Subject: [PATCH 16/39] convert __bpf_prog_get() to CLASS(fd, ...)

From: [email-masked]
Date: Tue, 30 Jul 2024 01:16:02 -0400

From: Al Viro <[email-masked]>

Irregularity here is fdput() not in the same scope as fdget();
just fold ____bpf_prog_get() into its (only) caller and that's
it...

Signed-off-by: Al Viro <[email-masked]>
---
 kernel/bpf/syscall.c | 32 +++++++++++---------------------
 1 file changed, 11 insertions(+), 21 deletions(-)

diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index 3093bf2cc266..c5b252c0faa8 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -2407,18 +2407,6 @@ int bpf_prog_new_fd(struct bpf_prog *prog)
 				O_RDWR | O_CLOEXEC);
 }
 
-static struct bpf_prog *____bpf_prog_get(struct fd f)
-{
-	if (!fd_file(f))
-		return ERR_PTR(-EBADF);
-	if (fd_file(f)->f_op != &bpf_prog_fops) {
-		fdput(f);
-		return ERR_PTR(-EINVAL);
-	}
-
-	return fd_file(f)->private_data;
-}
-
 void bpf_prog_add(struct bpf_prog *prog, int i)
 {
 	atomic64_add(i, &prog->aux->refcnt);
@@ -2474,20 +2462,22 @@ bool bpf_prog_get_ok(struct bpf_prog *prog,
 static struct bpf_prog *__bpf_prog_get(u32 ufd, enum bpf_prog_type *attach_type,
 				       bool attach_drv)
 {
-	struct fd f = fdget(ufd);
+	CLASS(fd, f)(ufd);
 	struct bpf_prog *prog;
 
-	prog = ____bpf_prog_get(f);
-	if (IS_ERR(prog))
+	if (fd_empty(f))
+		return ERR_PTR(-EBADF);
+	if (fd_file(f)->f_op != &bpf_prog_fops)
+		return ERR_PTR(-EINVAL);
+
+	prog = fd_file(f)->private_data;
+	if (IS_ERR(prog))	// can that actually happen?
 		return prog;
-	if (!bpf_prog_get_ok(prog, attach_type, attach_drv)) {
-		prog = ERR_PTR(-EINVAL);
-		goto out;
-	}
+
+	if (!bpf_prog_get_ok(prog, attach_type, attach_drv))
+		return ERR_PTR(-EINVAL);
 
 	bpf_prog_inc(prog);
-out:
-	fdput(f);
 	return prog;
 }
 
-- 
2.39.2