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2023-04-05kcsan: avoid passing -g for testMarco Elver
[ Upstream commit 5eb39cde1e2487ba5ec1802dc5e58a77e700d99e ] Nathan reported that when building with GNU as and a version of clang that defaults to DWARF5, the assembler will complain with: Error: non-constant .uleb128 is not supported This is because `-g` defaults to the compiler debug info default. If the assembler does not support some of the directives used, the above errors occur. To fix, remove the explicit passing of `-g`. All the test wants is that stack traces print valid function names, and debug info is not required for that. (I currently cannot recall why I added the explicit `-g`.) Link: https://lkml.kernel.org/r/20230316224705.709984-2-elver@google.com Fixes: 1fe84fd4a402 ("kcsan: Add test suite") Signed-off-by: Marco Elver <elver@google.com> Reported-by: Nathan Chancellor <nathan@kernel.org> Cc: Alexander Potapenko <glider@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-04-05kernel: kcsan: kcsan_test: build without structleak pluginAnders Roxell
[ Upstream commit 6fcd4267a840d0536b8e5334ad5f31e4105fce85 ] Building kcsan_test with structleak plugin enabled makes the stack frame size to grow. kernel/kcsan/kcsan_test.c:704:1: error: the frame size of 3296 bytes is larger than 2048 bytes [-Werror=frame-larger-than=] Turn off the structleak plugin checks for kcsan_test. Link: https://lkml.kernel.org/r/20221128104358.2660634-1-anders.roxell@linaro.org Signed-off-by: Anders Roxell <anders.roxell@linaro.org> Suggested-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Marco Elver <elver@google.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: David Gow <davidgow@google.com> Cc: Jason A. Donenfeld <Jason@zx2c4.com> Cc: Kees Cook <keescook@chromium.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Stable-dep-of: 5eb39cde1e24 ("kcsan: avoid passing -g for test") Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-03-30sched/fair: Sanitize vruntime of entity being migratedVincent Guittot
commit a53ce18cacb477dd0513c607f187d16f0fa96f71 upstream. Commit 829c1651e9c4 ("sched/fair: sanitize vruntime of entity being placed") fixes an overflowing bug, but ignore a case that se->exec_start is reset after a migration. For fixing this case, we delay the reset of se->exec_start after placing the entity which se->exec_start to detect long sleeping task. In order to take into account a possible divergence between the clock_task of 2 rqs, we increase the threshold to around 104 days. Fixes: 829c1651e9c4 ("sched/fair: sanitize vruntime of entity being placed") Originally-by: Zhang Qiao <zhangqiao22@huawei.com> Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Tested-by: Zhang Qiao <zhangqiao22@huawei.com> Link: https://lore.kernel.org/r/20230317160810.107988-1-vincent.guittot@linaro.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-30sched/fair: sanitize vruntime of entity being placedZhang Qiao
commit 829c1651e9c4a6f78398d3e67651cef9bb6b42cc upstream. When a scheduling entity is placed onto cfs_rq, its vruntime is pulled to the base level (around cfs_rq->min_vruntime), so that the entity doesn't gain extra boost when placed backwards. However, if the entity being placed wasn't executed for a long time, its vruntime may get too far behind (e.g. while cfs_rq was executing a low-weight hog), which can inverse the vruntime comparison due to s64 overflow. This results in the entity being placed with its original vruntime way forwards, so that it will effectively never get to the cpu. To prevent that, ignore the vruntime of the entity being placed if it didn't execute for much longer than the characteristic sheduler time scale. [rkagan: formatted, adjusted commit log, comments, cutoff value] Signed-off-by: Zhang Qiao <zhangqiao22@huawei.com> Co-developed-by: Roman Kagan <rkagan@amazon.de> Signed-off-by: Roman Kagan <rkagan@amazon.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20230130122216.3555094-1-rkagan@amazon.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-30entry/rcu: Check TIF_RESCHED _after_ delayed RCU wake-upFrederic Weisbecker
[ Upstream commit b416514054810cf2d2cc348ae477cea619b64da7 ] RCU sometimes needs to perform a delayed wake up for specific kthreads handling offloaded callbacks (RCU_NOCB). These wakeups are performed by timers and upon entry to idle (also to guest and to user on nohz_full). However the delayed wake-up on kernel exit is actually performed after the thread flags are fetched towards the fast path check for work to do on exit to user. As a result, and if there is no other pending work to do upon that kernel exit, the current task will resume to userspace with TIF_RESCHED set and the pending wake up ignored. Fix this with fetching the thread flags _after_ the delayed RCU-nocb kthread wake-up. Fixes: 47b8ff194c1f ("entry: Explicitly flush pending rcuog wakeup before last rescheduling point") Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Signed-off-by: Paul E. McKenney <paulmck@kernel.org> Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20230315194349.10798-3-joel@joelfernandes.org Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-03-30entry: Snapshot thread flagsMark Rutland
[ Upstream commit 6ce895128b3bff738fe8d9dd74747a03e319e466 ] Some thread flags can be set remotely, and so even when IRQs are disabled, the flags can change under our feet. Generally this is unlikely to cause a problem in practice, but it is somewhat unsound, and KCSAN will legitimately warn that there is a data race. To avoid such issues, a snapshot of the flags has to be taken prior to using them. Some places already use READ_ONCE() for that, others do not. Convert them all to the new flag accessor helpers. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Paul E. McKenney <paulmck@kernel.org> Link: https://lore.kernel.org/r/20211129130653.2037928-3-mark.rutland@arm.com Stable-dep-of: b41651405481 ("entry/rcu: Check TIF_RESCHED _after_ delayed RCU wake-up") Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-03-30bpf: Adjust insufficient default bpf_jit_limitDaniel Borkmann
[ Upstream commit 10ec8ca8ec1a2f04c4ed90897225231c58c124a7 ] We've seen recent AWS EKS (Kubernetes) user reports like the following: After upgrading EKS nodes from v20230203 to v20230217 on our 1.24 EKS clusters after a few days a number of the nodes have containers stuck in ContainerCreating state or liveness/readiness probes reporting the following error: Readiness probe errored: rpc error: code = Unknown desc = failed to exec in container: failed to start exec "4a11039f730203ffc003b7[...]": OCI runtime exec failed: exec failed: unable to start container process: unable to init seccomp: error loading seccomp filter into kernel: error loading seccomp filter: errno 524: unknown However, we had not been seeing this issue on previous AMIs and it only started to occur on v20230217 (following the upgrade from kernel 5.4 to 5.10) with no other changes to the underlying cluster or workloads. We tried the suggestions from that issue (sysctl net.core.bpf_jit_limit=452534528) which helped to immediately allow containers to be created and probes to execute but after approximately a day the issue returned and the value returned by cat /proc/vmallocinfo | grep bpf_jit | awk '{s+=$2} END {print s}' was steadily increasing. I tested bpf tree to observe bpf_jit_charge_modmem, bpf_jit_uncharge_modmem their sizes passed in as well as bpf_jit_current under tcpdump BPF filter, seccomp BPF and native (e)BPF programs, and the behavior all looks sane and expected, that is nothing "leaking" from an upstream perspective. The bpf_jit_limit knob was originally added in order to avoid a situation where unprivileged applications loading BPF programs (e.g. seccomp BPF policies) consuming all the module memory space via BPF JIT such that loading of kernel modules would be prevented. The default limit was defined back in 2018 and while good enough back then, we are generally seeing far more BPF consumers today. Adjust the limit for the BPF JIT pool from originally 1/4 to now 1/2 of the module memory space to better reflect today's needs and avoid more users running into potentially hard to debug issues. Fixes: fdadd04931c2 ("bpf: fix bpf_jit_limit knob for PAGE_SIZE >= 64K") Reported-by: Stephen Haynes <sh@synk.net> Reported-by: Lefteris Alexakis <lefteris.alexakis@kpn.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://github.com/awslabs/amazon-eks-ami/issues/1179 Link: https://github.com/awslabs/amazon-eks-ami/issues/1219 Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com> Link: https://lore.kernel.org/r/20230320143725.8394-1-daniel@iogearbox.net Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-03-30trace/hwlat: Do not start per-cpu thread if it is already runningTero Kristo
