ericonr
/
util-linux
mirror of https://github.com/ericonr/util-linux.git
1
0
Fork 0
Code Issues Projects Releases Wiki Activity

lib/canonicalize: fix truncation warning 

lib/canonicalize.c: In function ‘canonicalize_dm_name’:
lib/canonicalize.c:42:45: warning: ‘%s’ directive output may be truncated
writing up to 255 bytes into a region of size 244 [-Wformat-truncation=]
   snprintf(path, sizeof(path), "/dev/mapper/%s", name);

Notice that this warnign fix does not improve code enormously.  The earlier
snprintf() truncation will not happen a bit earlier when fgets() is called.
In that sense this change merely makes one easy to silence warning to
disappear, and therefore improve change of noticing useful messaging as such
crops up.

[kzak@redhat.com: - use macro rather than hardcoded string for mapper path]

Signed-off-by: Sami Kerola <kerolasa@iki.fi>
Signed-off-by: Karel Zak <kzak@redhat.com>
This commit is contained in:
Sami Kerola 2018-05-03 22:57:57 +01:00 committed by Karel Zak
parent 1c199a6e15
commit bf99940f64
2 changed files with 5 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
include/pathnames.h
View File

@ -131,6 +131,8 @@
# define _PATH_DEV "/dev/"
#endif
#define _PATH_DEV_MAPPER "/dev/mapper"
#define _PATH_DEV_MEM "/dev/mem"
#define _PATH_DEV_LOOP "/dev/loop"

5
lib/canonicalize.c
View File

@ -16,6 +16,7 @@
#include <sys/stat.h>
#include "canonicalize.h"
#include "pathnames.h"
/*
* Converts private "dm-N" names to "/dev/mapper/<name>"
@ -27,7 +28,7 @@ char *canonicalize_dm_name(const char *ptname)
{
FILE *f;
size_t sz;
char path[256], name[256], *res = NULL;
char path[256], name[sizeof(path) - sizeof(_PATH_DEV_MAPPER)], *res = NULL;
if (!ptname || !*ptname)
return NULL;
@ -39,7 +40,7 @@ char *canonicalize_dm_name(const char *ptname)
/* read "<name>\n" from sysfs */
if (fgets(name, sizeof(name), f) && (sz = strlen(name)) > 1) {
name[sz - 1] = '\0';
snprintf(path, sizeof(path), "/dev/mapper/%s", name);
snprintf(path, sizeof(path), _PATH_DEV_MAPPER "/%s", name);
if (access(path, F_OK) == 0)
res = strdup(path);