On Fri, 6 Nov 2020 11:17:58 +0900 Masami Hiramatsu <mhiramat@xxxxxxxxxx> wrote: > On Tue, 3 Nov 2020 08:42:44 +0100 > Helge Deller <deller@xxxxxx> wrote: > > > As noticed by Masami Hiramatsu, get_kprobe() must be called with preempt > > disabled. > > Doesn't parisc ftrace implementation preempt off? Then it is required. > > Steve, can we expect that op->func() is called under preempt off always > on any arch or is it arch dependent? > Currently all kprobe function callbacks are called with preempt disabled, because it doesn't have the RECURSIVE_SAFE flag set. And for callbacks without that set, it goes through a helper function that disables preemption. My current patch set (which is not upstreamed yet) is changing that, and I just posted a new patch series that does the preempt disable before the get_kprobe() function for parsic and other archs, to handle the new code. Thus, parsic is currently OK (without my new patch set, it's called with preemption disabled). -- Steve
