* misc/sys/cdefs.h (__warndecl, __errordecl): For GCC 4.3+ define

	with __warning__/__error__ attributes.
	(__warnattr): Define.
	* stdlib/bits/stdlib.h (__realpath_chk_warn, __ptsname_r_chk_warn,
	__mbstowcs_chk_warn, __wcstombs_chk_warn): New aliases with
	__warnattr.
	(realpath, ptsname_r, mbstowcs, wcstombs): Call __*_chk_warn instead
	of __*_chk if compile time detectable overflow is found.
	* libio/bits/stdio2.h (__fgets_chk_warn, __fread_chk_warn,
	__fgets_unlocked_chk_warn, __fread_unlocked_chk_warn): New aliases
	with __warnattr.
	(fgets, fread, fgets_unlocked, fread_unlocked): Call __*_chk_warn
	instead of __*_chk if compile time detectable overflow is found.
	(__gets_alias): Rename to...
	(__gets_warn): ... this.  Add __warnattr.
	(gets): Call __gets_warn instead of __gets_alias.
	* socket/bits/socket2.h (__recv_chk_warn, __recvfrom_chk_warn): New
	aliases with __warnattr.
	(recv, recvfrom): Call __*_chk_warn instead of __*_chk if compile
	time detectable overflow is found.
	* posix/bits/unistd.h (__read_chk_warn, __pread_chk_warn,
	__pread64_chk_warn, __readlink_chk_warn, __readlinkat_chk_warn,
	__getcwd_chk_warn, __confstr_chk_warn, __getgroups_chk_warn,
	__ttyname_r_chk_warn, __getlogin_r_chk_warn, __gethostname_chk_warn,
	__getdomainname_chk_warn): New aliases with __warnattr.
	(read, pread, pread64, readlink, readlinkat, getcwd, confstr,
	getgroups, ttyname_r, getlogin_r, gethostname, getdomainname): Call
	__*_chk_warn instead of __*_chk if compile time detectable overflow
	is found.
	(__getgroups_chk): Rename argument to __listlen from listlen.
	(__getwd_alias): Rename to...
	(__getwd_warn): ... this.  Add __warnattr.
	(getwd): Call __getwd_warn instead of __getwd_alias.
	* wcsmbs/bits/wchar2.h (__wmemcpy_chk_warn, __wmemmove_chk_warn,
	__wmempcpy_chk_warn, __wmemset_chk_warn, __wcsncpy_chk_warn,
	__wcpncpy_chk_warn, __fgetws_chk_warn, __fgetws_unlocked_chk_warn,
	__mbsrtowcs_chk_warn, __wcsrtombs_chk_warn, __mbsnrtowcs_chk_warn,
	__wcsnrtombs_chk_warn): New aliases with __warnattr.
	(wmemcpy, wmemmove, wmempcpy, wmemset, mbsrtowcs, wcsrtombs,
	mbsnrtowcs, wcsnrtombs): Call __*_chk_warn instead of __*_chk if
	compile time detectable overflow is found.
	(wcsncpy, wcpncpy): Likewise.  For constant __n fix check whether
	to use __*_chk or not.
	(fgetws, fgetws_unlocked): Divide __bos by sizeof (wchar_t), both
	in comparisons which function should be called and in __*_chk*
	arguments.  Call __*_chk_warn instead of __*_chk if compile time
	detectable overflow is found.
	(swprintf, vswprintf): Divide __bos by sizeof (wchar_t) in
	__*_chk argument.
	* debug/tst-chk1.c (do_test): Add a few more tests.

