Change internal gid datatype from __gid16_t to __gid32_t

	throughout.
	* cygwin.din: Export new symbols chown32, fchown32, getegid32,
	getgid32, getgrgid32, getgrnam32, getgroups32, initgroups32, lchown32,
	setgid32, setegid32, getgrent32.
	* grp.cc (grp32togrp16): New static function.
	(getgrgid32): New function.
	(getgrnam32): Ditto.
	(getgrent32): Ditto.
	(getgroups32): Change name of internal function from getgroups.
	(getgroups32): New function.
	(initgroups32): Ditto.
	* syscalls.cc (chown32): Ditto.
	(lchown32): Ditto.
	(fchown32): Ditto.
	(setegid32): Ditto.
	(setgid32): Ditto.
	* uinfo.cc (getgid32): Ditto.
	(getegid32): Ditto.
	* include/cygwin/grp.h: Remove declaration of getgrgid() and getgrnam().
	Declare getgrgid32() and getgrnam32() instead.  Declare getgid32().

15 files changed, 235 insertions, 74 deletions

diff --git a/winsup/cygwin/ChangeLog b/winsup/cygwin/ChangeLog
index 0438b3777..40eed8495 100644
--- a/winsup/cygwin/ChangeLog
+++ b/winsup/cygwin/ChangeLog
@@ -1,3 +1,27 @@
+2002-05-28  Corinna Vinschen  <corinna@vinschen.de>
+
+	Change internal gid datatype from __gid16_t to __gid32_t
+	throughout.
+	* cygwin.din: Export new symbols chown32, fchown32, getegid32,
+	getgid32, getgrgid32, getgrnam32, getgroups32, initgroups32, lchown32,
+	setgid32, setegid32, getgrent32.
+	* grp.cc (grp32togrp16): New static function.
+	(getgrgid32): New function.
+	(getgrnam32): Ditto.
+	(getgrent32): Ditto.
+	(getgroups32): Change name of internal function from getgroups.
+	(getgroups32): New function.
+	(initgroups32): Ditto.
+	* syscalls.cc (chown32): Ditto.
+	(lchown32): Ditto.
+	(fchown32): Ditto.
+	(setegid32): Ditto.
+	(setgid32): Ditto.
+	* uinfo.cc (getgid32): Ditto.
+	(getegid32): Ditto.
+	* include/cygwin/grp.h: Remove declaration of getgrgid() and getgrnam().
+	Declare getgrgid32() and getgrnam32() instead.  Declare getgid32().
+
 2002-05-27  Christopher Faylor  <cgf@redhat.com>
 
 	* autoload.cc (noload): Properly mask low order word for determining
diff --git a/winsup/cygwin/cygheap.h b/winsup/cygwin/cygheap.h
index f7c507e46..aa4e525ab 100644
--- a/winsup/cygwin/cygheap.h
+++ b/winsup/cygwin/cygheap.h
@@ -97,9 +97,9 @@ class cygheap_user
   PSID   orig_psid;     /* Remains intact even after impersonation */
 public:
   __uid16_t orig_uid;      /* Remains intact even after impersonation */
-  __uid16_t orig_gid;      /* Ditto */
+  __gid32_t orig_gid;      /* Ditto */
   __uid16_t real_uid;      /* Remains intact on seteuid, replaced by setuid */
-  __gid16_t real_gid;      /* Ditto */
+  __gid32_t real_gid;      /* Ditto */
 
