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2024-11-18Merge tag 'vfs-6.13.file' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs Pull vfs file updates from Christian Brauner: "This contains changes the changes for files for this cycle: - Introduce a new reference counting mechanism for files. As atomic_inc_not_zero() is implemented with a try_cmpxchg() loop it has O(N^2) behaviour under contention with N concurrent operations and it is in a hot path in __fget_files_rcu(). The rcuref infrastructures remedies this problem by using an unconditional increment relying on safe- and dead zones to make this work and requiring rcu protection for the data structure in question. This not just scales better it also introduces overflow protection. However, in contrast to generic rcuref, files require a memory barrier and thus cannot rely on *_relaxed() atomic operations and also require to be built on atomic_long_t as having massive amounts of reference isn't unheard of even if it is just an attack. This adds a file specific variant instead of making this a generic library. This has been tested by various people and it gives consistent improvement up to 3-5% on workloads with loads of threads. - Add a fastpath for find_next_zero_bit(). Skip 2-levels searching via find_next_zero_bit() when there is a free slot in the word that contains the next fd. This improves pts/blogbench-1.1.0 read by 8% and write by 4% on Intel ICX 160. - Conditionally clear full_fds_bits since it's very likely that a bit in full_fds_bits has been cleared during __clear_open_fds(). This improves pts/blogbench-1.1.0 read up to 13%, and write up to 5% on Intel ICX 160. - Get rid of all lookup_*_fdget_rcu() variants. They were used to lookup files without taking a reference count. That became invalid once files were switched to SLAB_TYPESAFE_BY_RCU and now we're always taking a reference count. Switch to an already existing helper and remove the legacy variants. - Remove pointless includes of <linux/fdtable.h>. - Avoid cmpxchg() in close_files() as nobody else has a reference to the files_struct at that point. - Move close_range() into fs/file.c and fold __close_range() into it. - Cleanup calling conventions of alloc_fdtable() and expand_files(). - Merge __{set,clear}_close_on_exec() into one. - Make __set_open_fd() set cloexec as well instead of doing it in two separate steps" * tag 'vfs-6.13.file' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: selftests: add file SLAB_TYPESAFE_BY_RCU recycling stressor fs: port files to file_ref fs: add file_ref expand_files(): simplify calling conventions make __set_open_fd() set cloexec state as well fs: protect backing files with rcu file.c: merge __{set,clear}_close_on_exec() alloc_fdtable(): change calling conventions. fs/file.c: add fast path in find_next_fd() fs/file.c: conditionally clear full_fds fs/file.c: remove sanity_check and add likely/unlikely in alloc_fd() move close_range(2) into fs/file.c, fold __close_range() into it close_files(): don't bother with xchg() remove pointless includes of <linux/fdtable.h> get rid of ...lookup...fdget_rcu() family
2024-11-18Merge tag 'vfs-6.13.mgtime' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs Pull vfs multigrain timestamps from Christian Brauner: "This is another try at implementing multigrain timestamps. This time with significant help from the timekeeping maintainers to reduce the performance impact. Thomas provided a base branch that contains the required timekeeping interfaces for the VFS. It serves as the base for the multi-grain timestamp work: - Multigrain timestamps allow the kernel to use fine-grained timestamps when an inode's attributes is being actively observed via ->getattr(). With this support, it's possible for a file to get a fine-grained timestamp, and another modified after it to get a coarse-grained stamp that is earlier than the fine-grained time. If this happens then the files can appear to have been modified in reverse order, which breaks VFS ordering guarantees. To prevent this, a floor value is maintained for multigrain timestamps. Whenever a fine-grained timestamp is handed out, record it, and when later coarse-grained stamps are handed out, ensure they are not earlier than that value. If the coarse-grained timestamp is earlier than the fine-grained floor, return the floor value instead. The timekeeper changes add a static singleton atomic64_t into timekeeper.c that is used to keep track of the latest fine-grained time ever handed out. This is tracked as a monotonic ktime_t value to ensure that it isn't affected by clock jumps. Because it is updated at different times than the rest of the timekeeper object, the floor value is managed independently of the timekeeper via a cmpxchg() operation, and sits on its own cacheline. Two new public timekeeper interfaces are added: (1) ktime_get_coarse_real_ts64_mg() fills a timespec64 with the later of the coarse-grained clock and the floor time (2) ktime_get_real_ts64_mg() gets the fine-grained clock value, and tries to swap it into the floor. A timespec64 is filled with the result. - The VFS has always used coarse-grained timestamps when updating the ctime and mtime after a change. This has the benefit of allowing filesystems to optimize away a lot metadata updates, down to around 1 per jiffy, even when a file is under heavy writes. Unfortunately, this has always been an issue when we're exporting via NFSv3, which relies on timestamps to validate caches. A lot of changes can happen in a jiffy, so timestamps aren't sufficient to help the client decide when to invalidate the cache. Even with NFSv4, a lot of exported filesystems don't properly support a change attribute and are subject to the same problems with timestamp granularity. Other applications have similar issues with timestamps (e.g backup applications). If we were to always use fine-grained timestamps, that would improve the situation, but that becomes rather expensive, as the underlying filesystem would have to log a lot more metadata updates. This adds a way to only use fine-grained timestamps when they are being actively queried. Use the (unused) top bit in inode->i_ctime_nsec as a flag that indicates whether the current timestamps have been queried via stat() or the like. When it's set, we allow the kernel to use a fine-grained timestamp iff it's necessary to make the ctime show a different value. This solves the problem of being able to distinguish the timestamp between updates, but introduces a new problem: it's now possible for a file being changed to get a fine-grained timestamp. A file that is altered just a bit later can then get a coarse-grained one that appears older than the earlier fine-grained time. This violates timestamp ordering guarantees. This is where the earlier mentioned timkeeping interfaces help. A global monotonic atomic64_t value is kept that acts as a timestamp floor. When we go to stamp a file, we first get the latter of the current floor value and the current coarse-grained time. If the inode ctime hasn't been queried then we just attempt to stamp it with that value. If it has been queried, then first see whether the current coarse time is later than the existing ctime. If it is, then we accept that value. If it isn't, then we get a fine-grained time and try to swap that into the global floor. Whether that succeeds or fails, we take the resulting floor time, convert it to realtime and try to swap that into the ctime. We take the result of the ctime swap whether it succeeds or fails, since either is just as valid. Filesystems can opt into this by setting the FS_MGTIME fstype flag. Others should be unaffected (other than being subject to the same floor value as multigrain filesystems)" * tag 'vfs-6.13.mgtime' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: fs: reduce pointer chasing in is_mgtime() test tmpfs: add support for multigrain timestamps btrfs: convert to multigrain timestamps ext4: switch to multigrain timestamps xfs: switch to multigrain timestamps Documentation: add a new file documenting multigrain timestamps fs: add percpu counters for significant multigrain timestamp events fs: tracepoints around multigrain timestamp events fs: handle delegated timestamps in setattr_copy_mgtime timekeeping: Add percpu counter for tracking floor swap events timekeeping: Add interfaces for handling timestamps with a floor value fs: have setattr_copy handle multigrain timestamps appropriately fs: add infrastructure for multigrain timestamps
2024-11-18posix-timers: Fix spurious warning on double enqueue versus do_exit()Frederic Weisbecker
