[tip:x86/cache] x86/intel_rdt: Propagate error in rdt_mount() properly

[tip-bot for Shaohua Li <tipbot@zytor.com>]

Commit-ID:  7bff0af51012500718971f9cc3485f67252353eb
Gitweb:     http://git.kernel.org/tip/7bff0af51012500718971f9cc3485f67252353eb
Author:     Shaohua Li <shli@fb.com>
AuthorDate: Thu, 3 Nov 2016 14:09:05 -0700
Committer:  Thomas Gleixner <tglx@linutronix.de>
CommitDate: Mon, 7 Nov 2016 12:20:52 +0100

x86/intel_rdt: Propagate error in rdt_mount() properly

gcc complains:
"warning: ‘dentry’ may be used uninitialized in this function"

The error exit path in rdt_mount(), which deals with a failure in
rdtgroup_create_info_dir(), does not set the error code in dentry and
returns the uninitialized dentry value.

Add the missing error propagation.

[tglx: Massaged changelog ]
Fixes: 4e978d06dedb ("x86/intel_rdt: Add "info" files to resctrl file system")
Signed-off-by: Shaohua Li <shli@fb.com>
Cc: fenghua.yu@intel.com
Cc: tony.luck@intel.com
Link: http://lkml.kernel.org/r/a56a556f6768dc12cadbf97f49e000189056f90e.1478207143.git.shli@fb.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

---
 arch/x86/kernel/cpu/intel_rdt_rdtgroup.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c b/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c
index a90ad22..e66c7a5 100644
--- a/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c
+++ b/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c
@@ -691,8 +691,10 @@ static struct dentry *rdt_mount(struct file_system_type *fs_type,
 	closid_init();
 
 	ret = rdtgroup_create_info_dir(rdtgroup_default.kn);
-	if (ret)
+	if (ret) {
+		dentry = ERR_PTR(ret);
 		goto out_cdp;
+	}
 
 	dentry = kernfs_mount(fs_type, flags, rdt_root,
 			      RDTGROUP_SUPER_MAGIC, NULL);