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

On Tue, 2019-06-11 at 10:44 +0530, Anshuman Khandual wrote:

On 06/10/2019 08:57 PM, Leonardo Bras wrote:

quoted

On Mon, 2019-06-10 at 08:09 +0530, Anshuman Khandual wrote:

quoted

quoted

quoted

+    /*
+     * 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))

don't need an 'if A if B', can do 'if A && B'

Which will make it a very lengthy condition check.

Well, is there any problem line-breaking the if condition?

if (A && B && C &&
    D && E )

Also, if it's used only to decide the return value, maybe would be fine
to do somethink like that:

return (A && B && C &&
        D && E ); 

Got it. But as Dave and Matthew had pointed out earlier, the current x86
implementation has better readability. Hence will probably stick with it.

Sure, I agree with them. It's way more readable.