Adding upstream version 6.6.15.upstream/6.6.15

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 364 insertions, 0 deletions

diff --git a/include/linux/userfaultfd_k.h b/include/linux/userfaultfd_k.h
new file mode 100644
index 000000000..ac8c68540
--- /dev/null
+++ b/include/linux/userfaultfd_k.h
@@ -0,0 +1,364 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ *  include/linux/userfaultfd_k.h
+ *
+ *  Copyright (C) 2015  Red Hat, Inc.
+ *
+ */
+
+#ifndef _LINUX_USERFAULTFD_K_H
+#define _LINUX_USERFAULTFD_K_H
+
+#ifdef CONFIG_USERFAULTFD
+
+#include <linux/userfaultfd.h> /* linux/include/uapi/linux/userfaultfd.h */
+
+#include <linux/fcntl.h>
+#include <linux/mm.h>
+#include <linux/swap.h>
+#include <linux/swapops.h>
+#include <asm-generic/pgtable_uffd.h>
+#include <linux/hugetlb_inline.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
+ * new flags, since they might collide with O_* ones. We want
+ * to re-use O_* flags that couldn't possibly have a meaning
+ * from userfaultfd, in order to leave a free define-space for
+ * shared O_* flags.
+ */
+#define UFFD_CLOEXEC O_CLOEXEC
+#define UFFD_NONBLOCK O_NONBLOCK
+
+#define UFFD_SHARED_FCNTL_FLAGS (O_CLOEXEC | O_NONBLOCK)
+#define UFFD_FLAGS_SET (EFD_SHARED_FCNTL_FLAGS)
+
+extern vm_fault_t handle_userfault(struct vm_fault *vmf, unsigned long reason);
+
+/* A combined operation mode + behavior flags. */
+typedef unsigned int __bitwise uffd_flags_t;
+
+/* Mutually exclusive modes of operation. */
+enum mfill_atomic_mode {
+	MFILL_ATOMIC_COPY,
+	MFILL_ATOMIC_ZEROPAGE,
+	MFILL_ATOMIC_CONTINUE,
+	MFILL_ATOMIC_POISON,
+	NR_MFILL_ATOMIC_MODES,
+};
+
+#define MFILL_ATOMIC_MODE_BITS (const_ilog2(NR_MFILL_ATOMIC_MODES - 1) + 1)
+#define MFILL_ATOMIC_BIT(nr) BIT(MFILL_ATOMIC_MODE_BITS + (nr))
+#define MFILL_ATOMIC_FLAG(nr) ((__force uffd_flags_t) MFILL_ATOMIC_BIT(nr))
+#define MFILL_ATOMIC_MODE_MASK ((__force uffd_flags_t) (MFILL_ATOMIC_BIT(0) - 1))
+
+static inline bool uffd_flags_mode_is(uffd_flags_t flags, enum mfill_atomic_mode expected)
+{
+	return (flags & MFILL_ATOMIC_MODE_MASK) == ((__force uffd_flags_t) expected);
+}
+
+static inline uffd_flags_t uffd_flags_set_mode(uffd_flags_t flags, enum mfill_atomic_mode mode)
+{
+	flags &= ~MFILL_ATOMIC_MODE_MASK;
+	return flags | ((__force uffd_flags_t) mode);
+}
+
+/* Flags controlling behavior. These behavior changes are mode-independent. */
+#define MFILL_ATOMIC_WP MFILL_ATOMIC_FLAG(0)
+
+extern int mfill_atomic_install_pte(pmd_t *dst_pmd,
+				    struct vm_area_struct *dst_vma,
+				    unsigned long dst_addr, struct page *page,
+				    bool newly_allocated, uffd_flags_t flags);
+
+extern ssize_t mfill_atomic_copy(struct mm_struct *dst_mm, unsigned long dst_start,
+				 unsigned long src_start, unsigned long len,
+				 atomic_t *mmap_changing, uffd_flags_t flags);
+extern ssize_t mfill_atomic_zeropage(struct mm_struct *dst_mm,
+				     unsigned long dst_start,
+				     unsigned long len,
+				     atomic_t *mmap_changing);
+extern ssize_t mfill_atomic_continue(struct mm_struct *dst_mm, unsigned long dst_start,
+				     unsigned long len, atomic_t *mmap_changing,
+				     uffd_flags_t flags);
+extern ssize_t mfill_atomic_poison(struct mm_struct *dst_mm, unsigned long start,
+				   unsigned long len, atomic_t *mmap_changing,
+				   uffd_flags_t flags);
+extern int mwriteprotect_range(struct mm_struct *dst_mm,
+			       unsigned long start, unsigned long len,
+			       bool enable_wp, atomic_t *mmap_changing);
+extern long uffd_wp_range(struct vm_area_struct *vma,
+			  unsigned long start, unsigned long len, bool enable_wp);
+
+/* mm helpers */
+static inline bool is_mergeable_vm_userfaultfd_ctx(struct vm_area_struct *vma,
+					struct vm_userfaultfd_ctx vm_ctx)
+{
+	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);
+}
+
+/*
+ * Don't do fault around for either WP or MINOR registered uffd range.  For
+ * MINOR registered range, fault around will be a total disaster and ptes can
+ * be installed without notifications; for WP it should mostly be fine as long
+ * as the fault around checks for pte_none() before the installation, however
+ * to be super safe we just forbid it.