8 files changed, 601 insertions, 122 deletions

diff --git a/ChangeLog b/ChangeLog
index 682c2e3d1f..ed21b4f857 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,56 @@
+2007-09-26  Jakub Jelinek  <jakub@redhat.com>
+
+	* misc/sys/cdefs.h (__warndecl, __errordecl): For GCC 4.3+ define
+	with __warning__/__error__ attributes.
+	(__warnattr): Define.
+	* stdlib/bits/stdlib.h (__realpath_chk_warn, __ptsname_r_chk_warn,
+	__mbstowcs_chk_warn, __wcstombs_chk_warn): New aliases with
+	__warnattr.
+	(realpath, ptsname_r, mbstowcs, wcstombs): Call __*_chk_warn instead
+	of __*_chk if compile time detectable overflow is found.
+	* libio/bits/stdio2.h (__fgets_chk_warn, __fread_chk_warn,
+	__fgets_unlocked_chk_warn, __fread_unlocked_chk_warn): New aliases
+	with __warnattr.
+	(fgets, fread, fgets_unlocked, fread_unlocked): Call __*_chk_warn
+	instead of __*_chk if compile time detectable overflow is found.
+	(__gets_alias): Rename to...
+	(__gets_warn): ... this.  Add __warnattr.
+	(gets): Call __gets_warn instead of __gets_alias.
+	* socket/bits/socket2.h (__recv_chk_warn, __recvfrom_chk_warn): New
+	aliases with __warnattr.
+	(recv, recvfrom): Call __*_chk_warn instead of __*_chk if compile
+	time detectable overflow is found.
+	* posix/bits/unistd.h (__read_chk_warn, __pread_chk_warn,
+	__pread64_chk_warn, __readlink_chk_warn, __readlinkat_chk_warn,
+	__getcwd_chk_warn, __confstr_chk_warn, __getgroups_chk_warn,
+	__ttyname_r_chk_warn, __getlogin_r_chk_warn, __gethostname_chk_warn,
+	__getdomainname_chk_warn): New aliases with __warnattr.
+	(read, pread, pread64, readlink, readlinkat, getcwd, confstr,
+	getgroups, ttyname_r, getlogin_r, gethostname, getdomainname): Call
+	__*_chk_warn instead of __*_chk if compile time detectable overflow
+	is found.
+	(__getgroups_chk): Rename argument to __listlen from listlen.
+	(__getwd_alias): Rename to...
+	(__getwd_warn): ... this.  Add __warnattr.
+	(getwd): Call __getwd_warn instead of __getwd_alias.
+	* wcsmbs/bits/wchar2.h (__wmemcpy_chk_warn, __wmemmove_chk_warn,
+	__wmempcpy_chk_warn, __wmemset_chk_warn, __wcsncpy_chk_warn,
+	__wcpncpy_chk_warn, __fgetws_chk_warn, __fgetws_unlocked_chk_warn,
+	__mbsrtowcs_chk_warn, __wcsrtombs_chk_warn, __mbsnrtowcs_chk_warn,
+	__wcsnrtombs_chk_warn): New aliases with __warnattr.
+	(wmemcpy, wmemmove, wmempcpy, wmemset, mbsrtowcs, wcsrtombs,
+	mbsnrtowcs, wcsnrtombs): Call __*_chk_warn instead of __*_chk if
+	compile time detectable overflow is found.
+	(wcsncpy, wcpncpy): Likewise.  For constant __n fix check whether
+	to use __*_chk or not.
+	(fgetws, fgetws_unlocked): Divide __bos by sizeof (wchar_t), both
+	in comparisons which function should be called and in __*_chk*
+	arguments.  Call __*_chk_warn instead of __*_chk if compile time
+	detectable overflow is found.
+	(swprintf, vswprintf): Divide __bos by sizeof (wchar_t) in
+	__*_chk argument.
+	* debug/tst-chk1.c (do_test): Add a few more tests.
+
 2007-09-24  Ulrich Drepper  <drepper@redhat.com>
 
 	[BZ #5058]
diff --git a/debug/tst-chk1.c b/debug/tst-chk1.c
index 78a61be53b..487b071026 100644
--- a/debug/tst-chk1.c
+++ b/debug/tst-chk1.c
@@ -317,6 +317,14 @@ do_test (void)
   CHK_FAIL_START
   snprintf (buf + 8, l0 + 3, "%d", num2);
   CHK_FAIL_END
+
+  CHK_FAIL_START
+  swprintf (wbuf + 8, 3, L"%d", num1);
+  CHK_FAIL_END
+
+  CHK_FAIL_START
+  swprintf (wbuf + 8, l0 + 3, L"%d", num1);
+  CHK_FAIL_END
 # endif
 
   memcpy (buf, str1 + 2, l0 + 9);
@@ -514,11 +522,15 @@ do_test (void)
   CHK_FAIL_END
 
   CHK_FAIL_START
+  wmemcpy (wbuf + 9, L"abcdefghij", l0 + 10);
+  CHK_FAIL_END
+
+  CHK_FAIL_START
   wmemmove (wbuf + 2, wbuf + 1, l0 + 9);
   CHK_FAIL_END
 