[ Upstream commit 08697bca9bbba15f2058fdbd9f970bd5f6a8a2e8 ] The hwlatd tracer will end up starting multiple per-cpu threads with the following script: #!/bin/sh cd /sys/kernel/debug/tracing echo 0 > tracing_on echo hwlat > current_tracer echo per-cpu > hwlat_detector/mode echo 100000 > hwlat_detector/width echo 200000 > hwlat_detector/window echo 1 > tracing_on To fix the issue, check if the hwlatd thread for the cpu is already running, before starting a new one. Along with the previous patch, this avoids running multiple instances of the same CPU thread on the system. Link: https://lore.kernel.org/all/20230302113654.2984709-1-tero.kristo@linux.intel.com/ Link: https://lkml.kernel.org/r/20230310100451.3948583-3-tero.kristo@linux.intel.com Cc: stable@vger.kernel.org Fixes: f46b16520a087 ("trace/hwlat: Implement the per-cpu mode") Signed-off-by: Tero Kristo <tero.kristo@linux.intel.com> Acked-by: Daniel Bristot de Oliveira <bristot@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-03-30trace/hwlat: make use of the helper function kthread_run_on_cpu()Cai Huoqing
[ Upstream commit ff78f6679d2e223e073fcbdc8f70b6bc0abadf99 ] Replace kthread_create_on_cpu/wake_up_process() with kthread_run_on_cpu() to simplify the code. Link: https://lkml.kernel.org/r/20211022025711.3673-7-caihuoqing@baidu.com Signed-off-by: Cai Huoqing <caihuoqing@baidu.com> Cc: Bernard Metzler <bmt@zurich.ibm.com> Cc: Daniel Bristot de Oliveira <bristot@kernel.org> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Doug Ledford <dledford@redhat.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Joel Fernandes (Google) <joel@joelfernandes.org> Cc: Josh Triplett <josh@joshtriplett.org> Cc: Lai Jiangshan <jiangshanlai@gmail.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: "Paul E . McKenney" <paulmck@kernel.org> Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Stable-dep-of: 08697bca9bbb ("trace/hwlat: Do not start per-cpu thread if it is already running") Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-03-30kthread: add the helper function kthread_run_on_cpu()Cai Huoqing
[ Upstream commit 800977f6f32e452cba6b04ef21d2f5383ca29209 ] Add a new helper function kthread_run_on_cpu(), which includes kthread_create_on_cpu/wake_up_process(). In some cases, use kthread_run_on_cpu() directly instead of kthread_create_on_node/kthread_bind/wake_up_process() or kthread_create_on_cpu/wake_up_process() or kthreadd_create/kthread_bind/wake_up_process() to simplify the code. [akpm@linux-foundation.org: export kthread_create_on_cpu to modules] Link: https://lkml.kernel.org/r/20211022025711.3673-2-caihuoqing@baidu.com Signed-off-by: Cai Huoqing <caihuoqing@baidu.com> Cc: Bernard Metzler <bmt@zurich.ibm.com> Cc: Cai Huoqing <caihuoqing@baidu.com> Cc: Daniel Bristot de Oliveira <bristot@kernel.org> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Doug Ledford <dledford@redhat.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Joel Fernandes (Google) <joel@joelfernandes.org> Cc: Josh Triplett <josh@joshtriplett.org> Cc: Lai Jiangshan <jiangshanlai@gmail.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: "Paul E . McKenney" <paulmck@kernel.org> Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Stable-dep-of: 08697bca9bbb ("trace/hwlat: Do not start per-cpu thread if it is already running") Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-03-30tracing/hwlat: Replace sched_setaffinity with set_cpus_allowed_ptrCosta Shulyupin
[ Upstream commit 71c7a30442b724717a30d5e7d1662ba4904eb3d4 ] There is a problem with the behavior of hwlat in a container, resulting in incorrect output. A warning message is generated: "cpumask changed while in round-robin mode, switching to mode none", and the tracing_cpumask is ignored. This issue arises because the kernel thread, hwlatd, is not a part of the container, and the function sched_setaffinity is unable to locate it using its PID. Additionally, the task_struct of hwlatd is already known. Ultimately, the function set_cpus_allowed_ptr achieves the same outcome as sched_setaffinity, but employs task_struct instead of PID. Test case: # cd /sys/kernel/tracing # echo 0 > tracing_on # echo round-robin > hwlat_detector/mode # echo hwlat > current_tracer # unshare --fork --pid bash -c 'echo 1 > tracing_on' # dmesg -c Actual behavior: [573502.809060] hwlat_detector: cpumask changed while in round-robin mode, switching to mode none Link: https://lore.kernel.org/linux-trace-kernel/20230316144535.1004952-1-costa.shul@redhat.com Cc: Masami Hiramatsu <mhiramat@kernel.org> Fixes: 0330f7aa8ee63 ("tracing: Have hwlat trace migrate across tracing_cpumask CPUs") Signed-off-by: Costa Shulyupin <costa.shul@redhat.com> Acked-by: Daniel Bristot de Oliveira <bristot@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-03-30perf: fix perf_event_context->timeSong Liu
[ Upstream commit baf1b12a67f5b24f395baca03e442ce27cab0c18 ] Time readers rely on perf_event_context->[time|timestamp|timeoffset] to get accurate time_enabled and time_running for an event. The difference between ctx->timestamp and ctx->time is the among of time when the context is not enabled. __update_context_time(ctx, false) is used to increase timestamp, but not time. Therefore, it should only be called in ctx_sched_in() when EVENT_TIME was not enabled. Fixes: 09f5e7dc7ad7 ("perf: Fix perf_event_read_local() time") Signed-off-by: Song Liu <song@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Namhyung Kim <namhyung@kernel.org> Link: https://lkml.kernel.org/r/20230313171608.298734-1-song@kernel.org Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-03-30perf/core: Fix perf_output_begin parameter is incorrectly invoked in ↵Yang Jihong
perf_event_bpf_output [ Upstream commit eb81a2ed4f52be831c9fb879752d89645a312c13 ] syzkaller reportes a KASAN issue with stack-out-of-bounds. The call trace is as follows: dump_stack+0x9c/0xd3 print_address_description.constprop.0+0x19/0x170 __kasan_report.cold+0x6c/0x84 kasan_report+0x3a/0x50 __perf_event_header__init_id+0x34/0x290 perf_event_header__init_id+0x48/0x60 perf_output_begin+0x4a4/0x560 perf_event_bpf_output+0x161/0x1e0 perf_iterate_sb_cpu+0x29e/0x340 perf_iterate_sb+0x4c/0xc0 perf_event_bpf_event+0x194/0x2c0 __bpf_prog_put.constprop.0+0x55/0xf0 __cls_bpf_delete_prog+0xea/0x120 [cls_bpf] cls_bpf_delete_prog_work+0x1c/0x30 [cls_bpf] process_one_work+0x3c2/0x730 worker_thread+0x93/0x650 kthread+0x1b8/0x210 ret_from_fork+0x1f/0x30 commit 267fb27352b6 ("perf: Reduce stack usage of perf_output_begin()") use on-stack struct perf_sample_data of the caller function. However, perf_event_bpf_output uses incorrect parameter to convert small-sized data (struct perf_bpf_event) into large-sized data (struct perf_sample_data), which causes memory overwriting occurs in __perf_event_header__init_id. Fixes: 267fb27352b6 ("perf: Reduce stack usage of perf_output_begin()") Signed-off-by: Yang Jihong <yangjihong1@huawei.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20230314044735.56551-1-yangjihong1@huawei.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-03-22perf: Fix check before add_event_to_groups() in perf_group_detach()Budimir Markovic
