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2024-04-09printk: Flag register_console() if console is set on command lineTony Lindgren
If add_preferred_console() is not called early in setup_console(), we can end up having register_console() call try_enable_default_console() before a console device has called add_preferred_console(). Let's set console_set_on_cmdline flag in console_setup() to prevent this from happening. Signed-off-by: Tony Lindgren <tony@atomide.com> Link: https://lore.kernel.org/r/20240327110021.59793-4-tony@atomide.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-04-09printk: Don't try to parse DEVNAME:0.0 console optionsTony Lindgren
Currently console_setup() tries to make a console index out of any digits passed in the kernel command line for console. In the DEVNAME:0.0 case, the name can contain a device IO address, so bail out on console names with a ':'. Signed-off-by: Tony Lindgren <tony@atomide.com> Link: https://lore.kernel.org/r/20240327110021.59793-3-tony@atomide.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-04-09printk: Save console options for add_preferred_console_match()Tony Lindgren
Driver subsystems may need to translate the preferred console name to the character device name used. We already do some of this in console_setup() with a few hardcoded names, but that does not scale well. The console options are parsed early in console_setup(), and the consoles are added with __add_preferred_console(). At this point we don't know much about the character device names and device drivers getting probed. To allow driver subsystems to set up a preferred console, let's save the kernel command line console options. To add a preferred console from a driver subsystem with optional character device name translation, let's add a new function add_preferred_console_match(). This allows the serial core layer to support console=DEVNAME:0.0 style hardware based addressing in addition to the current console=ttyS0 style naming. And we can start moving console_setup() character device parsing to the driver subsystem specific code. We use a separate array from the console_cmdline array as the character device name and index may be unknown at the console_setup() time. And eventually there's no need to call __add_preferred_console() until the subsystem is ready to handle the console. Adding the console name in addition to the character device name, and a flag for an added console, could be added to the struct console_cmdline. And the console_cmdline array handling could be modified accordingly. But that complicates things compared saving the console options, and then adding the consoles when the subsystems handling the consoles are ready. Co-developed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Tony Lindgren <tony@atomide.com> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/20240327110021.59793-2-tony@atomide.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-04-09bpf: Select new NEED_TASKS_RCU Kconfig optionPaul E. McKenney
Currently, if a Kconfig option depends on TASKS_RCU, it conditionally does "select TASKS_RCU if PREEMPTION". This works, but requires any change in this enablement logic to be replicated across all such "select" clauses. A new NEED_TASKS_RCU Kconfig option has been created to allow this enablement logic to be in one place in kernel/rcu/Kconfig. Therefore, make BPF select the new NEED_TASKS_RCU Kconfig option. Signed-off-by: Paul E. McKenney <paulmck@kernel.org> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: Andrii Nakryiko <andrii@kernel.org> Cc: Martin KaFai Lau <martin.lau@linux.dev> Cc: Song Liu <song@kernel.org> Cc: Yonghong Song <yonghong.song@linux.dev> Cc: John Fastabend <john.fastabend@gmail.com> Cc: KP Singh <kpsingh@kernel.org> Cc: Stanislav Fomichev <sdf@google.com> Cc: Hao Luo <haoluo@google.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: <bpf@vger.kernel.org> Cc: Ankur Arora <ankur.a.arora@oracle.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Steven Rostedt <rostedt@goodmis.org> Acked-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
2024-04-09rcu-tasks: Make Tasks RCU wait idly for grace-period delaysPaul E. McKenney
Currently, all waits for grace periods sleep at TASK_UNINTERRUPTIBLE, regardless of RCU flavor. This has worked well, but there have been cases where a longer-than-average Tasks RCU grace period has triggered softlockup splats, many of them, before the Tasks RCU CPU stall warning appears. These softlockup splats unnecessarily consume console bandwidth and complicate diagnosis of the underlying problem. Plus a long but not pathologically long Tasks RCU grace period might trigger a few softlockup splats before completing normally, which generates noise for no good reason. This commit therefore causes Tasks RCU grace periods to sleep at TASK_IDLE priority. If there really is a persistent problem, the eventual Tasks RCU CPU stall warning will flag it, and without the extra noise. Reported-by: Breno Leitao <leitao@debian.org> Signed-off-by: Paul E. McKenney <paulmck@kernel.org> Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