   /* token is needed if set(e)uid should be called. It can be set by a call
      to `set_impersonation_token()'. */
diff --git a/winsup/cygwin/cygwin.din b/winsup/cygwin/cygwin.din
index 165c26f03..1d8ae0b81 100644
--- a/winsup/cygwin/cygwin.din
+++ b/winsup/cygwin/cygwin.din
@@ -100,6 +100,7 @@ chmod
 _chmod = chmod
 chown
 _chown = chown
+chown32
 cleanup_glue
 clearerr
 _clearerr = clearerr
@@ -205,6 +206,7 @@ fchmod
 _fchmod = fchmod
 fchown
 _fchown = fchown
+fchown32
 fclose
 _fclose = fclose
 fcntl
@@ -344,16 +346,21 @@ getdtablesize
 _getdtablesize = getdtablesize
 getegid
 _getegid = getegid
+getegid32
 geteuid
 _geteuid = geteuid
 getgid
 _getgid = getgid
+getgid32
 getgrgid
 _getgrgid = getgrgid
+getgrgid32
 getgrnam
 _getgrnam = getgrnam
+getgrnam32
 getgroups
 _getgroups = getgroups
+getgroups32
 gethostname = cygwin_gethostname
 _gethostname = cygwin_gethostname
 getlogin
@@ -412,6 +419,7 @@ _infinity = infinity
 infinityf
 _infinityf = infinityf
 initgroups
+initgroups32
 ioctl
 _ioctl = ioctl
 iprintf
@@ -468,6 +476,7 @@ labs
 _labs = labs
 lchown
 _lchown = lchown
+lchown32
 ldexp
 _ldexp = ldexp
 ldexpf
@@ -658,6 +667,7 @@ setdtablesize
 _setdtablesize = setdtablesize
 setgid
 _setgid = setgid
+setgid32
 setjmp
 _setjmp = setjmp
 setlocale
@@ -674,6 +684,7 @@ seteuid
 _seteuid = seteuid
 setegid
 _setegid = setegid
+setegid32
 setuid
 _setuid = setuid
 setutent
@@ -1013,6 +1024,7 @@ getpgrp
 _getpgrp = getpgrp
 getgrent
 _getgrent = getgrent
+getgrent32
 ntohl
 _ntohl = ntohl
 htonl
diff --git a/winsup/cygwin/fhandler_disk_file.cc b/winsup/cygwin/fhandler_disk_file.cc
index aa6b50dc6..a1237cc3c 100644
--- a/winsup/cygwin/fhandler_disk_file.cc
+++ b/winsup/cygwin/fhandler_disk_file.cc
@@ -127,7 +127,7 @@ fhandler_disk_file::fstat (struct __stat64 *buf, path_conv *pc)
   int res = -1;
   int oret;
   __uid16_t uid;
-  __gid16_t gid;
+  __gid32_t gid;
   int open_flags = O_RDONLY | O_BINARY | O_DIROPEN;
   bool query_open_already;
 
@@ -238,7 +238,7 @@ fhandler_disk_file::fstat_helper (struct __stat64 *buf, path_conv *pc,
     buf->st_mode = S_IFSOCK;
 
   __uid16_t uid;
-  __gid16_t gid;
+  __gid32_t gid;
   if (get_file_attribute (pc->has_acls (), get_win32_name (), &buf->st_mode,
 			  &uid, &gid) == 0)
     {
diff --git a/winsup/cygwin/grp.cc b/winsup/cygwin/grp.cc
index 4002fbc00..3ec8cd988 100644
--- a/winsup/cygwin/grp.cc
+++ b/winsup/cygwin/grp.cc
@@ -31,7 +31,7 @@ details. */
    on the first call that needs information from it. */
 
 static const char *etc_group NO_COPY = "/etc/group";
-static struct __group16 *group_buf;		/* group contents in memory */
+static struct __group32 *group_buf;		/* group contents in memory */
 static int curr_lines;
 static int max_lines;
 
@@ -45,7 +45,7 @@ static int grp_pos = 0;
 static pwdgrp_check group_state;
 
 static int
-parse_grp (struct __group16 &grp, const char *line)
+parse_grp (struct __group32 &grp, const char *line)
 {
   int len = strlen(line);
   char *newline = (char *) malloc (len + 1);
@@ -110,7 +110,7 @@ add_grp_line (const char *line)
     if (curr_lines == max_lines)
     {
 	max_lines += 10;
-	group_buf = (struct __group16 *) realloc (group_buf, max_lines * sizeof (struct __group16));
+	group_buf = (struct __group32 *) realloc (group_buf, max_lines * sizeof (struct __group32));
     }
     if (parse_grp (group_buf[curr_lines], line))
       curr_lines++;
@@ -210,11 +210,28 @@ read_etc_group ()
   return;
 }
 
-extern "C"
+static
 struct __group16 *
-getgrgid (__gid16_t gid)
+grp32togrp16 (struct __group16 *gp16, struct __group32 *gp32)
 {
-  struct __group16 * default_grp = NULL;
+  if (!gp16 || !gp32)
+    return NULL;
+
+  /* Copying the pointers is actually unnecessary.  Just having the correct
+     return type is important. */
+  gp16->gr_name = gp32->gr_name;
+  gp16->gr_passwd = gp32->gr_passwd;
+  gp16->gr_gid = (__gid16_t) gp32->gr_gid;		/* Not loss-free */
+  gp16->gr_mem = gp32->gr_mem;
+
+  return gp16;
+}
+
+extern "C"
+struct __group32 *
+getgrgid32 (__gid32_t gid)
+{
+  struct __group32 * default_grp = NULL;
   if (group_state  <= initializing)
     read_etc_group();
 
