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From:   Andy Shevchenko <andriy.shevchenko@linux.intel.com>
To:     Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
        linux-nvdimm@lists.01.org, linux-kernel@vger.kernel.org
Cc:     Dan Williams <dan.j.williams@intel.com>,
        Vishal Verma <vishal.l.verma@intel.com>,
        Dave Jiang <dave.jiang@intel.com>,
        Ira Weiny <ira.weiny@intel.com>
Subject: [PATCH v1 1/1] libnvdimm: Don't use GUID APIs against raw buffer
Date:   Thu, 15 Apr 2021 17:37:54 +0300
Message-Id: <20210415143754.16553-1-andriy.shevchenko@linux.intel.com>
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Strictly speaking the comparison between guid_t and raw buffer
is not correct. Return to plain memcmp() since the data structures
haven't changed to use uuid_t / guid_t the current state of affairs
is inconsistent. Either it should be changed altogether or left
as is.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
---
 drivers/nvdimm/btt_devs.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/nvdimm/btt_devs.c b/drivers/nvdimm/btt_devs.c
index 05feb97e11ce..82bcd2e86a18 100644
--- a/drivers/nvdimm/btt_devs.c
+++ b/drivers/nvdimm/btt_devs.c
@@ -244,13 +244,14 @@ struct device *nd_btt_create(struct nd_region *nd_region)
  */
 bool nd_btt_arena_is_valid(struct nd_btt *nd_btt, struct btt_sb *super)
 {
+	static const u8 null_uuid[16];
 	const u8 *parent_uuid = nd_dev_to_uuid(&nd_btt->ndns->dev);
 	u64 checksum;
 
 	if (memcmp(super->signature, BTT_SIG, BTT_SIG_LEN) != 0)
 		return false;
 
-	if (!guid_is_null((guid_t *)&super->parent_uuid))
+	if (memcmp(super->parent_uuid, null_uuid, 16) != 0)
 		if (memcmp(super->parent_uuid, parent_uuid, 16) != 0)
 			return false;
 
-- 
2.30.2