2024-04-09rcutorture: ASSERT_EXCLUSIVE_WRITER() for ->rtort_pipe_count updatesPaul E. McKenney
It turns out that only one CPU at a time will ever invoke rcu_torture_pipe_update_one() on a given rcu_torture structure. This commit therefore adds three ASSERT_EXCLUSIVE_WRITER() calls to enlist KCSAN's aid in checking this. Signed-off-by: Paul E. McKenney <paulmck@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org> Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
2024-04-09rcutorture: Dump GP kthread state on insufficient cb-flood launderingPaul E. McKenney
If a callback flood prevents grace period from completing, rcutorture does a WARN_ON(). Avoiding this WARN_ON() currently requires that at least three grace periods elapse during an eight-second callback-flood interval. Unfortunately, the current debug information does not include anything about the grace-period state. This commit therefore adds a call to cur_ops->gp_kthread_dbg(), if this function pointer is non-NULL. Signed-off-by: Paul E. McKenney <paulmck@kernel.org> Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
2024-04-09rcutorture: Dump # online CPUs on insufficient cb-flood launderingPaul E. McKenney
This commit adds the number of online CPUs to the state dump following an unsuccesful callback-flood test. Signed-off-by: Paul E. McKenney <paulmck@kernel.org> Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
2024-04-09rcu: Add lockdep checks and kernel-doc header to rcu_softirq_qs()Paul E. McKenney
There is some indications that rcu_softirq_qs() might be more generally used than anticipated. This commit therefore adds some lockdep assertions and some cautionary tales in a new kernel-doc header. Link: https://lore.kernel.org/all/Zd4DXTyCf17lcTfq@debian.debian/ Signed-off-by: Paul E. McKenney <paulmck@kernel.org> Cc: Eric Dumazet <edumazet@google.com> Cc: Jakub Kicinski <kuba@kernel.org> Cc: "David S. Miller" <davem@davemloft.net> Cc: Yan Zhai <yan@cloudflare.com> Cc: <netdev@vger.kernel.org> Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
2024-04-09clockevents: Convert s[n]printf() to sysfs_emit()Li Zhijian
Per filesystems/sysfs.rst, show() should only use sysfs_emit() or sysfs_emit_at() when formatting the value to be returned to user space. coccinelle complains that there are still a couple of functions that use snprintf(). Convert them to sysfs_emit(). Signed-off-by: Li Zhijian <lizhijian@fujitsu.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20240314100402.1326582-2-lizhijian@fujitsu.com
2024-04-09clocksource: Convert s[n]printf() to sysfs_emit()Li Zhijian
Per filesystems/sysfs.rst, show() should only use sysfs_emit() or sysfs_emit_at() when formatting the value to be returned to user space. coccinelle complains that there are still a couple of functions that use snprintf(). Convert them to sysfs_emit(). Signed-off-by: Li Zhijian <lizhijian@fujitsu.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20240314100402.1326582-1-lizhijian@fujitsu.com
2024-04-09Merge tag 'v6.9-rc3' into locking/core, to pick up fixesIngo Molnar
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2024-04-08workqueue: Add destroy_work_on_stack() in workqueue_softirq_dead()Zqiang
This commit add missed destroy_work_on_stack() operations for dead_work.work. Signed-off-by: Zqiang <qiang.zhang1211@gmail.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2024-04-08cgroup/cpuset: Make cpuset hotplug processing synchronousWaiman Long
Since commit 3a5a6d0c2b03("cpuset: don't nest cgroup_mutex inside get_online_cpus()"), cpuset hotplug was done asynchronously via a work function. This is to avoid recursive locking of cgroup_mutex. Since then, the cgroup locking scheme has changed quite a bit. A cpuset_mutex was introduced to protect cpuset specific operations. The cpuset_mutex is then replaced by a cpuset_rwsem. With commit d74b27d63a8b ("cgroup/cpuset: Change cpuset_rwsem and hotplug lock order"), cpu_hotplug_lock is acquired before cpuset_rwsem. Later on, cpuset_rwsem is reverted back to cpuset_mutex. All these locking changes allow the hotplug code to call into cpuset core directly. The following commits were also merged due to the asynchronous nature of cpuset hotplug processing. - commit b22afcdf04c9 ("cpu/hotplug: Cure the cpusets trainwreck") - commit 50e76632339d ("sched/cpuset/pm: Fix cpuset vs. suspend-resume bugs") - commit 28b89b9e6f7b ("cpuset: handle race between CPU hotplug and cpuset_hotplug_work") Clean up all these bandages by making cpuset hotplug processing synchronous again with the exception that the call to cgroup_transfer_tasks() to transfer tasks out of an empty cgroup v1 cpuset, if necessary, will still be done via a work function due to the existing cgroup_mutex -> cpu_hotplug_lock dependency. It is possible to reverse that dependency, but that will require updating a number of different cgroup controllers. This special hotplug code path should be rarely taken anyway. As all the cpuset states will be updated by the end of the hotplug operation, we can revert most the above commits except commit 50e76632339d ("sched/cpuset/pm: Fix cpuset vs. suspend-resume bugs") which is partially reverted. Also removing some cpus_read_lock trylock attempts in the cpuset partition code as they are no longer necessary since the cpu_hotplug_lock is now held for the whole duration of the cpuset hotplug code path. Signed-off-by: Waiman Long <longman@redhat.com> Tested-by: Valentin Schneider <vschneid@redhat.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2024-04-08PM: EM: Add em_dev_update_chip_binning()Lukasz Luba