   CHK_FAIL_START
-    wp = wmempcpy (wbuf + 6, L"abcde", l0 + 5);
+  wp = wmempcpy (wbuf + 6, L"abcde", l0 + 5);
   CHK_FAIL_END
 
   CHK_FAIL_START
@@ -538,6 +550,14 @@ do_test (void)
   CHK_FAIL_END
 
   CHK_FAIL_START
+  wcsncpy (wbuf + 9, L"XABCDEFGH", 8);
+  CHK_FAIL_END
+
+  CHK_FAIL_START
+  wcpncpy (wbuf + 9, L"XABCDEFGH", 8);
+  CHK_FAIL_END
+
+  CHK_FAIL_START
   wcpncpy (wbuf + 6, L"cd", l0 + 5);
   CHK_FAIL_END
 
diff --git a/libio/bits/stdio2.h b/libio/bits/stdio2.h
index 841a0ff6aa..8889540689 100644
--- a/libio/bits/stdio2.h
+++ b/libio/bits/stdio2.h
@@ -131,14 +131,16 @@ vfprintf (FILE *__restrict __stream,
 #endif
 
 extern char *__gets_chk (char *__str, size_t) __wur;
-extern char *__REDIRECT (__gets_alias, (char *__str), gets) __wur;
+extern char *__REDIRECT (__gets_warn, (char *__str), gets)
+     __wur __warnattr ("please use fgets or getline instead, gets can't "
+		       "specify buffer size");
 
 __extern_always_inline __wur char *
 gets (char *__str)
 {
   if (__bos (__str) != (size_t) -1)
     return __gets_chk (__str, __bos (__str));
-  return __gets_alias (__str);
+  return __gets_warn (__str);
 }
 
 extern char *__fgets_chk (char *__restrict __s, size_t __size, int __n,
@@ -146,13 +148,23 @@ extern char *__fgets_chk (char *__restrict __s, size_t __size, int __n,
 extern char *__REDIRECT (__fgets_alias,
 			 (char *__restrict __s, int __n,
 			  FILE *__restrict __stream), fgets) __wur;
+extern char *__REDIRECT (__fgets_chk_warn,
+			 (char *__restrict __s, size_t __size, int __n,
+			  FILE *__restrict __stream), __fgets_chk)
+     __wur __warnattr ("fgets called with bigger size than length "
+		       "of destination buffer");
 
 __extern_always_inline __wur char *
 fgets (char *__restrict __s, int __n, FILE *__restrict __stream)
 {
-  if (__bos (__s) != (size_t) -1
-      && (!__builtin_constant_p (__n) || (size_t) __n > __bos (__s)))
-    return __fgets_chk (__s, __bos (__s), __n, __stream);
+  if (__bos (__s) != (size_t) -1)
+    {
+      if (!__builtin_constant_p (__n) || __n <= 0)
+	return __fgets_chk (__s, __bos (__s), __n, __stream);
+
+      if ((size_t) __n > __bos (__s))
+	return __fgets_chk_warn (__s, __bos (__s), __n, __stream);
+    }
   return __fgets_alias (__s, __n, __stream);
 }
 
@@ -163,17 +175,28 @@ extern size_t __REDIRECT (__fread_alias,
 			  (void *__restrict __ptr, size_t __size,
 			   size_t __n, FILE *__restrict __stream),
 			  fread) __wur;
+extern size_t __REDIRECT (__fread_chk_warn,
+			  (void *__restrict __ptr, size_t __ptrlen,
+			   size_t __size, size_t __n,
+			   FILE *__restrict __stream),
+			  __fread_chk)
+     __wur __warnattr ("fread called with bigger size * nmemb than length "
+		       "of destination buffer");
 
 __extern_always_inline __wur size_t
 fread (void *__restrict __ptr, size_t __size, size_t __n,
        FILE *__restrict __stream)
 {
-  if (__bos0 (__ptr) != (size_t) -1
-      && (!__builtin_constant_p (__size)
+  if (__bos0 (__ptr) != (size_t) -1)
+    {
+      if (!__builtin_constant_p (__size)
 	  || !__builtin_constant_p (__n)
-	  || (__size | __n) >= (((size_t) 1) << (8 * sizeof (size_t) / 2))
-	  || __size * __n > __bos0 (__ptr)))
-    return __fread_chk (__ptr, __bos0 (__ptr), __size, __n, __stream);
+	  || (__size | __n) >= (((size_t) 1) << (8 * sizeof (size_t) / 2)))
+	return __fread_chk (__ptr, __bos0 (__ptr), __size, __n, __stream);
+
+      if (__size * __n > __bos0 (__ptr))
+	return __fread_chk_warn (__ptr, __bos0 (__ptr), __size, __n, __stream);
+    }
   return __fread_alias (__ptr, __size, __n, __stream);
 }
 