+ */
+static inline bool uffd_disable_fault_around(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_FLAGS;
+}
+
+static inline bool vma_can_userfault(struct vm_area_struct *vma,
+				     unsigned long vm_flags)
+{
+	if ((vm_flags & VM_UFFD_MINOR) &&
+	    (!is_vm_hugetlb_page(vma) && !vma_is_shmem(vma)))
+		return false;
+#ifndef CONFIG_PTE_MARKER_UFFD_WP
+	/*
+	 * If user requested uffd-wp but not enabled pte markers for
+	 * uffd-wp, then shmem & hugetlbfs are not supported but only
+	 * anonymous.
+	 */
+	if ((vm_flags & VM_UFFD_WP) && !vma_is_anonymous(vma))
+		return false;
+#endif
+	return vma_is_anonymous(vma) || is_vm_hugetlb_page(vma) ||
+	    vma_is_shmem(vma);
+}
+
+extern int dup_userfaultfd(struct vm_area_struct *, struct list_head *);
+extern void dup_userfaultfd_complete(struct list_head *);
+
+extern void mremap_userfaultfd_prep(struct vm_area_struct *,
+				    struct vm_userfaultfd_ctx *);
+extern void mremap_userfaultfd_complete(struct vm_userfaultfd_ctx *,
+					unsigned long from, unsigned long to,
+					unsigned long len);
+
+extern bool userfaultfd_remove(struct vm_area_struct *vma,
+			       unsigned long start,
+			       unsigned long end);
+
+extern int userfaultfd_unmap_prep(struct vm_area_struct *vma,
+		unsigned long start, unsigned long end, struct list_head *uf);
+extern void userfaultfd_unmap_complete(struct mm_struct *mm,
+				       struct list_head *uf);
+extern bool userfaultfd_wp_unpopulated(struct vm_area_struct *vma);
+
+#else /* CONFIG_USERFAULTFD */
+
+/* mm helpers */
+static inline vm_fault_t handle_userfault(struct vm_fault *vmf,
+				unsigned long reason)
+{
+	return VM_FAULT_SIGBUS;
+}
+
+static inline bool is_mergeable_vm_userfaultfd_ctx(struct vm_area_struct *vma,
+					struct vm_userfaultfd_ctx vm_ctx)
+{
+	return true;
+}
+
+static inline bool userfaultfd_missing(struct vm_area_struct *vma)
+{
+	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;
+}
+
+static inline int dup_userfaultfd(struct vm_area_struct *vma,
+				  struct list_head *l)
+{
+	return 0;
+}
+
+static inline void dup_userfaultfd_complete(struct list_head *l)
+{
+}
+
+static inline void mremap_userfaultfd_prep(struct vm_area_struct *vma,
+					   struct vm_userfaultfd_ctx *ctx)
+{
+}
+
+static inline void mremap_userfaultfd_complete(struct vm_userfaultfd_ctx *ctx,
+					       unsigned long from,
+					       unsigned long to,
+					       unsigned long len)
+{
+}
+
+static inline bool userfaultfd_remove(struct vm_area_struct *vma,
+				      unsigned long start,
+				      unsigned long end)
+{
+	return true;
+}
+
+static inline int userfaultfd_unmap_prep(struct vm_area_struct *vma,
+					 unsigned long start, unsigned long end,
+					 struct list_head *uf)
+{
+	return 0;
+}
+
+static inline void userfaultfd_unmap_complete(struct mm_struct *mm,
+					      struct list_head *uf)
+{
+}
+
+static inline bool uffd_disable_fault_around(struct vm_area_struct *vma)
+{
+	return false;
+}
+
+static inline bool userfaultfd_wp_unpopulated(struct vm_area_struct *vma)
+{
+	return false;
+}
+
+#endif /* CONFIG_USERFAULTFD */
+
+static inline bool userfaultfd_wp_use_markers(struct vm_area_struct *vma)
+{
+	/* Only wr-protect mode uses pte markers */
+	if (!userfaultfd_wp(vma))
+		return false;
+
+	/* File-based uffd-wp always need markers */
+	if (!vma_is_anonymous(vma))
+		return true;
+
+	/*
+	 * Anonymous uffd-wp only needs the markers if WP_UNPOPULATED
+	 * enabled (to apply markers on zero pages).
+	 */
+	return userfaultfd_wp_unpopulated(vma);
+}
+
+static inline bool pte_marker_entry_uffd_wp(swp_entry_t entry)
+{
+#ifdef CONFIG_PTE_MARKER_UFFD_WP
+	return is_pte_marker_entry(entry) &&
+	    (pte_marker_get(entry) & PTE_MARKER_UFFD_WP);
+#else
+	return false;
+#endif
+}
+
+static inline bool pte_marker_uffd_wp(pte_t pte)
+{
+#ifdef CONFIG_PTE_MARKER_UFFD_WP
+	swp_entry_t entry;
+
+	if (!is_swap_pte(pte))
+		return false;
+
+	entry = pte_to_swp_entry(pte);
+
+	return pte_marker_entry_uffd_wp(entry);
+#else
+	return false;
+#endif
+}
+
+/*
+ * Returns true if this is a swap pte and was uffd-wp wr-protected in either
+ * forms (pte marker or a normal swap pte), false otherwise.
+ */
+static inline bool pte_swp_uffd_wp_any(pte_t pte)
+{
+#ifdef CONFIG_PTE_MARKER_UFFD_WP
+	if (!is_swap_pte(pte))
+		return false;
+
+	if (pte_swp_uffd_wp(pte))
+		return true;
+
+	if (pte_marker_uffd_wp(pte))
+		return true;
+#endif
+	return false;
+}
+
+#endif /* _LINUX_USERFAULTFD_K_H */