perf: Enqueue SIGTRAP always via task_work.
A signal is delivered by raising irq_work() which works from any context including NMI. irq_work() can be delayed if the architecture does not provide an interrupt vector. In order not to lose a signal, the signal is injected via task_work during event_sched_out(). Instead going via irq_work, the signal could be added directly via task_work. The signal is sent to current and can be enqueued on its return path to userland. Queue signal via task_work and consider possible NMI context. Remove perf_event::pending_sigtrap and and use perf_event::pending_work instead. Reported-by:Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by:
Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by:
Peter Zijlstra (Intel) <peterz@infradead.org> Tested-by:
Marco Elver <elver@google.com> Tested-by:
Arnaldo Carvalho de Melo <acme@redhat.com> Link: https://lore.kernel.org/r/20240704170424.1466941-4-bigeasy@linutronix.de
Loading
Please register or sign in to comment