@@ -183,13 +206,23 @@ extern char *__fgets_unlocked_chk (char *__restrict __s, size_t __size,
 extern char *__REDIRECT (__fgets_unlocked_alias,
 			 (char *__restrict __s, int __n,
 			  FILE *__restrict __stream), fgets_unlocked) __wur;
+extern char *__REDIRECT (__fgets_unlocked_chk_warn,
+			 (char *__restrict __s, size_t __size, int __n,
+			  FILE *__restrict __stream), __fgets_unlocked_chk)
+     __wur __warnattr ("fgets_unlocked called with bigger size than length "
+		       "of destination buffer");
 
 __extern_always_inline __wur char *
 fgets_unlocked (char *__restrict __s, int __n, FILE *__restrict __stream)
 {
-  if (__bos (__s) != (size_t) -1
-      && (!__builtin_constant_p (__n) || (size_t) __n > __bos (__s)))
-    return __fgets_unlocked_chk (__s, __bos (__s), __n, __stream);
+  if (__bos (__s) != (size_t) -1)
+    {
+      if (!__builtin_constant_p (__n) || __n <= 0)
+	return __fgets_unlocked_chk (__s, __bos (__s), __n, __stream);
+
+      if ((size_t) __n > __bos (__s))
+	return __fgets_unlocked_chk_warn (__s, __bos (__s), __n, __stream);
+    }
   return __fgets_unlocked_alias (__s, __n, __stream);
 }
 #endif
@@ -203,17 +236,30 @@ extern size_t __REDIRECT (__fread_unlocked_alias,
 			  (void *__restrict __ptr, size_t __size,
 			   size_t __n, FILE *__restrict __stream),
 			  fread_unlocked) __wur;
+extern size_t __REDIRECT (__fread_unlocked_chk_warn,
+			  (void *__restrict __ptr, size_t __ptrlen,
+			   size_t __size, size_t __n,
+			   FILE *__restrict __stream),
+			  __fread_unlocked_chk)
+     __wur __warnattr ("fread_unlocked called with bigger size * nmemb than "
+		       "length of destination buffer");
 
 __extern_always_inline __wur size_t
 fread_unlocked (void *__restrict __ptr, size_t __size, size_t __n,
 		FILE *__restrict __stream)
 {
-  if (__bos0 (__ptr) != (size_t) -1
-      && (!__builtin_constant_p (__size)
+  if (__bos0 (__ptr) != (size_t) -1)
+    {
+      if (!__builtin_constant_p (__size)
 	  || !__builtin_constant_p (__n)
-	  || (__size | __n) >= (((size_t) 1) << (8 * sizeof (size_t) / 2))
-	  || __size * __n > __bos0 (__ptr)))
-    return __fread_unlocked_chk (__ptr, __bos0 (__ptr), __size, __n, __stream);
+	  || (__size | __n) >= (((size_t) 1) << (8 * sizeof (size_t) / 2)))
+	return __fread_unlocked_chk (__ptr, __bos0 (__ptr), __size, __n,
+				     __stream);
+
+      if (__size * __n > __bos0 (__ptr))
+	return __fread_unlocked_chk_warn (__ptr, __bos0 (__ptr), __size, __n,
+					  __stream);
+    }
 
 # ifdef __USE_EXTERN_INLINES
   if (__builtin_constant_p (__size)
diff --git a/misc/sys/cdefs.h b/misc/sys/cdefs.h
index 26b9490bad..4650d5f74e 100644
--- a/misc/sys/cdefs.h
+++ b/misc/sys/cdefs.h
@@ -131,9 +131,18 @@
 /* Fortify support.  */
 #define __bos(ptr) __builtin_object_size (ptr, __USE_FORTIFY_LEVEL > 1)
 #define __bos0(ptr) __builtin_object_size (ptr, 0)
-#define __warndecl(name, msg) extern void name (void)
-#define __errordecl(name, msg) extern void name (void)
 
