mm/userfaultfd: Introduce uffd_info struct for arguments

Introduce a helper function so that any updates to any memory type does
not require all memory types to use a new function definition.

Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>

diff --git a/include/linux/userfaultfd_k.h b/include/linux/userfaultfd_k.h
index 38aac8085c4b5950432426860f6e1c2862de8af6..ba61ff6eba00e11133d93629d02a88ece58fbef0 100644 (file)
--- a/include/linux/userfaultfd_k.h
+++ b/include/linux/userfaultfd_k.h
@@ -116,6 +116,25 @@ struct vm_uffd_ops {
                        unsigned long src_addr);
 };
 
+struct uffd_info {
+       unsigned long dst_addr;                 /* Target address */
+       unsigned long src_addr;                 /* Source address */
+       unsigned long len;                      /* Total length to copy */
+
+       struct vm_area_struct *dst_vma;         /* Target vma */
+       unsigned long increment;                /* Size of each operation */
+       bool wp;                                /* Operation is requesting write protection */
+       struct folio **foliop;                  /* folio pointer for retry */
+       const struct vm_uffd_ops *uffd_ops;     /* The vma uffd_ops pointer */
+};
+
+#define UFFD_STRUCT_INIT(__dst_addr, __src_addr, __len, __wp) {        \
+       .dst_addr = (__dst_addr),                                       \
+       .src_addr = (__src_addr),                                       \
+       .len = (__len),                                                 \
+       .wp = (__wp),                                                   \
+}
+
 #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))

diff --git a/mm/userfaultfd.c b/mm/userfaultfd.c
index 6fa840bdeee050f03793116d4ccf10376cfa04f6..931b428dd7ec286c81aab7ef9dd1101cfdf9c546 100644 (file)
--- a/mm/userfaultfd.c
+++ b/mm/userfaultfd.c
@@ -96,18 +96,21 @@ static struct vm_area_struct *uffd_lock_vma(struct mm_struct *mm,
        return vma;
 }
 
-static struct vm_area_struct *uffd_mfill_lock(struct mm_struct *dst_mm,
-                                             unsigned long dst_start,
-                                             unsigned long len)
+static int uffd_mfill_lock(struct mm_struct *dst_mm, struct uffd_info *us)
 {
        struct vm_area_struct *dst_vma;
 
-       dst_vma = uffd_lock_vma(dst_mm, dst_start);
-       if (IS_ERR(dst_vma) || validate_dst_vma(dst_vma, dst_start + len))
-               return dst_vma;
+       dst_vma = uffd_lock_vma(dst_mm, us->dst_addr);
+       if (IS_ERR(dst_vma))
+               return PTR_ERR(dst_vma);
+
+       if (validate_dst_vma(dst_vma, us->dst_addr + us->len)) {
+               us->dst_vma = dst_vma;
+               return 0;
+       }
 
        vma_end_read(dst_vma);
-       return ERR_PTR(-ENOENT);
+       return -ENOENT;
 }
 
 static void uffd_mfill_unlock(struct vm_area_struct *vma)
@@ -117,24 +120,24 @@ static void uffd_mfill_unlock(struct vm_area_struct *vma)
 
 #else
 
-static struct vm_area_struct *uffd_mfill_lock(struct mm_struct *dst_mm,
-                                             unsigned long dst_start,
-                                             unsigned long len)
+static int uffd_mfill_lock(struct mm_struct *dst_mm, struct uffd_info *us)
 {
        struct vm_area_struct *dst_vma;
 
        mmap_read_lock(dst_mm);
-       dst_vma = find_vma_and_prepare_anon(dst_mm, dst_start);
+       dst_vma = find_vma_and_prepare_anon(dst_mm, uf->dst_addr);
        if (IS_ERR(dst_vma))
                goto out_unlock;
 
-       if (validate_dst_vma(dst_vma, dst_start + len))
-               return dst_vma;
+       if (validate_dst_vma(dst_vma, uf->dst_addr, uf->len)) {
+               us->dst_vma = dst_vma;
+               return 0;
+       }
 
-       dst_vma = ERR_PTR(-ENOENT);
+       dst_vma = -ENOENT;
 out_unlock:
        mmap_read_unlock(dst_mm);
-       return dst_vma;
+       return PTR_ERR(dst_vma);
 }
 
 static void uffd_mfill_unlock(struct vm_area_struct *vma)
@@ -647,6 +650,8 @@ static __always_inline ssize_t mfill_atomic(struct userfaultfd_ctx *ctx,
        struct folio *folio;
        const struct vm_uffd_ops *uffd_ops;
        unsigned long increment;
+       struct uffd_info info = UFFD_STRUCT_INIT(dst_start, src_start, len,
+                                                flags & MFILL_ATOMIC_WP);
 
        /*
         * Sanitize the command parameters:
@@ -668,11 +673,11 @@ retry:
         * Make sure the vma is not shared, that the dst range is
         * both valid and fully within a single existing vma.
         */
-       dst_vma = uffd_mfill_lock(dst_mm, dst_start, len);
-       if (IS_ERR(dst_vma)) {
-               err = PTR_ERR(dst_vma);
+       err = uffd_mfill_lock(dst_mm, &info);
+       if (err)
                goto out;
-       }
+
+       dst_vma = info.dst_vma;
        uffd_ops = vma_get_uffd_ops(dst_vma);
        if (WARN_ON_ONCE(!uffd_ops->increment)) {
                increment = PAGE_SIZE;
@@ -690,6 +695,7 @@ retry:
            uffd_flags_mode_is(flags, MFILL_ATOMIC_CONTINUE))
                goto out_unlock;
 
+       info.increment = increment;
        while (src_addr < src_start + len) {
                VM_WARN_ON_ONCE(dst_addr >= dst_start + len);