[PATCH 05/13] selftests/bpf: handle d_real_data_inode() errors in bpf_testmod

[Christian Brauner <brauner@kernel.org>]

d_real() is about to be able to fail for D_REAL_DATA. So switch
testmod_register_uprobe() from d_real_inode() to d_real_data_inode()
and drop the path again if the data of /proc/self/exe can't be
resolved.

That's hard to hit in practice because exec opened the file already but
it is the only modular user and d_real_inode() is going away.

Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
---
 tools/testing/selftests/bpf/test_kmods/bpf_testmod.c | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/tools/testing/selftests/bpf/test_kmods/bpf_testmod.c b/tools/testing/selftests/bpf/test_kmods/bpf_testmod.c
index 76fbe64755ef9..9d065a800f655 100644
--- a/tools/testing/selftests/bpf/test_kmods/bpf_testmod.c
+++ b/tools/testing/selftests/bpf/test_kmods/bpf_testmod.c
@@ -948,6 +948,7 @@ static struct testmod_uprobe uprobe = {
 
 static __always_inline int testmod_register_uprobe(loff_t offset)
 {
+	struct inode *inode;
 	int err = -EBUSY;
 
 	if (uprobe.uprobe)
@@ -962,8 +963,14 @@ static __always_inline int testmod_register_uprobe(loff_t offset)
 	if (err)
 		goto out;
 
-	uprobe.uprobe = uprobe_register(d_real_inode(uprobe.path.dentry),
-					offset, 0, &uprobe.consumer);
+	inode = d_real_data_inode(uprobe.path.dentry);
+	if (IS_ERR(inode)) {
+		err = PTR_ERR(inode);
+		path_put(&uprobe.path);
+		goto out;
+	}
+
+	uprobe.uprobe = uprobe_register(inode, offset, 0, &uprobe.consumer);
 	if (IS_ERR(uprobe.uprobe)) {
 		err = PTR_ERR(uprobe.uprobe);
 		path_put(&uprobe.path);

-- 
2.53.0