Add a function which allows to modify easily the EM after the new voltage information is available. The device drivers for the chip can adjust the voltage values after setup. The voltage for the same frequency in OPP can be different due to chip binning. The voltage impacts the power usage and the EM power values can be updated to reflect that. Reviewed-by: Dietmar Eggemann <dietmar.eggemann@arm.com> Signed-off-by: Lukasz Luba <lukasz.luba@arm.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2024-04-08PM: EM: Refactor em_adjust_new_capacity()Lukasz Luba
Extract em_table_dup() and em_recalc_and_update() from em_adjust_new_capacity(). Both functions will be later reused by the 'update EM due to chip binning' functionality. Reviewed-by: Dietmar Eggemann <dietmar.eggemann@arm.com> Signed-off-by: Lukasz Luba <lukasz.luba@arm.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2024-04-08PM: s2idle: Make sure CPUs will wakeup directly on resumeAnna-Maria Behnsen
s2idle works like a regular suspend with freezing processes and freezing devices. All CPUs except the control CPU go into idle. Once this is completed the control CPU kicks all other CPUs out of idle, so that they reenter the idle loop and then enter s2idle state. The control CPU then issues an swait() on the suspend state and therefore enters the idle loop as well. Due to being kicked out of idle, the other CPUs leave their NOHZ states, which means the tick is active and the corresponding hrtimer is programmed to the next jiffie. On entering s2idle the CPUs shut down their local clockevent device to prevent wakeups. The last CPU which enters s2idle shuts down its local clockevent and freezes timekeeping. On resume, one of the CPUs receives the wakeup interrupt, unfreezes timekeeping and its local clockevent and starts the resume process. At that point all other CPUs are still in s2idle with their clockevents switched off. They only resume when they are kicked by another CPU or after resuming devices and then receiving a device interrupt. That means there is no guarantee that all CPUs will wakeup directly on resume. As a consequence there is no guarantee that timers which are queued on those CPUs and should expire directly after resume, are handled. Also timer list timers which are remotely queued to one of those CPUs after resume will not result in a reprogramming IPI as the tick is active. Queueing a hrtimer will also not result in a reprogramming IPI because the first hrtimer event is already in the past. The recent introduction of the timer pull model (7ee988770326 ("timers: Implement the hierarchical pull model")) amplifies this problem, if the current migrator is one of the non woken up CPUs. When a non pinned timer list timer is queued and the queuing CPU goes idle, it relies on the still suspended migrator CPU to expire the timer which will happen by chance. The problem exists since commit 8d89835b0467 ("PM: suspend: Do not pause cpuidle in the suspend-to-idle path"). There the cpuidle_pause() call which in turn invoked a wakeup for all idle CPUs was moved to a later point in the resume process. This might not be reached or reached very late because it waits on a timer of a still suspended CPU. Address this by kicking all CPUs out of idle after the control CPU returns from swait() so that they resume their timers and restore consistent system state. Closes: https://bugzilla.kernel.org/show_bug.cgi?id=218641 Fixes: 8d89835b0467 ("PM: suspend: Do not pause cpuidle in the suspend-to-idle path") Signed-off-by: Anna-Maria Behnsen <anna-maria@linutronix.de> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Mario Limonciello <mario.limonciello@amd.com> Cc: 5.16+ <stable@kernel.org> # 5.16+ Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2024-04-08clocksource: Make watchdog and suspend-timing multiplication overflow safeAdrian Hunter
Kernel timekeeping is designed to keep the change in cycles (since the last timer interrupt) below max_cycles, which prevents multiplication overflow when converting cycles to nanoseconds. However, if timer interrupts stop, the clocksource_cyc2ns() calculation will eventually overflow. Add protection against that. Simplify by folding together clocksource_delta() and clocksource_cyc2ns() into cycles_to_nsec_safe(). Check against max_cycles, falling back to a slower higher precision calculation. Suggested-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20240325064023.2997-20-adrian.hunter@intel.com
2024-04-08timekeeping: Let timekeeping_cycles_to_ns() handle both under and overflowAdrian Hunter
