From 10ebd8556b7990499c896a550e3d416b444211e6 Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Fri, 10 May 2024 02:23:07 +0000
Subject: [PATCH] add led
---
kernel/include/linux/userfaultfd_k.h | 98 ++++++++++++++++++++++++++++++++++++++++++++++++-
1 files changed, 96 insertions(+), 2 deletions(-)
diff --git a/kernel/include/linux/userfaultfd_k.h b/kernel/include/linux/userfaultfd_k.h
index 37c9eba..331d2cc 100644
--- a/kernel/include/linux/userfaultfd_k.h
+++ b/kernel/include/linux/userfaultfd_k.h
@@ -14,6 +14,11 @@
#include <linux/userfaultfd.h> /* linux/include/uapi/linux/userfaultfd.h */
#include <linux/fcntl.h>
+#include <linux/mm.h>
+#include <asm-generic/pgtable_uffd.h>
+
+/* The set of all possible UFFD-related VM flags. */
+#define __VM_UFFD_FLAGS (VM_UFFD_MISSING | VM_UFFD_WP | VM_UFFD_MINOR)
/*
* CAREFUL: Check include/uapi/asm-generic/fcntl.h when defining
@@ -28,15 +33,43 @@
#define UFFD_SHARED_FCNTL_FLAGS (O_CLOEXEC | O_NONBLOCK)
#define UFFD_FLAGS_SET (EFD_SHARED_FCNTL_FLAGS)
+extern int sysctl_unprivileged_userfaultfd;
+
extern vm_fault_t handle_userfault(struct vm_fault *vmf, unsigned long reason);
+
+/*
+ * The mode of operation for __mcopy_atomic and its helpers.
+ *
+ * This is almost an implementation detail (mcopy_atomic below doesn't take this
+ * as a parameter), but it's exposed here because memory-kind-specific
+ * implementations (e.g. hugetlbfs) need to know the mode of operation.
+ */
+enum mcopy_atomic_mode {
+ /* A normal copy_from_user into the destination range. */
+ MCOPY_ATOMIC_NORMAL,
+ /* Don't copy; map the destination range to the zero page. */
+ MCOPY_ATOMIC_ZEROPAGE,
+ /* Just install pte(s) with the existing page(s) in the page cache. */
+ MCOPY_ATOMIC_CONTINUE,
+};
+
+extern int mfill_atomic_install_pte(struct mm_struct *dst_mm, pmd_t *dst_pmd,
+ struct vm_area_struct *dst_vma,
+ unsigned long dst_addr, struct page *page,
+ bool newly_allocated, bool wp_copy);
extern ssize_t mcopy_atomic(struct mm_struct *dst_mm, unsigned long dst_start,
unsigned long src_start, unsigned long len,
- bool *mmap_changing);
+ bool *mmap_changing, __u64 mode);
extern ssize_t mfill_zeropage(struct mm_struct *dst_mm,
unsigned long dst_start,
unsigned long len,
bool *mmap_changing);
+extern ssize_t mcopy_continue(struct mm_struct *dst_mm, unsigned long dst_start,
+ unsigned long len, bool *mmap_changing);
+extern int mwriteprotect_range(struct mm_struct *dst_mm,
+ unsigned long start, unsigned long len,
+ bool enable_wp, bool *mmap_changing);
/* mm helpers */
static inline bool is_mergeable_vm_userfaultfd_ctx(struct vm_area_struct *vma,
@@ -45,14 +78,52 @@
return vma->vm_userfaultfd_ctx.ctx == vm_ctx.ctx;
}
+/*
+ * Never enable huge pmd sharing on some uffd registered vmas:
+ *
+ * - VM_UFFD_WP VMAs, because write protect information is per pgtable entry.
+ *
+ * - VM_UFFD_MINOR VMAs, because otherwise we would never get minor faults for
+ * VMAs which share huge pmds. (If you have two mappings to the same
+ * underlying pages, and fault in the non-UFFD-registered one with a write,
+ * with huge pmd sharing this would *also* setup the second UFFD-registered
+ * mapping, and we'd not get minor faults.)
+ */
+static inline bool uffd_disable_huge_pmd_share(struct vm_area_struct *vma)
+{
+ return vma->vm_flags & (VM_UFFD_WP | VM_UFFD_MINOR);
+}
+
static inline bool userfaultfd_missing(struct vm_area_struct *vma)
{
return vma->vm_flags & VM_UFFD_MISSING;
}
+static inline bool userfaultfd_wp(struct vm_area_struct *vma)
+{
+ return vma->vm_flags & VM_UFFD_WP;
+}
+
+static inline bool userfaultfd_minor(struct vm_area_struct *vma)
+{
+ return vma->vm_flags & VM_UFFD_MINOR;
+}
+
+static inline bool userfaultfd_pte_wp(struct vm_area_struct *vma,
+ pte_t pte)
+{
+ return userfaultfd_wp(vma) && pte_uffd_wp(pte);
+}
+
+static inline bool userfaultfd_huge_pmd_wp(struct vm_area_struct *vma,
+ pmd_t pmd)
+{
+ return userfaultfd_wp(vma) && pmd_uffd_wp(pmd);
+}
+
static inline bool userfaultfd_armed(struct vm_area_struct *vma)
{
- return vma->vm_flags & (VM_UFFD_MISSING | VM_UFFD_WP);
+ return vma->vm_flags & __VM_UFFD_FLAGS;
}
extern int dup_userfaultfd(struct vm_area_struct *, struct list_head *);
@@ -94,6 +165,29 @@
return false;
}
+static inline bool userfaultfd_wp(struct vm_area_struct *vma)
+{
+ return false;
+}
+
+static inline bool userfaultfd_minor(struct vm_area_struct *vma)
+{
+ return false;
+}
+
+static inline bool userfaultfd_pte_wp(struct vm_area_struct *vma,
+ pte_t pte)
+{
+ return false;
+}
+
+static inline bool userfaultfd_huge_pmd_wp(struct vm_area_struct *vma,
+ pmd_t pmd)
+{
+ return false;
+}
+
+
static inline bool userfaultfd_armed(struct vm_area_struct *vma)
{
return false;
--
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