On 09.09.25 11:56, Chunyan Zhang wrote:
Some platforms can customize the PTE uffd_wp bit and make it unavailable
even if the architecture allows providing the PTE resource.
This patch adds a macro API which allows architectures to define
their specific ones for checking if the PTE uffd_wp bit is available.
Signed-off-by: Chunyan Zhang <zhangchunyan@xxxxxxxxxxx>
---
fs/userfaultfd.c | 25 +++++++++--------
include/asm-generic/pgtable_uffd.h | 12 ++++++++
include/linux/mm_inline.h | 7 +++++
include/linux/userfaultfd_k.h | 44 +++++++++++++++++++-----------
mm/memory.c | 6 ++--
5 files changed, 65 insertions(+), 29 deletions(-)
diff --git a/fs/userfaultfd.c b/fs/userfaultfd.c
index 54c6cc7fe9c6..68e5006e5158 100644
--- a/fs/userfaultfd.c
+++ b/fs/userfaultfd.c
@@ -1270,9 +1270,10 @@ static int userfaultfd_register(struct userfaultfd_ctx *ctx,
if (uffdio_register.mode & UFFDIO_REGISTER_MODE_MISSING)
vm_flags |= VM_UFFD_MISSING;
if (uffdio_register.mode & UFFDIO_REGISTER_MODE_WP) {
-#ifndef CONFIG_HAVE_ARCH_USERFAULTFD_WP
- goto out;
-#endif
+ if (!IS_ENABLED(CONFIG_HAVE_ARCH_USERFAULTFD_WP) ||
+ !pte_uffd_wp_available())
+ goto out;
+
Same comment as for the other patch: make the
CONFIG_HAVE_ARCH_USERFAULTFD_WP part of the pte_uffd_wp_available()
check and better call it "pgtable_uffd_wp_" ... available/supported.
--
Cheers
David / dhildenb