@@ -231,7 +248,16 @@ getgrgid (__gid16_t gid)
 
 extern "C"
 struct __group16 *
-getgrnam (const char *name)
+getgrgid (__gid16_t gid)
+{
+  static struct __group16 g16;
+
+  return grp32togrp16 (&g16, getgrgid32 ((__gid32_t) gid));
+}
+
+extern "C"
+struct __group32 *
+getgrnam32 (const char *name)
 {
   if (group_state  <= initializing)
     read_etc_group();
@@ -245,6 +271,15 @@ getgrnam (const char *name)
 }
 
 extern "C"
+struct __group16 *
+getgrnam (const char *name)
+{
+  static struct __group16 g16;
+
+  return grp32togrp16 (&g16, getgrnam32 (name));
+}
+
+extern "C"
 void
 endgrent()
 {
@@ -252,8 +287,8 @@ endgrent()
 }
 
 extern "C"
-struct __group16 *
-getgrent()
+struct __group32 *
+getgrent32()
 {
   if (group_state  <= initializing)
     read_etc_group();
@@ -265,6 +300,15 @@ getgrent()
 }
 
 extern "C"
+struct __group16 *
+getgrent()
+{
+  static struct __group16 g16;
+
+  return grp32togrp16 (&g16, getgrent32 ());
+}
+
+extern "C"
 void
 setgrent ()
 {
@@ -272,7 +316,7 @@ setgrent ()
 }
 
 /* Internal function. ONLY USE THIS INTERNALLY, NEVER `getgrent'!!! */
-struct __group16 *
+struct __group32 *
 internal_getgrent (int pos)
 {
   if (group_state  <= initializing)
@@ -284,12 +328,13 @@ internal_getgrent (int pos)
 }
 
 int
-getgroups (int gidsetsize, __gid16_t *grouplist, __gid16_t gid, const char *username)
+getgroups32 (int gidsetsize, __gid32_t *grouplist, __gid32_t gid,
+	     const char *username)
 {
   HANDLE hToken = NULL;
   DWORD size;
   int cnt = 0;
-  struct __group16 *gr;
+  struct __group32 *gr;
 
   if (group_state  <= initializing)
     read_etc_group();
@@ -359,9 +404,41 @@ error:
 
 extern "C"
 int
+getgroups32 (int gidsetsize, __gid32_t *grouplist)
+{
+  return getgroups32 (gidsetsize, grouplist, myself->gid,
+		      cygheap->user.name ());
+}
+
+extern "C"
+int
 getgroups (int gidsetsize, __gid16_t *grouplist)
 {
-  return getgroups (gidsetsize, grouplist, myself->gid, cygheap->user.name ());
+  __gid32_t *grouplist32 = NULL;
+
+  if (gidsetsize < 0)
+    {
+      set_errno (EINVAL);
+      return -1;
+    }
+  if (gidsetsize > 0 && grouplist)
+    grouplist32 = (__gid32_t *) alloca (gidsetsize * sizeof (__gid32_t));
+
+  int ret = getgroups32 (gidsetsize, grouplist32, myself->gid,
+			 cygheap->user.name ());
+
+  if (gidsetsize > 0 && grouplist)
+    for (int i = 0; i < ret; ++ i)
+      grouplist[i] = grouplist32[i];
+
+  return ret;
+}
+
+extern "C"
+int
+initgroups32 (const char *, __gid32_t)
+{
+  return 0;
 }
 
 extern "C"
diff --git a/winsup/cygwin/include/cygwin/grp.h b/winsup/cygwin/include/cygwin/grp.h
index 3a58e2058..46874df0d 100644
--- a/winsup/cygwin/include/cygwin/grp.h
+++ b/winsup/cygwin/include/cygwin/grp.h
@@ -35,8 +35,9 @@ struct __group32
   char **gr_mem;
 };
 
-struct __group16 * getgrgid (__gid16_t gid);
-struct __group16 * getgrnam (const char *name);
+struct __group32 * getgrgid32 (__gid32_t gid);
+struct __group32 * getgrnam32 (const char *name);
+__gid32_t getgid32 ();
 #endif
 