commit fd0815f632c24878e325821943edccc7fde947a2 upstream. Events should only be added to a groups rb tree if they have not been removed from their context by list_del_event(). Since remove_on_exec made it possible to call list_del_event() on individual events before they are detached from their group, perf_group_detach() should check each sibling's attach_state before calling add_event_to_groups() on it. Fixes: 2e498d0a74e5 ("perf: Add support for event removal on exec") Signed-off-by: Budimir Markovic <markovicbudimir@gmail.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/ZBFzvQV9tEqoHEtH@gentoo Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-22trace/hwlat: Do not wipe the contents of per-cpu thread dataTero Kristo
commit 4c42f5f0d1dd20bddd9f940beb1e6ccad60c4498 upstream. Do not wipe the contents of the per-cpu kthread data when starting the tracer, as this will completely forget about already running instances and can later start new additional per-cpu threads. Link: https://lore.kernel.org/all/20230302113654.2984709-1-tero.kristo@linux.intel.com/ Link: https://lkml.kernel.org/r/20230310100451.3948583-2-tero.kristo@linux.intel.com Cc: stable@vger.kernel.org Fixes: f46b16520a087 ("trace/hwlat: Implement the per-cpu mode") Signed-off-by: Tero Kristo <tero.kristo@linux.intel.com> Acked-by: Daniel Bristot de Oliveira <bristot@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-22ftrace: Fix invalid address access in lookup_rec() when index is 0Chen Zhongjin
commit ee92fa443358f4fc0017c1d0d325c27b37802504 upstream. KASAN reported follow problem: BUG: KASAN: use-after-free in lookup_rec Read of size 8 at addr ffff000199270ff0 by task modprobe CPU: 2 Comm: modprobe Call trace: kasan_report __asan_load8 lookup_rec ftrace_location arch_check_ftrace_location check_kprobe_address_safe register_kprobe When checking pg->records[pg->index - 1].ip in lookup_rec(), it can get a pg which is newly added to ftrace_pages_start in ftrace_process_locs(). Before the first pg->index++, index is 0 and accessing pg->records[-1].ip will cause this problem. Don't check the ip when pg->index is 0. Link: https://lore.kernel.org/linux-trace-kernel/20230309080230.36064-1-chenzhongjin@huawei.com Cc: stable@vger.kernel.org Fixes: 9644302e3315 ("ftrace: Speed up search by skipping pages by address") Suggested-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Chen Zhongjin <chenzhongjin@huawei.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-22tracing: Check field value in hist_field_name()Steven Rostedt (Google)
commit 9f116f76fa8c04c81aef33ad870dbf9a158e5b70 upstream. The function hist_field_name() cannot handle being passed a NULL field parameter. It should never be NULL, but due to a previous bug, NULL was passed to the function and the kernel crashed due to a NULL dereference. Mark Rutland reported this to me on IRC. The bug was fixed, but to prevent future bugs from crashing the kernel, check the field and add a WARN_ON() if it is NULL. Link: https://lkml.kernel.org/r/20230302020810.762384440@goodmis.org Cc: stable@vger.kernel.org Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Reported-by: Mark Rutland <mark.rutland@arm.com> Fixes: c6afad49d127f ("tracing: Add hist trigger 'sym' and 'sym-offset' modifiers") Tested-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-22tracing: Make splice_read available againSung-hun Kim
commit e400be674a1a40e9dcb2e95f84d6c1fd2d88f31d upstream. Since the commit 36e2c7421f02 ("fs: don't allow splice read/write without explicit ops") is applied to the kernel, splice() and sendfile() calls on the trace file (/sys/kernel/debug/tracing /trace) return EINVAL. This patch restores these system calls by initializing splice_read in file_operations of the trace file. This patch only enables such functionalities for the read case. Link: https://lore.kernel.org/linux-trace-kernel/20230314013707.28814-1-sfoon.kim@samsung.com Cc: stable@vger.kernel.org Fixes: 36e2c7421f02 ("fs: don't allow splice read/write without explicit ops") Signed-off-by: Sung-hun Kim <sfoon.kim@samsung.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-17watch_queue: fix IOC_WATCH_QUEUE_SET_SIZE alloc error pathsDavid Disseldorp
[ Upstream commit 03e1d60e177eedbd302b77af4ea5e21b5a7ade31 ] The watch_queue_set_size() allocation error paths return the ret value set via the prior pipe_resize_ring() call, which will always be zero. As a result, IOC_WATCH_QUEUE_SET_SIZE callers such as "keyctl watch" fail to detect kernel wqueue->notes allocation failures and proceed to KEYCTL_WATCH_KEY, with any notifications subsequently lost. Fixes: c73be61cede58 ("pipe: Add general notification queue support") Signed-off-by: David Disseldorp <ddiss@suse.de> Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-03-17irqdomain: Fix mapping-creation raceJohan Hovold
[ Upstream commit 601363cc08da25747feb87c55573dd54de91d66a ] Parallel probing of devices that share interrupts (e.g. when a driver uses asynchronous probing) can currently result in two mappings for the same hardware interrupt to be created due to missing serialisation. Make sure to hold the irq_domain_mutex when creating mappings so that looking for an existing mapping before creating a new one is done atomically. Fixes: 765230b5f084 ("driver-core: add asynchronous probing support for drivers") Fixes: b62b2cf5759b ("irqdomain: Fix handling of type settings for existing mappings") Link: https://lore.kernel.org/r/YuJXMHoT4ijUxnRb@hovoldconsulting.com Cc: stable@vger.kernel.org # 4.8 Cc: Dmitry Torokhov <dtor@chromium.org> Cc: Jon Hunter <jonathanh@nvidia.com> Tested-by: Hsin-Yi Wang <hsinyi@chromium.org> Tested-by: Mark-PK Tsai <mark-pk.tsai@mediatek.com> Signed-off-by: Johan Hovold <johan+linaro@kernel.org> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20230213104302.17307-7-johan+linaro@kernel.org Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-03-17btf: fix resolving BTF_KIND_VAR after ARRAY, STRUCT, UNION, PTRLorenz Bauer
[ Upstream commit 9b459804ff9973e173fabafba2a1319f771e85fa ] btf_datasec_resolve contains a bug that causes the following BTF to fail loading: [1] DATASEC a size=2 vlen=2 type_id=4 offset=0 size=1 type_id=7 offset=1 size=1 [2] INT (anon) size=1 bits_offset=0 nr_bits=8 encoding=(none) [3] PTR (anon) type_id=2 [4] VAR a type_id=3 linkage=0 [5] INT (anon) size=1 bits_offset=0 nr_bits=8 encoding=(none) [6] TYPEDEF td type_id=5 [7] VAR b type_id=6 linkage=0 This error message is printed during btf_check_all_types: [1] DATASEC a size=2 vlen=2 type_id=7 offset=1 size=1 Invalid type By tracing btf_*_resolve we can pinpoint the problem: btf_datasec_resolve(depth: 1, type_id: 1, mode: RESOLVE_TBD) = 0 btf_var_resolve(depth: 2, type_id: 4, mode: RESOLVE_TBD) = 0 btf_ptr_resolve(depth: 3, type_id: 3, mode: RESOLVE_PTR) = 0 btf_var_resolve(depth: 2, type_id: 4, mode: RESOLVE_PTR) = 0 btf_datasec_resolve(depth: 1, type_id: 1, mode: RESOLVE_PTR) = -22 The last invocation of btf_datasec_resolve should invoke btf_var_resolve by means of env_stack_push, instead it returns EINVAL. The reason is that env_stack_push is never executed for the second VAR. if (!env_type_is_resolve_sink(env, var_type) && !env_type_is_resolved(env, var_type_id)) { env_stack_set_next_member(env, i + 1); return env_stack_push(env, var_type, var_type_id); } env_type_is_resolve_sink() changes its behaviour based on resolve_mode. For RESOLVE_PTR, we can simplify the if condition to the following: (btf_type_is_modifier() || btf_type_is_ptr) && !env_type_is_resolved() Since we're dealing with a VAR the clause evaluates to false. This is not sufficient to trigger the bug however. The log output and EINVAL are only generated if btf_type_id_size() fails. if (!btf_type_id_size(btf, &type_id, &type_size)) { btf_verifier_log_vsi(env, v->t, vsi, "Invalid type"); return -EINVAL; } Most types are sized, so for example a VAR referring to an INT is not a problem. The bug is only triggered if a VAR points at a modifier. Since we skipped btf_var_resolve that modifier was also never resolved, which means that btf_resolved_type_id returns 0 aka VOID for the modifier. This in turn causes btf_type_id_size to return NULL, triggering EINVAL. To summarise, the following conditions are necessary: - VAR pointing at PTR, STRUCT, UNION or ARRAY - Followed by a VAR pointing at TYPEDEF, VOLATILE, CONST, RESTRICT or TYPE_TAG The fix is to reset resolve_mode to RESOLVE_TBD before attempting to resolve a VAR from a DATASEC. Fixes: 1dc92851849c ("bpf: kernel side support for BTF Var and DataSec") Signed-off-by: Lorenz Bauer <lmb@isovalent.com> Link: https://lore.kernel.org/r/20230306112138.155352-2-lmb@isovalent.com Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-03-17irqdomain: Refactor __irq_domain_alloc_irqs()Johan Hovold
