S/390: Change struct statfs[64] member types to unsigned values

Kay Sievers reported that coreutils' stat tool has a problem with
s390's statfs[64] definition:

> The definition of struct statfs::f_type needs a fix. s390 is the only
> architecture in the kernel that uses an int and expects magic
> constants lager than INT_MAX to fit into.
>
> A fix is needed to make Fedora boot on s390, it currently fails to do
> so. Userspace does not want to add code to paper-over this issue.

[...]

> Even coreutils cannot handle it:
>   #define RAMFS_MAGIC  0x858458f6
>   # stat -f -c%t /
>   ffffffff858458f6
>
>   #define BTRFS_SUPER_MAGIC 0x9123683E
>   # stat -f -c%t /mnt
>   ffffffff9123683e

The bug is caused by an implicit sign extension within the stat tool:

out_uint_x (pformat, prefix_len, statfsbuf->f_type);

where the format finally will be "%lx".
A similar problem can be found in the 'tail' tool.
s390 is the only architecture which has an int type f_type member in
struct statfs[64]. Other architectures have either unsigned ints or
long values, so that the problem doesn't occur there.

Therefore change the type of the f_type member to unsigned int, so
that we get zero extension instead sign extension when assignment to
a long value happens.

Reported-by: Kay Sievers <kay@vrfy.org>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>

2 files changed, 18 insertions, 12 deletions

diff --git a/ChangeLog b/ChangeLog
index e16ef0a4e9..4b41c6ddca 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+2013-04-23  Heiko Carstens  <heiko.carstens@de.ibm.com>
+
+	* sysdeps/unix/sysv/linux/s390/bits/statfs.h: Change types of
+	f_type, f_bsize, f_namelen, f_frsize, f_flags,and f_spare to
+	unsigned.
+
 2013-04-22  Jan-Benedict Glaw  <jbglaw@getslash.de>
 
 	* nss/getent.c (shadow_keys): Call endspent, not endpwent.
diff --git a/sysdeps/unix/sysv/linux/s390/bits/statfs.h b/sysdeps/unix/sysv/linux/s390/bits/statfs.h
index ff54607fa2..91dde15339 100644
--- a/sysdeps/unix/sysv/linux/s390/bits/statfs.h
+++ b/sysdeps/unix/sysv/linux/s390/bits/statfs.h
@@ -23,8 +23,8 @@
 
 struct statfs
   {
-    int f_type;
-    int f_bsize;
+    unsigned int f_type;
+    unsigned int f_bsize;
 #ifndef __USE_FILE_OFFSET64
     __fsblkcnt_t f_blocks;
     __fsblkcnt_t f_bfree;
@@ -39,27 +39,27 @@ struct statfs
     __fsfilcnt64_t f_ffree;
 #endif
     __fsid_t f_fsid;
-    int f_namelen;
-    int f_frsize;
-    int f_flags;
-    int f_spare[4];
+    unsigned int f_namelen;
+    unsigned int f_frsize;
+    unsigned int f_flags;
+    unsigned int f_spare[4];
   };
 
 #ifdef __USE_LARGEFILE64
 struct statfs64
   {
-    int f_type;
-    int f_bsize;
+    unsigned int f_type;
+    unsigned int f_bsize;
     __fsblkcnt64_t f_blocks;
     __fsblkcnt64_t f_bfree;
     __fsblkcnt64_t f_bavail;
     __fsfilcnt64_t f_files;
     __fsfilcnt64_t f_ffree;
     __fsid_t f_fsid;
-    int f_namelen;
-    int f_frsize;
-    int f_flags;
-    int f_spare[4];
+    unsigned int f_namelen;
+    unsigned int f_frsize;
+    unsigned int f_flags;
+    unsigned int f_spare[4];
   };
 #endif