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authorJoseph Myers <joseph@codesourcery.com>2015-12-04 20:36:28 +0000
committerJoseph Myers <joseph@codesourcery.com>2015-12-04 20:36:28 +0000
commit8f5e8b01a1da2a207228f2072c934fa5918554b8 (patch)
treec9d9d33b21af5a9df86f398d2d1fd6b42eee1e28 /math
parent79e0d340a9e7fb2c931686462131c92b99611003 (diff)
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Fix nan functions handling of payload strings (bug 16961, bug 16962).
The nan, nanf and nanl functions handle payload strings by doing e.g.: if (tagp[0] != '\0') { char buf[6 + strlen (tagp)]; sprintf (buf, "NAN(%s)", tagp); return strtod (buf, NULL); } This is an unbounded stack allocation based on the length of the argument. Furthermore, if the argument starts with an n-char-sequence followed by ')', that n-char-sequence is wrongly treated as significant for determining the payload of the resulting NaN, when ISO C says the call should be equivalent to strtod ("NAN", NULL), without being affected by that initial n-char-sequence. This patch fixes both those problems by using the __strtod_nan etc. functions recently factored out of strtod etc. for that purpose, with those functions being exported from libc at version GLIBC_PRIVATE. Tested for x86_64, x86, mips64 and powerpc. [BZ #16961] [BZ #16962] * math/s_nan.c (__nan): Use __strtod_nan instead of constructing a string on the stack for strtod. * math/s_nanf.c (__nanf): Use __strtof_nan instead of constructing a string on the stack for strtof. * math/s_nanl.c (__nanl): Use __strtold_nan instead of constructing a string on the stack for strtold. * stdlib/Versions (libc): Add __strtof_nan, __strtod_nan and __strtold_nan to GLIBC_PRIVATE. * math/test-nan-overflow.c: New file. * math/test-nan-payload.c: Likewise. * math/Makefile (tests): Add test-nan-overflow and test-nan-payload.
Diffstat (limited to 'math')
-rw-r--r--math/Makefile3
-rw-r--r--math/s_nan.c9
-rw-r--r--math/s_nanf.c9
-rw-r--r--math/s_nanl.c9
-rw-r--r--math/test-nan-overflow.c66
-rw-r--r--math/test-nan-payload.c122
6 files changed, 193 insertions, 25 deletions
diff --git a/math/Makefile b/math/Makefile
index 20f90d9..32f5730 100644
--- a/math/Makefile
+++ b/math/Makefile
@@ -113,7 +113,8 @@ tests = test-matherr test-fenv atest-exp atest-sincos atest-exp2 basic-test \
test-signgam-finite-c99 test-signgam-finite-c11 \
test-nearbyint-except-2 test-signgam-uchar test-signgam-uchar-init \
test-signgam-uint test-signgam-uint-init test-signgam-ullong \
- test-signgam-ullong-init $(tests-static)
+ test-signgam-ullong-init test-nan-overflow test-nan-payload \
+ $(tests-static)
tests-static = test-fpucw-static test-fpucw-ieee-static \
test-signgam-uchar-static test-signgam-uchar-init-static \
test-signgam-uint-static test-signgam-uint-init-static \
diff --git a/math/s_nan.c b/math/s_nan.c
index f4b30a2..a6f3006 100644
--- a/math/s_nan.c
+++ b/math/s_nan.c
@@ -28,14 +28,7 @@
double
__nan (const char *tagp)
{
- if (tagp[0] != '\0')
- {
- char buf[6 + strlen (tagp)];
- sprintf (buf, "NAN(%s)", tagp);
- return strtod (buf, NULL);
- }
-
- return NAN;
+ return __strtod_nan (tagp, NULL, 0);
}
weak_alias (__nan, nan)
#ifdef NO_LONG_DOUBLE
diff --git a/math/s_nanf.c b/math/s_nanf.c
index 2d3fcc5..6a98422 100644
--- a/math/s_nanf.c
+++ b/math/s_nanf.c
@@ -28,13 +28,6 @@
float
__nanf (const char *tagp)
{
- if (tagp[0] != '\0')
- {
- char buf[6 + strlen (tagp)];
- sprintf (buf, "NAN(%s)", tagp);
- return strtof (buf, NULL);
- }
-
- return NAN;
+ return __strtof_nan (tagp, NULL, 0);
}
weak_alias (__nanf, nanf)
diff --git a/math/s_nanl.c b/math/s_nanl.c
index 73387a9..4e1fc80 100644
--- a/math/s_nanl.c
+++ b/math/s_nanl.c
@@ -28,13 +28,6 @@
long double
__nanl (const char *tagp)
{
- if (tagp[0] != '\0')
- {
- char buf[6 + strlen (tagp)];
- sprintf (buf, "NAN(%s)", tagp);
- return strtold (buf, NULL);
- }
-
- return NAN;
+ return __strtold_nan (tagp, NULL, 0);
}
weak_alias (__nanl, nanl)
diff --git a/math/test-nan-overflow.c b/math/test-nan-overflow.c
new file mode 100644
index 0000000..f56aaf3
--- /dev/null
+++ b/math/test-nan-overflow.c
@@ -0,0 +1,66 @@
+/* Test nan functions stack overflow (bug 16962).
