signalfd: convert do_signalfd4() to FD_ADD()

Link: https://patch.msgid.link/20251123-work-fd-prepare-v4-14-b6efa1706cfd@kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>

diff --git a/fs/signalfd.c b/fs/signalfd.c
index d469782f97f4d3cb8f4f39ea05aa8571c980331b..d69eab584bc6d3d85455dd2830ff7a8ae0119e7a 100644 (file)
--- a/fs/signalfd.c
+++ b/fs/signalfd.c
@@ -250,8 +250,6 @@ static const struct file_operations signalfd_fops = {
 
 static int do_signalfd4(int ufd, sigset_t *mask, int flags)
 {
-       struct signalfd_ctx *ctx;
-
        /* Check the SFD_* constants for consistency.  */
        BUILD_BUG_ON(SFD_CLOEXEC != O_CLOEXEC);
        BUILD_BUG_ON(SFD_NONBLOCK != O_NONBLOCK);
@@ -263,7 +261,8 @@ static int do_signalfd4(int ufd, sigset_t *mask, int flags)
        signotset(mask);
 
        if (ufd == -1) {
-               struct file *file;
+               int fd;
+               struct signalfd_ctx *ctx __free(kfree) = NULL;
 
                ctx = kmalloc(sizeof(*ctx), GFP_KERNEL);
                if (!ctx)
@@ -271,22 +270,16 @@ static int do_signalfd4(int ufd, sigset_t *mask, int flags)
 
                ctx->sigmask = *mask;
 
-               ufd = get_unused_fd_flags(flags & O_CLOEXEC);
-               if (ufd < 0) {
-                       kfree(ctx);
-                       return ufd;
-               }
-
-               file = anon_inode_getfile_fmode("[signalfd]", &signalfd_fops,
-                                       ctx, O_RDWR | (flags & O_NONBLOCK),
-                                       FMODE_NOWAIT);
-               if (IS_ERR(file)) {
-                       put_unused_fd(ufd);
-                       kfree(ctx);
-                       return PTR_ERR(file);
-               }
-               fd_install(ufd, file);
+               fd = FD_ADD(flags & O_CLOEXEC,
+                           anon_inode_getfile_fmode(
+                                   "[signalfd]", &signalfd_fops, ctx,
+                                   O_RDWR | (flags & O_NONBLOCK), FMODE_NOWAIT));
+               if (fd >= 0)
+                       retain_and_null_ptr(ctx);
+               return fd;
        } else {
+               struct signalfd_ctx *ctx;
+
                CLASS(fd, f)(ufd);
                if (fd_empty(f))
                        return -EBADF;