For the case !CONFIG_CLOCKSOURCE_VALIDATE_LAST_CYCLE, forego overflow protection in the range (mask << 1) < delta <= mask, and interpret it always as an inconsistency between CPU clock values. That allows slightly neater code, and it is on a slow path so has no effect on performance. Suggested-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20240325064023.2997-19-adrian.hunter@intel.com
2024-04-08timekeeping: Make delta calculation overflow safeAdrian Hunter
Kernel timekeeping is designed to keep the change in cycles (since the last timer interrupt) below max_cycles, which prevents multiplication overflow when converting cycles to nanoseconds. However, if timer interrupts stop, the calculation will eventually overflow. Add protection against that. In timekeeping_cycles_to_ns() calculation, check against max_cycles, falling back to a slower higher precision calculation. In timekeeping_forward_now(), process delta in chunks of at most max_cycles. Suggested-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20240325064023.2997-18-adrian.hunter@intel.com
2024-04-08timekeeping: Prepare timekeeping_cycles_to_ns() for overflow safetyAdrian Hunter
Open code clocksource_delta() in timekeeping_cycles_to_ns() so that overflow safety can be added efficiently. Suggested-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20240325064023.2997-17-adrian.hunter@intel.com
2024-04-08timekeeping: Fold in timekeeping_delta_to_ns()Adrian Hunter
timekeeping_delta_to_ns() is now called only from timekeeping_cycles_to_ns(), and it is not useful otherwise. Simplify the code by folding it into timekeeping_cycles_to_ns(). No functional change. Suggested-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20240325064023.2997-16-adrian.hunter@intel.com
2024-04-08timekeeping: Consolidate timekeeping helpersAdrian Hunter
Consolidate timekeeping helpers, making use of timekeeping_cycles_to_ns() in preference to directly using timekeeping_delta_to_ns(). No functional change. Suggested-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20240325064023.2997-15-adrian.hunter@intel.com
2024-04-08timekeeping: Refactor timekeeping helpersAdrian Hunter
Simplify the usage of timekeeping sanity checking, in preparation for consolidating timekeeping helpers. This works towards eliminating timekeeping_delta_to_ns() in favour of timekeeping_cycles_to_ns(). No functional change. Suggested-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20240325064023.2997-14-adrian.hunter@intel.com
2024-04-08timekeeping: Reuse timekeeping_cycles_to_ns()Adrian Hunter
Simplify __timekeeping_get_ns() by reusing timekeeping_cycles_to_ns(). No functional change. Suggested-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20240325064023.2997-13-adrian.hunter@intel.com
2024-04-08timekeeping: Tidy timekeeping_cycles_to_ns() slightlyAdrian Hunter
Put together declaration and initialization of the local variable 'delta'. Suggested-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20240325064023.2997-12-adrian.hunter@intel.com
2024-04-08timekeeping: Rename fast_tk_get_delta_ns() to __timekeeping_get_ns()Adrian Hunter
Rename fast_tk_get_delta_ns() to __timekeeping_get_ns() to prepare for its reuse as a general timekeeping helper function. Suggested-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20240325064023.2997-11-adrian.hunter@intel.com
2024-04-08timekeeping: Move timekeeping helper functionsAdrian Hunter
Move timekeeping helper functions to prepare for their reuse. Suggested-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20240325064023.2997-10-adrian.hunter@intel.com
2024-04-08vdso: Add vdso_data:: Max_cyclesAdrian Hunter
Add vdso_data::max_cycles in preparation to use it to detect potential multiplication overflow. Suggested-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20240325064023.2997-7-adrian.hunter@intel.com
2024-04-08hrtimer: Remove unused functionJiapeng Chong
The function is defined, but not called anywhere: kernel/time/hrtimer.c:1880:20: warning: unused function '__hrtimer_peek_ahead_timers'. Remove it. Reported-by: Abaci Robot <abaci@linux.alibaba.com> Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20240322070441.29646-1-jiapeng.chong@linux.alibaba.com Closes: https://bugzilla.openanolis.cn/show_bug.cgi?id=8611
2024-04-08irqdomain: Check virq for 0 before use in irq_dispose_mapping()Andy Shevchenko
It's a bit hard to read the logic since the virq is used before checking it for 0. Rearrange the code to make it better to understand. This, in particular, should clearly answer the question whether the caller needs to perform this check or not, and there are plenty of places for both variants, confirming a confusion. Fun fact that the new code is shorter: Function old new delta irq_dispose_mapping 278 271 -7 Total: Before=11625, After=11618, chg -0.06% when compiled by GCC on Debian for x86_64. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20240405190105.3932034-1-andriy.shevchenko@linux.intel.com
