eventfs: Use ERR_CAST() in eventfs_create_events_dir()

When building with clang and CONFIG_RANDSTRUCT_FULL=y, there is an error
due to a cast in eventfs_create_events_dir():

  fs/tracefs/event_inode.c:734:10: error: casting from randomized structure pointer type 'struct dentry *' to 'struct eventfs_inode *'
    734 |                 return (struct eventfs_inode *)dentry;
        |                        ^
  1 error generated.

Use the ERR_CAST() function to resolve the error, as it was designed for
this exact situation (casting an error pointer to another type).

Link: https://lore.kernel.org/linux-trace-kernel/20231018-ftrace-fix-clang-randstruct-v1-1-338cb214abfb@kernel.org
Closes: https://github.com/ClangBuiltLinux/linux/issues/1947
Fixes: 5790b1fb3d67 ("eventfs: Remove eventfs_file and just use eventfs_inode")
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>

diff --git a/fs/tracefs/event_inode.c b/fs/tracefs/event_inode.c
index 1ccd100bc5659c4c075c2870b23b4b38246ea0da..9f19b660895488c459a4e4b28524d714cb26e4f3 100644 (file)
--- a/fs/tracefs/event_inode.c
+++ b/fs/tracefs/event_inode.c
@@ -731,7 +731,7 @@ struct eventfs_inode *eventfs_create_events_dir(const char *name, struct dentry
                return NULL;
 
        if (IS_ERR(dentry))
-               return (struct eventfs_inode *)dentry;
+               return ERR_CAST(dentry);
 
        ei = kzalloc(sizeof(*ei), GFP_KERNEL);
        if (!ei)