[ Upstream commit d55f7f4c58c07beb5050a834bf57ae2ede599c7e ] Refactor __irq_domain_alloc_irqs() so that it can be called internally while holding the irq_domain_mutex. This will be used to fix a shared-interrupt mapping race, hence the Fixes tag. Fixes: b62b2cf5759b ("irqdomain: Fix handling of type settings for existing mappings") Cc: stable@vger.kernel.org # 4.8 Tested-by: Hsin-Yi Wang <hsinyi@chromium.org> Tested-by: Mark-PK Tsai <mark-pk.tsai@mediatek.com> Signed-off-by: Johan Hovold <johan+linaro@kernel.org> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20230213104302.17307-6-johan+linaro@kernel.org Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-03-17fork: allow CLONE_NEWTIME in clone3 flagsTobias Klauser
commit a402f1e35313fc7ce2ca60f543c4402c2c7c3544 upstream. Currently, calling clone3() with CLONE_NEWTIME in clone_args->flags fails with -EINVAL. This is because CLONE_NEWTIME intersects with CSIGNAL. However, CSIGNAL was deprecated when clone3 was introduced in commit 7f192e3cd316 ("fork: add clone3"), allowing re-use of that part of clone flags. Fix this by explicitly allowing CLONE_NEWTIME in clone3_args_valid. This is also in line with the respective check in check_unshare_flags which allow CLONE_NEWTIME for unshare(). Fixes: 769071ac9f20 ("ns: Introduce Time Namespace") Cc: Andrey Vagin <avagin@openvz.org> Cc: Christian Brauner <brauner@kernel.org> Cc: stable@vger.kernel.org Signed-off-by: Tobias Klauser <tklauser@distanz.ch> Reviewed-by: Christian Brauner <brauner@kernel.org> Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-11kernel/fail_function: fix memory leak with using debugfs_lookup()Greg Kroah-Hartman
[ Upstream commit 2bb3669f576559db273efe49e0e69f82450efbca ] When calling debugfs_lookup() the result must have dput() called on it, otherwise the memory will leak over time. To make things simpler, just call debugfs_lookup_and_remove() instead which handles all of the logic at once. Cc: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Yang Yingliang <yangyingliang@huawei.com> Link: https://lore.kernel.org/r/20230202151633.2310897-1-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-03-11kernel/printk/index.c: fix memory leak with using debugfs_lookup()Greg Kroah-Hartman
[ Upstream commit 55bf243c514553e907efcf2bda92ba090eca8c64 ] When calling debugfs_lookup() the result must have dput() called on it, otherwise the memory will leak over time. To make things simpler, just call debugfs_lookup_and_remove() instead which handles all of the logic at once. Cc: Chris Down <chris@chrisdown.name> Cc: Petr Mladek <pmladek@suse.com> Cc: Sergey Senozhatsky <senozhatsky@chromium.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: John Ogness <john.ogness@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org> Reviewed-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/20230202151411.2308576-1-gregkh@linuxfoundation.org Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-03-11tracing: Add NULL checks for buffer in ring_buffer_free_read_page()Jia-Ju Bai
[ Upstream commit 3e4272b9954094907f16861199728f14002fcaf6 ] In a previous commit 7433632c9ff6, buffer, buffer->buffers and buffer->buffers[cpu] in ring_buffer_wake_waiters() can be NULL, and thus the related checks are added. However, in the same call stack, these variables are also used in ring_buffer_free_read_page(): tracing_buffers_release() ring_buffer_wake_waiters(iter->array_buffer->buffer) cpu_buffer = buffer->buffers[cpu] -> Add checks by previous commit ring_buffer_free_read_page(iter->array_buffer->buffer) cpu_buffer = buffer->buffers[cpu] -> No check Thus, to avod possible null-pointer derefernces, the related checks should be added. These results are reported by a static tool designed by myself. Link: https://lkml.kernel.org/r/20230113125501.760324-1-baijiaju1990@gmail.com Reported-by: TOTE Robot <oslab@tsinghua.edu.cn> Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-03-10ring-buffer: Handle race between rb_move_tail and rb_check_pagesMukesh Ojha
commit 8843e06f67b14f71c044bf6267b2387784c7e198 upstream. It seems a data race between ring_buffer writing and integrity check. That is, RB_FLAG of head_page is been updating, while at same time RB_FLAG was cleared when doing integrity check rb_check_pages(): rb_check_pages() rb_handle_head_page(): -------- -------- rb_head_page_deactivate() rb_head_page_set_normal() rb_head_page_activate() We do intergrity test of the list to check if the list is corrupted and it is still worth doing it. So, let's refactor rb_check_pages() such that we no longer clear and set flag during the list sanity checking. [1] and [2] are the test to reproduce and the crash report respectively. 1: ``` read_trace.sh while true; do # the "trace" file is closed after read head -1 /sys/kernel/tracing/trace > /dev/null done ``` ``` repro.sh sysctl -w kernel.panic_on_warn=1 # function tracer will writing enough data into ring_buffer echo function > /sys/kernel/tracing/current_tracer ./read_trace.sh & ./read_trace.sh & ./read_trace.sh & ./read_trace.sh & ./read_trace.sh & ./read_trace.sh & ./read_trace.sh & ./read_trace.sh & ``` 2: ------------[ cut here ]------------ WARNING: CPU: 9 PID: 62 at kernel/trace/ring_buffer.c:2653 rb_move_tail+0x450/0x470 Modules linked in: CPU: 9 PID: 62 Comm: ksoftirqd/9 Tainted: G W 6.2.0-rc6+ Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.15.0-0-g2dd4b9b3f840-prebuilt.qemu.org 04/01/2014 RIP: 0010:rb_move_tail+0x450/0x470 Code: ff ff 4c 89 c8 f0 4d 0f b1 02 48 89 c2 48 83 e2 fc 49 39 d0 75 24 83 e0 03 83 f8 02 0f 84 e1 fb ff ff 48 8b 57 10 f0 ff 42 08 <0f> 0b 83 f8 02 0f 84 ce fb ff ff e9 db RSP: 0018:ffffb5564089bd00 EFLAGS: 00000203 RAX: 0000000000000000 RBX: ffff9db385a2bf81 RCX: ffffb5564089bd18 RDX: ffff9db281110100 RSI: 0000000000000fe4 RDI: ffff9db380145400 RBP: ffff9db385a2bf80 R08: ffff9db385a2bfc0 R09: ffff9db385a2bfc2 R10: ffff9db385a6c000 R11: ffff9db385a2bf80 R12: 0000000000000000 R13: 00000000000003e8 R14: ffff9db281110100 R15: ffffffffbb006108 FS: 0000000000000000(0000) GS:ffff9db3bdcc0000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00005602323024c8 CR3: 0000000022e0c000 CR4: 00000000000006e0 Call Trace: <TASK> ring_buffer_lock_reserve+0x136/0x360 ? __do_softirq+0x287/0x2df ? __pfx_rcu_softirq_qs+0x10/0x10 trace_function+0x21/0x110 ? __pfx_rcu_softirq_qs+0x10/0x10 ? __do_softirq+0x287/0x2df function_trace_call+0xf6/0x120 0xffffffffc038f097 ? rcu_softirq_qs+0x5/0x140 rcu_softirq_qs+0x5/0x140 __do_softirq+0x287/0x2df run_ksoftirqd+0x2a/0x30 smpboot_thread_fn+0x188/0x220 ? __pfx_smpboot_thread_fn+0x10/0x10 kthread+0xe7/0x110 ? __pfx_kthread+0x10/0x10 ret_from_fork+0x2c/0x50 </TASK> ---[ end trace 0000000000000000 ]--- [ crash report and test reproducer credit goes to Zheng Yejian] Link: https://lore.kernel.org/linux-trace-kernel/1676376403-16462-1-git-send-email-quic_mojha@quicinc.com Cc: <mhiramat@kernel.org> Cc: stable@vger.kernel.org Fixes: 1039221cc278 ("ring-buffer: Do not disable recording when there is an iterator") Reported-by: Zheng Yejian <zhengyejian1@huawei.com> Signed-off-by: Mukesh Ojha <quic_mojha@quicinc.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-10dax/kmem: Fix leak of memory-hotplug resourcesDan Williams