2024-04-07Merge tag 'timers-urgent-2024-04-07' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull timer fixes from Ingo Molnar: "Fix various timer bugs: - Fix a timer migration bug that may result in missed events - Fix timer migration group hierarchy event updates - Fix a PowerPC64 build warning - Fix a handful of DocBook annotation bugs" * tag 'timers-urgent-2024-04-07' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: timers/migration: Return early on deactivation timers/migration: Fix ignored event due to missing CPU update vdso: Use CONFIG_PAGE_SHIFT in vdso/datapage.h timers: Fix text inconsistencies and spelling tick/sched: Fix struct tick_sched doc warnings tick/sched: Fix various kernel-doc warnings timers: Fix kernel-doc format and add Return values time/timekeeping: Fix kernel-doc warnings and typos time/timecounter: Fix inline documentation
2024-04-05bpf: Allow invoking kfuncs from BPF_PROG_TYPE_SYSCALL progsDavid Vernet
Currently, a set of core BPF kfuncs (e.g. bpf_task_*, bpf_cgroup_*, bpf_cpumask_*, etc) cannot be invoked from BPF_PROG_TYPE_SYSCALL programs. The whitelist approach taken for enabling kfuncs makes sense: it not safe to call these kfuncs from every program type. For example, it may not be safe to call bpf_task_acquire() in an fentry to free_task(). BPF_PROG_TYPE_SYSCALL, on the other hand, is a perfectly safe program type from which to invoke these kfuncs, as it's a very controlled environment, and we should never be able to run into any of the typical problems such as recursive invoations, acquiring references on freeing kptrs, etc. Being able to invoke these kfuncs would be useful, as BPF_PROG_TYPE_SYSCALL can be invoked with BPF_PROG_RUN, and would therefore enable user space programs to synchronously call into BPF to manipulate these kptrs. This patch therefore enables invoking the aforementioned core kfuncs from BPF_PROG_TYPE_SYSCALL progs. Signed-off-by: David Vernet <void@manifault.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Yonghong Song <yonghong.song@linux.dev> Link: https://lore.kernel.org/bpf/20240405143041.632519-2-void@manifault.com
2024-04-05bpf: allow invoking bpf_for_each_map_elem with different mapsPhilo Lu
Taking different maps within a single bpf_for_each_map_elem call is not allowed before, because from the second map, bpf_insn_aux_data->map_ptr_state will be marked as *poison*. In fact both map_ptr and state are needed to support this use case: map_ptr is used by set_map_elem_callback_state() while poison state is needed to determine whether to use direct call. Signed-off-by: Philo Lu <lulie@linux.alibaba.com> Acked-by: Yonghong Song <yonghong.song@linux.dev> Link: https://lore.kernel.org/r/20240405025536.18113-3-lulie@linux.alibaba.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-04-05bpf: store both map ptr and state in bpf_insn_aux_dataPhilo Lu
Currently, bpf_insn_aux_data->map_ptr_state is used to store either map_ptr or its poison state (i.e., BPF_MAP_PTR_POISON). Thus BPF_MAP_PTR_POISON must be checked before reading map_ptr. In certain cases, we may need valid map_ptr even in case of poison state. This will be explained in next patch with bpf_for_each_map_elem() helper. This patch changes map_ptr_state into a new struct including both map pointer and its state (poison/unpriv). It's in the same union with struct bpf_loop_inline_state, so there is no extra memory overhead. Besides, macros BPF_MAP_PTR_UNPRIV/BPF_MAP_PTR_POISON/BPF_MAP_PTR are no longer needed. This patch does not change any existing functionality. Signed-off-by: Philo Lu <lulie@linux.alibaba.com> Acked-by: Yonghong Song <yonghong.song@linux.dev> Link: https://lore.kernel.org/r/20240405025536.18113-2-lulie@linux.alibaba.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-04-05bpf: fix perf_snapshot_branch_stack link failureArnd Bergmann
The newly added code to handle bpf_get_branch_snapshot fails to link when CONFIG_PERF_EVENTS is disabled: aarch64-linux-ld: kernel/bpf/verifier.o: in function `do_misc_fixups': verifier.c:(.text+0x1090c): undefined reference to `__SCK__perf_snapshot_branch_stack' Add a build-time check for that Kconfig symbol around the code to remove the link time dependency. Fixes: 314a53623cd4 ("bpf: inline bpf_get_branch_snapshot() helper") Signed-off-by: Arnd Bergmann <arnd@arndb.de> Link: https://lore.kernel.org/r/20240405142637.577046-1-arnd@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-04-05timers/migration: Return early on deactivationAnna-Maria Behnsen