 #ifdef __cplusplus
diff --git a/winsup/cygwin/pinfo.h b/winsup/cygwin/pinfo.h
index 55284d15b..a54c9b677 100644
--- a/winsup/cygwin/pinfo.h
+++ b/winsup/cygwin/pinfo.h
@@ -65,8 +65,8 @@ public:
      if not found.  This data resides in the shared data area (allowing
      tasks to store whatever they want here) so it's for informational
      purposes only. */
-  __uid16_t uid;		/* User ID */
-  __gid16_t gid;		/* Group ID */
+  __uid32_t uid;	/* User ID */
+  __gid32_t gid;	/* Group ID */
   pid_t pgid;		/* Process group ID */
   pid_t sid;		/* Session ID */
   int ctty;		/* Control tty */
diff --git a/winsup/cygwin/sec_acl.cc b/winsup/cygwin/sec_acl.cc
index 0ef423f7b..47f1cb426 100644
--- a/winsup/cygwin/sec_acl.cc
+++ b/winsup/cygwin/sec_acl.cc
@@ -107,7 +107,7 @@ setacl (const char *file, int nentries, __aclent16_t *aclbufp)
 
   cygsid sid;
   struct passwd *pw;
-  struct __group16 *gr;
+  struct __group32 *gr;
   int pos;
 
   if (!InitializeAcl (acl, 3072, ACL_REVISION))
@@ -172,7 +172,7 @@ setacl (const char *file, int nentries, __aclent16_t *aclbufp)
 	  break;
 	case GROUP:
 	case DEF_GROUP:
-	  if (!(gr = getgrgid (aclbufp[i].a_id))
+	  if (!(gr = getgrgid32 (aclbufp[i].a_id))
 	      || !sid.getfromgr (gr)
 	      || !add_access_allowed_ace (acl, ace_off++, allow,
 					   sid, acl_len, inheritance))
@@ -256,7 +256,7 @@ getacl (const char *file, DWORD attr, int nentries, __aclent16_t *aclbufp)
   PSID group_sid;
   BOOL dummy;
   __uid16_t uid;
-  __gid16_t gid;
+  __gid32_t gid;
 
   if (!GetSecurityDescriptorOwner (psd, &owner_sid, &dummy))
     {
@@ -424,7 +424,7 @@ acl_access (const char *path, int flags)
 	      cygsid owner;
 	      cygsid group;
 	      struct passwd *pw;
-	      struct __group16 *gr = NULL;
+	      struct __group32 *gr = NULL;
 
 	      if ((pw = getpwuid (acls[i].a_id)) != NULL
 		  && owner.getfrompw (pw))
@@ -994,7 +994,7 @@ aclfromtext (char *acltextp, int *)
 	      c += 5;
 	      if (isalpha (*c))
 		{
-		  struct __group16 *gr = getgrnam (c);
+		  struct __group32 *gr = getgrnam32 (c);
 		  if (!gr)
 		    {
 		      set_errno (EINVAL);
diff --git a/winsup/cygwin/sec_helper.cc b/winsup/cygwin/sec_helper.cc
index 365364d9f..c5341128f 100644
--- a/winsup/cygwin/sec_helper.cc
+++ b/winsup/cygwin/sec_helper.cc
@@ -127,7 +127,7 @@ cygsid::getfrompw (const struct passwd *pw)
 }
 
 BOOL
-cygsid::getfromgr (const struct __group16 *gr)
+cygsid::getfromgr (const struct __group32 *gr)
 {
   char *sp = (gr && gr->gr_passwd) ? gr->gr_passwd : NULL;
   return (*this = sp ?: "") != NULL;
@@ -174,7 +174,7 @@ cygsid::get_id (BOOL search_grp, int *type)
 	}
       if (search_grp || type)
 	{
-	  struct __group16 *gr;
+	  struct __group32 *gr;
 	  for (int gidx = 0; (gr = internal_getgrent (gidx)); ++gidx)
 	    {
 	      if (sid.getfromgr (gr) && sid == psid)
@@ -224,7 +224,7 @@ cygsid::get_id (BOOL search_grp, int *type)
 	      *type = GROUP;
 	    if (id == -1)
 	      {
-		struct __group16 *gr = getgrnam (account);
+		struct __group32 *gr = getgrnam32 (account);
 		if (gr)
 		  id = gr->gr_gid;
 	      }
@@ -249,16 +249,16 @@ cygsid::get_id (BOOL search_grp, int *type)
 }
 