commit e686c32590f40bffc45f105c04c836ffad3e531a upstream. While experimenting with CXL region removal the following corruption of /proc/iomem appeared. Before: f010000000-f04fffffff : CXL Window 0 f010000000-f02fffffff : region4 f010000000-f02fffffff : dax4.0 f010000000-f02fffffff : System RAM (kmem) After (modprobe -r cxl_test): f010000000-f02fffffff : **redacted binary garbage** f010000000-f02fffffff : System RAM (kmem) ...and testing further the same is visible with persistent memory assigned to kmem: Before: 480000000-243fffffff : Persistent Memory 480000000-57e1fffff : namespace3.0 580000000-243fffffff : dax3.0 580000000-243fffffff : System RAM (kmem) After (ndctl disable-region all): 480000000-243fffffff : Persistent Memory 580000000-243fffffff : ***redacted binary garbage*** 580000000-243fffffff : System RAM (kmem) The corrupted data is from a use-after-free of the "dax4.0" and "dax3.0" resources, and it also shows that the "System RAM (kmem)" resource is not being removed. The bug does not appear after "modprobe -r kmem", it requires the parent of "dax4.0" and "dax3.0" to be removed which re-parents the leaked "System RAM (kmem)" instances. Those in turn reference the freed resource as a parent. First up for the fix is release_mem_region_adjustable() needs to reliably delete the resource inserted by add_memory_driver_managed(). That is thwarted by a check for IORESOURCE_SYSRAM that predates the dax/kmem driver, from commit: 65c78784135f ("kernel, resource: check for IORESOURCE_SYSRAM in release_mem_region_adjustable") That appears to be working around the behavior of HMM's "MEMORY_DEVICE_PUBLIC" facility that has since been deleted. With that check removed the "System RAM (kmem)" resource gets removed, but corruption still occurs occasionally because the "dax" resource is not reliably removed. The dax range information is freed before the device is unregistered, so the driver can not reliably recall (another use after free) what it is meant to release. Lastly if that use after free got lucky, the driver was covering up the leak of "System RAM (kmem)" due to its use of release_resource() which detaches, but does not free, child resources. The switch to remove_resource() forces remove_memory() to be responsible for the deletion of the resource added by add_memory_driver_managed(). Fixes: c2f3011ee697 ("device-dax: add an allocation interface for device-dax instances") Cc: <stable@vger.kernel.org> Cc: Oscar Salvador <osalvador@suse.de> Cc: David Hildenbrand <david@redhat.com> Cc: Pavel Tatashin <pasha.tatashin@soleen.com> Reviewed-by: Vishal Verma <vishal.l.verma@intel.com> Reviewed-by: Pasha Tatashin <pasha.tatashin@soleen.com> Reviewed-by: Dave Jiang <dave.jiang@intel.com> Link: https://lore.kernel.org/r/167653656244.3147810.5705900882794040229.stgit@dwillia2-xfh.jf.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-10irqdomain: Fix domain registration raceMarc Zyngier
commit 8932c32c3053accd50702b36e944ac2016cd103c upstream. Hierarchical domains created using irq_domain_create_hierarchy() are currently added to the domain list before having been fully initialised. This specifically means that a racing allocation request might fail to allocate irq data for the inner domains of a hierarchy in case the parent domain pointer has not yet been set up. Note that this is not really any issue for irqchip drivers that are registered early (e.g. via IRQCHIP_DECLARE() or IRQCHIP_ACPI_DECLARE()) but could potentially cause trouble with drivers that are registered later (e.g. modular drivers using IRQCHIP_PLATFORM_DRIVER_BEGIN(), gpiochip drivers, etc.). Fixes: afb7da83b9f4 ("irqdomain: Introduce helper function irq_domain_add_hierarchy()") Cc: stable@vger.kernel.org # 3.19 Signed-off-by: Marc Zyngier <maz@kernel.org> [ johan: add commit message ] Signed-off-by: Johan Hovold <johan+linaro@kernel.org> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20230213104302.17307-8-johan+linaro@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-10irqdomain: Drop bogus fwspec-mapping error handlingJohan Hovold
commit e3b7ab025e931accdc2c12acf9b75c6197f1c062 upstream. In case a newly allocated IRQ ever ends up not having any associated struct irq_data it would not even be possible to dispose the mapping. Replace the bogus disposal with a WARN_ON(). This will also be used to fix a shared-interrupt mapping race, hence the CC-stable tag. Fixes: 1e2a7d78499e ("irqdomain: Don't set type when mapping an IRQ") Cc: stable@vger.kernel.org # 4.8 Tested-by: Hsin-Yi Wang <hsinyi@chromium.org> Tested-by: Mark-PK Tsai <mark-pk.tsai@mediatek.com> Signed-off-by: Johan Hovold <johan+linaro@kernel.org> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20230213104302.17307-4-johan+linaro@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-10irqdomain: Look for existing mapping only onceJohan Hovold
commit 6e6f75c9c98d2d246d90411ff2b6f0cd271f4cba upstream. Avoid looking for an existing mapping twice when creating a new mapping using irq_create_fwspec_mapping() by factoring out the actual allocation which is shared with irq_create_mapping_affinity(). The new helper function will also be used to fix a shared-interrupt mapping race, hence the Fixes tag. Fixes: b62b2cf5759b ("irqdomain: Fix handling of type settings for existing mappings") Cc: stable@vger.kernel.org # 4.8 Tested-by: Hsin-Yi Wang <hsinyi@chromium.org> Tested-by: Mark-PK Tsai <mark-pk.tsai@mediatek.com> Signed-off-by: Johan Hovold <johan+linaro@kernel.org> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20230213104302.17307-5-johan+linaro@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-10irqdomain: Fix disassociation raceJohan Hovold
commit 3f883c38f5628f46b30bccf090faec054088e262 upstream. The global irq_domain_mutex is held when mapping interrupts from non-hierarchical domains but currently not when disposing them. This specifically means that updates of the domain mapcount is racy (currently only used for statistics in debugfs). Make sure to hold the global irq_domain_mutex also when disposing mappings from non-hierarchical domains. Fixes: 9dc6be3d4193 ("genirq/irqdomain: Add map counter") Cc: stable@vger.kernel.org # 4.13 Tested-by: Hsin-Yi Wang <hsinyi@chromium.org> Tested-by: Mark-PK Tsai <mark-pk.tsai@mediatek.com> Signed-off-by: Johan Hovold <johan+linaro@kernel.org> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20230213104302.17307-3-johan+linaro@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-10irqdomain: Fix association raceJohan Hovold
commit b06730a571a9ff1ba5bd6b20bf9e50e5a12f1ec6 upstream. The sanity check for an already mapped virq is done outside of the irq_domain_mutex-protected section which means that an (unlikely) racing association may not be detected. Fix this by factoring out the association implementation, which will also be used in a follow-on change to fix a shared-interrupt mapping race. Fixes: ddaf144c61da ("irqdomain: Refactor irq_domain_associate_many()") Cc: stable@vger.kernel.org # 3.11 Tested-by: Hsin-Yi Wang <hsinyi@chromium.org> Tested-by: Mark-PK Tsai <mark-pk.tsai@mediatek.com> Signed-off-by: Johan Hovold <johan+linaro@kernel.org> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20230213104302.17307-2-johan+linaro@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-10x86/kprobes: Fix arch_check_optimized_kprobe check within optimized_kprobe rangeYang Jihong
