diff options
| author | Linus Torvalds <torvalds@linux-foundation.org> | 2024-07-29 12:05:06 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2024-11-01 01:58:34 +0100 |
| commit | 7a26cb660775067a4d7da6ca48e024a8543bf848 (patch) | |
| tree | 2613bfef89fb4c053bcfa71ca2ba3984c100f247 | |
| parent | 81507f633e791b2dbce44b52e67f9210b5b05d6e (diff) | |
| download | linux-rpi-7a26cb660775067a4d7da6ca48e024a8543bf848.tar.gz linux-rpi-7a26cb660775067a4d7da6ca48e024a8543bf848.tar.bz2 linux-rpi-7a26cb660775067a4d7da6ca48e024a8543bf848.zip | |
task_work: make TWA_NMI_CURRENT handling conditional on IRQ_WORK
commit cec6937dd1aae1b38d147bd190cb895d06cf96d0 upstream.
The TWA_NMI_CURRENT handling very much depends on IRQ_WORK, but that
isn't universally enabled everywhere.
Maybe the IRQ_WORK infrastructure should just be unconditional - x86
ends up indirectly enabling it through unconditionally enabling
PERF_EVENTS, for example. But it also gets enabled by having SMP
support, or even if you just have PRINTK enabled.
But in the meantime TWA_NMI_CURRENT causes tons of build failures on
various odd minimal configs. Which did show up in linux-next, but
despite that nobody bothered to fix it or even inform me until -rc1 was
out.
Fixes: 466e4d801cd4 ("task_work: Add TWA_NMI_CURRENT as an additional notify mode")
Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Reported-by: kernelci.org bot <bot@kernelci.org>
Reported-by: Guenter Roeck <linux@roeck-us.net>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | kernel/task_work.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/kernel/task_work.c b/kernel/task_work.c index 8aa43204cb7d..c969f1f26be5 100644 --- a/kernel/task_work.c +++ b/kernel/task_work.c @@ -6,12 +6,14 @@ static struct callback_head work_exited; /* all we need is ->next == NULL */ +#ifdef CONFIG_IRQ_WORK static void task_work_set_notify_irq(struct irq_work *entry) { test_and_set_tsk_thread_flag(current, TIF_NOTIFY_RESUME); } static DEFINE_PER_CPU(struct irq_work, irq_work_NMI_resume) = IRQ_WORK_INIT_HARD(task_work_set_notify_irq); +#endif /** * task_work_add - ask the @task to execute @work->func() @@ -59,6 +61,8 @@ int task_work_add(struct task_struct *task, struct callback_head *work, if (notify == TWA_NMI_CURRENT) { if (WARN_ON_ONCE(task != current)) return -EINVAL; + if (!IS_ENABLED(CONFIG_IRQ_WORK)) + return -EINVAL; } else { /* * Record the work call stack in order to print it in KASAN @@ -92,9 +96,11 @@ int task_work_add(struct task_struct *task, struct callback_head *work, case TWA_SIGNAL_NO_IPI: __set_notify_signal(task); break; +#ifdef CONFIG_IRQ_WORK case TWA_NMI_CURRENT: irq_work_queue(this_cpu_ptr(&irq_work_NMI_resume)); break; +#endif default: WARN_ON_ONCE(1); break; |