 BOOL
-is_grp_member (__uid16_t uid, __gid16_t gid)
+is_grp_member (__uid32_t uid, __gid32_t gid)
 {
-  extern int getgroups (int, __gid16_t *, __gid16_t, const char *);
+  extern int getgroups32 (int, __gid32_t *, __gid32_t, const char *);
   BOOL grp_member = TRUE;
 
   struct passwd *pw = getpwuid (uid);
-  __gid16_t grps[NGROUPS_MAX];
-  int cnt = getgroups (NGROUPS_MAX, grps,
-		       pw ? pw->pw_gid : myself->gid,
-		       pw ? pw->pw_name : cygheap->user.name ());
+  __gid32_t grps[NGROUPS_MAX];
+  int cnt = getgroups32 (NGROUPS_MAX, grps,
+			 pw ? pw->pw_gid : myself->gid,
+			 pw ? pw->pw_name : cygheap->user.name ());
   int i;
   for (i = 0; i < cnt; ++i)
     if (grps[i] == gid)
diff --git a/winsup/cygwin/security.cc b/winsup/cygwin/security.cc
index 2c90f621f..b16934114 100644
--- a/winsup/cygwin/security.cc
+++ b/winsup/cygwin/security.cc
@@ -456,7 +456,7 @@ get_user_primary_group (WCHAR *wlogonserver, const char *user,
 static int
 get_supplementary_group_sidlist (const char *username, cygsidlist &grp_list)
 {
-  struct __group16 *gr;
+  struct __group32 *gr;
   int cnt = 0;
 
   for (int gidx = 0; (gr = internal_getgrent (gidx)); ++gidx)
@@ -1130,7 +1130,7 @@ write_sd(const char *file, PSECURITY_DESCRIPTOR sd_buf, DWORD sd_size)
 
 static int
 get_nt_attribute (const char *file, int *attribute,
-		  __uid16_t *uidret, __gid16_t *gidret)
+		  __uid16_t *uidret, __gid32_t *gidret)
 {
   if (!wincap.has_security ())
     return 0;
@@ -1169,7 +1169,7 @@ get_nt_attribute (const char *file, int *attribute,
     }
 
   __uid16_t uid = cygsid(owner_sid).get_uid ();
-  __gid16_t gid = cygsid(group_sid).get_gid ();
+  __gid32_t gid = cygsid(group_sid).get_gid ();
   if (uidret)
     *uidret = uid;
   if (gidret)
@@ -1279,7 +1279,7 @@ get_nt_attribute (const char *file, int *attribute,
 
 int
 get_file_attribute (int use_ntsec, const char *file,
-		    int *attribute, __uid16_t *uidret, __gid16_t *gidret)
+		    int *attribute, __uid16_t *uidret, __gid32_t *gidret)
 {
   int res;
 
@@ -1294,7 +1294,7 @@ get_file_attribute (int use_ntsec, const char *file,
   if (uidret)
     *uidret = getuid ();
   if (gidret)
-    *gidret = getgid ();
+    *gidret = getgid32 ();
 
   if (!attribute)
     return 0;
@@ -1350,7 +1350,7 @@ add_access_denied_ace (PACL acl, int offset, DWORD attributes,
 }
 
 PSECURITY_DESCRIPTOR
-alloc_sd (__uid16_t uid, __gid16_t gid, const char *logsrv, int attribute,
+alloc_sd (__uid16_t uid, __gid32_t gid, const char *logsrv, int attribute,
 	  PSECURITY_DESCRIPTOR sd_ret, DWORD *sd_size_ret)
 {
   BOOL dummy;
@@ -1378,7 +1378,7 @@ alloc_sd (__uid16_t uid, __gid16_t gid, const char *logsrv, int attribute,
 