commit f1c97a1b4ef709e3f066f82e3ba3108c3b133ae6 upstream. When arch_prepare_optimized_kprobe calculating jump destination address, it copies original instructions from jmp-optimized kprobe (see __recover_optprobed_insn), and calculated based on length of original instruction. arch_check_optimized_kprobe does not check KPROBE_FLAG_OPTIMATED when checking whether jmp-optimized kprobe exists. As a result, setup_detour_execution may jump to a range that has been overwritten by jump destination address, resulting in an inval opcode error. For example, assume that register two kprobes whose addresses are <func+9> and <func+11> in "func" function. The original code of "func" function is as follows: 0xffffffff816cb5e9 <+9>: push %r12 0xffffffff816cb5eb <+11>: xor %r12d,%r12d 0xffffffff816cb5ee <+14>: test %rdi,%rdi 0xffffffff816cb5f1 <+17>: setne %r12b 0xffffffff816cb5f5 <+21>: push %rbp 1.Register the kprobe for <func+11>, assume that is kp1, corresponding optimized_kprobe is op1. After the optimization, "func" code changes to: 0xffffffff816cc079 <+9>: push %r12 0xffffffff816cc07b <+11>: jmp 0xffffffffa0210000 0xffffffff816cc080 <+16>: incl 0xf(%rcx) 0xffffffff816cc083 <+19>: xchg %eax,%ebp 0xffffffff816cc084 <+20>: (bad) 0xffffffff816cc085 <+21>: push %rbp Now op1->flags == KPROBE_FLAG_OPTIMATED; 2. Register the kprobe for <func+9>, assume that is kp2, corresponding optimized_kprobe is op2. register_kprobe(kp2) register_aggr_kprobe alloc_aggr_kprobe __prepare_optimized_kprobe arch_prepare_optimized_kprobe __recover_optprobed_insn // copy original bytes from kp1->optinsn.copied_insn, // jump address = <func+14> 3. disable kp1: disable_kprobe(kp1) __disable_kprobe ... if (p == orig_p || aggr_kprobe_disabled(orig_p)) { ret = disarm_kprobe(orig_p, true) // add op1 in unoptimizing_list, not unoptimized orig_p->flags |= KPROBE_FLAG_DISABLED; // op1->flags == KPROBE_FLAG_OPTIMATED | KPROBE_FLAG_DISABLED ... 4. unregister kp2 __unregister_kprobe_top ... if (!kprobe_disabled(ap) && !kprobes_all_disarmed) { optimize_kprobe(op) ... if (arch_check_optimized_kprobe(op) < 0) // because op1 has KPROBE_FLAG_DISABLED, here not return return; p->kp.flags |= KPROBE_FLAG_OPTIMIZED; // now op2 has KPROBE_FLAG_OPTIMIZED } "func" code now is: 0xffffffff816cc079 <+9>: int3 0xffffffff816cc07a <+10>: push %rsp 0xffffffff816cc07b <+11>: jmp 0xffffffffa0210000 0xffffffff816cc080 <+16>: incl 0xf(%rcx) 0xffffffff816cc083 <+19>: xchg %eax,%ebp 0xffffffff816cc084 <+20>: (bad) 0xffffffff816cc085 <+21>: push %rbp 5. if call "func", int3 handler call setup_detour_execution: if (p->flags & KPROBE_FLAG_OPTIMIZED) { ... regs->ip = (unsigned long)op->optinsn.insn + TMPL_END_IDX; ... } The code for the destination address is 0xffffffffa021072c: push %r12 0xffffffffa021072e: xor %r12d,%r12d 0xffffffffa0210731: jmp 0xffffffff816cb5ee <func+14> However, <func+14> is not a valid start instruction address. As a result, an error occurs. Link: https://lore.kernel.org/all/20230216034247.32348-3-yangjihong1@huawei.com/ Fixes: f66c0447cca1 ("kprobes: Set unoptimized flag after unoptimizing code") Signed-off-by: Yang Jihong <yangjihong1@huawei.com> Cc: stable@vger.kernel.org Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-10x86/kprobes: Fix __recover_optprobed_insn check optimizing logicYang Jihong
commit 868a6fc0ca2407622d2833adefe1c4d284766c4c upstream. Since the following commit: commit f66c0447cca1 ("kprobes: Set unoptimized flag after unoptimizing code") modified the update timing of the KPROBE_FLAG_OPTIMIZED, a optimized_kprobe may be in the optimizing or unoptimizing state when op.kp->flags has KPROBE_FLAG_OPTIMIZED and op->list is not empty. The __recover_optprobed_insn check logic is incorrect, a kprobe in the unoptimizing state may be incorrectly determined as unoptimizing. As a result, incorrect instructions are copied. The optprobe_queued_unopt function needs to be exported for invoking in arch directory. Link: https://lore.kernel.org/all/20230216034247.32348-2-yangjihong1@huawei.com/ Fixes: f66c0447cca1 ("kprobes: Set unoptimized flag after unoptimizing code") Cc: stable@vger.kernel.org Signed-off-by: Yang Jihong <yangjihong1@huawei.com> Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-10locking/rwsem: Prevent non-first waiter from spinning in down_write() slowpathWaiman Long
commit b613c7f31476c44316bfac1af7cac714b7d6bef9 upstream. A non-first waiter can potentially spin in the for loop of rwsem_down_write_slowpath() without sleeping but fail to acquire the lock even if the rwsem is free if the following sequence happens: Non-first RT waiter First waiter Lock holder ------------------- ------------ ----------- Acquire wait_lock rwsem_try_write_lock(): Set handoff bit if RT or wait too long Set waiter->handoff_set Release wait_lock Acquire wait_lock Inherit waiter->handoff_set Release wait_lock Clear owner Release lock if (waiter.handoff_set) { rwsem_spin_on_owner((); if (OWNER_NULL) goto trylock_again; } trylock_again: Acquire wait_lock rwsem_try_write_lock(): if (first->handoff_set && (waiter != first)) return false; Release wait_lock A non-first waiter cannot really acquire the rwsem even if it mistakenly believes that it can spin on OWNER_NULL value. If that waiter happens to be an RT task running on the same CPU as the first waiter, it can block the first waiter from acquiring the rwsem leading to live lock. Fix this problem by making sure that a non-first waiter cannot spin in the slowpath loop without sleeping. Fixes: d257cc8cb8d5 ("locking/rwsem: Make handoff bit handling more consistent") Signed-off-by: Waiman Long <longman@redhat.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Tested-by: Mukesh Ojha <quic_mojha@quicinc.com> Reviewed-by: Mukesh Ojha <quic_mojha@quicinc.com> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20230126003628.365092-2-longman@redhat.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-10PM: EM: fix memory leak with using debugfs_lookup()Greg Kroah-Hartman
[ Upstream commit a0e8c13ccd6a9a636d27353da62c2410c4eca337 ] When calling debugfs_lookup() the result must have dput() called on it, otherwise the memory will leak over time. To make things simpler, just call debugfs_lookup_and_remove() instead which handles all of the logic at once. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-03-10time/debug: Fix memory leak with using debugfs_lookup()Greg Kroah-Hartman
[ Upstream commit 5b268d8abaec6cbd4bd70d062e769098d96670aa ] When calling debugfs_lookup() the result must have dput() called on it, otherwise the memory will leak over time. To make things simpler, just call debugfs_lookup_and_remove() instead which handles all of the logic at once. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20230202151214.2306822-1-gregkh@linuxfoundation.org Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-03-10clocksource: Suspend the watchdog temporarily when high read latency detectedFeng Tang