+ 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 <math.h>
+#include <stdio.h>
+#include <string.h>
+#include <sys/resource.h>
+
+#define STACK_LIM 1048576
+#define STRING_SIZE (2 * STACK_LIM)
+
+static int
+do_test (void)
+{
+ int result = 0;
+ struct rlimit lim;
+ getrlimit (RLIMIT_STACK, &lim);
+ lim.rlim_cur = STACK_LIM;
+ setrlimit (RLIMIT_STACK, &lim);
+ char *nanstr = malloc (STRING_SIZE);
+ if (nanstr == NULL)
+ {
+ puts ("malloc failed, cannot test");
+ return 77;
+ }
+ memset (nanstr, '0', STRING_SIZE - 1);
+ nanstr[STRING_SIZE - 1] = 0;
+#define NAN_TEST(TYPE, FUNC) \
+ do \
+ { \
+ char *volatile p = nanstr; \
+ volatile TYPE v = FUNC (p); \
+ if (isnan (v)) \
+ puts ("PASS: " #FUNC); \
+ else \
+ { \
+ puts ("FAIL: " #FUNC); \
+ result = 1; \
+ } \
+ } \
+ while (0)
+ NAN_TEST (float, nanf);
+ NAN_TEST (double, nan);
+#ifndef NO_LONG_DOUBLE
+ NAN_TEST (long double, nanl);
+#endif
+ return result;
+}
+
+#define TEST_FUNCTION do_test ()
+#include "../test-skeleton.c"
diff --git a/math/test-nan-payload.c b/math/test-nan-payload.c
new file mode 100644
index 0000000..358ff71
--- /dev/null
+++ b/math/test-nan-payload.c
@@ -0,0 +1,122 @@
+/* Test nan functions payload handling (bug 16961).
+ 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 <float.h>
+#include <math.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+/* Avoid built-in functions. */
+#define WRAP_NAN(FUNC, STR) \
+ ({ const char *volatile wns = (STR); FUNC (wns); })
+#define WRAP_STRTO(FUNC, STR) \
+ ({ const char *volatile wss = (STR); FUNC (wss, NULL); })
+
+#define CHECK_IS_NAN(TYPE, A) \
+ do \
+ { \
+ if (isnan (A)) \
+ puts ("PASS: " #TYPE " " #A); \
+ else \
+ { \
+ puts ("FAIL: " #TYPE " " #A); \
+ result = 1; \
+ } \
+ } \
+ while (0)
+
+#define CHECK_SAME_NAN(TYPE, A, B) \
+ do \
+ { \
+ if (memcmp (&(A), &(B), sizeof (A)) == 0) \
+ puts ("PASS: " #TYPE " " #A " = " #B); \
+ else \
+ { \
+ puts ("FAIL: " #TYPE " " #A " = " #B); \
+ result = 1; \
+ } \
+ } \
+ while (0)
+
+#define CHECK_DIFF_NAN(TYPE, A, B) \
+ do \
+ { \
+ if (memcmp (&(A), &(B), sizeof (A)) != 0) \
+ puts ("PASS: " #TYPE " " #A " != " #B); \
+ else \
+ { \
+ puts ("FAIL: " #TYPE " " #A " != " #B); \
+ result = 1; \
+ } \
+ } \
+ while (0)
+
+/* Cannot test payloads by memcmp for formats where NaNs have padding
+ bits. */
+#define CAN_TEST_EQ(MANT_DIG) ((MANT_DIG) != 64 && (MANT_DIG) != 106)
+
+#define RUN_TESTS(TYPE, SFUNC, FUNC, MANT_DIG) \
+ do \
+ { \
+ TYPE n123 = WRAP_NAN (FUNC, "123"); \
+ CHECK_IS_NAN (TYPE, n123); \
+ TYPE s123 = WRAP_STRTO (SFUNC, "NAN(123)"); \
+ CHECK_IS_NAN (TYPE, s123); \
+ TYPE n456 = WRAP_NAN (FUNC, "456"); \
+ CHECK_IS_NAN (TYPE, n456); \
+ TYPE s456 = WRAP_STRTO (SFUNC, "NAN(456)"); \
+ CHECK_IS_NAN (TYPE, s456); \
+ TYPE n123x = WRAP_NAN (FUNC, "123)"); \
+ CHECK_IS_NAN (TYPE, n123x); \
+ TYPE nemp = WRAP_NAN (FUNC, ""); \
+ CHECK_IS_NAN (TYPE, nemp); \
+ TYPE semp = WRAP_STRTO (SFUNC, "NAN()"); \
+ CHECK_IS_NAN (TYPE, semp); \
+ TYPE sx = WRAP_STRTO (SFUNC, "NAN"); \
+ CHECK_IS_NAN (TYPE, sx); \
+ if (CAN_TEST_EQ (MANT_DIG)) \
+ CHECK_SAME_NAN (TYPE, n123, s123); \
+ if (CAN_TEST_EQ (MANT_DIG)) \
+ CHECK_SAME_NAN (TYPE, n456, s456); \
+ if (CAN_TEST_EQ (MANT_DIG)) \
+ CHECK_SAME_NAN (TYPE, nemp, semp); \
+ if (CAN_TEST_EQ (MANT_DIG)) \
+ CHECK_SAME_NAN (TYPE, n123x, sx); \
+ CHECK_DIFF_NAN (TYPE, n123, n456); \
+ CHECK_DIFF_NAN (TYPE, n123, nemp); \
+ CHECK_DIFF_NAN (TYPE, n123, n123x); \
+ CHECK_DIFF_NAN (TYPE, n456, nemp); \
+ CHECK_DIFF_NAN (TYPE, n456, n123x); \
+ } \
+ while (0)
+
+static int
+do_test (void)
+{
+ int result = 0;
+ RUN_TESTS (float, strtof, nanf, FLT_MANT_DIG);
+ RUN_TESTS (double, strtod, nan, DBL_MANT_DIG);
+#ifndef NO_LONG_DOUBLE
+ RUN_TESTS (long double, strtold, nanl, LDBL_MANT_DIG);
+#endif
+ return result;
+}
+
+#define TEST_FUNCTION do_test ()
+#include "../test-skeleton.c"