   /* Get SID and name of new group. */
   cygsid group_sid (NO_SID);
-  struct __group16 *grp = getgrgid (gid);
+  struct __group32 *grp = getgrgid32 (gid);
   if (grp)
     {
       if ((!grp || !group_sid.getfromgr (grp))
@@ -1619,7 +1619,7 @@ set_security_attribute (int attribute, PSECURITY_ATTRIBUTES psa,
 }
 
 static int
-set_nt_attribute (const char *file, __uid16_t uid, __gid16_t gid,
+set_nt_attribute (const char *file, __uid16_t uid, __gid32_t gid,
 		  const char *logsrv, int attribute)
 {
   if (!wincap.has_security ())
@@ -1645,7 +1645,7 @@ set_nt_attribute (const char *file, __uid16_t uid, __gid16_t gid,
 
 int
 set_file_attribute (int use_ntsec, const char *file,
-		    __uid16_t uid, __gid16_t gid,
+		    __uid16_t uid, __gid32_t gid,
 		    int attribute, const char *logsrv)
 {
   int ret = 0;
diff --git a/winsup/cygwin/security.h b/winsup/cygwin/security.h
index 81cbd51e2..db3df2901 100644
--- a/winsup/cygwin/security.h
+++ b/winsup/cygwin/security.h
@@ -57,7 +57,7 @@ public:
   inline PSID set () { return psid = (PSID) sbuf; }
 
   BOOL getfrompw (const struct passwd *pw);
-  BOOL getfromgr (const struct __group16 *gr);
+  BOOL getfromgr (const struct __group32 *gr);
 
   int get_id (BOOL search_grp, int *type = NULL);
   inline int get_uid () { return get_id (FALSE); }
@@ -161,14 +161,14 @@ extern BOOL allow_smbntsec;
    and group lists so they are somehow security related. Besides that
    I didn't find a better place to declare them. */
 extern struct passwd *internal_getpwent (int);
-extern struct __group16 *internal_getgrent (int);
+extern struct __group32 *internal_getgrent (int);
 
 /* File manipulation */
 int __stdcall set_process_privileges ();
 int __stdcall get_file_attribute (int, const char *, int *,
-				  __uid16_t * = NULL, __gid16_t * = NULL);
+				  __uid16_t * = NULL, __gid32_t * = NULL);
 int __stdcall set_file_attribute (int, const char *, int);
-int __stdcall set_file_attribute (int, const char *, __uid16_t, __gid16_t, int, const char *);
+int __stdcall set_file_attribute (int, const char *, __uid16_t, __gid32_t, int, const char *);
 LONG __stdcall read_sd(const char *file, PSECURITY_DESCRIPTOR sd_buf, LPDWORD sd_size);
 LONG __stdcall write_sd(const char *file, PSECURITY_DESCRIPTOR sd_buf, DWORD sd_size);
 BOOL __stdcall add_access_allowed_ace (PACL acl, int offset, DWORD attributes, PSID sid, size_t &len_add, DWORD inherit);
@@ -190,7 +190,7 @@ void extract_nt_dom_user (const struct passwd *pw, char *domain, char *user);
 BOOL get_logon_server_and_user_domain (char *logonserver, char *domain);
 
 /* sec_helper.cc: Security helper functions. */
-BOOL __stdcall is_grp_member (__uid16_t uid, __gid16_t gid);
+BOOL __stdcall is_grp_member (__uid32_t uid, __gid32_t gid);
 /* `lookup_name' should be called instead of LookupAccountName.
  * logsrv may be NULL, in this case only the local system is used for lookup.
  * The buffer for ret_sid (40 Bytes) has to be allocated by the caller! */
@@ -209,7 +209,7 @@ extern BOOL sec_acl (PACL acl, BOOL admins, PSID sid1 = NO_SID, PSID sid2 = NO_S
 
 int __stdcall NTReadEA (const char *file, const char *attrname, char *buf, int len);
 BOOL __stdcall NTWriteEA (const char *file, const char *attrname, const char *buf, int len);
-PSECURITY_DESCRIPTOR alloc_sd (uid_t uid, gid_t gid, const char *logsrv, int attribute,
+PSECURITY_DESCRIPTOR alloc_sd (__uid16_t uid, __gid32_t gid, const char *logsrv, int attribute,
           PSECURITY_DESCRIPTOR sd_ret, DWORD *sd_size_ret);
 
 extern inline SECURITY_ATTRIBUTES *
diff --git a/winsup/cygwin/shm.cc b/winsup/cygwin/shm.cc
index ab808aecd..8a32efb66 100644
--- a/winsup/cygwin/shm.cc
+++ b/winsup/cygwin/shm.cc
@@ -442,7 +442,7 @@ shmctl (int shmid, int cmd, struct shmid_ds *buf)
   return 0;
 }
 
