Re: [RFC V3] mm: Generalize and rename notify_page_fault() as kprobe_page_fault()

Dave Hansen
2019-06-07T15:06:30Z

On 6/7/19 3:34 AM, Anshuman Khandual wrote:
> +static nokprobe_inline bool kprobe_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;
> +}

Nits: Other that taking the nice, readable, x86 one and globbing it onto
a single line, looks OK to me. It does seem a _bit_ silly to go to the
trouble of converting to 'bool' and then using 0/1 and an 'int'
internally instead of true/false and a bool, though. It's also not a
horrible thing to add a single line comment to this sucker to say:

/* returns true if kprobes handled the fault */

In any case, and even if you don't clean any of this up:

Reviewed-by: Dave Hansen <dave.hansen@linux.intel.com>