Fix nvme initiator handling when not enabled.

[karo-tx-linux.git] / fs / userfaultfd.c

diff --git a/fs/userfaultfd.c b/fs/userfaultfd.c
index 668bbbd2e04dc8379d5b43c1aea723941312a848..1d227b0fcf49ff26b40bdd726b3839fb8f353f35 100644 (file)
--- a/fs/userfaultfd.c
+++ b/fs/userfaultfd.c
@@ -138,8 +138,6 @@ out:
  * userfaultfd_ctx_get - Acquires a reference to the internal userfaultfd
  * context.
  * @ctx: [in] Pointer to the userfaultfd context.
- *
- * Returns: In case of success, returns not zero.
  */
 static void userfaultfd_ctx_get(struct userfaultfd_ctx *ctx)
 {
@@ -267,6 +265,7 @@ static inline bool userfaultfd_must_wait(struct userfaultfd_ctx *ctx,
 {
        struct mm_struct *mm = ctx->mm;
        pgd_t *pgd;
+       p4d_t *p4d;
        pud_t *pud;
        pmd_t *pmd, _pmd;
        pte_t *pte;
@@ -277,7 +276,10 @@ static inline bool userfaultfd_must_wait(struct userfaultfd_ctx *ctx,
        pgd = pgd_offset(mm, address);
        if (!pgd_present(*pgd))
                goto out;
-       pud = pud_offset(pgd, address);
+       p4d = p4d_offset(pgd, address);
+       if (!p4d_present(*p4d))
+               goto out;
+       pud = pud_offset(p4d, address);
        if (!pud_present(*pud))
                goto out;
        pmd = pmd_offset(pud, address);
@@ -527,16 +529,12 @@ out:
        return ret;
 }
 
-static int userfaultfd_event_wait_completion(struct userfaultfd_ctx *ctx,
-                                            struct userfaultfd_wait_queue *ewq)
+static void userfaultfd_event_wait_completion(struct userfaultfd_ctx *ctx,
+                                             struct userfaultfd_wait_queue *ewq)
 {
-       int ret;
-
-       ret = -1;
        if (WARN_ON_ONCE(current->flags & PF_EXITING))
                goto out;
 
-       ret = 0;
        ewq->ctx = ctx;
        init_waitqueue_entry(&ewq->wq, current);
 
@@ -552,8 +550,16 @@ static int userfaultfd_event_wait_completion(struct userfaultfd_ctx *ctx,
                        break;
                if (ACCESS_ONCE(ctx->released) ||
                    fatal_signal_pending(current)) {
-                       ret = -1;
                        __remove_wait_queue(&ctx->event_wqh, &ewq->wq);
+                       if (ewq->msg.event == UFFD_EVENT_FORK) {
+                               struct userfaultfd_ctx *new;
+
+                               new = (struct userfaultfd_ctx *)
+                                       (unsigned long)
+                                       ewq->msg.arg.reserved.reserved1;
+
+                               userfaultfd_ctx_put(new);
+                       }
                        break;
                }
 
@@ -573,7 +579,6 @@ static int userfaultfd_event_wait_completion(struct userfaultfd_ctx *ctx,
         */
 out:
        userfaultfd_ctx_put(ctx);
-       return ret;
 }
 
 static void userfaultfd_event_complete(struct userfaultfd_ctx *ctx,
@@ -631,7 +636,7 @@ int dup_userfaultfd(struct vm_area_struct *vma, struct list_head *fcs)
        return 0;
 }
 
-static int dup_fctx(struct userfaultfd_fork_ctx *fctx)
+static void dup_fctx(struct userfaultfd_fork_ctx *fctx)
 {
        struct userfaultfd_ctx *ctx = fctx->orig;
        struct userfaultfd_wait_queue ewq;
@@ -641,17 +646,15 @@ static int dup_fctx(struct userfaultfd_fork_ctx *fctx)
        ewq.msg.event = UFFD_EVENT_FORK;
        ewq.msg.arg.reserved.reserved1 = (unsigned long)fctx->new;
 
-       return userfaultfd_event_wait_completion(ctx, &ewq);
+       userfaultfd_event_wait_completion(ctx, &ewq);
 }
 
 void dup_userfaultfd_complete(struct list_head *fcs)
 {
-       int ret = 0;
        struct userfaultfd_fork_ctx *fctx, *n;
 
        list_for_each_entry_safe(fctx, n, fcs, list) {
-               if (!ret)
-                       ret = dup_fctx(fctx);
+               dup_fctx(fctx);
                list_del(&fctx->list);
                kfree(fctx);
        }
@@ -694,8 +697,7 @@ void mremap_userfaultfd_complete(struct vm_userfaultfd_ctx *vm_ctx,
        userfaultfd_event_wait_completion(ctx, &ewq);
 }
 
-void userfaultfd_remove(struct vm_area_struct *vma,
-                       struct vm_area_struct **prev,
+bool userfaultfd_remove(struct vm_area_struct *vma,
                        unsigned long start, unsigned long end)
 {
        struct mm_struct *mm = vma->vm_mm;
@@ -704,13 +706,11 @@ void userfaultfd_remove(struct vm_area_struct *vma,
 
        ctx = vma->vm_userfaultfd_ctx.ctx;
        if (!ctx || !(ctx->features & UFFD_FEATURE_EVENT_REMOVE))
-               return;
+               return true;
 
        userfaultfd_ctx_get(ctx);
        up_read(&mm->mmap_sem);
 
-       *prev = NULL; /* We wait for ACK w/o the mmap semaphore */
-
        msg_init(&ewq.msg);
 
        ewq.msg.event = UFFD_EVENT_REMOVE;
@@ -719,7 +719,7 @@ void userfaultfd_remove(struct vm_area_struct *vma,
 
        userfaultfd_event_wait_completion(ctx, &ewq);
 
-       down_read(&mm->mmap_sem);
+       return false;
 }
 
 static bool has_unmap_ctx(struct userfaultfd_ctx *ctx, struct list_head *unmaps,