-/* FIXME: evaluate getuid() and getgid() against the requested mode. Then
+/* FIXME: evaluate getuid() and getgid32() against the requested mode. Then
  * choose PAGE_READWRITE | PAGE_READONLY and FILE_MAP_WRITE  |  FILE_MAP_READ
  * appropriately
  */
@@ -461,7 +461,7 @@ shmget (key_t key, size_t size, int shmflg)
   /* create a sd for our open requests based on shmflag & 0x01ff */
   InitializeSecurityDescriptor (psd,
 				    SECURITY_DESCRIPTOR_REVISION);
-  psd = alloc_sd (getuid (), getgid (), cygheap->user.logsrv (),
+  psd = alloc_sd (getuid (), getgid32 (), cygheap->user.logsrv (),
 		  shmflg & 0x01ff, psd, &sd_size);
 
   if (key == (key_t) - 1)
@@ -540,7 +540,7 @@ shmget (key_t key, size_t size, int shmflg)
   /* fill out the node data */
   shmtemp->shm_perm.cuid = getuid ();
   shmtemp->shm_perm.uid = shmtemp->shm_perm.cuid;
-  shmtemp->shm_perm.cgid = getgid ();
+  shmtemp->shm_perm.cgid = getgid32 ();
   shmtemp->shm_perm.gid = shmtemp->shm_perm.cgid;
   shmtemp->shm_perm.mode = shmflg & 0x01ff;
   shmtemp->shm_lpid = 0;
diff --git a/winsup/cygwin/syscalls.cc b/winsup/cygwin/syscalls.cc
index 1511e7642..afdc457e9 100644
--- a/winsup/cygwin/syscalls.cc
+++ b/winsup/cygwin/syscalls.cc
@@ -750,11 +750,11 @@ done:
  * systems, it is only a stub that always returns zero.
  */
 static int
-chown_worker (const char *name, unsigned fmode, __uid16_t uid, __gid16_t gid)
+chown_worker (const char *name, unsigned fmode, __uid16_t uid, __gid32_t gid)
 {
   int res;
   __uid16_t old_uid;
-  __gid16_t old_gid;
+  __gid32_t old_gid;
 
   if (check_null_empty_str_errno (name))
     return -1;
@@ -815,21 +815,35 @@ done:
 }
 
 extern "C" int
-chown (const char * name, __uid16_t uid, __gid16_t gid)
+chown32 (const char * name, __uid16_t uid, __gid32_t gid)
 {
   sigframe thisframe (mainthread);
   return chown_worker (name, PC_SYM_FOLLOW, uid, gid);
 }
 
 extern "C" int
-lchown (const char * name, __uid16_t uid, __gid16_t gid)
+chown (const char * name, __uid16_t uid, __gid16_t gid)
+{
+  sigframe thisframe (mainthread);
+  return chown_worker (name, PC_SYM_FOLLOW, uid, (__gid32_t) gid);
+}
+
+extern "C" int
+lchown32 (const char * name, __uid16_t uid, __gid32_t gid)
 {
   sigframe thisframe (mainthread);
   return chown_worker (name, PC_SYM_NOFOLLOW, uid, gid);
 }
 
 extern "C" int
-fchown (int fd, __uid16_t uid, __gid16_t gid)
+lchown (const char * name, __uid16_t uid, __gid16_t gid)
+{
+  sigframe thisframe (mainthread);
+  return chown_worker (name, PC_SYM_NOFOLLOW, uid, (__gid32_t) gid);
+}
+
+extern "C" int
+fchown32 (int fd, __uid16_t uid, __gid32_t gid)
 {
   sigframe thisframe (mainthread);
   cygheap_fdget cfd (fd);
@@ -853,6 +867,12 @@ fchown (int fd, __uid16_t uid, __gid16_t gid)
   return chown_worker (path, PC_SYM_FOLLOW, uid, gid);
 }
 
+extern "C" int
+fchown (int fd, __uid16_t uid, __gid16_t gid)
+{
+  return fchown32 (fd, uid, (__gid32_t) gid);
+}
+
 /* umask: POSIX 5.3.3.1 */
 extern "C" mode_t
 umask (mode_t mask)
@@ -895,7 +915,7 @@ chmod (const char *path, mode_t mode)
       SetFileAttributes (win32_path, (DWORD) win32_path & ~FILE_ATTRIBUTE_READONLY);
 
       __uid16_t uid;
-      __gid16_t gid;
+      __gid32_t gid;
 
       if (win32_path.isdir ())
 	mode |= S_IFDIR;
@@ -1912,16 +1932,6 @@ mkfifo (const char *_path, mode_t mode)
   return -1;
 }
 