A timer sigqueue may find itself already pending when it is tried to be enqueued. This situation can happen if the timer sigqueue is enqueued but then the timer is reset afterwards and fires before the pending signal managed to be delivered. However when such a double enqueue occurs while the corresponding signal is ignored, the sigqueue is expected to be found either on the dedicated ignored list if the timer was periodic or dropped if the timer was one-shot. In any case it is not supposed to be queued on the real signal queue. An assertion verifies the latter expectation on top of the return value of prepare_signal(), assuming "false" means that the signal is being ignored. But prepare_signal() may also fail if the target is exiting as the last task of its group. In this case the double enqueue observes the sigqueue queued, as in such a situation: TASK A (same group as B) TASK B (same group as A) ------------------------ ------------------------ // timer event // queue signal to TASK B posix_timer_queue_signal() // reset timer through syscall do_timer_settime() // exit, leaving task B alone do_exit() do_exit() synchronize_group_exit() signal->flags = SIGNAL_GROUP_EXIT // ========> <IRQ> timer event posix_timer_queue_signal() // return false due to SIGNAL_GROUP_EXIT if (!prepare_signal()) WARN_ON_ONCE(!list_empty(&q->list)) And this spuriously triggers this warning: WARNING: CPU: 0 PID: 5854 at kernel/signal.c:2008 posixtimer_send_sigqueue CPU: 0 UID: 0 PID: 5854 Comm: syz-executor139 Not tainted 6.12.0-rc6-next-20241108-syzkaller #0 RIP: 0010:posixtimer_send_sigqueue+0x9da/0xbc0 kernel/signal.c:2008 Call Trace: <IRQ> alarm_handle_timer alarmtimer_fired __run_hrtimer __hrtimer_run_queues hrtimer_interrupt local_apic_timer_interrupt __sysvec_apic_timer_interrupt instr_sysvec_apic_timer_interrupt sysvec_apic_timer_interrupt </IRQ> Fortunately the recovery code in that case already does the right thing: just exit from posixtimer_send_sigqueue() and wait for __exit_signal() to flush the pending signal. Just make sure to warn only the case when the sigqueue is queued and the signal is really ignored. Fixes: df7a996b4dab ("signal: Queue ignored posixtimers on ignore list") Reported-by: syzbot+852e935b899bde73626e@syzkaller.appspotmail.com Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: syzbot+852e935b899bde73626e@syzkaller.appspotmail.com Link: https://lore.kernel.org/all/20241116234823.28497-1-frederic@kernel.org Closes: https://lore.kernel.org/all/673549c6.050a0220.1324f8.008c.GAE@google.com
2024-11-18ftrace: Get the true parent ip for function tracerJeff Xie
When using both function tracer and function graph simultaneously, it is found that function tracer sometimes captures a fake parent ip (return_to_handler) instead of the true parent ip. This issue is easy to reproduce. Below are my reproduction steps: jeff-labs:~/bin # ./trace-net.sh jeff-labs:~/bin # cat /sys/kernel/debug/tracing/instances/foo/trace | grep return_to_handler trace-net.sh-405 [001] ...2. 31.859501: avc_has_perm+0x4/0x190 <-return_to_handler+0x0/0x40 trace-net.sh-405 [001] ...2. 31.859503: simple_setattr+0x4/0x70 <-return_to_handler+0x0/0x40 trace-net.sh-405 [001] ...2. 31.859503: truncate_pagecache+0x4/0x60 <-return_to_handler+0x0/0x40 trace-net.sh-405 [001] ...2. 31.859505: unmap_mapping_range+0x4/0x140 <-return_to_handler+0x0/0x40 trace-net.sh-405 [001] ...3. 31.859508: _raw_spin_unlock+0x4/0x30 <-return_to_handler+0x0/0x40 [...] The following is my simple trace script: <snip> jeff-labs:~/bin # cat ./trace-net.sh TRACE_PATH="/sys/kernel/tracing" set_events() { echo 1 > $1/events/net/enable echo 1 > $1/events/tcp/enable echo 1 > $1/events/sock/enable echo 1 > $1/events/napi/enable echo 1 > $1/events/fib/enable echo 1 > $1/events/neigh/enable } set_events ${TRACE_PATH} echo 1 > ${TRACE_PATH}/options/sym-offset echo 1 > ${TRACE_PATH}/options/funcgraph-tail echo 1 > ${TRACE_PATH}/options/funcgraph-proc echo 1 > ${TRACE_PATH}/options/funcgraph-abstime echo 'tcp_orphan*' > ${TRACE_PATH}/set_ftrace_notrace echo function_graph > ${TRACE_PATH}/current_tracer INSTANCE_FOO=${TRACE_PATH}/instances/foo if [ ! -e $INSTANCE_FOO ]; then mkdir ${INSTANCE_FOO} fi set_events ${INSTANCE_FOO} echo 1 > ${INSTANCE_FOO}/options/sym-offset echo 'tcp_orphan*' > ${INSTANCE_FOO}/set_ftrace_notrace echo function > ${INSTANCE_FOO}/current_tracer echo 1 > ${TRACE_PATH}/tracing_on echo 1 > ${INSTANCE_FOO}/tracing_on echo > ${TRACE_PATH}/trace echo > ${INSTANCE_FOO}/trace </snip> Link: https://lore.kernel.org/20241008033159.22459-1-jeff.xie@linux.dev Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Jeff Xie <jeff.xie@linux.dev> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-11-18cpu: Remove spurious NULL in attribute_group definitionThomas Weißschuh
This NULL value is most-likely a copy-paste error from an array definition. The NULL doesn't have any effect. Signed-off-by: Thomas Weißschuh <linux@weissschuh.net> Link: https://lore.kernel.org/r/20241118-sysfs-const-attribute_group-fixes-v1-3-48e0b0ad8cba@weissschuh.net Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-11-18kdb: fix ctrl+e/a/f/b/d/p/n broken in keyboard modeNir Lichtman
Problem: When using kdb via keyboard it does not react to control characters which are supported in serial mode. Example: Chords such as ctrl+a/e/d/p do not work in keyboard mode Solution: Before disregarding non-printable key characters, check if they are one of the supported control characters, I have took the control characters from the switch case upwards in this function that translates scan codes of arrow keys/backspace/home/.. to the control characters. Suggested-by: Douglas Anderson <dianders@chromium.org> Signed-off-by: Nir Lichtman <nir@lichtman.org> Reviewed-by: Douglas Anderson <dianders@chromium.org> Link: https://lore.kernel.org/r/20241111215622.GA161253@lichtman.org Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
2024-11-18ring-buffer: Correct a grammatical error in a commentliujing
The word "trace" begins with a consonant sound, so "a" should be used instead of "an". Link: https://lore.kernel.org/20241107095327.6390-1-liujing@cmss.chinamobile.com Signed-off-by: liujing <liujing@cmss.chinamobile.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-11-18Merge branch 'for-6.13-force-console' into for-linusPetr Mladek
2024-11-16Merge tag 'mm-hotfixes-stable-2024-11-16-15-33' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull hotfixes from Andrew Morton: "10 hotfixes, 7 of which are cc:stable. All singletons, please see the changelogs for details" * tag 'mm-hotfixes-stable-2024-11-16-15-33' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: mm: revert "mm: shmem: fix data-race in shmem_getattr()" ocfs2: uncache inode which has failed entering the group mm: fix NULL pointer dereference in alloc_pages_bulk_noprof mm, doc: update read_ahead_kb for MADV_HUGEPAGE fs/proc/task_mmu: prevent integer overflow in pagemap_scan_get_args() sched/task_stack: fix object_is_on_stack() for KASAN tagged pointers crash, powerpc: default to CRASH_DUMP=n on PPC_BOOK3S_32 mm/mremap: fix address wraparound in move_page_tables() tools/mm: fix compile error mm, swap: fix allocation and scanning race with swapoff
2024-11-16Merge tag 'trace-ringbuffer-v6.12-rc7-2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace Pull ring buffer fixes from Steven Rostedt: - Revert: "ring-buffer: Do not have boot mapped buffers hook to CPU hotplug" A crash that happened on cpu hotplug was actually caused by the incorrect ref counting that was fixed by commit 2cf9733891a4 ("ring-buffer: Fix refcount setting of boot mapped buffers"). The removal of calling cpu hotplug callbacks on memory mapped buffers was not an issue even though the tests at the time pointed toward it. But in fact, there's a check in that code that tests to see if the buffers are already allocated or not, and will not allocate them again if they are. Not calling the cpu hotplug callbacks ended up not initializing the non boot CPU buffers. Simply remove that change. - Clear all CPU buffers when starting tracing in a boot mapped buffer To properly process events from a previous boot, the address space needs to be accounted for due to KASLR and the events in the buffer are updated accordingly when read. This also requires that when the buffer has tracing enabled again in the current boot that the buffers are reset so that events from the previous boot do not interact with the events of the current boot and cause confusing due to not having the proper meta data. It was found that if a CPU is taken offline, that its per CPU buffer is not reset when tracing starts. This allows for events to be from both the previous boot and the current boot to be in the buffer at the same time. Clear all CPU buffers when tracing is started in a boot mapped buffer. * tag 'trace-ringbuffer-v6.12-rc7-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: tracing/ring-buffer: Clear all memory mapped CPU ring buffers on first recording Revert: "ring-buffer: Do not have boot mapped buffers hook to CPU hotplug"
2024-11-15Merge branches 'rcu/fixes', 'rcu/nocb', 'rcu/torture', 'rcu/stall' and ↵Frederic Weisbecker
'rcu/srcu' into rcu/dev
2024-11-15rcuscale: Remove redundant WARN_ON_ONCE() splatUladzislau Rezki (Sony)
