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authorAxel Rasmussen <axelrasmussen@google.com>2023-07-08 00:55:37 +0300
committerAndrew Morton <akpm@linux-foundation.org>2023-08-18 20:12:17 +0300
commit8a13897fb0daa8f56821f263f0c63661e1c6acae (patch)
tree955b1c31005b80034199141954f498f96970573f /mm
parent597425df4fecd272ca48f73feca7833433c16e12 (diff)
downloadlinux-8a13897fb0daa8f56821f263f0c63661e1c6acae.tar.xz
mm: userfaultfd: support UFFDIO_POISON for hugetlbfs
The behavior here is the same as it is for anon/shmem. This is done separately because hugetlb pte marker handling is a bit different. Link: https://lkml.kernel.org/r/20230707215540.2324998-6-axelrasmussen@google.com Signed-off-by: Axel Rasmussen <axelrasmussen@google.com> Acked-by: Peter Xu <peterx@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Brian Geffon <bgeffon@google.com> Cc: Christian Brauner <brauner@kernel.org> Cc: David Hildenbrand <david@redhat.com> Cc: Gaosheng Cui <cuigaosheng1@huawei.com> Cc: Huang, Ying <ying.huang@intel.com> Cc: Hugh Dickins <hughd@google.com> Cc: James Houghton <jthoughton@google.com> Cc: Jan Alexander Steffens (heftig) <heftig@archlinux.org> Cc: Jiaqi Yan <jiaqiyan@google.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Mike Rapoport (IBM) <rppt@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Nadav Amit <namit@vmware.com> Cc: Naoya Horiguchi <naoya.horiguchi@nec.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Shuah Khan <shuah@kernel.org> Cc: Suleiman Souhlal <suleiman@google.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: T.J. Alumbaugh <talumbau@google.com> Cc: Yu Zhao <yuzhao@google.com> Cc: ZhangPeng <zhangpeng362@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'mm')
-rw-r--r--mm/hugetlb.c19
-rw-r--r--mm/userfaultfd.c3
2 files changed, 20 insertions, 2 deletions
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index ffee2978dfed..7b076eb07a29 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -6262,6 +6262,25 @@ int hugetlb_mfill_atomic_pte(pte_t *dst_pte,
int writable;
bool folio_in_pagecache = false;
+ if (uffd_flags_mode_is(flags, MFILL_ATOMIC_POISON)) {
+ ptl = huge_pte_lock(h, dst_mm, dst_pte);
+
+ /* Don't overwrite any existing PTEs (even markers) */
+ if (!huge_pte_none(huge_ptep_get(dst_pte))) {
+ spin_unlock(ptl);
+ return -EEXIST;
+ }
+
+ _dst_pte = make_pte_marker(PTE_MARKER_POISONED);
+ set_huge_pte_at(dst_mm, dst_addr, dst_pte, _dst_pte);
+
+ /* No need to invalidate - it was non-present before */
+ update_mmu_cache(dst_vma, dst_addr, dst_pte);
+
+ spin_unlock(ptl);
+ return 0;
+ }
+
if (is_continue) {
ret = -EFAULT;
folio = filemap_lock_folio(mapping, idx);
diff --git a/mm/userfaultfd.c b/mm/userfaultfd.c
index dd167184575e..0fc69efa4f1f 100644
--- a/mm/userfaultfd.c
+++ b/mm/userfaultfd.c
@@ -377,8 +377,7 @@ static __always_inline ssize_t mfill_atomic_hugetlb(
* by THP. Since we can not reliably insert a zero page, this
* feature is not supported.
*/
- if (uffd_flags_mode_is(flags, MFILL_ATOMIC_ZEROPAGE) ||
- uffd_flags_mode_is(flags, MFILL_ATOMIC_POISON)) {
+ if (uffd_flags_mode_is(flags, MFILL_ATOMIC_ZEROPAGE)) {
mmap_read_unlock(dst_mm);
return -EINVAL;
}