-/* setgid: POSIX 4.2.2.1 */
-extern "C" int
-setgid (__gid16_t gid)
-{
-  int ret = setegid (gid);
-  if (!ret)
-    cygheap->user.real_gid = myself->gid;
-  return ret;
-}
-
 /* setuid: POSIX 4.2.2.1 */
 extern "C" int
 setuid (__uid16_t uid)
@@ -1966,7 +1976,7 @@ seteuid (__uid16_t uid)
 
   pw_new = getpwuid (uid);
   if (!usersid.getfrompw (pw_new) ||
-      (!pgrpsid.getfromgr (getgrgid (myself->gid))))
+      (!pgrpsid.getfromgr (getgrgid32 (myself->gid))))
     {
       set_errno (EINVAL);
       return -1;
@@ -2137,7 +2147,7 @@ seteuid (__uid16_t uid)
 
 /* setegid: from System V.  */
 extern "C" int
-setegid (__gid16_t gid)
+setegid32 (__gid32_t gid)
 {
   if ((!wincap.has_security ()) ||
       (gid == ILLEGAL_GID))
@@ -2147,7 +2157,7 @@ setegid (__gid16_t gid)
   cygsid gsid;
   HANDLE ptok;
 
-  if (!(gsid.getfromgr (getgrgid (gid))))
+  if (!(gsid.getfromgr (getgrgid32 (gid))))
     {
       set_errno (EINVAL);
       return -1;
@@ -2184,6 +2194,31 @@ setegid (__gid16_t gid)
   return 0;
 }
 
+extern "C" int
+setegid (__gid16_t gid)
+{
+  return setegid32 ((__gid32_t) gid);
+}
+
+/* setgid: POSIX 4.2.2.1 */
+extern "C" int
+setgid32 (__gid32_t gid)
+{
+  int ret = setegid32 (gid);
+  if (!ret)
+    cygheap->user.real_gid = myself->gid;
+  return ret;
+}
+
+extern "C" int
+setgid (__gid16_t gid)
+{
+  int ret = setegid32 ((__gid32_t) gid);
+  if (!ret)
+    cygheap->user.real_gid = myself->gid;
+  return ret;
+}
+
 /* chroot: privileged Unix system call.  */
 /* FIXME: Not privileged here. How should this be done? */
 extern "C" int
diff --git a/winsup/cygwin/uinfo.cc b/winsup/cygwin/uinfo.cc
index 6a6b702c7..b851b384d 100644
--- a/winsup/cygwin/uinfo.cc
+++ b/winsup/cygwin/uinfo.cc
@@ -173,7 +173,7 @@ internal_getlogin (cygheap_user &user)
 	    if (psid.getfrompw (pw) && EqualSid (user.sid (), psid))
 	      {
 		user.set_name (pw->pw_name);
-		struct __group16 *gr = getgrgid (pw->pw_gid);
+		struct __group32 *gr = getgrgid32 (pw->pw_gid);
 		if (gr)
 		  if (!gsid.getfromgr (gr))
 		      gsid = NO_SID;
@@ -288,6 +288,12 @@ getuid (void)
   return cygheap->user.real_uid;
 }
 
+extern "C" __gid32_t
+getgid32 (void)
+{
+  return cygheap->user.real_gid;
+}
+
 extern "C" __gid16_t
 getgid (void)
 {
@@ -300,6 +306,12 @@ geteuid (void)
   return myself->uid;
 }
 
+extern "C" __gid32_t
+getegid32 (void)
+{
+  return myself->gid;
+}
+
 extern "C" __gid16_t
 getegid (void)
 {
diff --git a/winsup/cygwin/winsup.h b/winsup/cygwin/winsup.h
index 2d1fc1bc5..69d5938ae 100644
--- a/winsup/cygwin/winsup.h
+++ b/winsup/cygwin/winsup.h
@@ -148,7 +148,7 @@ extern "C" void __stdcall do_exit (int) __attribute__ ((noreturn));
 void uinfo_init (void);
 
 #define ILLEGAL_UID ((__uid16_t)-1)
-#define ILLEGAL_GID ((__gid16_t)-1)
+#define ILLEGAL_GID ((__gid32_t)-1)
 #define ILLEGAL_SEEK ((__off64_t)-1)
 
 /* various events */