There are two places where WARN_ON_ONCE() is called two times in the error paths. One which is encapsulated into if() condition and another one, which is unnecessary, is placed in the brackets. Remove an extra WARN_ON_ONCE() splat which is in brackets. Reviewed-by: Paul E. McKenney <paulmck@kernel.org> Reviewed-by: Neeraj Upadhyay <Neeraj.Upadhyay@amd.com> Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com> Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
2024-11-15rcuscale: Do a proper cleanup if kfree_scale_init() failsUladzislau Rezki (Sony)
A static analyzer for C, Smatch, reports and triggers below warnings: kernel/rcu/rcuscale.c:1215 rcu_scale_init() warn: inconsistent returns 'global &fullstop_mutex'. The checker complains about, we do not unlock the "fullstop_mutex" mutex, in case of hitting below error path: <snip> ... if (WARN_ON_ONCE(jiffies_at_lazy_cb - jif_start < 2 * HZ)) { pr_alert("ERROR: call_rcu() CBs are not being lazy as expected!\n"); WARN_ON_ONCE(1); return -1; ^^^^^^^^^^ ... <snip> it happens because "-1" is returned right away instead of doing a proper unwinding. Fix it by jumping to "unwind" label instead of returning -1. Reported-by: Dan Carpenter <dan.carpenter@linaro.org> Reviewed-by: Paul E. McKenney <paulmck@kernel.org> Reviewed-by: Neeraj Upadhyay <Neeraj.Upadhyay@amd.com> Closes: https://lore.kernel.org/rcu/ZxfTrHuEGtgnOYWp@pc636/T/ Fixes: 084e04fff160 ("rcuscale: Add laziness and kfree tests") Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com> Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
2024-11-15srcu: Unconditionally record srcu_read_lock_lite() in ->srcu_reader_flavorPaul E. McKenney
Currently, srcu_read_lock_lite() uses the SRCU_READ_FLAVOR_LITE bit in ->srcu_reader_flavor to communicate to the grace-period processing in srcu_readers_active_idx_check() that the smp_mb() must be replaced by a synchronize_rcu(). Unfortunately, ->srcu_reader_flavor is not updated unless the kernel is built with CONFIG_PROVE_RCU=y. Therefore in all kernels built with CONFIG_PROVE_RCU=n, srcu_readers_active_idx_check() incorrectly uses smp_mb() instead of synchronize_rcu() for srcu_struct structures whose readers use srcu_read_lock_lite(). This commit therefore causes Tree SRCU srcu_read_lock_lite() to unconditionally update ->srcu_reader_flavor so that srcu_readers_active_idx_check() can make the correct choice. Reported-by: Neeraj Upadhyay <Neeraj.Upadhyay@amd.com> Closes: https://lore.kernel.org/all/d07e8f4a-d5ff-4c8e-8e61-50db285c57e9@amd.com/ Fixes: c0f08d6b5a61 ("srcu: Add srcu_read_lock_lite() and srcu_read_unlock_lite()") Signed-off-by: Paul E. McKenney <paulmck@kernel.org> Cc: Frederic Weisbecker <frederic@kernel.org> Reviewed-by: Neeraj Upadhyay <Neeraj.Upadhyay@amd.com> Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
2024-11-15Merge branches 'pm-cpuidle' and 'pm-em'Rafael J. Wysocki
Merge cpuidle and Energy Model changes for 6.13-rc1: - Add a built-in idle states table for Granite Rapids Xeon D to the intel_idle driver (Artem Bityutskiy). - Fix some typos in comments in the cpuidle core and drivers (Shen Lichuan). - Remove iowait influence from the menu cpuidle governor (Christian Loehle). - Add min/max available performance state limits to the Energy Model management code (Lukasz Luba). * pm-cpuidle: intel_idle: add Granite Rapids Xeon D support cpuidle: Correct some typos in comments cpuidle: menu: Remove iowait influence * pm-em: PM: EM: Add min/max available performance state limits
2024-11-15bpf: use common instruction history across all statesAndrii Nakryiko
Instead of allocating and copying instruction history each time we enqueue child verifier state, switch to a model where we use one common dynamically sized array of instruction history entries across all states. The key observation for proving this is correct is that instruction history is only relevant while state is active, which means it either is a current state (and thus we are actively modifying instruction history and no other state can interfere with us) or we are checkpointed state with some children still active (either enqueued or being current). In the latter case our portion of instruction history is finalized and won't change or grow, so as long as we keep it immutable until the state is finalized, we are good. Now, when state is finalized and is put into state hash for potentially future pruning lookups, instruction history is not used anymore. This is because instruction history is only used by precision marking logic, and we never modify precision markings for finalized states. So, instead of each state having its own small instruction history, we keep a global dynamically-sized instruction history, where each state in current DFS path from root to active state remembers its portion of instruction history. Current state can append to this history, but cannot modify any of its parent histories. Async callback state enqueueing, while logically detached from parent state, still is part of verification backtracking tree, so has to follow the same schema as normal state checkpoints. Because the insn_hist array can be grown through realloc, states don't keep pointers, they instead maintain two indices, [start, end), into global instruction history array. End is exclusive index, so `start == end` means there is no relevant instruction history. This eliminates a lot of allocations and minimizes overall memory usage. For instance, running a worst-case test from [0] (but without the heuristics-based fix [1]), it took 12.5 minutes until we get -ENOMEM. With the changes in this patch the whole test succeeds in 10 minutes (very slow, so heuristics from [1] is important, of course). To further validate correctness, veristat-based comparison was performed for Meta production BPF objects and BPF selftests objects. In both cases there were no differences *at all* in terms of verdict or instruction and state counts, providing a good confidence in the change. Having this low-memory-overhead solution of keeping dynamic per-instruction history cheaply opens up some new possibilities, like keeping extra information for literally every single validated instruction. This will be used for simplifying precision backpropagation logic in follow up patches. [0] https://lore.kernel.org/bpf/20241029172641.1042523-2-eddyz87@gmail.com/ [1] https://lore.kernel.org/bpf/20241029172641.1042523-1-eddyz87@gmail.com/ Acked-by: Eduard Zingerman <eddyz87@gmail.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20241115001303.277272-1-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-11-15Merge tag 'sched_ext-for-6.12-rc7-fixes-2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tj/sched_ext Pull sched_ext fix from Tejun Heo: "One more fix for v6.12-rc7 ops.cpu_acquire() was being invoked with the wrong kfunc mask allowing the operation to call kfuncs which shouldn't be allowed. Fix it by using SCX_KF_REST instead, which is trivial and low risk" * tag 'sched_ext-for-6.12-rc7-fixes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/sched_ext: sched_ext: ops.cpu_acquire() should be called with SCX_KF_REST
2024-11-15workqueue: Reduce expensive locks for unbound workqueueWangyang Guo
For unbound workqueue, pwqs usually map to just a few pools. Most of the time, pwqs will be linked sequentially to wq->pwqs list by cpu index. Usually, consecutive CPUs have the same workqueue attribute (e.g. belong to the same NUMA node). This makes pwqs with the same pool cluster together in the pwq list. Only do lock/unlock if the pool has changed in flush_workqueue_prep_pwqs(). This reduces the number of expensive lock operations. The performance data shows this change boosts FIO by 65x in some cases when multiple concurrent threads write to xfs mount points with fsync. FIO Benchmark Details - FIO version: v3.35 - FIO Options: ioengine=libaio,iodepth=64,norandommap=1,rw=write, size=128M,bs=4k,fsync=1 - FIO Job Configs: 64 jobs in total writing to 4 mount points (ramdisks formatted as xfs file system). - Kernel Codebase: v6.12-rc5 - Test Platform: Xeon 8380 (2 sockets) Reviewed-by: Tim Chen <tim.c.chen@linux.intel.com> Signed-off-by: Wangyang Guo <wangyang.guo@intel.com> Reviewed-by: Lai Jiangshan <jiangshanlai@gmail.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2024-11-15bpf: Add necessary migrate_disable to range_tree.Yonghong Song
When running bpf selftest (./test_progs -j), the following warnings showed up: $ ./test_progs -t arena_atomics ... BUG: using smp_processor_id() in preemptible [00000000] code: kworker/u19:0/12501 caller is bpf_mem_free+0x128/0x330 ... Call Trace: <TASK> dump_stack_lvl check_preemption_disabled bpf_mem_free range_tree_destroy arena_map_free bpf_map_free_deferred process_scheduled_works ... For selftests arena_htab and arena_list, similar smp_process_id() BUGs are dumped, and the following are two stack trace: <TASK> dump_stack_lvl check_preemption_disabled bpf_mem_alloc range_tree_set arena_map_alloc map_create ... <TASK> dump_stack_lvl check_preemption_disabled bpf_mem_alloc range_tree_clear arena_vm_fault do_pte_missing handle_mm_fault do_user_addr_fault ... Add migrate_{disable,enable}() around related bpf_mem_{alloc,free}() calls to fix the issue. Fixes: b795379757eb ("bpf: Introduce range_tree data structure and use it in bpf arena") Signed-off-by: Yonghong Song <yonghong.song@linux.dev> Link: https://lore.kernel.org/r/20241115060354.2832495-1-yonghong.song@linux.dev Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-11-15bpf: Do not alloc arena on unsupported archesViktor Malik
