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From: Guenter Roeck <linux@roeck-us.net>
To: Karsten Keil <isdn@linux-pingi.de>
Cc: Kees Cook <keescook@chromium.org>,
	linux-kernel@vger.kernel.org, netdev@vger.kernel.org,
	Guenter Roeck <linux@roeck-us.net>
Subject: [PATCH] TTY: isdn: Replace strncpy with memcpy
Date: Sun,  1 Jul 2018 13:57:38 -0700	[thread overview]
Message-ID: <1530478658-23070-1-git-send-email-linux@roeck-us.net> (raw)

gcc 8.1.0 complains:

drivers/isdn/i4l/isdn_tty.c: In function 'isdn_tty_suspend.isra.1':
drivers/isdn/i4l/isdn_tty.c:790:3: warning:
	'strncpy' output truncated before terminating nul copying
	as many bytes from a string as its length
drivers/isdn/i4l/isdn_tty.c:778:6: note: length computed here

drivers/isdn/i4l/isdn_tty.c: In function 'isdn_tty_resume':
drivers/isdn/i4l/isdn_tty.c:880:3: warning:
	'strncpy' output truncated before terminating nul copying
	as many bytes from a string as its length
drivers/isdn/i4l/isdn_tty.c:817:6: note: length computed here

Using strncpy() is indeed less than perfect since the length of data to
be copied has already been determined with strlen(). Replace strncpy()
with memcpy() to address the warning and optimize the code a little.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
---
 drivers/isdn/i4l/isdn_tty.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/isdn/i4l/isdn_tty.c b/drivers/isdn/i4l/isdn_tty.c
index 960f26348bb5..b730037a0e2d 100644
--- a/drivers/isdn/i4l/isdn_tty.c
+++ b/drivers/isdn/i4l/isdn_tty.c
@@ -787,7 +787,7 @@ isdn_tty_suspend(char *id, modem_info *info, atemu *m)
 		cmd.parm.cmsg.para[3] = 4; /* 16 bit 0x0004 Suspend */
 		cmd.parm.cmsg.para[4] = 0;
 		cmd.parm.cmsg.para[5] = l;
-		strncpy(&cmd.parm.cmsg.para[6], id, l);
+		memcpy(&cmd.parm.cmsg.para[6], id, l);
 		cmd.command = CAPI_PUT_MESSAGE;
 		cmd.driver = info->isdn_driver;
 		cmd.arg = info->isdn_channel;
@@ -877,7 +877,7 @@ isdn_tty_resume(char *id, modem_info *info, atemu *m)
 		cmd.parm.cmsg.para[3] = 5; /* 16 bit 0x0005 Resume */
 		cmd.parm.cmsg.para[4] = 0;
 		cmd.parm.cmsg.para[5] = l;
-		strncpy(&cmd.parm.cmsg.para[6], id, l);
+		memcpy(&cmd.parm.cmsg.para[6], id, l);
 		cmd.command = CAPI_PUT_MESSAGE;
 		info->dialing = 1;
 //		strcpy(dev->num[i], n);
-- 
2.7.4

             reply	other threads:[~2018-07-01 20:57 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-07-01 20:57 Guenter Roeck [this message]
2018-07-02 13:43 ` [PATCH] TTY: isdn: Replace strncpy with memcpy David Miller

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