[ Upstream commit b7082cdfc464bf9231300605d03eebf943dda307 ] Bugs have been reported on 8 sockets x86 machines in which the TSC was wrongly disabled when the system is under heavy workload. [ 818.380354] clocksource: timekeeping watchdog on CPU336: hpet wd-wd read-back delay of 1203520ns [ 818.436160] clocksource: wd-tsc-wd read-back delay of 181880ns, clock-skew test skipped! [ 819.402962] clocksource: timekeeping watchdog on CPU338: hpet wd-wd read-back delay of 324000ns [ 819.448036] clocksource: wd-tsc-wd read-back delay of 337240ns, clock-skew test skipped! [ 819.880863] clocksource: timekeeping watchdog on CPU339: hpet read-back delay of 150280ns, attempt 3, marking unstable [ 819.936243] tsc: Marking TSC unstable due to clocksource watchdog [ 820.068173] TSC found unstable after boot, most likely due to broken BIOS. Use 'tsc=unstable'. [ 820.092382] sched_clock: Marking unstable (818769414384, 1195404998) [ 820.643627] clocksource: Checking clocksource tsc synchronization from CPU 267 to CPUs 0,4,25,70,126,430,557,564. [ 821.067990] clocksource: Switched to clocksource hpet This can be reproduced by running memory intensive 'stream' tests, or some of the stress-ng subcases such as 'ioport'. The reason for these issues is the when system is under heavy load, the read latency of the clocksources can be very high. Even lightweight TSC reads can show high latencies, and latencies are much worse for external clocksources such as HPET or the APIC PM timer. These latencies can result in false-positive clocksource-unstable determinations. These issues were initially reported by a customer running on a production system, and this problem was reproduced on several generations of Xeon servers, especially when running the stress-ng test. These Xeon servers were not production systems, but they did have the latest steppings and firmware. Given that the clocksource watchdog is a continual diagnostic check with frequency of twice a second, there is no need to rush it when the system is under heavy load. Therefore, when high clocksource read latencies are detected, suspend the watchdog timer for 5 minutes. Signed-off-by: Feng Tang <feng.tang@intel.com> Acked-by: Waiman Long <longman@redhat.com> Cc: John Stultz <jstultz@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Stephen Boyd <sboyd@kernel.org> Cc: Feng Tang <feng.tang@intel.com> Signed-off-by: Paul E. McKenney <paulmck@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-03-10timers: Prevent union confusion from unexpected restart_syscall()Jann Horn
[ Upstream commit 9f76d59173d9d146e96c66886b671c1915a5c5e5 ] The nanosleep syscalls use the restart_block mechanism, with a quirk: The `type` and `rmtp`/`compat_rmtp` fields are set up unconditionally on syscall entry, while the rest of the restart_block is only set up in the unlikely case that the syscall is actually interrupted by a signal (or pseudo-signal) that doesn't have a signal handler. If the restart_block was set up by a previous syscall (futex(..., FUTEX_WAIT, ...) or poll()) and hasn't been invalidated somehow since then, this will clobber some of the union fields used by futex_wait_restart() and do_restart_poll(). If userspace afterwards wrongly calls the restart_syscall syscall, futex_wait_restart()/do_restart_poll() will read struct fields that have been clobbered. This doesn't actually lead to anything particularly interesting because none of the union fields contain trusted kernel data, and futex(..., FUTEX_WAIT, ...) and poll() aren't syscalls where it makes much sense to apply seccomp filters to their arguments. So the current consequences are just of the "if userspace does bad stuff, it can damage itself, and that's not a problem" flavor. But still, it seems like a hazard for future developers, so invalidate the restart_block when partly setting it up in the nanosleep syscalls. Signed-off-by: Jann Horn <jannh@google.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20230105134403.754986-1-jannh@google.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-03-10rcu-tasks: Make rude RCU-Tasks work well with CPU hotplugZqiang
[ Upstream commit ea5c8987fef20a8cca07e428aa28bc64649c5104 ] The synchronize_rcu_tasks_rude() function invokes rcu_tasks_rude_wait_gp() to wait one rude RCU-tasks grace period. The rcu_tasks_rude_wait_gp() function in turn checks if there is only a single online CPU. If so, it will immediately return, because a call to synchronize_rcu_tasks_rude() is by definition a grace period on a single-CPU system. (We could have blocked!) Unfortunately, this check uses num_online_cpus() without synchronization, which can result in too-short grace periods. To see this, consider the following scenario: CPU0 CPU1 (going offline) migration/1 task: cpu_stopper_thread -> take_cpu_down -> _cpu_disable (dec __num_online_cpus) ->cpuhp_invoke_callback preempt_disable access old_data0 task1 del old_data0 ..... synchronize_rcu_tasks_rude() task1 schedule out .... task2 schedule in rcu_tasks_rude_wait_gp() ->__num_online_cpus == 1 ->return .... task1 schedule in ->free old_data0 preempt_enable When CPU1 decrements __num_online_cpus, its value becomes 1. However, CPU1 has not finished going offline, and will take one last trip through the scheduler and the idle loop before it actually stops executing instructions. Because synchronize_rcu_tasks_rude() is mostly used for tracing, and because both the scheduler and the idle loop can be traced, this means that CPU0's prematurely ended grace period might disrupt the tracing on CPU1. Given that this disruption might include CPU1 executing instructions in memory that was just now freed (and maybe reallocated), this is a matter of some concern. This commit therefore removes that problematic single-CPU check from the rcu_tasks_rude_wait_gp() function. This dispenses with the single-CPU optimization, but there is no evidence indicating that this optimization is important. In addition, synchronize_rcu_tasks_generic() contains a similar optimization (albeit only for early boot), which also splats. (As in exactly why are you invoking synchronize_rcu_tasks_rude() so early in boot, anyway???) It is OK for the synchronize_rcu_tasks_rude() function's check to be unsynchronized because the only times that this check can evaluate to true is when there is only a single CPU running with preemption disabled. While in the area, this commit also fixes a minor bug in which a call to synchronize_rcu_tasks_rude() would instead be attributed to synchronize_rcu_tasks(). [ paulmck: Add "synchronize_" prefix and "()" suffix. ] Signed-off-by: Zqiang <qiang1.zhang@intel.com> Signed-off-by: Paul E. McKenney <paulmck@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-03-10rcu: Suppress smp_processor_id() complaint in synchronize_rcu_expedited_wait()Paul E. McKenney
[ Upstream commit 2d7f00b2f01301d6e41fd4a28030dab0442265be ] The normal grace period's RCU CPU stall warnings are invoked from the scheduling-clock interrupt handler, and can thus invoke smp_processor_id() with impunity, which allows them to directly invoke dump_cpu_task(). In contrast, the expedited grace period's RCU CPU stall warnings are invoked from process context, which causes the dump_cpu_task() function's calls to smp_processor_id() to complain bitterly in debug kernels. This commit therefore causes synchronize_rcu_expedited_wait() to disable preemption around its call to dump_cpu_task(). Signed-off-by: Paul E. McKenney <paulmck@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-03-10trace/blktrace: fix memory leak with using debugfs_lookup()Greg Kroah-Hartman
[ Upstream commit 83e8864fee26f63a7435e941b7c36a20fd6fe93e ] When calling debugfs_lookup() the result must have dput() called on it, otherwise the memory will leak over time. To make things simpler, just call debugfs_lookup_and_remove() instead which handles all of the logic at once. Cc: Jens Axboe <axboe@kernel.dk> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: linux-block@vger.kernel.org Cc: linux-kernel@vger.kernel.org Cc: linux-trace-kernel@vger.kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Bart Van Assche <bvanassche@acm.org> Link: https://lore.kernel.org/r/20230202141956.2299521-1-gregkh@linuxfoundation.org Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-03-10bpf: Fix global subprog context argument resolution logicAndrii Nakryiko
