Re: [RFC V2] mm: Generalize notify_page_fault()

Anshuman Khandual
2019-06-04T08:12:06Z

On 06/04/2019 12:24 PM, Peter Zijlstra wrote:
> On Tue, Jun 04, 2019 at 12:04:06PM +0530, Anshuman Khandual wrote:
>> diff --git a/mm/memory.c b/mm/memory.c
>> index ddf20bd..b6bae8f 100644
>> --- a/mm/memory.c
>> +++ b/mm/memory.c
>> @@ -52,6 +52,7 @@
>> #include <linux/pagemap.h>
>> #include <linux/memremap.h>
>> #include <linux/ksm.h>
>> +#include <linux/kprobes.h>
>> #include <linux/rmap.h>
>> #include <linux/export.h>
>> #include <linux/delayacct.h>
>> @@ -141,6 +142,21 @@ static int __init init_zero_pfn(void)
>> core_initcall(init_zero_pfn);
>>
>>
>> +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;
>> +}
>
> That thing should be called kprobe_page_fault() or something,
> notify_page_fault() is a horribly crap name for this function.

Agreed. kprobe_page_fault() sounds good.