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References: <20230330155707.3106228-1-peterx@redhat.com> <20230330160711.3106988-1-peterx@redhat.com>
In-Reply-To: <20230330160711.3106988-1-peterx@redhat.com>
From:   Axel Rasmussen <axelrasmussen@google.com>
Date:   Thu, 30 Mar 2023 14:08:50 -0700
Message-ID: <CAJHvVch1uY4JUtxLcKFe=LL3FgryrdqYrrcy20WXvbt7tdLhKw@mail.gmail.com>
Subject: Re: [PATCH 09/29] selftests/mm: Reuse pagemap_get_entry() in vm_util.h
To:     Peter Xu <peterx@redhat.com>
Cc:     linux-mm@kvack.org, linux-kernel@vger.kernel.org,
        David Hildenbrand <david@redhat.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        Andrea Arcangeli <aarcange@redhat.com>,
        Mike Kravetz <mike.kravetz@oracle.com>,
        Leonardo Bras Soares Passos <lsoaresp@redhat.com>,
        Mike Rapoport <rppt@linux.vnet.ibm.com>,
        Nadav Amit <nadav.amit@gmail.com>
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On Thu, Mar 30, 2023 at 9:07=E2=80=AFAM Peter Xu <peterx@redhat.com> wrote:
>
> Meanwhile drop pagemap_read_vaddr().
>
> Signed-off-by: Peter Xu <peterx@redhat.com>

Reviewed-by: Axel Rasmussen <axelrasmussen@google.com>

> ---
>  tools/testing/selftests/mm/userfaultfd.c | 31 +++++++-----------------
>  1 file changed, 9 insertions(+), 22 deletions(-)
>
> diff --git a/tools/testing/selftests/mm/userfaultfd.c b/tools/testing/sel=
ftests/mm/userfaultfd.c
> index 7e841f7e2884..795fbc4d84f8 100644
> --- a/tools/testing/selftests/mm/userfaultfd.c
> +++ b/tools/testing/selftests/mm/userfaultfd.c
> @@ -1399,19 +1399,6 @@ static int pagemap_open(void)
>         return fd;
>  }
>
> -static uint64_t pagemap_read_vaddr(int fd, void *vaddr)
> -{
> -       uint64_t value;
> -       int ret;
> -
> -       ret =3D pread(fd, &value, sizeof(uint64_t),
> -                   ((uint64_t)vaddr >> 12) * sizeof(uint64_t));
> -       if (ret !=3D sizeof(uint64_t))
> -               err("pread() on pagemap failed");
> -
> -       return value;
> -}
> -
>  /* This macro let __LINE__ works in err() */
>  #define  pagemap_check_wp(value, wp) do {                              \
>                 if (!!(value & PM_UFFD_WP) !=3D wp)                      =
 \
> @@ -1427,7 +1414,7 @@ static int pagemap_test_fork(bool present)
>         if (!child) {
>                 /* Open the pagemap fd of the child itself */
>                 fd =3D pagemap_open();
> -               value =3D pagemap_read_vaddr(fd, area_dst);
> +               value =3D pagemap_get_entry(fd, area_dst);
>                 /*
>                  * After fork() uffd-wp bit should be gone as long as we'=
re
>                  * without UFFD_FEATURE_EVENT_FORK
> @@ -1446,24 +1433,24 @@ static void userfaultfd_wp_unpopulated_test(int p=
agemap_fd)
>
>         /* Test applying pte marker to anon unpopulated */
>         wp_range(uffd, (uint64_t)area_dst, page_size, true);
> -       value =3D pagemap_read_vaddr(pagemap_fd, area_dst);
> +       value =3D pagemap_get_entry(pagemap_fd, area_dst);
>         pagemap_check_wp(value, true);
>
>         /* Test unprotect on anon pte marker */
>         wp_range(uffd, (uint64_t)area_dst, page_size, false);
> -       value =3D pagemap_read_vaddr(pagemap_fd, area_dst);
> +       value =3D pagemap_get_entry(pagemap_fd, area_dst);
>         pagemap_check_wp(value, false);
>
>         /* Test zap on anon marker */
>         wp_range(uffd, (uint64_t)area_dst, page_size, true);
>         if (madvise(area_dst, page_size, MADV_DONTNEED))
>                 err("madvise(MADV_DONTNEED) failed");
> -       value =3D pagemap_read_vaddr(pagemap_fd, area_dst);
> +       value =3D pagemap_get_entry(pagemap_fd, area_dst);
>         pagemap_check_wp(value, false);
>
>         /* Test fault in after marker removed */
>         *area_dst =3D 1;
> -       value =3D pagemap_read_vaddr(pagemap_fd, area_dst);
> +       value =3D pagemap_get_entry(pagemap_fd, area_dst);
>         pagemap_check_wp(value, false);
>         /* Drop it to make pte none again */
>         if (madvise(area_dst, page_size, MADV_DONTNEED))
> @@ -1522,7 +1509,7 @@ static void userfaultfd_pagemap_test(unsigned int t=
est_pgsize)
>         /* Touch the page */
>         *area_dst =3D 1;
>         wp_range(uffd, (uint64_t)area_dst, test_pgsize, true);
> -       value =3D pagemap_read_vaddr(pagemap_fd, area_dst);
> +       value =3D pagemap_get_entry(pagemap_fd, area_dst);
>         pagemap_check_wp(value, true);
>         /* Make sure uffd-wp bit dropped when fork */
>         if (pagemap_test_fork(true))
> @@ -1536,7 +1523,7 @@ static void userfaultfd_pagemap_test(unsigned int t=
est_pgsize)
>                 err("madvise(MADV_PAGEOUT) failed");
>
>         /* Uffd-wp should persist even swapped out */
> -       value =3D pagemap_read_vaddr(pagemap_fd, area_dst);
> +       value =3D pagemap_get_entry(pagemap_fd, area_dst);
>         pagemap_check_wp(value, true);
>         /* Make sure uffd-wp bit dropped when fork */
>         if (pagemap_test_fork(false))
> @@ -1544,12 +1531,12 @@ static void userfaultfd_pagemap_test(unsigned int=
 test_pgsize)
>
>         /* Unprotect; this tests swap pte modifications */
>         wp_range(uffd, (uint64_t)area_dst, page_size, false);
> -       value =3D pagemap_read_vaddr(pagemap_fd, area_dst);
> +       value =3D pagemap_get_entry(pagemap_fd, area_dst);
>         pagemap_check_wp(value, false);
>
>         /* Fault in the page from disk */
>         *area_dst =3D 2;
> -       value =3D pagemap_read_vaddr(pagemap_fd, area_dst);
> +       value =3D pagemap_get_entry(pagemap_fd, area_dst);
>         pagemap_check_wp(value, false);
>
>         close(pagemap_fd);
> --
> 2.39.1
>