Do not allocate BPF arena on arches that do not support it, instead return EOPNOTSUPP. This is useful to prevent bugs such as soft lockups while trying to free the arena which we have witnessed on ppc64le [1]. [1] https://lore.kernel.org/bpf/4afdcb50-13f2-4772-8db1-3fd02bd985b3@redhat.com/ Signed-off-by: Viktor Malik <vmalik@redhat.com> Link: https://lore.kernel.org/r/20241115082548.74972-1-vmalik@redhat.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-11-14crash, powerpc: default to CRASH_DUMP=n on PPC_BOOK3S_32Dave Vasilevsky
Fixes boot failures on 6.9 on PPC_BOOK3S_32 machines using Open Firmware. On these machines, the kernel refuses to boot from non-zero PHYSICAL_START, which occurs when CRASH_DUMP is on. Since most PPC_BOOK3S_32 machines boot via Open Firmware, it should default to off for them. Users booting via some other mechanism can still turn it on explicitly. Does not change the default on any other architectures for the time being. Link: https://lkml.kernel.org/r/20240917163720.1644584-1-dave@vasilevsky.ca Fixes: 75bc255a7444 ("crash: clean up kdump related config items") Signed-off-by: Dave Vasilevsky <dave@vasilevsky.ca> Reported-by: Reimar Döffinger <Reimar.Doeffinger@gmx.de> Closes: https://lists.debian.org/debian-powerpc/2024/07/msg00001.html Acked-by: Michael Ellerman <mpe@ellerman.id.au> [powerpc] Acked-by: Baoquan He <bhe@redhat.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de> Cc: Reimar Döffinger <Reimar.Doeffinger@gmx.de> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-11-14sched_ext: Replace scx_next_task_picked() with switch_class() in commentZhao Mengmeng
scx_next_task_picked() has been replaced with siwtch_class(), but comment is still referencing old one, so replace it. Signed-off-by: Zhao Mengmeng <zhaomengmeng@kylinos.cn> Signed-off-by: Tejun Heo <tj@kernel.org>
2024-11-14scftorture: Handle NULL argument passed to scf_add_to_free_list().Sebastian Andrzej Siewior
Dan reported that after the rework the newly introduced scf_add_to_free_list() may get a NULL pointer passed. This replaced kfree() which was fine with a NULL pointer but scf_add_to_free_list() isn't. Let scf_add_to_free_list() handle NULL pointer. Reported-by: Dan Carpenter <dan.carpenter@linaro.org> Closes: https://lore.kernel.org/all/2375aa2c-3248-4ffa-b9b0-f0a24c50f237@stanley.mountain Fixes: 4788c861ad7e9 ("scftorture: Use a lock-less list to free memory.") Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2024-11-14Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski
Cross-merge networking fixes after downstream PR (net-6.12-rc8). Conflicts: tools/testing/selftests/net/.gitignore 252e01e68241 ("selftests: net: add netlink-dumps to .gitignore") be43a6b23829 ("selftests: ncdevmem: Move ncdevmem under drivers/net/hw") https://lore.kernel.org/all/20241113122359.1b95180a@canb.auug.org.au/ drivers/net/phy/phylink.c 671154f174e0 ("net: phylink: ensure PHY momentary link-fails are handled") 7530ea26c810 ("net: phylink: remove "using_mac_select_pcs"") Adjacent changes: drivers/net/ethernet/stmicro/stmmac/dwmac-intel-plat.c 5b366eae7193 ("stmmac: dwmac-intel-plat: fix call balance of tx_clk handling routines") e96321fad3ad ("net: ethernet: Switch back to struct platform_driver::remove()") Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-11-14sched_ext: ops.cpu_acquire() should be called with SCX_KF_RESTTejun Heo
ops.cpu_acquire() is currently called with 0 kf_maks which is interpreted as SCX_KF_UNLOCKED which allows all unlocked kfuncs, but ops.cpu_acquire() is called from balance_one() under the rq lock and should only be allowed call kfuncs that are safe under the rq lock. Update it to use SCX_KF_REST. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: David Vernet <void@manifault.com> Cc: Zhao Mengmeng <zhaomzhao@126.com> Link: http://lkml.kernel.org/r/ZzYvf2L3rlmjuKzh@slm.duckdns.org Fixes: 245254f7081d ("sched_ext: Implement sched_ext_ops.cpu_acquire/release()")
2024-11-14cgroup/cpuset: Disable cpuset_cpumask_can_shrink() test if not load balancingWaiman Long
With some recent proposed changes [1] in the deadline server code, it has caused a test failure in test_cpuset_prs.sh when a change is being made to an isolated partition. This is due to failing the cpuset_cpumask_can_shrink() check for SCHED_DEADLINE tasks at validate_change(). This is actually a false positive as the failed test case involves an isolated partition with load balancing disabled. The deadline check is not meaningful in this case and the users should know what they are doing. Fix this by doing the cpuset_cpumask_can_shrink() check only when loading balanced is enabled. Also change its arguments to use effective_cpus for the current cpuset and user_xcpus() as an approiximation for the target effective_cpus as the real effective_cpus hasn't been fully computed yet as this early stage. As the check isn't comprehensive, there may be false positives or negatives. We may have to revise the code to do a more thorough check in the future if this becomes a concern. [1] https://lore.kernel.org/lkml/82be06c1-6d6d-4651-86c9-bcc828cbcb80@redhat.com/T/#t Signed-off-by: Waiman Long <longman@redhat.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2024-11-14tracing/ring-buffer: Clear all memory mapped CPU ring buffers on first recordingSteven Rostedt
The events of a memory mapped ring buffer from the previous boot should not be mixed in with events from the current boot. There's meta data that is used to handle KASLR so that function names can be shown properly. Also, since the timestamps of the previous boot have no meaning to the timestamps of the current boot, having them intermingled in a buffer can also cause confusion because there could possibly be events in the future. When a trace is activated the meta data is reset so that the pointers of are now processed for the new address space. The trace buffers are reset when tracing starts for the first time. The problem here is that the reset only happens on online CPUs. If a CPU is offline, it does not get reset. To demonstrate the issue, a previous boot had tracing enabled in the boot mapped ring buffer on reboot. On the following boot, tracing has not been started yet so the function trace from the previous boot is still visible. # trace-cmd show -B boot_mapped -c 3 | tail <idle>-0 [003] d.h2. 156.462395: __rcu_read_lock <-cpu_emergency_disable_virtualization <idle>-0 [003] d.h2. 156.462396: vmx_emergency_disable_virtualization_cpu <-cpu_emergency_disable_virtualization <idle>-0 [003] d.h2. 156.462396: __rcu_read_unlock <-__sysvec_reboot <idle>-0 [003] d.h2. 156.462397: stop_this_cpu <-__sysvec_reboot <idle>-0 [003] d.h2. 156.462397: set_cpu_online <-stop_this_cpu <idle>-0 [003] d.h2. 156.462397: disable_local_APIC <-stop_this_cpu <idle>-0 [003] d.h2. 156.462398: clear_local_APIC <-disable_local_APIC <idle>-0 [003] d.h2. 156.462574: mcheck_cpu_clear <-stop_this_cpu <idle>-0 [003] d.h2. 156.462575: mce_intel_feature_clear <-stop_this_cpu <idle>-0 [003] d.h2. 156.462575: lmce_supported <-mce_intel_feature_clear Now, if CPU 3 is taken offline, and tracing is started on the memory mapped ring buffer, the events from the previous boot in the CPU 3 ring buffer is not reset. Now those events are using the meta data from the current boot and produces just hex values. # echo 0 > /sys/devices/system/cpu/cpu3/online # trace-cmd start -B boot_mapped -p function # trace-cmd show -B boot_mapped -c 3 | tail <idle>-0 [003] d.h2. 156.462395: 0xffffffff9a1e3194 <-0xffffffff9a0f655e <idle>-0 [003] d.h2. 156.462396: 0xffffffff9a0a1d24 <-0xffffffff9a0f656f <idle>-0 [003] d.h2. 156.462396: 0xffffffff9a1e6bc4 <-0xffffffff9a0f7323 <idle>-0 [003] d.h2. 156.462397: 0xffffffff9a0d12b4 <-0xffffffff9a0f732a <idle>-0 [003] d.h2. 156.462397: 0xffffffff9a1458d4 <-0xffffffff9a0d12e2 <idle>-0 [003] d.h2. 156.462397: 0xffffffff9a0faed4 <-0xffffffff9a0d12e7 <idle>-0 [003] d.h2. 156.462398: 0xffffffff9a0faaf4 <-0xffffffff9a0faef2 <idle>-0 [003] d.h2. 156.462574: 0xffffffff9a0e3444 <-0xffffffff9a0d12ef <idle>-0 [003] d.h2. 156.462575: 0xffffffff9a0e4964 <-0xffffffff9a0d12ef <idle>-0 [003] d.h2. 156.462575: 0xffffffff9a0e3fb0 <-0xffffffff9a0e496f Reset all CPUs when starting a boot mapped ring buffer for the first time, and not just the online CPUs. Fixes: 7a1d1e4b9639f ("tracing/ring-buffer: Add last_boot_info file to boot instance") Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-11-14Revert: "ring-buffer: Do not have boot mapped buffers hook to CPU hotplug"Steven Rostedt