Commit 4b6f4c5a67c0 ("timer/migration: Remove buggy early return on deactivation") removed the logic to return early in tmigr_update_events() on deactivation. With this the problem with a not properly updated first global event in a hierarchy containing only a single group was fixed. But when having a look at this code path with a hierarchy with more than a single level, now unnecessary work is done (example is partially copied from the message of the commit mentioned above): [GRP1:0] migrator = GRP0:0 active = GRP0:0 nextevt = T0:0i, T0:1 / \ [GRP0:0] [GRP0:1] migrator = 0 migrator = NONE active = 0 active = NONE nextevt = T0i, T1 nextevt = T2 / \ / \ 0 (T0i) 1 (T1) 2 (T2) 3 active idle idle idle 0) CPU 0 is active thus its event is ignored (the letter 'i') and so are upper levels' events. CPU 1 is idle and has the timer T1 enqueued. CPU 2 also has a timer. The expiry order is T0 (ignored) < T1 < T2 [GRP1:0] migrator = GRP0:0 active = GRP0:0 nextevt = T0:0i, T0:1 / \ [GRP0:0] [GRP0:1] migrator = NONE migrator = NONE active = NONE active = NONE nextevt = T1 nextevt = T2 / \ / \ 0 (T0i) 1 (T1) 2 (T2) 3 idle idle idle idle 1) CPU 0 goes idle without global event queued. Therefore KTIME_MAX is pushed as its next expiry and its own event kept as "ignore". Without this early return the following steps happen in tmigr_update_events() when child = null and group = GRP0:0 : lock(GRP0:0->lock); timerqueue_del(GRP0:0, T0i); unlock(GRP0:0->lock); [GRP1:0] migrator = NONE active = NONE nextevt = T0:0, T0:1 / \ [GRP0:0] [GRP0:1] migrator = NONE migrator = NONE active = NONE active = NONE nextevt = T1 nextevt = T2 / \ / \ 0 (T0i) 1 (T1) 2 (T2) 3 idle idle idle idle 2) The change now propagates up to the top. Then tmigr_update_events() updates the group event of GRP0:0 and executes the following steps (child = GRP0:0 and group = GRP0:0): lock(GRP0:0->lock); lock(GRP1:0->lock); evt = tmigr_next_groupevt(GRP0:0); -> this removes the ignored events in GRP0:0 ... update GRP1:0 group event and timerqueue ... unlock(GRP1:0->lock); unlock(GRP0:0->lock); So the dance in 1) with locking the GRP0:0->lock and removing the T0i from the timerqueue is redundand as this is done nevertheless in 2) when tmigr_next_groupevt(GRP0:0) is executed. Revert commit 4b6f4c5a67c0 ("timer/migration: Remove buggy early return on deactivation") and add a condition into return path to skip the return only, when hierarchy contains a single group. Adapt comments accordingly. Fixes: 4b6f4c5a67c0 ("timer/migration: Remove buggy early return on deactivation") Signed-off-by: Anna-Maria Behnsen <anna-maria@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Link: https://lore.kernel.org/r/87cyr49on2.fsf@somnus
2024-04-05timers/migration: Fix ignored event due to missing CPU updateFrederic Weisbecker
When a group event is updated with its expiry unchanged but a different CPU, that target change may go unnoticed and the event may be propagated up with a stale CPU value. The following depicts a scenario that has been actually observed: [GRP2:0] migrator = GRP1:1 active = GRP1:1 nextevt = TGRP1:0 (T0) / \ [GRP1:0] [GRP1:1] migrator = NONE [...] active = NONE nextevt = TGRP0:0 (T0) / \ [GRP0:0] [...] migrator = NONE active = NONE nextevt = T0 / \ 0 (T0) 1 (T1) idle idle 0) The hierarchy has 3 levels. The left part (GRP1:0) is all idle, including CPU 0 and CPU 1 which have a timer each: T0 and T1. They have the same expiry value. [GRP2:0] migrator = GRP1:1 active = GRP1:1 nextevt = KTIME_MAX / \ [GRP1:0] [GRP1:1] migrator = NONE [...] active = NONE nextevt = TGRP0:0 (T0) / \ [GRP0:0] [...] migrator = NONE active = NONE nextevt = T0 / \ 0 (T0) 1 (T1) idle idle 1) The migrator in GRP1:1 handles remotely T0. The event is dequeued from the top and T0 executed. [GRP2:0] migrator = GRP1:1 active = GRP1:1 nextevt = KTIME_MAX / \ [GRP1:0] [GRP1:1] migrator = NONE [...] active = NONE nextevt = TGRP0:0 (T0) / \ [GRP0:0] [...] migrator = NONE active = NONE nextevt = T1 / \ 0 1 (T1) idle idle 2) The migrator in GRP1:1 fetches the next timer for CPU 0 and finds none. But it updates the events from its groups, starting with GRP0:0 which now has T1 as its next event. So far so good. [GRP2:0] migrator = GRP1:1 active = GRP1:1 nextevt = KTIME_MAX / \ [GRP1:0] [GRP1:1] migrator = NONE [...] active = NONE nextevt = TGRP0:0 (T0) / \ [GRP0:0] [...] migrator = NONE active = NONE nextevt = T1 / \ 0 1 (T1) idle idle 3) The migrator in GRP1:1 proceeds upward and updates the events in GRP1:0. The child event TGRP0:0 is found queued with the same expiry as before. And therefore it is left unchanged. However the target CPU is not the same but that fact is ignored so TGRP0:0 still points to CPU 0 when it should point to CPU 1. [GRP2:0] migrator = GRP1:1 active = GRP1:1 nextevt = TGRP1:0 (T0) / \ [GRP1:0] [GRP1:1] migrator = NONE [...] active = NONE nextevt = TGRP0:0 (T0) / \ [GRP0:0] [...] migrator = NONE active = NONE nextevt = T1 / \ 0 1 (T1) idle idle 4) The propagation has reached the top level and TGRP1:0, having TGRP0:0 as its first event, also wrongly points to CPU 0. TGRP1:0 is added to the top level group. [GRP2:0] migrator = GRP1:1 active = GRP1:1 nextevt = KTIME_MAX / \ [GRP1:0] [GRP1:1] migrator = NONE [...] active = NONE nextevt = TGRP0:0 (T0) / \ [GRP0:0] [...] migrator = NONE active = NONE nextevt = T1 / \ 0 1 (T1) idle idle 5) The migrator in GRP1:1 dequeues the next event in top level pointing to CPU 0. But since it actually doesn't see any real event in CPU 0, it early returns. 6) T1 is left unhandled until either CPU 0 or CPU 1 wake up. Some other bad scenario may involve trees with just two levels. Fix this with unconditionally updating the CPU of the child event before considering to early return while updating a queued event with an unchanged expiry value. Fixes: 7ee988770326 ("timers: Implement the hierarchical pull model") Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Anna-Maria Behnsen <anna-maria@linutronix.de> Link: https://lore.kernel.org/r/Zg2Ct6M2RJAYHgCB@localhost.localdomain
