: linker script do not match C names unless LD_DEAD_CODE_DATA_ELIMINATION is configured") Signed-off-by: Masahiro Yamada Signed-off-by: Sasha Levin

Merge tag 'mm-nonmm-stable-2024-07-21-15-07' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

2024-07-22T00:56:22Z

Pull non-MM updates from Andrew Morton: - In the series "treewide: Refactor heap related implementation", Kuan-Wei Chiu has significantly reworked the min_heap library code and has taught bcachefs to use the new more generic implementation. - Yury Norov's series "Cleanup cpumask.h inclusion in core headers" reworks the cpumask and nodemask headers to make things generally more rational. - Kuan-Wei Chiu has sent along some maintenance work against our sorting library code in the series "lib/sort: Optimizations and cleanups". - More library maintainance work from Christophe Jaillet in the series "Remove usage of the deprecated ida_simple_xx() API". - Ryusuke Konishi continues with the nilfs2 fixes and clanups in the series "nilfs2: eliminate the call to inode_attach_wb()". - Kuan-Ying Lee has some fixes to the gdb scripts in the series "Fix GDB command error". - Plus the usual shower of singleton patches all over the place. Please see the relevant changelogs for details. * tag 'mm-nonmm-stable-2024-07-21-15-07' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (98 commits) ia64: scrub ia64 from poison.h watchdog/perf: properly initialize the turbo mode timestamp and rearm counter tsacct: replace strncpy() with strscpy() lib/bch.c: use swap() to improve code test_bpf: convert comma to semicolon init/modpost: conditionally check section mismatch to __meminit* init: remove unused __MEMINIT* macros nilfs2: Constify struct kobj_type nilfs2: avoid undefined behavior in nilfs_cnt32_ge macro math: rational: add missing MODULE_DESCRIPTION() macro lib/zlib: add missing MODULE_DESCRIPTION() macro fs: ufs: add MODULE_DESCRIPTION() lib/rbtree.c: fix the example typo ocfs2: add bounds checking to ocfs2_check_dir_entry() fs: add kernel-doc comments to ocfs2_prepare_orphan_dir() coredump: simplify zap_process() selftests/fpu: add missing MODULE_DESCRIPTION() macro compiler.h: simplify data_race() macro build-id: require program headers to be right after ELF header resource: add missing MODULE_DESCRIPTION() ...

Merge branches 'doc.2024.06.06a', 'fixes.2024.07.04a', 'mb.2024.06.28a', 'nocb.2024.06.03a', 'rcu-tasks.2024.06.06a', 'rcutorture.2024.06.06a' and 'srcu.2024.06.18a' into HEAD

2024-07-04T20:54:17Z

doc.2024.06.06a: Documentation updates. fixes.2024.07.04a: Miscellaneous fixes. mb.2024.06.28a: Grace-period memory-barrier redundancy removal. nocb.2024.06.03a: No-CB CPU updates. rcu-tasks.2024.06.06a: RCU-Tasks updates. rcutorture.2024.06.06a: Torture-test updates. srcu.2024.06.18a: SRCU polled-grace-period updates.

cpumask: cleanup core headers inclusion

2024-06-25T05:25:02Z

Many core headers include cpumask.h for nothing. Drop it. Link: https://lkml.kernel.org/r/20240528005648.182376-6-yury.norov@gmail.com Signed-off-by: Yury Norov Cc: Amit Daniel Kachhap Cc: Anna-Maria Behnsen Cc: Christoph Lameter Cc: Daniel Lezcano Cc: Dennis Zhou Cc: Frederic Weisbecker Cc: Johannes Weiner Cc: Juri Lelli Cc: Kees Cook Cc: Mathieu Desnoyers Cc: Paul E. McKenney Cc: Peter Zijlstra Cc: Rafael J. Wysocki Cc: Rasmus Villemoes Cc: Tejun Heo Cc: Thomas Gleixner Cc: Ulf Hansson Cc: Vincent Guittot Cc: Viresh Kumar Cc: Yury Norov Signed-off-by: Andrew Morton

Revert "rcu-tasks: Fix synchronize_rcu_tasks() VS zap_pid_ns_processes()"