A crash happened when testing cpu hotplug with respect to the memory mapped ring buffers. It was assumed that the hot plug code was adding a per CPU buffer that was already created that caused the crash. The real problem was due to ref counting and was fixed by commit 2cf9733891a4 ("ring-buffer: Fix refcount setting of boot mapped buffers"). When a per CPU buffer is created, it will not be created again even with CPU hotplug, so the fix to not use CPU hotplug was a red herring. In fact, it caused only the boot CPU buffer to be created, leaving the other CPU per CPU buffers disabled. Revert that change as it was not the culprit of the fix it was intended to be. Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Link: https://lore.kernel.org/20241113230839.6c03640f@gandalf.local.home Fixes: 912da2c384d5 ("ring-buffer: Do not have boot mapped buffers hook to CPU hotplug") Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-11-14Merge branches 'for-next/gcs', 'for-next/probes', 'for-next/asm-offsets', ↵Catalin Marinas
'for-next/tlb', 'for-next/misc', 'for-next/mte', 'for-next/sysreg', 'for-next/stacktrace', 'for-next/hwcap3', 'for-next/kselftest', 'for-next/crc32', 'for-next/guest-cca', 'for-next/haft' and 'for-next/scs', remote-tracking branch 'arm64/for-next/perf' into for-next/core * arm64/for-next/perf: perf: Switch back to struct platform_driver::remove() perf: arm_pmuv3: Add support for Samsung Mongoose PMU dt-bindings: arm: pmu: Add Samsung Mongoose core compatible perf/dwc_pcie: Fix typos in event names perf/dwc_pcie: Add support for Ampere SoCs ARM: pmuv3: Add missing write_pmuacr() perf/marvell: Marvell PEM performance monitor support perf/arm_pmuv3: Add PMUv3.9 per counter EL0 access control perf/dwc_pcie: Convert the events with mixed case to lowercase perf/cxlpmu: Support missing events in 3.1 spec perf: imx_perf: add support for i.MX91 platform dt-bindings: perf: fsl-imx-ddr: Add i.MX91 compatible drivers perf: remove unused field pmu_node * for-next/gcs: (42 commits) : arm64 Guarded Control Stack user-space support kselftest/arm64: Fix missing printf() argument in gcs/gcs-stress.c arm64/gcs: Fix outdated ptrace documentation kselftest/arm64: Ensure stable names for GCS stress test results kselftest/arm64: Validate that GCS push and write permissions work kselftest/arm64: Enable GCS for the FP stress tests kselftest/arm64: Add a GCS stress test kselftest/arm64: Add GCS signal tests kselftest/arm64: Add test coverage for GCS mode locking kselftest/arm64: Add a GCS test program built with the system libc kselftest/arm64: Add very basic GCS test program kselftest/arm64: Always run signals tests with GCS enabled kselftest/arm64: Allow signals tests to specify an expected si_code kselftest/arm64: Add framework support for GCS to signal handling tests kselftest/arm64: Add GCS as a detected feature in the signal tests kselftest/arm64: Verify the GCS hwcap arm64: Add Kconfig for Guarded Control Stack (GCS) arm64/ptrace: Expose GCS via ptrace and core files arm64/signal: Expose GCS state in signal frames arm64/signal: Set up and restore the GCS context for signal handlers arm64/mm: Implement map_shadow_stack() ... * for-next/probes: : Various arm64 uprobes/kprobes cleanups arm64: insn: Simulate nop instruction for better uprobe performance arm64: probes: Remove probe_opcode_t arm64: probes: Cleanup kprobes endianness conversions arm64: probes: Move kprobes-specific fields arm64: probes: Fix uprobes for big-endian kernels arm64: probes: Fix simulate_ldr*_literal() arm64: probes: Remove broken LDR (literal) uprobe support * for-next/asm-offsets: : arm64 asm-offsets.c cleanup (remove unused offsets) arm64: asm-offsets: remove PREEMPT_DISABLE_OFFSET arm64: asm-offsets: remove DMA_{TO,FROM}_DEVICE arm64: asm-offsets: remove VM_EXEC and PAGE_SZ arm64: asm-offsets: remove MM_CONTEXT_ID arm64: asm-offsets: remove COMPAT_{RT_,SIGFRAME_REGS_OFFSET arm64: asm-offsets: remove VMA_VM_* arm64: asm-offsets: remove TSK_ACTIVE_MM * for-next/tlb: : TLB flushing optimisations arm64: optimize flush tlb kernel range arm64: tlbflush: add __flush_tlb_range_limit_excess() * for-next/misc: : Miscellaneous patches arm64: tls: Fix context-switching of tpidrro_el0 when kpti is enabled arm64/ptrace: Clarify documentation of VL configuration via ptrace acpi/arm64: remove unnecessary cast arm64/mm: Change protval as 'pteval_t' in map_range() arm64: uprobes: Optimize cache flushes for xol slot acpi/arm64: Adjust error handling procedure in gtdt_parse_timer_block() arm64: fix .data.rel.ro size assertion when CONFIG_LTO_CLANG arm64/ptdump: Test both PTE_TABLE_BIT and PTE_VALID for block mappings arm64/mm: Sanity check PTE address before runtime P4D/PUD folding arm64/mm: Drop setting PTE_TYPE_PAGE in pte_mkcont() ACPI: GTDT: Tighten the check for the array of platform timer structures arm64/fpsimd: Fix a typo arm64: Expose ID_AA64ISAR1_EL1.XS to sanitised feature consumers arm64: Return early when break handler is found on linked-list arm64/mm: Re-organize arch_make_huge_pte() arm64/mm: Drop _PROT_SECT_DEFAULT arm64: Add command-line override for ID_AA64MMFR0_EL1.ECV arm64: head: Drop SWAPPER_TABLE_SHIFT arm64: cpufeature: add POE to cpucap_is_possible() arm64/mm: Change pgattr_change_is_safe() arguments as pteval_t * for-next/mte: : Various MTE improvements selftests: arm64: add hugetlb mte tests hugetlb: arm64: add mte support * for-next/sysreg: : arm64 sysreg updates arm64/sysreg: Update ID_AA64MMFR1_EL1 to DDI0601 2024-09 * for-next/stacktrace: : arm64 stacktrace improvements arm64: preserve pt_regs::stackframe during exec*() arm64: stacktrace: unwind exception boundaries arm64: stacktrace: split unwind_consume_stack() arm64: stacktrace: report recovered PCs arm64: stacktrace: report source of unwind data arm64: stacktrace: move dump_backtrace() to kunwind_stack_walk() arm64: use a common struct frame_record arm64: pt_regs: swap 'unused' and 'pmr' fields arm64: pt_regs: rename "pmr_save" -> "pmr" arm64: pt_regs: remove stale big-endian layout arm64: pt_regs: assert pt_regs is a multiple of 16 bytes * for-next/hwcap3: : Add AT_HWCAP3 support for arm64 (also wire up AT_HWCAP4) arm64: Support AT_HWCAP3 binfmt_elf: Wire up AT_HWCAP3 at AT_HWCAP4 * for-next/kselftest: (30 commits) : arm64 kselftest fixes/cleanups kselftest/arm64: Try harder to generate different keys during PAC tests kselftest/arm64: Don't leak pipe fds in pac.exec_sign_all() kselftest/arm64: Corrupt P0 in the irritator when testing SSVE kselftest/arm64: Add FPMR coverage to fp-ptrace kselftest/arm64: Expand the set of ZA writes fp-ptrace does kselftets/arm64: Use flag bits for features in fp-ptrace assembler code kselftest/arm64: Enable build of PAC tests with LLVM=1 kselftest/arm64: Check that SVCR is 0 in signal handlers kselftest/arm64: Fix printf() compiler warnings in the arm64 syscall-abi.c tests kselftest/arm64: Fix printf() warning in the arm64 MTE prctl() test kselftest/arm64: Fix printf() compiler warnings in the arm64 fp tests kselftest/arm64: Fix build with stricter assemblers kselftest/arm64: Test signal handler state modification in fp-stress kselftest/arm64: Provide a SIGUSR1 handler in the kernel mode FP stress test kselftest/arm64: Implement irritators for ZA and ZT kselftest/arm64: Remove unused ADRs from irritator handlers kselftest/arm64: Correct misleading comments on fp-stress irritators kselftest/arm64: Poll less often while waiting for fp-stress children kselftest/arm64: Increase frequency of signal delivery in fp-stress kselftest/arm64: Fix encoding for SVE B16B16 test ... * for-next/crc32: : Optimise CRC32 using PMULL instructions arm64/crc32: Implement 4-way interleave using PMULL arm64/crc32: Reorganize bit/byte ordering macros arm64/lib: Handle CRC-32 alternative in C code * for-next/guest-cca: : Support for running Linux as a guest in Arm CCA arm64: Document Arm Confidential Compute virt: arm-cca-guest: TSM_REPORT support for realms arm64: Enable memory encrypt for Realms arm64: mm: Avoid TLBI when marking pages as valid arm64: Enforce bounce buffers for realm DMA efi: arm64: Map Device with Prot Shared arm64: rsi: Map unprotected MMIO as decrypted arm64: rsi: Add support for checking whether an MMIO is protected arm64: realm: Query IPA size from the RMM arm64: Detect if in a realm and set RIPAS RAM arm64: rsi: Add RSI definitions * for-next/haft: : Support for arm64 FEAT_HAFT arm64: pgtable: Warn unexpected pmdp_test_and_clear_young() arm64: Enable ARCH_HAS_NONLEAF_PMD_YOUNG arm64: Add support for FEAT_HAFT arm64: setup: name 'tcr2' register arm64/sysreg: Update ID_AA64MMFR1_EL1 register * for-next/scs: : Dynamic shadow call stack fixes arm64/scs: Drop unused prototype __pi_scs_patch_vmlinux() arm64/scs: Deal with 64-bit relative offsets in FDE frames arm64/scs: Fix handling of DWARF augmentation data in CIE/FDE frames
2024-11-14Merge tag 'loongarch-kvm-6.13' of ↵Paolo Bonzini
git://git.kernel.org/pub/scm/linux/kernel/git/chenhuacai/linux-loongson into HEAD LoongArch KVM changes for v6.13 1. Add iocsr and mmio bus simulation in kernel. 2. Add in-kernel interrupt controller emulation. 3. Add virt extension support for eiointc irqchip.
