Refactor strtod parsing of NaN payloads.

The nan* functions handle their string argument by constructing a NAN(...) string on the stack as a VLA and passing it to strtod functions. This approach has problems discussed in bug 16961 and bug 16962: the stack usage is unbounded, and it gives incorrect results in certain cases where the argument is not a valid n-char-sequence. The natural fix for both issues is to refactor the NaN payload parsing out of strtod into a separate function that the nan* functions can call directly, so that no temporary string needs constructing on the stack at all. This patch does that refactoring in preparation for fixing those bugs (but without actually using the new functions from nan* - which will also require exporting them from libc at version GLIBC_PRIVATE). This patch is not intended to change any user-visible behavior, so no tests are added (fixes for the above bugs will of course add tests for them). This patch builds on my recent fixes for strtol and strtod issues in Turkish locales. Given those fixes, the parsing of NaN payloads is locale-independent; thus, the new functions do not need to take a locale_t argument. Tested for x86_64, x86, mips64 and powerpc. * stdlib/strtod_nan.c: New file. * stdlib/strtod_nan_double.h: Likewise. * stdlib/strtod_nan_float.h: Likewise. * stdlib/strtod_nan_main.c: Likewise. * stdlib/strtod_nan_narrow.h: Likewise. * stdlib/strtod_nan_wide.h: Likewise. * stdlib/strtof_nan.c: Likewise. * stdlib/strtold_nan.c: Likewise. * sysdeps/ieee754/ldbl-128/strtod_nan_ldouble.h: Likewise. * sysdeps/ieee754/ldbl-128ibm/strtod_nan_ldouble.h: Likewise. * sysdeps/ieee754/ldbl-96/strtod_nan_ldouble.h: Likewise. * wcsmbs/wcstod_nan.c: Likewise. * wcsmbs/wcstof_nan.c: Likewise. * wcsmbs/wcstold_nan.c: Likewise. * stdlib/Makefile (routines): Add strtof_nan, strtod_nan and strtold_nan. * wcsmbs/Makefile (routines): Add wcstod_nan, wcstold_nan and wcstof_nan. * include/stdlib.h (__strtof_nan): Declare and use libc_hidden_proto. (__strtod_nan): Likewise. (__strtold_nan): Likewise. (__wcstof_nan): Likewise. (__wcstod_nan): Likewise. (__wcstold_nan): Likewise. * include/wchar.h (____wcstoull_l_internal): Declare. * stdlib/strtod_l.c: Do not include <ieee754.h>. (____strtoull_l_internal): Remove declaration. (STRTOF_NAN): Define macro. (SET_MANTISSA): Remove macro. (STRTOULL): Likewise. (____STRTOF_INTERNAL): Use STRTOF_NAN to parse NaN payload. * stdlib/strtof_l.c (____strtoull_l_internal): Remove declaration. (STRTOF_NAN): Define macro. (SET_MANTISSA): Remove macro. * sysdeps/ieee754/ldbl-128/strtold_l.c (STRTOF_NAN): Define macro. (SET_MANTISSA): Remove macro. * sysdeps/ieee754/ldbl-128ibm/strtold_l.c (STRTOF_NAN): Define macro. (SET_MANTISSA): Remove macro. * sysdeps/ieee754/ldbl-64-128/strtold_l.c (STRTOF_NAN): Define macro. (SET_MANTISSA): Remove macro. * sysdeps/ieee754/ldbl-96/strtold_l.c (STRTOF_NAN): Define macro. (SET_MANTISSA): Remove macro. * wcsmbs/wcstod_l.c (____wcstoull_l_internal): Remove declaration. * wcsmbs/wcstof_l.c (____wcstoull_l_internal): Likewise. * wcsmbs/wcstold_l.c (____wcstoull_l_internal): Likewise.
Manhelp · Nov 24, 2015 · e02cabe · e02cabe
1 parent a7f0c5a
commit e02cabe
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diff --git a/ChangeLog b/ChangeLog
@@ -1,5 +1,54 @@
 2015-11-24  Joseph Myers  <[email protected]>
 
