Anshuman Khandual <anshuman.khandual@xxxxxxx> writes: > Similar notify_page_fault() definitions are being used by architectures > duplicating much of the same code. This attempts to unify them into a > single implementation, generalize it and then move it to a common place. > kprobes_built_in() can detect CONFIG_KPROBES, hence notify_page_fault() > need not be wrapped again within CONFIG_KPROBES. Trap number argument can > now contain upto an 'unsigned int' accommodating all possible platforms. ... > diff --git a/arch/arm/mm/fault.c b/arch/arm/mm/fault.c > index 58f69fa..1bc3b18 100644 > --- a/arch/arm/mm/fault.c > +++ b/arch/arm/mm/fault.c > @@ -30,28 +30,6 @@ > > #ifdef CONFIG_MMU > > -#ifdef CONFIG_KPROBES > -static inline int notify_page_fault(struct pt_regs *regs, unsigned int fsr) > -{ > - int ret = 0; > - > - if (!user_mode(regs)) { > - /* kprobe_running() needs smp_processor_id() */ > - preempt_disable(); > - if (kprobe_running() && kprobe_fault_handler(regs, fsr)) > - ret = 1; > - preempt_enable(); > - } > - > - return ret; > -} > -#else You've changed several of the architectures from something like above, where it disables preemption around the call into the below: > +int __kprobes notify_page_fault(struct pt_regs *regs, unsigned int trap) > +{ > + int ret = 0; > + > + /* > + * To be potentially processing a kprobe fault and to be allowed > + * to call kprobe_running(), we have to be non-preemptible. > + */ > + if (kprobes_built_in() && !preemptible() && !user_mode(regs)) { > + if (kprobe_running() && kprobe_fault_handler(regs, trap)) > + ret = 1; > + } > + return ret; > +} Which skips everything if we're preemptible. Is that an equivalent change? If so can you please explain why in more detail. Also why not have it return bool? cheers