2024-11-14Merge tag 'kvmarm-6.13' of ↵Paolo Bonzini
https://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD KVM/arm64 changes for 6.13, part #1 - Support for stage-1 permission indirection (FEAT_S1PIE) and permission overlays (FEAT_S1POE), including nested virt + the emulated page table walker - Introduce PSCI SYSTEM_OFF2 support to KVM + client driver. This call was introduced in PSCIv1.3 as a mechanism to request hibernation, similar to the S4 state in ACPI - Explicitly trap + hide FEAT_MPAM (QoS controls) from KVM guests. As part of it, introduce trivial initialization of the host's MPAM context so KVM can use the corresponding traps - PMU support under nested virtualization, honoring the guest hypervisor's trap configuration and event filtering when running a nested guest - Fixes to vgic ITS serialization where stale device/interrupt table entries are not zeroed when the mapping is invalidated by the VM - Avoid emulated MMIO completion if userspace has requested synchronous external abort injection - Various fixes and cleanups affecting pKVM, vCPU initialization, and selftests
2024-11-14dma-mapping: save base/size instead of pointer to shared DMA poolGeert Uytterhoeven
On RZ/Five, which is non-coherent, and uses CONFIG_DMA_GLOBAL_POOL=y: Oops - store (or AMO) access fault [#1] CPU: 0 UID: 0 PID: 1 Comm: swapper Not tainted 6.12.0-rc1-00015-g8a6e02d0c00e #201 Hardware name: Renesas SMARC EVK based on r9a07g043f01 (DT) epc : __memset+0x60/0x100 ra : __dma_alloc_from_coherent+0x150/0x17a epc : ffffffff8062d2bc ra : ffffffff80053a94 sp : ffffffc60000ba20 gp : ffffffff812e9938 tp : ffffffd601920000 t0 : ffffffc6000d0000 t1 : 0000000000000000 t2 : ffffffffe9600000 s0 : ffffffc60000baa0 s1 : ffffffc6000d0000 a0 : ffffffc6000d0000 a1 : 0000000000000000 a2 : 0000000000001000 a3 : ffffffc6000d1000 a4 : 0000000000000000 a5 : 0000000000000000 a6 : ffffffd601adacc0 a7 : ffffffd601a841a8 s2 : ffffffd6018573c0 s3 : 0000000000001000 s4 : ffffffd6019541e0 s5 : 0000000200000022 s6 : ffffffd6018f8410 s7 : ffffffd6018573e8 s8 : 0000000000000001 s9 : 0000000000000001 s10: 0000000000000010 s11: 0000000000000000 t3 : 0000000000000000 t4 : ffffffffdefe62d1 t5 : 000000001cd6a3a9 t6 : ffffffd601b2aad6 status: 0000000200000120 badaddr: ffffffc6000d0000 cause: 0000000000000007 [<ffffffff8062d2bc>] __memset+0x60/0x100 [<ffffffff80053e1a>] dma_alloc_from_global_coherent+0x1c/0x28 [<ffffffff80053056>] dma_direct_alloc+0x98/0x112 [<ffffffff8005238c>] dma_alloc_attrs+0x78/0x86 [<ffffffff8035fdb4>] rz_dmac_probe+0x3f6/0x50a [<ffffffff803a0694>] platform_probe+0x4c/0x8a If CONFIG_DMA_GLOBAL_POOL=y, the reserved_mem structure passed to rmem_dma_setup() is saved for later use, by saving the passed pointer. However, when dma_init_reserved_memory() is called later, the pointer has become stale, causing a crash. E.g. in the RZ/Five case, the referenced memory now contains the reserved_mem structure for the "mmode_resv0@30000" node (with base 0x30000 and size 0x10000), instead of the correct "pma_resv0@58000000" node (with base 0x58000000 and size 0x8000000). Fix this by saving the needed reserved_mem structure's contents instead. Fixes: 8a6e02d0c00e7b62 ("of: reserved_mem: Restructure how the reserved memory regions are processed") Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Reviewed-by: Oreoluwa Babatunde <quic_obabatun@quicinc.com> Tested-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com> Signed-off-by: Christoph Hellwig <hch@lst.de>
2024-11-14perf/core: Correct perf sampling with guest VMsColton Lewis
Previously any PMU overflow interrupt that fired while a VCPU was loaded was recorded as a guest event whether it truly was or not. This resulted in nonsense perf recordings that did not honor perf_event_attr.exclude_guest and recorded guest IPs where it should have recorded host IPs. Rework the sampling logic to only record guest samples for events with exclude_guest = 0. This way any host-only events with exclude_guest set will never see unexpected guest samples. The behaviour of events with exclude_guest = 0 is unchanged. Note that events configured to sample both host and guest may still misattribute a PMI that arrived in the host as a guest event depending on KVM arch and vendor behavior. Signed-off-by: Colton Lewis <coltonlewis@google.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Oliver Upton <oliver.upton@linux.dev> Acked-by: Mark Rutland <mark.rutland@arm.com> Acked-by: Kan Liang <kan.liang@linux.intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Namhyung Kim <namhyung@kernel.org> Link: https://lore.kernel.org/r/20241113190156.2145593-6-coltonlewis@google.com
2024-11-14perf/core: Hoist perf_instruction_pointer() and perf_misc_flags()Colton Lewis
For clarity, rename the arch-specific definitions of these functions to perf_arch_* to denote they are arch-specifc. Define the generic-named functions in one place where they can call the arch-specific ones as needed. Signed-off-by: Colton Lewis <coltonlewis@google.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Oliver Upton <oliver.upton@linux.dev> Acked-by: Thomas Richter <tmricht@linux.ibm.com> Acked-by: Mark Rutland <mark.rutland@arm.com> Acked-by: Madhavan Srinivasan <maddy@linux.ibm.com> Acked-by: Kan Liang <kan.liang@linux.intel.com> Link: https://lore.kernel.org/r/20241113190156.2145593-3-coltonlewis@google.com
2024-11-13bpf: Introduce range_tree data structure and use it in bpf arenaAlexei Starovoitov
Introduce range_tree data structure and use it in bpf arena to track ranges of allocated pages. range_tree is a large bitmap that is implemented as interval tree plus rbtree. The contiguous sequence of bits represents unallocated pages. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Link: https://lore.kernel.org/bpf/20241108025616.17625-2-alexei.starovoitov@gmail.com
2024-11-13Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpfAlexei Starovoitov
Cross-merge bpf fixes after downstream PR. In particular to bring the fix in commit aa30eb3260b2 ("bpf: Force checkpoint when jmp history is too long"). The follow up verifier work depends on it. And the fix in commit 6801cf7890f2 ("selftests/bpf: Use -4095 as the bad address for bits iterator"). It's fixing instability of BPF CI on s390 arch. No conflicts. Adjacent changes in: Auto-merging arch/Kconfig Auto-merging kernel/bpf/helpers.c Auto-merging kernel/bpf/memalloc.c Auto-merging kernel/bpf/verifier.c Auto-merging mm/slab_common.c Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-11-13genirq/proc: Use seq_put_decimal_ull_width() for decimal valuesDavid Wang
seq_printf() is more expensive than seq_put_decimal_ull_width() due to the format string parsing costs. Profiling on a x86 8-core system indicates seq_printf() takes ~47% samples of show_interrupts(). Replacing it with seq_put_decimal_ull_width() yields almost 30% performance gain. [ tglx: Massaged changelog and fixed up coding style ] Signed-off-by: David Wang <00107082@163.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/all/20241108160717.9547-1-00107082@163.com
2024-11-12bpf: Add kernel symbol for struct_ops trampolineXu Kuohai
