Re: [RFC PATCH v2 1/2] mm/mremap: Fix uprobe anon page be overwritten when expanding vma during mremap

[Oleg Nesterov <oleg@redhat.com>]

Not that this is really important, but the test-case looks broken,

On 05/27, Pu Lehui wrote:
>
> #define _GNU_SOURCE
> #include <fcntl.h>
> #include <unistd.h>
> #include <syscall.h>
> #include <sys/mman.h>
> #include <linux/perf_event.h>
> 
> int main(int argc, char *argv[])
> {
>     int fd = open(FNAME, O_RDWR|O_CREAT, 0600);

FNAME is not defined

>     struct perf_event_attr attr = {
>         .type = 9,

Cough ;) Yes I too used perf_event_attr.type == 9 when I wrote another
test-case. Because I am lazy and this is what I see in
/sys/bus/event_source/devices/uprobe/type on my machine.

But me should not assume that perf_pmu_register(&perf_uprobe) -> idr_alloc()
will return 9.

>     write(fd, "x", 1);

looks unnecessary.

Oleg.