ARM64: configs: tizen_bcm2711_defconfig: create tizen config from rpi os config

[platform/kernel/linux-rpi.git] / fs / userfaultfd.c

diff --git a/fs/userfaultfd.c b/fs/userfaultfd.c
index 003f0d3..b56e8e3 100644 (file)
--- a/fs/userfaultfd.c
+++ b/fs/userfaultfd.c
@@ -982,7 +982,7 @@ static int resolve_userfault_fork(struct userfaultfd_ctx *new,
        int fd;
 
        fd = anon_inode_getfd_secure("[userfaultfd]", &userfaultfd_fops, new,
-                       O_RDWR | (new->flags & UFFD_SHARED_FCNTL_FLAGS), inode);
+                       O_RDONLY | (new->flags & UFFD_SHARED_FCNTL_FLAGS), inode);
        if (fd < 0)
                return fd;
 
@@ -1827,9 +1827,15 @@ static int userfaultfd_writeprotect(struct userfaultfd_ctx *ctx,
        if (mode_wp && mode_dontwake)
                return -EINVAL;
 
-       ret = mwriteprotect_range(ctx->mm, uffdio_wp.range.start,
-                                 uffdio_wp.range.len, mode_wp,
-                                 &ctx->mmap_changing);
+       if (mmget_not_zero(ctx->mm)) {
+               ret = mwriteprotect_range(ctx->mm, uffdio_wp.range.start,
+                                         uffdio_wp.range.len, mode_wp,
+                                         &ctx->mmap_changing);
+               mmput(ctx->mm);
+       } else {
+               return -ESRCH;
+       }
+
        if (ret)
                return ret;
 
@@ -2091,7 +2097,7 @@ SYSCALL_DEFINE1(userfaultfd, int, flags)
        mmgrab(ctx->mm);
 
        fd = anon_inode_getfd_secure("[userfaultfd]", &userfaultfd_fops, ctx,
-                       O_RDWR | (flags & UFFD_SHARED_FCNTL_FLAGS), NULL);
+                       O_RDONLY | (flags & UFFD_SHARED_FCNTL_FLAGS), NULL);
        if (fd < 0) {
                mmdrop(ctx->mm);
                kmem_cache_free(userfaultfd_ctx_cachep, ctx);