Without kernel symbols for struct_ops trampoline, the unwinder may produce unexpected stacktraces. For example, the x86 ORC and FP unwinders check if an IP is in kernel text by verifying the presence of the IP's kernel symbol. When a struct_ops trampoline address is encountered, the unwinder stops due to the absence of symbol, resulting in an incomplete stacktrace that consists only of direct and indirect child functions called from the trampoline. The arm64 unwinder is another example. While the arm64 unwinder can proceed across a struct_ops trampoline address, the corresponding symbol name is displayed as "unknown", which is confusing. Thus, add kernel symbol for struct_ops trampoline. The name is bpf__<struct_ops_name>_<member_name>, where <struct_ops_name> is the type name of the struct_ops, and <member_name> is the name of the member that the trampoline is linked to. Below is a comparison of stacktraces captured on x86 by perf record, before and after this patch. Before: ffffffff8116545d __lock_acquire+0xad ([kernel.kallsyms]) ffffffff81167fcc lock_acquire+0xcc ([kernel.kallsyms]) ffffffff813088f4 __bpf_prog_enter+0x34 ([kernel.kallsyms]) After: ffffffff811656bd __lock_acquire+0x30d ([kernel.kallsyms]) ffffffff81167fcc lock_acquire+0xcc ([kernel.kallsyms]) ffffffff81309024 __bpf_prog_enter+0x34 ([kernel.kallsyms]) ffffffffc000d7e9 bpf__tcp_congestion_ops_cong_avoid+0x3e ([kernel.kallsyms]) ffffffff81f250a5 tcp_ack+0x10d5 ([kernel.kallsyms]) ffffffff81f27c66 tcp_rcv_established+0x3b6 ([kernel.kallsyms]) ffffffff81f3ad03 tcp_v4_do_rcv+0x193 ([kernel.kallsyms]) ffffffff81d65a18 __release_sock+0xd8 ([kernel.kallsyms]) ffffffff81d65af4 release_sock+0x34 ([kernel.kallsyms]) ffffffff81f15c4b tcp_sendmsg+0x3b ([kernel.kallsyms]) ffffffff81f663d7 inet_sendmsg+0x47 ([kernel.kallsyms]) ffffffff81d5ab40 sock_write_iter+0x160 ([kernel.kallsyms]) ffffffff8149c67b vfs_write+0x3fb ([kernel.kallsyms]) ffffffff8149caf6 ksys_write+0xc6 ([kernel.kallsyms]) ffffffff8149cb5d __x64_sys_write+0x1d ([kernel.kallsyms]) ffffffff81009200 x64_sys_call+0x1d30 ([kernel.kallsyms]) ffffffff82232d28 do_syscall_64+0x68 ([kernel.kallsyms]) ffffffff8240012f entry_SYSCALL_64_after_hwframe+0x76 ([kernel.kallsyms]) Fixes: 85d33df357b6 ("bpf: Introduce BPF_MAP_TYPE_STRUCT_OPS") Signed-off-by: Xu Kuohai <xukuohai@huawei.com> Acked-by: Yonghong Song <yonghong.song@linux.dev> Link: https://lore.kernel.org/r/20241112145849.3436772-4-xukuohai@huaweicloud.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-11-12bpf: Use function pointers count as struct_ops links countXu Kuohai
Only function pointers in a struct_ops structure can be linked to bpf progs, so set the links count to the function pointers count, instead of the total members count in the structure. Suggested-by: Martin KaFai Lau <martin.lau@linux.dev> Signed-off-by: Xu Kuohai <xukuohai@huawei.com> Link: https://lore.kernel.org/r/20241112145849.3436772-3-xukuohai@huaweicloud.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-11-12bpf: Remove unused member rcu from bpf_struct_ops_mapXu Kuohai
The rcu member in bpf_struct_ops_map is not used after commit b671c2067a04 ("bpf: Retire the struct_ops map kvalue->refcnt.") Remove it. Suggested-by: Martin KaFai Lau <martin.lau@linux.dev> Signed-off-by: Xu Kuohai <xukuohai@huawei.com> Link: https://lore.kernel.org/r/20241112145849.3436772-2-xukuohai@huaweicloud.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-11-12bpf: Support private stack for struct_ops progsYonghong Song
For struct_ops progs, whether a particular prog uses private stack depends on prog->aux->priv_stack_requested setting before actual insn-level verification for that prog. One particular implementation is to piggyback on struct_ops->check_member(). The next patch has an example for this. The struct_ops->check_member() sets prog->aux->priv_stack_requested to be true which enables private stack usage. The struct_ops prog follows the same rule as kprobe/tracing progs after function bpf_enable_priv_stack(). For example, even a struct_ops prog requests private stack, it could still use normal kernel stack if the stack size is small (< 64 bytes). Similar to tracing progs, nested same cpu same prog run will be skipped. A field (recursion_detected()) is added to bpf_prog_aux structure. If bpf_prog->aux->recursion_detected is implemented by the struct_ops subsystem and nested same cpu/prog happens, the function will be triggered to report an error, collect related info, etc. Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Yonghong Song <yonghong.song@linux.dev> Link: https://lore.kernel.org/r/20241112163933.2224962-1-yonghong.song@linux.dev Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-11-12bpf: Enable private stack for eligible subprogsYonghong Song
If private stack is used by any subprog, set that subprog prog->aux->jits_use_priv_stack to be true so later jit can allocate private stack for that subprog properly. Also set env->prog->aux->jits_use_priv_stack to be true if any subprog uses private stack. This is a use case for a single main prog (no subprogs) to use private stack, and also a use case for later struct-ops progs where env->prog->aux->jits_use_priv_stack will enable recursion check if any subprog uses private stack. Signed-off-by: Yonghong Song <yonghong.song@linux.dev> Link: https://lore.kernel.org/r/20241112163912.2224007-1-yonghong.song@linux.dev Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-11-12bpf: Find eligible subprogs for private stack supportYonghong Song
Private stack will be allocated with percpu allocator in jit time. To avoid complexity at runtime, only one copy of private stack is available per cpu per prog. So runtime recursion check is necessary to avoid stack corruption. Current private stack only supports kprobe/perf_event/tp/raw_tp which has recursion check in the kernel, and prog types that use bpf trampoline recursion check. For trampoline related prog types, currently only tracing progs have recursion checking. To avoid complexity, all async_cb subprogs use normal kernel stack including those subprogs used by both main prog subtree and async_cb subtree. Any prog having tail call also uses kernel stack. To avoid jit penalty with private stack support, a subprog stack size threshold is set such that only if the stack size is no less than the threshold, private stack is supported. The current threshold is 64 bytes. This avoids jit penality if the stack usage is small. A useless 'continue' is also removed from a loop in func check_max_stack_depth(). Signed-off-by: Yonghong Song <yonghong.song@linux.dev> Link: https://lore.kernel.org/r/20241112163907.2223839-1-yonghong.song@linux.dev Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-11-12srcu: Check for srcu_read_lock_lite() across all CPUsPaul E. McKenney
If srcu_read_lock_lite() is used on a given srcu_struct structure, then the grace-period processing must do synchronize_rcu() instead of smp_mb() between the scans of the ->srcu_unlock_count[] and ->srcu_lock_count[] counters. Currently, it does that by testing the SRCU_READ_FLAVOR_LITE bit of the ->srcu_reader_flavor mask, which works well. But only if the CPU running that srcu_struct structure's grace period has previously executed srcu_read_lock_lite(), which might not be the case, especially just after that srcu_struct structure has been created and initialized. This commit therefore updates the srcu_readers_unlock_idx() function to OR together the ->srcu_reader_flavor masks from all CPUs, and then make the srcu_readers_active_idx_check() function that test the SRCU_READ_FLAVOR_LITE bit in the resulting mask. Note that the srcu_readers_unlock_idx() function is already scanning all the CPUs to sum up the ->srcu_unlock_count[] fields and that this is on the grace-period slow path, hence no concerns about the small amount of extra work. Reported-by: Neeraj Upadhyay <Neeraj.Upadhyay@amd.com> Closes: https://lore.kernel.org/all/d07e8f4a-d5ff-4c8e-8e61-50db285c57e9@amd.com/ Fixes: c0f08d6b5a61 ("srcu: Add srcu_read_lock_lite() and srcu_read_unlock_lite()") Signed-off-by: Paul E. McKenney <paulmck@kernel.org> Cc: Frederic Weisbecker <frederic@kernel.org> Reviewed-by: Neeraj Upadhyay <Neeraj.Upadhyay@amd.com> Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
2024-11-12rcutorture: Avoid printing cpu=-1 for no-fault RCU boost failurePaul E. McKenney