+#if __GNUC_PREREQ (4,3)
+# define __warndecl(name, msg) \
+  extern void name (void) __attribute__((__warning__ (msg)))
+# define __warnattr(msg) __attribute__((__warning__ (msg)))
+# define __errordecl(name, msg) \
+  extern void name (void) __attribute__((__error__ (msg)))
+#else
+# define __warndecl(name, msg) extern void name (void)
+# define __warnattr(msg)
+# define __errordecl(name, msg) extern void name (void)
+#endif
 
 /* Support for flexible arrays.  */
 #if __GNUC_PREREQ (2,97)
diff --git a/posix/bits/unistd.h b/posix/bits/unistd.h
index 331e8ea3b9..efd7f75a50 100644
--- a/posix/bits/unistd.h
+++ b/posix/bits/unistd.h
@@ -25,13 +25,23 @@ extern ssize_t __read_chk (int __fd, void *__buf, size_t __nbytes,
 			   size_t __buflen) __wur;
 extern ssize_t __REDIRECT (__read_alias, (int __fd, void *__buf,
 					  size_t __nbytes), read) __wur;
+extern ssize_t __REDIRECT (__read_chk_warn,
+			   (int __fd, void *__buf, size_t __nbytes,
+			    size_t __buflen), __read_chk)
+     __wur __warnattr ("read called with bigger length than size of "
+		       "the destination buffer");
 
 __extern_always_inline __wur ssize_t
 read (int __fd, void *__buf, size_t __nbytes)
 {
-  if (__bos0 (__buf) != (size_t) -1
-      && (!__builtin_constant_p (__nbytes) || __nbytes > __bos0 (__buf)))
-    return __read_chk (__fd, __buf, __nbytes, __bos0 (__buf));
+  if (__bos0 (__buf) != (size_t) -1)
+    {
+      if (!__builtin_constant_p (__nbytes))
+	return __read_chk (__fd, __buf, __nbytes, __bos0 (__buf));
+
+      if (__nbytes > __bos0 (__buf))
+	return __read_chk_warn (__fd, __buf, __nbytes, __bos0 (__buf));
+    }
   return __read_alias (__fd, __buf, __nbytes);
 }
 
@@ -46,23 +56,47 @@ extern ssize_t __REDIRECT (__pread_alias,
 extern ssize_t __REDIRECT (__pread64_alias,
 			   (int __fd, void *__buf, size_t __nbytes,
 			    __off64_t __offset), pread64) __wur;
+extern ssize_t __REDIRECT (__pread_chk_warn,
+			   (int __fd, void *__buf, size_t __nbytes,
+			    __off_t __offset, size_t __bufsize), __pread_chk)
+     __wur __warnattr ("pread called with bigger length than size of "
+		       "the destination buffer");
+extern ssize_t __REDIRECT (__pread64_chk_warn,
+			   (int __fd, void *__buf, size_t __nbytes,
+			    __off64_t __offset, size_t __bufsize),
+			    __pread64_chk)
+     __wur __warnattr ("pread64 called with bigger length than size of "
+		       "the destination buffer");
 