+	* stdlib/strtod_nan.c: New file.
+	* stdlib/strtod_nan_double.h: Likewise.
+	* stdlib/strtod_nan_float.h: Likewise.
+	* stdlib/strtod_nan_main.c: Likewise.
+	* stdlib/strtod_nan_narrow.h: Likewise.
+	* stdlib/strtod_nan_wide.h: Likewise.
+	* stdlib/strtof_nan.c: Likewise.
+	* stdlib/strtold_nan.c: Likewise.
+	* sysdeps/ieee754/ldbl-128/strtod_nan_ldouble.h: Likewise.
+	* sysdeps/ieee754/ldbl-128ibm/strtod_nan_ldouble.h: Likewise.
+	* sysdeps/ieee754/ldbl-96/strtod_nan_ldouble.h: Likewise.
+	* wcsmbs/wcstod_nan.c: Likewise.
+	* wcsmbs/wcstof_nan.c: Likewise.
+	* wcsmbs/wcstold_nan.c: Likewise.
+	* stdlib/Makefile (routines): Add strtof_nan, strtod_nan and
+	strtold_nan.
+	* wcsmbs/Makefile (routines): Add wcstod_nan, wcstold_nan and
+	wcstof_nan.
+	* include/stdlib.h (__strtof_nan): Declare and use
+	libc_hidden_proto.
+	(__strtod_nan): Likewise.
+	(__strtold_nan): Likewise.
+	(__wcstof_nan): Likewise.
+	(__wcstod_nan): Likewise.
+	(__wcstold_nan): Likewise.
+	* include/wchar.h (____wcstoull_l_internal): Declare.
+	* stdlib/strtod_l.c: Do not include <ieee754.h>.
+	(____strtoull_l_internal): Remove declaration.
+	(STRTOF_NAN): Define macro.
+	(SET_MANTISSA): Remove macro.
+	(STRTOULL): Likewise.
+	(____STRTOF_INTERNAL): Use STRTOF_NAN to parse NaN payload.
+	* stdlib/strtof_l.c (____strtoull_l_internal): Remove declaration.
+	(STRTOF_NAN): Define macro.
+	(SET_MANTISSA): Remove macro.
+	* sysdeps/ieee754/ldbl-128/strtold_l.c (STRTOF_NAN): Define macro.
+	(SET_MANTISSA): Remove macro.
+	* sysdeps/ieee754/ldbl-128ibm/strtold_l.c (STRTOF_NAN): Define
+	macro.
+	(SET_MANTISSA): Remove macro.
+	* sysdeps/ieee754/ldbl-64-128/strtold_l.c (STRTOF_NAN): Define
+	macro.
+	(SET_MANTISSA): Remove macro.
+	* sysdeps/ieee754/ldbl-96/strtold_l.c (STRTOF_NAN): Define macro.
+	(SET_MANTISSA): Remove macro.
+	* wcsmbs/wcstod_l.c (____wcstoull_l_internal): Remove declaration.
+	* wcsmbs/wcstof_l.c (____wcstoull_l_internal): Likewise.
+	* wcsmbs/wcstold_l.c (____wcstoull_l_internal): Likewise.
+
 	[BZ #19266]
 	* stdlib/strtod_l.c (____STRTOF_INTERNAL): Check directly for
 	upper case and lower case letters inside NAN(), not using TOLOWER.

diff --git a/include/stdlib.h b/include/stdlib.h
@@ -203,6 +203,24 @@ libc_hidden_proto (strtoll)
 libc_hidden_proto (strtoul)
 libc_hidden_proto (strtoull)
 
+extern float __strtof_nan (const char *, char **, char) internal_function;
+extern double __strtod_nan (const char *, char **, char) internal_function;
+extern long double __strtold_nan (const char *, char **, char)
+     internal_function;
+extern float __wcstof_nan (const wchar_t *, wchar_t **, wchar_t)
+     internal_function;
+extern double __wcstod_nan (const wchar_t *, wchar_t **, wchar_t)
+     internal_function;
+extern long double __wcstold_nan (const wchar_t *, wchar_t **, wchar_t)
+     internal_function;
+
+libc_hidden_proto (__strtof_nan)
+libc_hidden_proto (__strtod_nan)
+libc_hidden_proto (__strtold_nan)
+libc_hidden_proto (__wcstof_nan)
+libc_hidden_proto (__wcstod_nan)
+libc_hidden_proto (__wcstold_nan)
+
 extern char *__ecvt (double __value, int __ndigit, int *__restrict __decpt,
 		     int *__restrict __sign);
 extern char *__fcvt (double __value, int __ndigit, int *__restrict __decpt,

diff --git a/include/wchar.h b/include/wchar.h
@@ -52,6 +52,9 @@ extern unsigned long long int __wcstoull_internal (const wchar_t *
 						   __restrict __endptr,
 						   int __base,
 						   int __group) __THROW;
+extern unsigned long long int ____wcstoull_l_internal (const wchar_t *,
+						       wchar_t **, int, int,
+						       __locale_t);
 libc_hidden_proto (__wcstof_internal)
 libc_hidden_proto (__wcstod_internal)
 libc_hidden_proto (__wcstold_internal)

