diff mbox series

[1/4] fsx: fix strncpy usage error

Message ID 160505548377.1389938.2367585875193826371.stgit@magnolia (mailing list archive)
State New, archived
Headers show
Series xfstests: fix compiler warnings with fsx/fsstress | expand

Commit Message

Darrick J. Wong Nov. 11, 2020, 12:44 a.m. UTC 
From: Darrick J. Wong <darrick.wong@oracle.com>

We shouldn't feed sizeof() to strncpy as the string length.  Just use
snprintf, which at least doesn't have the zero termination problems.

In file included from /usr/include/string.h:495,
                 from ../src/global.h:73,
                 from fsx.c:16:
In function 'strncpy',
    inlined from 'main' at fsx.c:2944:5:
/usr/include/x86_64-linux-gnu/bits/string_fortified.h:106:10: warning:
'__builtin_strncpy' specified bound 4096 equals destination size
[-Wstringop-truncation]
  106 |   return __builtin___strncpy_chk (__dest, __src, __len, __bos (__dest));
      |          ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
In function 'strncpy',
    inlined from 'main' at fsx.c:2914:4:
/usr/include/x86_64-linux-gnu/bits/string_fortified.h:106:10: warning:
'__builtin_strncpy' specified bound 1024 equals destination size
[-Wstringop-truncation]
  106 |   return __builtin___strncpy_chk (__dest, __src, __len, __bos (__dest));
      |          ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
---
 ltp/fsx.c |    5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

Comments

Christoph Hellwig Nov. 14, 2020, 10:42 a.m. UTC | #1 
On Tue, Nov 10, 2020 at 04:44:43PM -0800, Darrick J. Wong wrote:
> From: Darrick J. Wong <darrick.wong@oracle.com>
> 
> We shouldn't feed sizeof() to strncpy as the string length.  Just use
> snprintf, which at least doesn't have the zero termination problems.

Looks good,

Reviewed-by: Christoph Hellwig <hch@lst.de>
diff mbox series

Patch

diff --git a/ltp/fsx.c b/ltp/fsx.c
index 0abd7de1..cd0bae55 100644
--- a/ltp/fsx.c
+++ b/ltp/fsx.c
@@ -2769,8 +2769,7 @@  main(int argc, char **argv)
 			randomoplen = 0;
 			break;
 		case 'P':
-			strncpy(dname, optarg, sizeof(dname));
-			strcat(dname, "/");
+			snprintf(dname, sizeof(dname), "%s/", optarg);
 			dirpath = strlen(dname);
 			break;
                 case 'R':
@@ -2799,7 +2798,7 @@  main(int argc, char **argv)
 			break;
 		case 255:  /* --record-ops */
 			if (optarg)
-				strncpy(opsfile, optarg, sizeof(opsfile));
+				snprintf(opsfile, sizeof(opsfile), "%s", optarg);
 			recordops = opsfile;
 			break;
 		case 256:  /* --replay-ops */