 # ifndef __USE_FILE_OFFSET64
 __extern_always_inline __wur ssize_t
 pread (int __fd, void *__buf, size_t __nbytes, __off_t __offset)
 {
-  if (__bos0 (__buf) != (size_t) -1
-      && (!__builtin_constant_p (__nbytes) || __nbytes > __bos0 (__buf)))
-    return __pread_chk (__fd, __buf, __nbytes, __offset, __bos0 (__buf));
+  if (__bos0 (__buf) != (size_t) -1)
+    {
+      if (!__builtin_constant_p (__nbytes))
+	return __pread_chk (__fd, __buf, __nbytes, __offset, __bos0 (__buf));
+
+      if ( __nbytes > __bos0 (__buf))
+	return __pread_chk_warn (__fd, __buf, __nbytes, __offset,
+				 __bos0 (__buf));
+    }
   return __pread_alias (__fd, __buf, __nbytes, __offset);
 }
 # else
 __extern_always_inline __wur ssize_t
 pread (int __fd, void *__buf, size_t __nbytes, __off64_t __offset)
 {
-  if (__bos0 (__buf) != (size_t) -1
-      && (!__builtin_constant_p (__nbytes) || __nbytes > __bos0 (__buf)))
-    return __pread64_chk (__fd, __buf, __nbytes, __offset, __bos0 (__buf));
+  if (__bos0 (__buf) != (size_t) -1)
+    {
+      if (!__builtin_constant_p (__nbytes))
+	return __pread64_chk (__fd, __buf, __nbytes, __offset, __bos0 (__buf));
+
+      if ( __nbytes > __bos0 (__buf))
+	return __pread64_chk_warn (__fd, __buf, __nbytes, __offset,
+				   __bos0 (__buf));
+    }
+
   return __pread64_alias (__fd, __buf, __nbytes, __offset);
 }
 # endif
@@ -71,9 +105,16 @@ pread (int __fd, void *__buf, size_t __nbytes, __off64_t __offset)
 __extern_always_inline __wur ssize_t
 pread64 (int __fd, void *__buf, size_t __nbytes, __off64_t __offset)
 {
-  if (__bos0 (__buf) != (size_t) -1
-      && (!__builtin_constant_p (__nbytes) || __nbytes > __bos0 (__buf)))
-    return __pread64_chk (__fd, __buf, __nbytes, __offset, __bos0 (__buf));
+  if (__bos0 (__buf) != (size_t) -1)
+    {
+      if (!__builtin_constant_p (__nbytes))
+	return __pread64_chk (__fd, __buf, __nbytes, __offset, __bos0 (__buf));
+
+      if ( __nbytes > __bos0 (__buf))
+	return __pread64_chk_warn (__fd, __buf, __nbytes, __offset,
+				   __bos0 (__buf));
+    }
+
   return __pread64_alias (__fd, __buf, __nbytes, __offset);
 }
 # endif
@@ -88,14 +129,25 @@ extern ssize_t __REDIRECT_NTH (__readlink_alias,
 			       (__const char *__restrict __path,
 				char *__restrict __buf, size_t __len), readlink)
      __nonnull ((1, 2)) __wur;
+extern ssize_t __REDIRECT_NTH (__readlink_chk_warn,
+			       (__const char *__restrict __path,
+				char *__restrict __buf, size_t __len,
+				size_t __buflen), __readlink_chk)
+     __nonnull ((1, 2)) __wur __warnattr ("readlink called with bigger length "
+					  "than size of destination buffer");
 
 __extern_always_inline __nonnull ((1, 2)) __wur ssize_t
 __NTH (readlink (__const char *__restrict __path, char *__restrict __buf,
 		 size_t __len))
 {
-  if (__bos (__buf) != (size_t) -1
-      && (!__builtin_constant_p (__len) || __len > __bos (__buf)))
-    return __readlink_chk (__path, __buf, __len, __bos (__buf));
+  if (__bos (__buf) != (size_t) -1)
+    {
+      if (!__builtin_constant_p (__len))
+	return __readlink_chk (__path, __buf, __len, __bos (__buf));
+
+      if ( __len > __bos (__buf))
+	return __readlink_chk_warn (__path, __buf, __len, __bos (__buf));
+    }
   return __readlink_alias (__path, __buf, __len);
 }
 #endif
@@ -110,14 +162,27 @@ extern ssize_t __REDIRECT_NTH (__readlinkat_alias,
 				char *__restrict __buf, size_t __len),
 			       readlinkat)
      __nonnull ((2, 3)) __wur;
+extern ssize_t __REDIRECT_NTH (__readlinkat_chk_warn,
+			       (int __fd, __const char *__restrict __path,
+				char *__restrict __buf, size_t __len,
+				size_t __buflen), __readlinkat_chk)
+     __nonnull ((2, 3)) __wur __warnattr ("readlinkat called with bigger "
+					  "length than size of destination "
+					  "buffer");
 
 __extern_always_inline __nonnull ((2, 3)) __wur ssize_t
 __NTH (readlinkat (int __fd, __const char *__restrict __path,
 		   char *__restrict __buf, size_t __len))
 {
-  if (__bos (__buf) != (size_t) -1
-      && (!__builtin_constant_p (__len) || __len > __bos (__buf)))
-    return __readlinkat_chk (__fd, __path, __buf, __len, __bos (__buf));
+  if (__bos (__buf) != (size_t) -1)
+    {
+      if (!__builtin_constant_p (__len))
+	return __readlinkat_chk (__fd, __path, __buf, __len, __bos (__buf));
+
+      if (__len > __bos (__buf))
+	return __readlinkat_chk_warn (__fd, __path, __buf, __len,
+				      __bos (__buf));
+    }
   return __readlinkat_alias (__fd, __path, __buf, __len);
 }
 #endif
@@ -126,28 +191,39 @@ extern char *__getcwd_chk (char *__buf, size_t __size, size_t __buflen)
      __THROW __wur;
 extern char *__REDIRECT_NTH (__getcwd_alias,
 			     (char *__buf, size_t __size), getcwd) __wur;
+extern char *__REDIRECT_NTH (__getcwd_chk_warn,
+			     (char *__buf, size_t __size, size_t __buflen),
+			     __getcwd_chk)
+     __wur __warnattr ("getcwd caller with bigger length than size of "
+		       "destination buffer");
 