2024-04-04bpf: prevent r10 register from being marked as preciseAndrii Nakryiko
r10 is a special register that is not under BPF program's control and is always effectively precise. The rest of precision logic assumes that only r0-r9 SCALAR registers are marked as precise, so prevent r10 from being marked precise. This can happen due to signed cast instruction allowing to do something like `r0 = (s8)r10;`, which later, if r0 needs to be precise, would lead to an attempt to mark r10 as precise. Prevent this with an extra check during instruction backtracking. Fixes: 8100928c8814 ("bpf: Support new sign-extension mov insns") Reported-by: syzbot+148110ee7cf72f39f33e@syzkaller.appspotmail.com Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Yonghong Song <yonghong.song@linux.dev> Link: https://lore.kernel.org/r/20240404214536.3551295-1-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-04-04Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski
Cross-merge networking fixes after downstream PR. Conflicts: net/ipv4/ip_gre.c 17af420545a7 ("erspan: make sure erspan_base_hdr is present in skb->head") 5832c4a77d69 ("ip_tunnel: convert __be16 tunnel flags to bitmaps") https://lore.kernel.org/all/20240402103253.3b54a1cf@canb.auug.org.au/ Adjacent changes: net/ipv6/ip6_fib.c d21d40605bca ("ipv6: Fix infinite recursion in fib6_dump_done().") 5fc68320c1fb ("ipv6: remove RTNL protection from inet6_dump_fib()") Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-04-04Merge tag 'net-6.9-rc3' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net Pull networking fixes from Jakub Kicinski: "Including fixes from netfilter, bluetooth and bpf. Fairly usual collection of driver and core fixes. The large selftest accompanying one of the fixes is also becoming a common occurrence. Current release - regressions: - ipv6: fix infinite recursion in fib6_dump_done() - net/rds: fix possible null-deref in newly added error path Current release - new code bugs: - net: do not consume a full cacheline for system_page_pool - bpf: fix bpf_arena-related file descriptor leaks in the verifier - drv: ice: fix freeing uninitialized pointers, fixing misuse of the newfangled __free() auto-cleanup Previous releases - regressions: - x86/bpf: fixes the BPF JIT with retbleed=stuff - xen-netfront: add missing skb_mark_for_recycle, fix page pool accounting leaks, revealed by recently added explicit warning - tcp: fix bind() regression for v6-only wildcard and v4-mapped-v6 non-wildcard addresses - Bluetooth: - replace "hci_qca: Set BDA quirk bit if fwnode exists in DT" with better workarounds to un-break some buggy Qualcomm devices - set conn encrypted before conn establishes, fix re-connecting to some headsets which use slightly unusual sequence of msgs - mptcp: - prevent BPF accessing lowat from a subflow socket - don't account accept() of non-MPC client as fallback to TCP - drv: mana: fix Rx DMA datasize and skb_over_panic - drv: i40e: fix VF MAC filter removal Previous releases - always broken: - gro: various fixes related to UDP tunnels - netns crossing problems, incorrect checksum conversions, and incorrect packet transformations which may lead to panics - bpf: support deferring bpf_link dealloc to after RCU grace period - nf_tables: - release batch on table validation from abort path - release mutex after nft_gc_seq_end from abort path - flush pending destroy work before exit_net release - drv: r8169: skip DASH fw status checks when DASH is disabled" * tag 'net-6.9-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (81 commits) netfilter: validate user input for expected length net/sched: act_skbmod: prevent kernel-infoleak net: usb: ax88179_178a: avoid the interface always configured as random address net: dsa: sja1105: Fix parameters order in sja1110_pcs_mdio_write_c45() net: ravb: Always update error counters net: ravb: Always process TX descriptor ring netfilter: nf_tables: discard table flag update with pending basechain deletion netfilter: nf_tables: Fix potential data-race in __nft_flowtable_type_get() netfilter: nf_tables: reject new basechain after table flag update netfilter: nf_tables: flush pending destroy work before exit_net release netfilter: nf_tables: release mutex after nft_gc_seq_end from abort path netfilter: nf_tables: release batch on table validation from abort path Revert "tg3: Remove residual error handling in tg3_suspend" tg3: Remove residual error handling in tg3_suspend net: mana: Fix Rx DMA datasize and skb_over_panic net/sched: fix lockdep splat in qdisc_tree_reduce_backlog() net: phy: micrel: lan8814: Fix when enabling/disabling 1-step timestamping net: stmmac: fix rx queue priority assignment net: txgbe: fix i2c dev name cannot match clkdev net: fec: Set mac_managed_pm during probe ...