diff --git a/stdlib/Makefile b/stdlib/Makefile
@@ -50,6 +50,7 @@ routines	:=							      \
 	strtol_l strtoul_l strtoll_l strtoull_l				      \
 	strtof strtod strtold						      \
 	strtof_l strtod_l strtold_l					      \
+	strtof_nan strtod_nan strtold_nan				      \
 	system canonicalize						      \
 	a64l l64a							      \
 	rpmatch strfmon strfmon_l getsubopt xpg_basename fmtmsg		      \

diff --git a/stdlib/strtod_l.c b/stdlib/strtod_l.c
@@ -20,8 +20,6 @@
 #include <xlocale.h>
 
 extern double ____strtod_l_internal (const char *, char **, int, __locale_t);
-extern unsigned long long int ____strtoull_l_internal (const char *, char **,
-						       int, int, __locale_t);
 
 /* Configuration part.  These macros are defined by `strtold.c',
    `strtof.c', `wcstod.c', `wcstold.c', and `wcstof.c' to produce the
@@ -33,27 +31,20 @@ extern unsigned long long int ____strtoull_l_internal (const char *, char **,
 # ifdef USE_WIDE_CHAR
 #  define STRTOF	wcstod_l
 #  define __STRTOF	__wcstod_l
+#  define STRTOF_NAN	__wcstod_nan
 # else
 #  define STRTOF	strtod_l
 #  define __STRTOF	__strtod_l
+#  define STRTOF_NAN	__strtod_nan
 # endif
 # define MPN2FLOAT	__mpn_construct_double
 # define FLOAT_HUGE_VAL	HUGE_VAL
-# define SET_MANTISSA(flt, mant) \
-  do { union ieee754_double u;						      \
-       u.d = (flt);							      \
-       u.ieee_nan.mantissa0 = (mant) >> 32;				      \
-       u.ieee_nan.mantissa1 = (mant);					      \
-       if ((u.ieee.mantissa0 | u.ieee.mantissa1) != 0)			      \
-	 (flt) = u.d;							      \
-  } while (0)
 #endif
 /* End of configuration part.  */
 
 #include <ctype.h>
 #include <errno.h>
 #include <float.h>
-#include <ieee754.h>
 #include "../locale/localeinfo.h"
 #include <locale.h>
 #include <math.h>
@@ -105,7 +96,6 @@ extern unsigned long long int ____strtoull_l_internal (const char *, char **,
 # define TOLOWER_C(Ch) __towlower_l ((Ch), _nl_C_locobj_ptr)
 # define STRNCASECMP(S1, S2, N) \
   __wcsncasecmp_l ((S1), (S2), (N), _nl_C_locobj_ptr)
-# define STRTOULL(S, E, B) ____wcstoull_l_internal ((S), (E), (B), 0, loc)
 #else
 # define STRING_TYPE char
 # define CHAR_TYPE char
@@ -117,7 +107,6 @@ extern unsigned long long int ____strtoull_l_internal (const char *, char **,
 # define TOLOWER_C(Ch) __tolower_l ((Ch), _nl_C_locobj_ptr)
 # define STRNCASECMP(S1, S2, N) \
   __strncasecmp_l ((S1), (S2), (N), _nl_C_locobj_ptr)
-# define STRTOULL(S, E, B) ____strtoull_l_internal ((S), (E), (B), 0, loc)
 #endif
 
 
@@ -649,33 +638,14 @@ ____STRTOF_INTERNAL (const STRING_TYPE *nptr, STRING_TYPE **endptr, int group,
 	  if (*cp == L_('('))
 	    {
 	      const STRING_TYPE *startp = cp;
-	      do
-		++cp;
-	      while ((*cp >= L_('0') && *cp <= L_('9'))
-		     || (*cp >= L_('A') && *cp <= L_('Z'))
-		     || (*cp >= L_('a') && *cp <= L_('z'))
-		     || *cp == L_('_'));
-
-	      if (*cp != L_(')'))
-		/* The closing brace is missing.  Only match the NAN
-		   part.  */
-		cp = startp;
+	      STRING_TYPE *endp;
+	      retval = STRTOF_NAN (cp + 1, &endp, L_(')'));
+	      if (*endp == L_(')'))
+		/* Consume the closing parenthesis.  */
+		cp = endp + 1;
 	      else
-		{
-		  /* This is a system-dependent way to specify the
-		     bitmask used for the NaN.  We expect it to be
-		     a number which is put in the mantissa of the
-		     number.  */
-		  STRING_TYPE *endp;
-		  unsigned long long int mant;
-
-		  mant = STRTOULL (startp + 1, &endp, 0);
-		  if (endp == cp)
-		    SET_MANTISSA (retval, mant);
-
-		  /* Consume the closing brace.  */
-		  ++cp;
-		}
+		/* Only match the NAN part.  */
+		cp = startp;
 	    }
 