 __extern_always_inline __wur char *
 __NTH (getcwd (char *__buf, size_t __size))
 {
-  if (__bos (__buf) != (size_t) -1
-      && (!__builtin_constant_p (__size) || __size > __bos (__buf)))
-    return __getcwd_chk (__buf, __size, __bos (__buf));
+  if (__bos (__buf) != (size_t) -1)
+    {
+      if (!__builtin_constant_p (__size))
+	return __getcwd_chk (__buf, __size, __bos (__buf));
+
+      if (__size > __bos (__buf))
+	return __getcwd_chk_warn (__buf, __size, __bos (__buf));
+    }
   return __getcwd_alias (__buf, __size);
 }
 
 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
 extern char *__getwd_chk (char *__buf, size_t buflen)
      __THROW __nonnull ((1)) __wur;
-extern char *__REDIRECT_NTH (__getwd_alias, (char *__buf), getwd)
-     __nonnull ((1)) __wur;
+extern char *__REDIRECT_NTH (__getwd_warn, (char *__buf), getwd)
+     __nonnull ((1)) __wur __warnattr ("please use getcwd instead, as getwd "
+				       "doesn't specify buffer size");
 
 __extern_always_inline __nonnull ((1)) __attribute_deprecated__ __wur char *
 __NTH (getwd (char *__buf))
 {
   if (__bos (__buf) != (size_t) -1)
     return __getwd_chk (__buf, __bos (__buf));
-  return __getwd_alias (__buf);
+  return __getwd_warn (__buf);
 }
 #endif
 
@@ -155,29 +231,48 @@ extern size_t __confstr_chk (int __name, char *__buf, size_t __len,
 			     size_t __buflen) __THROW;
 extern size_t __REDIRECT_NTH (__confstr_alias, (int __name, char *__buf,
 						size_t __len), confstr);
+extern size_t __REDIRECT_NTH (__confstr_chk_warn,
+			      (int __name, char *__buf, size_t __len,
+			       size_t __buflen), __confstr_chk)
+     __warnattr ("confstr called with bigger length than size of destination "
+		 "buffer");
 
 __extern_always_inline size_t
 __NTH (confstr (int __name, char *__buf, size_t __len))
 {
-  if (__bos (__buf) != (size_t) -1
-      && (!__builtin_constant_p (__len) || __bos (__buf) < __len))
-    return __confstr_chk (__name, __buf, __len, __bos (__buf));
+  if (__bos (__buf) != (size_t) -1)
+    {
+      if (!__builtin_constant_p (__len))
+	return __confstr_chk (__name, __buf, __len, __bos (__buf));
+
+      if (__bos (__buf) < __len)
+	return __confstr_chk_warn (__name, __buf, __len, __bos (__buf));
+    }
   return __confstr_alias (__name, __buf, __len);
 }
 
 
-extern int __getgroups_chk (int __size, __gid_t __list[], size_t listlen)
+extern int __getgroups_chk (int __size, __gid_t __list[], size_t __listlen)
      __THROW __wur;
 extern int __REDIRECT_NTH (__getgroups_alias, (int __size, __gid_t __list[]),
 			   getgroups) __wur;
+extern int __REDIRECT_NTH (__getgroups_chk_warn,
+			   (int __size, __gid_t __list[], size_t __listlen),
+			   __getgroups_chk)
+     __wur __warnattr ("getgroups called with bigger group count than what "
+		       "can fit into destination buffer");
 
 __extern_always_inline int
 __NTH (getgroups (int __size, __gid_t __list[]))
 {
-  if (__bos (__list) != (size_t) -1
-      && (!__builtin_constant_p (__size)
-	  || __size * sizeof (__gid_t) > __bos (__list)))
-    return __getgroups_chk (__size, __list, __bos (__list));
+  if (__bos (__list) != (size_t) -1)
+    {
+      if (!__builtin_constant_p (__size))
+	return __getgrou