If a CPU runs throughout the stalled grace period without passing through a quiescent state, RCU priority boosting cannot help. The rcu_torture_boost_failed() function therefore prints a message flagging the first such CPU. However, if the stall was instead due to (for example) RCU's grace-period kthread being starved of CPU, there will be no such CPU, causing rcu_check_boost_fail() to instead pass back -1 through its cpup CPU-pointer parameter. Therefore, the current message complains about a mythical CPU -1. This commit therefore checks for this situation, and notes that all CPUs have passed through a quiescent state. Signed-off-by: Paul E. McKenney <paulmck@kernel.org> Reviewed-by: Neeraj Upadhyay <Neeraj.Upadhyay@amd.com> Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
2024-11-12rcuscale: Add guest_os_delay module parameterPaul E. McKenney
This commit adds a guest_os_delay module parameter that extends warm-up and cool-down the specified number of seconds before and after the series of test runs. This allows the data-collection intervals from any given rcuscale guest OSes to line up with active periods in the other rcuscale guest OSes, and also allows the thermal warm-up period required to obtain consistent results from one test to the next. Signed-off-by: Paul E. McKenney <paulmck@kernel.org> Reviewed-by: Neeraj Upadhyay <Neeraj.Upadhyay@amd.com> Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
2024-11-12refscale: Correct affinity checkPaul E. McKenney
The current affinity check works fine until there are more reader processes than CPUs, at which point the affinity check is looking for non-existent CPUs. This commit therefore applies the same modulus to the check as is present in the set_cpus_allowed_ptr() call. Signed-off-by: Paul E. McKenney <paulmck@kernel.org> Reviewed-by: Neeraj Upadhyay <Neeraj.Upadhyay@amd.com> Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
2024-11-12rcu/nocb: Fix missed RCU barrier on deoffloadingZqiang
Currently, running rcutorture test with torture_type=rcu fwd_progress=8 n_barrier_cbs=8 nocbs_nthreads=8 nocbs_toggle=100 onoff_interval=60 test_boost=2, will trigger the following warning: WARNING: CPU: 19 PID: 100 at kernel/rcu/tree_nocb.h:1061 rcu_nocb_rdp_deoffload+0x292/0x2a0 RIP: 0010:rcu_nocb_rdp_deoffload+0x292/0x2a0 Call Trace: <TASK> ? __warn+0x7e/0x120 ? rcu_nocb_rdp_deoffload+0x292/0x2a0 ? report_bug+0x18e/0x1a0 ? handle_bug+0x3d/0x70 ? exc_invalid_op+0x18/0x70 ? asm_exc_invalid_op+0x1a/0x20 ? rcu_nocb_rdp_deoffload+0x292/0x2a0 rcu_nocb_cpu_deoffload+0x70/0xa0 rcu_nocb_toggle+0x136/0x1c0 ? __pfx_rcu_nocb_toggle+0x10/0x10 kthread+0xd1/0x100 ? __pfx_kthread+0x10/0x10 ret_from_fork+0x2f/0x50 ? __pfx_kthread+0x10/0x10 ret_from_fork_asm+0x1a/0x30 </TASK> CPU0 CPU2 CPU3 //rcu_nocb_toggle //nocb_cb_wait //rcutorture // deoffload CPU1 // process CPU1's rdp rcu_barrier() rcu_segcblist_entrain() rcu_segcblist_add_len(1); // len == 2 // enqueue barrier // callback to CPU1's // rdp->cblist rcu_do_batch() // invoke CPU1's rdp->cblist // callback rcu_barrier_callback() rcu_barrier() mutex_lock(&rcu_state.barrier_mutex); // still see len == 2 // enqueue barrier callback // to CPU1's rdp->cblist rcu_segcblist_entrain() rcu_segcblist_add_len(1); // len == 3 // decrement len rcu_segcblist_add_len(-2); kthread_parkme() // CPU1's rdp->cblist len == 1 // Warn because there is // still a pending barrier // trigger warning WARN_ON_ONCE(rcu_segcblist_n_cbs(&rdp->cblist)); cpus_read_unlock(); // wait CPU1 to comes online and // invoke barrier callback on // CPU1 rdp's->cblist wait_for_completion(&rcu_state.barrier_completion); // deoffload CPU4 cpus_read_lock() rcu_barrier() mutex_lock(&rcu_state.barrier_mutex); // block on barrier_mutex // wait rcu_barrier() on // CPU3 to unlock barrier_mutex // but CPU3 unlock barrier_mutex // need to wait CPU1 comes online // when CPU1 going online will block on cpus_write_lock The above scenario will not only trigger a WARN_ON_ONCE(), but also trigger a deadlock. Thanks to nocb locking, a second racing rcu_barrier() on an offline CPU will either observe the decremented callback counter down to 0 and spare the callback enqueue, or rcuo will observe the new callback and keep rdp->nocb_cb_sleep to false. Therefore check rdp->nocb_cb_sleep before parking to make sure no further rcu_barrier() is waiting on the rdp. Fixes: 1fcb932c8b5c ("rcu/nocb: Simplify (de-)offloading state machine") Suggested-by: Frederic Weisbecker <frederic@kernel.org> Signed-off-by: Zqiang <qiang.zhang1211@gmail.com> Reviewed-by: Neeraj Upadhyay <Neeraj.Upadhyay@amd.com> Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
2024-11-12rcu/kvfree: Fix data-race in __mod_timer / kvfree_call_rcuUladzislau Rezki (Sony)
KCSAN reports a data race when access the krcp->monitor_work.timer.expires variable in the schedule_delayed_monitor_work() function: <snip> BUG: KCSAN: data-race in __mod_timer / kvfree_call_rcu read to 0xffff888237d1cce8 of 8 bytes by task 10149 on cpu 1: schedule_delayed_monitor_work kernel/rcu/tree.c:3520 [inline] kvfree_call_rcu+0x3b8/0x510 kernel/rcu/tree.c:3839 trie_update_elem+0x47c/0x620 kernel/bpf/lpm_trie.c:441 bpf_map_update_value+0x324/0x350 kernel/bpf/syscall.c:203 generic_map_update_batch+0x401/0x520 kernel/bpf/syscall.c:1849 bpf_map_do_batch+0x28c/0x3f0 kernel/bpf/syscall.c:5143 __sys_bpf+0x2e5/0x7a0 __do_sys_bpf kernel/bpf/syscall.c:5741 [inline] __se_sys_bpf kernel/bpf/syscall.c:5739 [inline] __x64_sys_bpf+0x43/0x50 kernel/bpf/syscall.c:5739 x64_sys_call+0x2625/0x2d60 arch/x86/include/generated/asm/syscalls_64.h:322 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xc9/0x1c0 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f write to 0xffff888237d1cce8 of 8 bytes by task 56 on cpu 0: __mod_timer+0x578/0x7f0 kernel/time/timer.c:1173 add_timer_global+0x51/0x70 kernel/time/timer.c:1330 __queue_delayed_work+0x127/0x1a0 kernel/workqueue.c:2523 queue_delayed_work_on+0xdf/0x190 kernel/workqueue.c:2552 queue_delayed_work include/linux/workqueue.h:677 [inline] schedule_delayed_monitor_work kernel/rcu/tree.c:3525 [inline] kfree_rcu_monitor+0x5e8/0x660 kernel/rcu/tree.c:3643 process_one_work kernel/workqueue.c:3229 [inline] process_scheduled_works+0x483/0x9a0 kernel/workqueue.c:3310 worker_thread+0x51d/0x6f0 kernel/workqueue.c:3391 kthread+0x1d1/0x210 kernel/kthread.c:389 ret_from_fork+0x4b/0x60 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Reported by Kernel Concurrency Sanitizer on: CPU: 0 UID: 0 PID: 56 Comm: kworker/u8:4 Not tainted 6.12.0-rc2-syzkaller-00050-g5b7c893ed5ed #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Workqueue: events_unbound kfree_rcu_monitor <snip> kfree_rcu_monitor() rearms the work if a "krcp" has to be still offloaded and this is done without holding krcp->lock, whereas the kvfree_call_rcu() holds it. Fix it by acquiring the "krcp->lock" for kfree_rcu_monitor() so both functions do not race anymore. Reported-by: syzbot+061d370693bdd99f9d34@syzkaller.appspotmail.com Link: https://lore.kernel.org/lkml/ZxZ68KmHDQYU0yfD@pc636/T/ Fixes: 8fc5494ad5fa ("rcu/kvfree: Move need_offload_krc() out of krcp->lock") Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com> Reviewed-by: Neeraj Upadhyay <Neeraj.Upadhyay@amd.com> Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
2024-11-12rcu/srcutiny: don't return before reenabling preemptionMichal Schmidt
Code after the return statement is dead. Enable preemption before returning from srcu_drive_gp(). This will be important when/if PREEMPT_AUTO (lazy resched) gets merged. Fixes: 65b4a59557f6 ("srcu: Make Tiny SRCU explicitly disable preemption") Reviewed-by: Paul E. McKenney <paulmck@kernel.org> Signed-off-by: Michal Schmidt <mschmidt@redhat.com> Reviewed-by: Neeraj Upadhyay <Neeraj.Upadhyay@amd.com> Signed-off-by: Frederic Weisbecker <frederic@kernel.org>