2024-06-04T00:30:08Z

This reverts commit 28319d6dc5e2ffefa452c2377dd0f71621b5bff0. The race it fixed was subject to conditions that don't exist anymore since: 1612160b9127 ("rcu-tasks: Eliminate deadlocks involving do_exit() and RCU tasks") This latter commit removes the use of SRCU that used to cover the RCU-tasks blind spot on exit between the tasklist's removal and the final preemption disabling. The task is now placed instead into a temporary list inside which voluntary sleeps are accounted as RCU-tasks quiescent states. This would disarm the deadlock initially reported against PID namespace exit. Signed-off-by: Frederic Weisbecker Reviewed-by: Oleg Nesterov Signed-off-by: Paul E. McKenney

rcu: Add lockdep_assert_in_rcu_read_lock() and friends

2024-06-04T00:24:58Z

There is no direct RCU counterpart to lockdep_assert_irqs_disabled() and friends. Although it is possible to construct them, it would be more convenient to have the following lockdep assertions: lockdep_assert_in_rcu_read_lock() lockdep_assert_in_rcu_read_lock_bh() lockdep_assert_in_rcu_read_lock_sched() lockdep_assert_in_rcu_reader() This commit therefore creates them. Reported-by: Jens Axboe Signed-off-by: Paul E. McKenney

rcu: Mollify sparse with RCU guard

2024-04-15T17:43:48Z

When using "guard(rcu)();" sparse will complain, because even though it now understands the cleanup attribute, it doesn't evaluate the calls from it at function exit, and thus doesn't count the context correctly. Given that there's a conditional in the resulting code: static inline void class_rcu_destructor(class_rcu_t *_T) { if (_T->lock) { rcu_read_unlock(); } } it seems that even trying to teach sparse to evalulate the cleanup attribute function it'd still be difficult to really make it understand the full context here. Suppress the sparse warning by just releasing the context in the acquisition part of the function, after all we know it's safe with the guard, that's the whole point of it. Signed-off-by: Johannes Berg Reviewed-by: Boqun Feng Signed-off-by: Paul E. McKenney Signed-off-by: Uladzislau Rezki (Sony)

rcu: Remove redundant CONFIG_PROVE_RCU #if condition

2024-04-15T16:12:20Z

The #if condition controlling the rcu_preempt_sleep_check() definition has a redundant check for CONFIG_PREEMPT_RCU, which is already checked for by an enclosing #ifndef. This commit therefore removes this redundant condition from the inner #if. Signed-off-by: Paul E. McKenney Signed-off-by: Uladzislau Rezki (Sony)

rcu: Update lockdep while in RCU read-side critical section

2024-04-15T09:28:59Z

With Ankur's lazy-/auto-preemption patches applied and with a lazy-preemptible kernel in combination with a non-preemptible RCU, lockdep sometimes complains about context switches within RCU read-side critical sections. This is a false positive due to rcu_read_unlock() updating lockdep state too late: __release(RCU); __rcu_read_unlock(); // Context switch here results in lockdep false positive!!! rcu_lock_release(&rcu_lock_map); /* Keep acq info for rls diags. */ Although this complaint could also happen with preemptible RCU in a preemptible kernel, the odds of that happening aer quite low. In constrast, with non-preemptible RCU, a long critical section has a high probability of performing a context switch from the preempt_enable() in __rcu_read_unlock(). The fix is straightforward, just move the rcu_lock_release() within rcu_read_unlock() to obtain the reverse order from that of rcu_read_lock(): rcu_lock_release(&rcu_lock_map); /* Keep acq info for rls diags. */ __release(RCU); __rcu_read_unlock(); This commit makes this change. Co-developed-by: Frederic Weisbecker Signed-off-by: Frederic Weisbecker Co-developed-by: Joel Fernandes (Google) Signed-off-by: Joel Fernandes (Google) Co-developed-by: Boqun Feng Signed-off-by: Boqun Feng Signed-off-by: Uladzislau Rezki (Sony) Reviewed-by: Paul E. McKenney Cc: Ankur Arora Cc: Thomas Gleixner

rcu: add a helper to report consolidated flavor QS

2024-03-21T04:05:42Z

When under heavy load, network processing can run CPU-bound for many tens of seconds. Even in preemptible kernels (non-RT kernel), this can block RCU Tasks grace periods, which can cause trace-event removal to take more than a minute, which is unacceptably long. This commit therefore creates a new helper function that passes through both RCU and RCU-Tasks quiescent states every 100 milliseconds. This hard-coded value suffices for current workloads. Suggested-by: Paul E. McKenney Reviewed-by: Jesper Dangaard Brouer Signed-off-by: Yan Zhai Reviewed-by: Paul E. McKenney Acked-by: Jesper Dangaard Brouer Link: https://lore.kernel.org/r/90431d46ee112d2b0af04dbfe936faaca11810a5.1710877680.git.yan@cloudflare.com Signed-off-by: Jakub Kicinski