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Date:   Tue, 30 May 2023 15:30:20 -0600
From:   "Gustavo A. R. Silva" <gustavoars@kernel.org>
To:     James Smart <james.smart@broadcom.com>,
        Dick Kennedy <dick.kennedy@broadcom.com>,
        "James E.J. Bottomley" <jejb@linux.ibm.com>,
        "Martin K. Petersen" <martin.petersen@oracle.com>
Cc:     linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org,
        "Gustavo A. R. Silva" <gustavoars@kernel.org>,
        linux-hardening@vger.kernel.org
Subject: [PATCH][next] scsi: lpfc: Avoid -Wstringop-overflow warning
Message-ID: <ZHZq7AV9Q2WG1xRB@work>
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Avoid confusing the compiler about possible negative sizes.
Use size_t instead of int for variables size and copied.

Address the following warning found with GCC-13:
In function ‘lpfc_debugfs_ras_log_data’,
    inlined from ‘lpfc_debugfs_ras_log_open’ at drivers/scsi/lpfc/lpfc_debugfs.c:2271:15:
drivers/scsi/lpfc/lpfc_debugfs.c:2210:25: warning: ‘memcpy’ specified bound between 18446744071562067968 and 18446744073709551615 exceeds maximum object size 9223372036854775807 [-Wstringop-overflow=]
 2210 |                         memcpy(buffer + copied, dmabuf->virt,
      |                         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 2211 |                                size - copied - 1);
      |                                ~~~~~~~~~~~~~~~~~~

Link: https://github.com/KSPP/linux/issues/305
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
---
 drivers/scsi/lpfc/lpfc_debugfs.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/scsi/lpfc/lpfc_debugfs.c b/drivers/scsi/lpfc/lpfc_debugfs.c
index bdf34af4ef36..493729e74abe 100644
--- a/drivers/scsi/lpfc/lpfc_debugfs.c
+++ b/drivers/scsi/lpfc/lpfc_debugfs.c
@@ -2189,9 +2189,9 @@ lpfc_debugfs_lockstat_write(struct file *file, const char __user *buf,
 #endif
 
 static int lpfc_debugfs_ras_log_data(struct lpfc_hba *phba,
-				     char *buffer, int size)
+				     char *buffer, size_t size)
 {
-	int copied = 0;
+	size_t copied = 0;
 	struct lpfc_dmabuf *dmabuf, *next;
 
 	memset(buffer, 0, size);
@@ -2249,7 +2249,7 @@ lpfc_debugfs_ras_log_open(struct inode *inode, struct file *file)
 {
 	struct lpfc_hba *phba = inode->i_private;
 	struct lpfc_debug *debug;
-	int size;
+	size_t size;
 	int rc = -ENOMEM;
 
 	spin_lock_irq(&phba->hbalock);
-- 
2.34.1