[ Upstream commit d384dce281ed1b504fae2e279507827638d56fa3 ] KPROBE program's user-facing context type is defined as typedef bpf_user_pt_regs_t. This leads to a problem when trying to passing kprobe/uprobe/usdt context argument into global subprog, as kernel always strip away mods and typedefs of user-supplied type, but takes expected type from bpf_ctx_convert as is, which causes mismatch. Current way to work around this is to define a fake struct with the same name as expected typedef: struct bpf_user_pt_regs_t {}; __noinline my_global_subprog(struct bpf_user_pt_regs_t *ctx) { ... } This patch fixes the issue by resolving expected type, if it's not a struct. It still leaves the above work-around working for backwards compatibility. Fixes: 91cc1a99740e ("bpf: Annotate context types") Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Stanislav Fomichev <sdf@google.com> Link: https://lore.kernel.org/bpf/20230216045954.3002473-2-andrii@kernel.org Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-03-10rcu-tasks: Fix synchronize_rcu_tasks() VS zap_pid_ns_processes()Frederic Weisbecker
[ Upstream commit 28319d6dc5e2ffefa452c2377dd0f71621b5bff0 ] RCU Tasks and PID-namespace unshare can interact in do_exit() in a complicated circular dependency: 1) TASK A calls unshare(CLONE_NEWPID), this creates a new PID namespace that every subsequent child of TASK A will belong to. But TASK A doesn't itself belong to that new PID namespace. 2) TASK A forks() and creates TASK B. TASK A stays attached to its PID namespace (let's say PID_NS1) and TASK B is the first task belonging to the new PID namespace created by unshare() (let's call it PID_NS2). 3) Since TASK B is the first task attached to PID_NS2, it becomes the PID_NS2 child reaper. 4) TASK A forks() again and creates TASK C which get attached to PID_NS2. Note how TASK C has TASK A as a parent (belonging to PID_NS1) but has TASK B (belonging to PID_NS2) as a pid_namespace child_reaper. 5) TASK B exits and since it is the child reaper for PID_NS2, it has to kill all other tasks attached to PID_NS2, and wait for all of them to die before getting reaped itself (zap_pid_ns_process()). 6) TASK A calls synchronize_rcu_tasks() which leads to synchronize_srcu(&tasks_rcu_exit_srcu). 7) TASK B is waiting for TASK C to get reaped. But TASK B is under a tasks_rcu_exit_srcu SRCU critical section (exit_notify() is between exit_tasks_rcu_start() and exit_tasks_rcu_finish()), blocking TASK A. 8) TASK C exits and since TASK A is its parent, it waits for it to reap TASK C, but it can't because TASK A waits for TASK B that waits for TASK C. Pid_namespace semantics can hardly be changed at this point. But the coverage of tasks_rcu_exit_srcu can be reduced instead. The current task is assumed not to be concurrently reapable at this stage of exit_notify() and therefore tasks_rcu_exit_srcu can be temporarily relaxed without breaking its constraints, providing a way out of the deadlock scenario. [ paulmck: Fix build failure by adding additional declaration. ] Fixes: 3f95aa81d265 ("rcu: Make TASKS_RCU handle tasks that are almost done exiting") Reported-by: Pengfei Xu <pengfei.xu@intel.com> Suggested-by: Boqun Feng <boqun.feng@gmail.com> Suggested-by: Neeraj Upadhyay <quic_neeraju@quicinc.com> Suggested-by: Paul E. McKenney <paulmck@kernel.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Lai Jiangshan <jiangshanlai@gmail.com> Cc: Eric W . Biederman <ebiederm@xmission.com> Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Signed-off-by: Paul E. McKenney <paulmck@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-03-10rcu-tasks: Remove preemption disablement around srcu_read_[un]lock() callsFrederic Weisbecker
[ Upstream commit 44757092958bdd749775022f915b7ac974384c2a ] Ever since the following commit: 5a41344a3d83 ("srcu: Simplify __srcu_read_unlock() via this_cpu_dec()") SRCU doesn't rely anymore on preemption to be disabled in order to modify the per-CPU counter. And even then it used to be done from the API itself. Therefore and after checking further, it appears to be safe to remove the preemption disablement around __srcu_read_[un]lock() in exit_tasks_rcu_start() and exit_tasks_rcu_finish() Suggested-by: Boqun Feng <boqun.feng@gmail.com> Suggested-by: Paul E. McKenney <paulmck@kernel.org> Suggested-by: Neeraj Upadhyay <quic_neeraju@quicinc.com> Cc: Lai Jiangshan <jiangshanlai@gmail.com> Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Signed-off-by: Paul E. McKenney <paulmck@kernel.org> Stable-dep-of: 28319d6dc5e2 ("rcu-tasks: Fix synchronize_rcu_tasks() VS zap_pid_ns_processes()") Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-03-10rcu-tasks: Improve comments explaining tasks_rcu_exit_srcu purposeFrederic Weisbecker
[ Upstream commit e4e1e8089c5fd948da12cb9f4adc93821036945f ] Make sure we don't need to look again into the depths of git blame in order not to miss a subtle part about how rcu-tasks is dealing with exiting tasks. Suggested-by: Boqun Feng <boqun.feng@gmail.com> Suggested-by: Neeraj Upadhyay <quic_neeraju@quicinc.com> Suggested-by: Paul E. McKenney <paulmck@kernel.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Lai Jiangshan <jiangshanlai@gmail.com> Cc: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Signed-off-by: Paul E. McKenney <paulmck@kernel.org> Stable-dep-of: 28319d6dc5e2 ("rcu-tasks: Fix synchronize_rcu_tasks() VS zap_pid_ns_processes()") Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-03-10sched/rt: pick_next_rt_entity(): check list_entryPietro Borrello
[ Upstream commit 7c4a5b89a0b5a57a64b601775b296abf77a9fe97 ] Commit 326587b84078 ("sched: fix goto retry in pick_next_task_rt()") removed any path which could make pick_next_rt_entity() return NULL. However, BUG_ON(!rt_se) in _pick_next_task_rt() (the only caller of pick_next_rt_entity()) still checks the error condition, which can never happen, since list_entry() never returns NULL. Remove the BUG_ON check, and instead emit a warning in the only possible error condition here: the queue being empty which should never happen. Fixes: 326587b84078 ("sched: fix goto retry in pick_next_task_rt()") Signed-off-by: Pietro Borrello <borrello@diag.uniroma1.it> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Phil Auld <pauld@redhat.com> Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org> Link: https://lore.kernel.org/r/20230128-list-entry-null-check-sched-v3-1-b1a71bd1ac6b@diag.uniroma1.it Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-03-10sched/deadline,rt: Remove unused parameter from pick_next_[rt|dl]_entity()Dietmar Eggemann
[ Upstream commit 821aecd09e5ad2f8d4c3d8195333d272b392f7d3 ] The `struct rq *rq` parameter isn't used. Remove it. Signed-off-by: Dietmar Eggemann <dietmar.eggemann@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Juri Lelli <juri.lelli@redhat.com> Link: https://lore.kernel.org/r/20220302183433.333029-7-dietmar.eggemann@arm.com Stable-dep-of: 7c4a5b89a0b5 ("sched/rt: pick_next_rt_entity(): check list_entry") Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-03-10locking/rwsem: Disable preemption in all down_read*() and up_read() code pathsWaiman Long
[ Upstream commit 3f5245538a1964ae186ab7e1636020a41aa63143 ] Commit: 91d2a812dfb9 ("locking/rwsem: Make handoff writer optimistically spin on owner") ... assumes that when the owner field is changed to NULL, the lock will become free soon. But commit: 48dfb5d2560d ("locking/rwsem: Disable preemption while trying for rwsem lock") ... disabled preemption when acquiring rwsem for write. However, preemption has not yet been disabled when acquiring a read lock on a rwsem. So a reader can add a RWSEM_READER_BIAS to count without setting owner to signal a reader, got preempted out by a RT task which then spins in the writer slowpath as owner remains NULL leading to live lock. One easy way to fix this problem is to disable preemption at all the down_read*() and up_read() code paths as implemented in this patch. Fixes: 91d2a812dfb9 ("locking/rwsem: Make handoff writer optimistically spin on owner") Reported-by: Mukesh Ojha <quic_mojha@quicinc.com> Suggested-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Waiman Long <longman@redhat.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20230126003628.365092-3-longman@redhat.com Signed-off-by: Sasha Levin <sashal@kernel.org>