2024-04-04bpf: inline bpf_get_branch_snapshot() helperAndrii Nakryiko
Inline bpf_get_branch_snapshot() helper using architecture-agnostic inline BPF code which calls directly into underlying callback of perf_snapshot_branch_stack static call. This callback is set early during kernel initialization and is never updated or reset, so it's ok to fetch actual implementation using static_call_query() and call directly into it. This change eliminates a full function call and saves one LBR entry in PERF_SAMPLE_BRANCH_ANY LBR mode. Acked-by: John Fastabend <john.fastabend@gmail.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Yonghong Song <yonghong.song@linux.dev> Link: https://lore.kernel.org/r/20240404002640.1774210-3-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-04-04bpf: make bpf_get_branch_snapshot() architecture-agnosticAndrii Nakryiko
perf_snapshot_branch_stack is set up in an architecture-agnostic way, so there is no reason for BPF subsystem to keep track of which architectures do support LBR or not. E.g., it looks like ARM64 might soon get support for BRBE ([0]), which (with proper integration) should be possible to utilize using this BPF helper. perf_snapshot_branch_stack static call will point to __static_call_return0() by default, which just returns zero, which will lead to -ENOENT, as expected. So no need to guard anything here. [0] https://lore.kernel.org/linux-arm-kernel/20240125094119.2542332-1-anshuman.khandual@arm.com/ Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Yonghong Song <yonghong.song@linux.dev> Link: https://lore.kernel.org/r/20240404002640.1774210-2-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-04-04fsnotify: create a wrapper fsnotify_find_inode_mark()Amir Goldstein
In preparation to passing an object pointer to fsnotify_find_mark(), add a wrapper fsnotify_find_inode_mark() and use it where possible. Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz> Message-Id: <20240317184154.1200192-4-amir73il@gmail.com>
2024-04-04bpf: Optimize emit_mov_imm64().Alexei Starovoitov
Turned out that bpf prog callback addresses, bpf prog addresses used in bpf_trampoline, and in other cases the 64-bit address can be represented as sign extended 32-bit value. According to https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82339 "Skylake has 0.64c throughput for mov r64, imm64, vs. 0.25 for mov r32, imm32." So use shorter encoding and faster instruction when possible. Special care is needed in jit_subprogs(), since bpf_pseudo_func() instruction cannot change its size during the last step of JIT. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/CAADnVQKFfpY-QZBrOU2CG8v2du8Lgyb7MNVmOZVK_yTyOdNbBA@mail.gmail.com Link: https://lore.kernel.org/bpf/20240401233800.42737-1-alexei.starovoitov@gmail.com
2024-04-03bpf: inline bpf_map_lookup_elem() helper for PERCPU_HASH mapAndrii Nakryiko
Using new per-CPU BPF instruction, partially inline bpf_map_lookup_elem() helper for per-CPU hashmap BPF map. Just like for normal HASH map, we still generate a call into __htab_map_lookup_elem(), but after that we resolve per-CPU element address using a new instruction, saving on extra functions calls. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: John Fastabend <john.fastabend@gmail.com> Link: https://lore.kernel.org/r/20240402021307.1012571-5-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-04-03bpf: inline bpf_map_lookup_elem() for PERCPU_ARRAY mapsAndrii Nakryiko
Using new per-CPU BPF instruction implement inlining for per-CPU ARRAY map lookup helper, if BPF JIT support is present. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: John Fastabend <john.fastabend@gmail.com> Link: https://lore.kernel.org/r/20240402021307.1012571-4-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-04-03bpf: inline bpf_get_smp_processor_id() helperAndrii Nakryiko
If BPF JIT supports per-CPU MOV instruction, inline bpf_get_smp_processor_id() to eliminate unnecessary function calls. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: John Fastabend <john.fastabend@gmail.com> Link: https://lore.kernel.org/r/20240402021307.1012571-3-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-04-03bpf: add special internal-only MOV instruction to resolve per-CPU addrsAndrii Nakryiko
Add a new BPF instruction for resolving absolute addresses of per-CPU data from their per-CPU offsets. This instruction is internal-only and users are not allowed to use them directly. They will only be used for internal inlining optimizations for now between BPF verifier and BPF JITs. We use a special BPF_MOV | BPF_ALU64 | BPF_X form with insn->off field set to BPF_ADDR_PERCPU = -1. I used negative offset value to distinguish them from positive ones used by user-exposed instructions. Such instruction performs a resolution of a per-CPU offset stored in a register to a valid kernel address which can be dereferenced. It is useful in any use case where absolute address of a per-CPU data has to be resolved (e.g., in inlining bpf_map_lookup_elem()). BPF disassembler is also taught to recognize them to support dumping final BPF assembly code (non-JIT'ed version). Add arch-specific way for BPF JITs to mark support for this instructions. This patch also adds support for these instructions in x86-64 BPF JIT. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: John Fastabend <john.fastabend@gmail.com> Link: https://lore.kernel.org/r/20240402021307.1012571-2-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-04-03bpf: Replace deprecated strncpy with strscpyJustin Stitt
strncpy() is deprecated for use on NUL-terminated destination strings [1] and as such we should prefer more robust and less ambiguous string interfaces. bpf sym names get looked up and compared/cleaned with various string apis. This suggests they need to be NUL-terminated (strncpy() suggests this but does not guarantee it). | static int compare_symbol_name(const char *name, char *namebuf) | { | cleanup_symbol_name(namebuf); | return strcmp(name, namebuf); | } | static void cleanup_symbol_name(char *s) | { | ... | res = strstr(s, ".llvm."); | ... | } Use strscpy() as this method guarantees NUL-termination on the destination buffer. This patch also replaces two uses of strncpy() used in log.c. These are simple replacements as postfix has been zero-initialized on the stack and has source arguments with a size less than the destination's size. Note that this patch uses the new 2-argument version of strscpy introduced in commit e6584c3964f2f ("string: Allow 2-argument strscpy()"). Signed-off-by: Justin Stitt <justinstitt@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings [1] Link: https://manpages.debian.org/testing/linux-manual-4.8/strscpy.9.en.html [2] Link: https://github.com/KSPP/linux/issues/90 Link: https://lore.kernel.org/bpf/20240402-strncpy-kernel-bpf-core-c-v1-1-7cb07a426e78@google.com
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