 	  if (endptr != NULL)

diff --git a/stdlib/strtod_nan.c b/stdlib/strtod_nan.c
@@ -0,0 +1,24 @@
+/* Convert string for NaN payload to corresponding NaN.  Narrow
+   strings, double.
+   Copyright (C) 2015 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <strtod_nan_narrow.h>
+#include <strtod_nan_double.h>
+
+#define STRTOD_NAN __strtod_nan
+#include <strtod_nan_main.c>
diff --git a/stdlib/strtod_nan_double.h b/stdlib/strtod_nan_double.h
@@ -0,0 +1,30 @@
+/* Convert string for NaN payload to corresponding NaN.  For double.
+   Copyright (C) 1997-2015 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#define FLOAT		double
+#define SET_MANTISSA(flt, mant)				\
+  do							\
+    {							\
+      union ieee754_double u;				\
+      u.d = (flt);					\
+      u.ieee_nan.mantissa0 = (mant) >> 32;		\
+      u.ieee_nan.mantissa1 = (mant);			\
+      if ((u.ieee.mantissa0 | u.ieee.mantissa1) != 0)	\
+	(flt) = u.d;					\
+    }							\
+  while (0)
diff --git a/stdlib/strtod_nan_float.h b/stdlib/strtod_nan_float.h
@@ -0,0 +1,29 @@
+/* Convert string for NaN payload to corresponding NaN.  For float.
+   Copyright (C) 1997-2015 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#define	FLOAT		float
+#define SET_MANTISSA(flt, mant)			\
+  do						\
+    {						\
+      union ieee754_float u;			\
+      u.f = (flt);				\
+      u.ieee_nan.mantissa = (mant);		\
+      if (u.ieee.mantissa != 0)			\
+	(flt) = u.f;				\
+    }						\
+  while (0)
diff --git a/stdlib/strtod_nan_main.c b/stdlib/strtod_nan_main.c
@@ -0,0 +1,63 @@
+/* Convert string for NaN payload to corresponding NaN.
+   Copyright (C) 1997-2015 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <ieee754.h>
+#include <locale.h>
+#include <math.h>
+#include <stdlib.h>
+#include <wchar.h>
+
+
+/* If STR starts with an optional n-char-sequence as defined by ISO C
+   (a sequence of ASCII letters, digits and underscores), followed by
+   ENDC, return a NaN whose payload is set based on STR.  Otherwise,
+   return a default NAN.  If ENDPTR is not NULL, set *ENDPTR to point
+   to the character after the initial n-char-sequence.  */
+
+internal_function
+FLOAT
+STRTOD_NAN (const STRING_TYPE *str, STRING_TYPE **endptr, STRING_TYPE endc)
+{
+  const STRING_TYPE *cp = str;
+
+  while ((*cp >= L_('0') && *cp <= L_('9'))
+	 || (*cp >= L_('A') && *cp <= L_('Z'))
+	 || (*cp >= L_('a') && *cp <= L_('z'))
+	 || *cp == L_('_'))
+    ++cp;
+
+  FLOAT retval = NAN;
+  if (*cp != endc)
+    goto out;
+
+  /* This is a system-dependent way to specify the bitmask used for
+     the NaN.  We expect it to be a number which is put in the
+     mantissa of the number.  */
+  STRING_TYPE *endp;
+  unsigned long long int mant;
+
+  mant = STRTOULL (str, &endp, 0);
+  if (endp == cp)
+    SET_MANTISSA (retval, mant);
+
+ out:
+  if (endptr != NULL)
+    *endptr = (STRING_TYPE *) cp;
+  return retval;
+}
+libc_hidden_def (STRTOD_NAN)
diff --git a/stdlib/strtod_nan_narrow.h b/stdlib/strtod_nan_narrow.h
@@ -0,0 +1,22 @@
+/* Convert string for NaN payload to corresponding NaN.  Narrow strings.
+   Copyright (C) 1997-2015 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#define STRING_TYPE char
+#define L_(Ch) Ch
+#define STRTOULL(S, E, B) ____strtoull_l_internal ((S), (E), (B), 0,	\
+						   _nl_C_locobj_ptr)
diff --git a/stdlib/strtod_nan_wide.h b/stdlib/strtod_nan_wide.h
@@ -0,0 +1,22 @@
+/* Convert string for NaN payload to corresponding NaN.  Wide strings.
+   Copyright (C) 1997-2015 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#define STRING_TYPE wchar_t
+#define L_(Ch) L##Ch
+#define STRTOULL(S, E, B) ____wcstoull_l_internal ((S), (E), (B), 0,	\
+						   _nl_C_locobj_ptr)