forked from rpms/glibc
132 lines
4.7 KiB
Diff
132 lines
4.7 KiB
Diff
commit 2ef427168818ce04b03cecb7b739f9db0156e3e4
|
|
Author: Aurelien Jarno <aurelien@aurel32.net>
|
|
Date: Thu Jan 3 15:51:37 2019 +0100
|
|
|
|
Only build libm with -fno-math-errno (bug 24024)
|
|
|
|
Commit 1294b1892e ("Add support for sqrt asm redirects") added the
|
|
-fno-math-errno flag to build most of the glibc in order to enable GCC
|
|
to inline math functions. Due to GCC bug #88576, saving and restoring
|
|
errno around calls to malloc are optimized-out. In turn this causes
|
|
strerror to set errno to ENOMEM if it get passed an invalid error number
|
|
and if malloc sets errno to ENOMEM (which might happen even if it
|
|
succeeds). This is not allowed by POSIX.
|
|
|
|
This patch changes the build flags, building only libm with
|
|
-fno-math-errno and all the remaining code with -fno-math-errno. This
|
|
should be safe as libm doesn't contain any code saving and restoring
|
|
errno around malloc. This patch can probably be reverted once the GCC
|
|
bug is fixed and available in stable releases.
|
|
|
|
Tested on x86-64, no regression in the testsuite.
|
|
|
|
Changelog:
|
|
[BZ #24024]
|
|
* Makeconfig: Build libm with -fno-math-errno but build the remaining
|
|
code with -fmath-errno.
|
|
* string/Makefile [$(build-shared)] (tests): Add test-strerror-errno.
|
|
[$(build-shared)] (LDLIBS-test-strerror-errno): New variable.
|
|
* string/test-strerror-errno.c: New file.
|
|
|
|
diff --git a/Makeconfig b/Makeconfig
|
|
index 92e76d6200bbcd5b..8dc2fec9dc683416 100644
|
|
--- a/Makeconfig
|
|
+++ b/Makeconfig
|
|
@@ -831,8 +831,10 @@ endif
|
|
# disable any optimization that assume default rounding mode.
|
|
+math-flags = -frounding-math
|
|
|
|
-# Build libc/libm using -fno-math-errno, but run testsuite with -fmath-errno.
|
|
-+extra-math-flags = $(if $(filter libnldbl nonlib testsuite,$(in-module)),-fmath-errno,-fno-math-errno)
|
|
+# Logically only "libnldbl", "nonlib" and "testsuite" should be using
|
|
+# -fno-math-errno. However due to GCC bug #88576, only "libm" can use
|
|
+# -fno-math-errno.
|
|
++extra-math-flags = $(if $(filter libm,$(in-module)),-fno-math-errno,-fmath-errno)
|
|
|
|
# We might want to compile with some stack-protection flag.
|
|
ifneq ($(stack-protector),)
|
|
diff --git a/string/Makefile b/string/Makefile
|
|
index 680431f92185f914..aa2da9ca72262886 100644
|
|
--- a/string/Makefile
|
|
+++ b/string/Makefile
|
|
@@ -64,6 +64,12 @@ tests := tester inl-tester noinl-tester testcopy test-ffs \
|
|
# This test allocates a lot of memory and can run for a long time.
|
|
xtests = tst-strcoll-overflow
|
|
|
|
+# This test needs libdl.
|
|
+ifeq (yes,$(build-shared))
|
|
+tests += test-strerror-errno
|
|
+LDLIBS-test-strerror-errno = $(libdl)
|
|
+endif
|
|
+
|
|
ifeq ($(run-built-tests),yes)
|
|
tests-special += $(objpfx)tst-svc-cmp.out
|
|
endif
|
|
diff --git a/string/test-strerror-errno.c b/string/test-strerror-errno.c
|
|
new file mode 100644
|
|
index 0000000000000000..8e744e7ed9df5924
|
|
--- /dev/null
|
|
+++ b/string/test-strerror-errno.c
|
|
@@ -0,0 +1,61 @@
|
|
+/* BZ #24024 strerror and errno test.
|
|
+
|
|
+ Copyright (C) 2019 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 <dlfcn.h>
|
|
+#include <errno.h>
|
|
+#include <string.h>
|
|
+
|
|
+#include <support/check.h>
|
|
+#include <support/support.h>
|
|
+
|
|
+/* malloc is allowed to change errno to a value different than 0, even when
|
|
+ there is no actual error. This happens for example when the memory
|
|
+ allocation through sbrk fails. Simulate this by interposing our own
|
|
+ malloc implementation which sets errno to ENOMEM and calls the original
|
|
+ malloc. */
|
|
+void
|
|
+*malloc (size_t size)
|
|
+{
|
|
+ static void *(*real_malloc) (size_t size);
|
|
+
|
|
+ if (!real_malloc)
|
|
+ real_malloc = dlsym (RTLD_NEXT, "malloc");
|
|
+
|
|
+ errno = ENOMEM;
|
|
+
|
|
+ return (*real_malloc) (size);
|
|
+}
|
|
+
|
|
+/* strerror must not change the value of errno. Unfortunately due to GCC bug
|
|
+ #88576, this happens when -fmath-errno is used. This simple test checks
|
|
+ that it doesn't happen. */
|
|
+static int
|
|
+do_test (void)
|
|
+{
|
|
+ char *msg;
|
|
+
|
|
+ errno = 0;
|
|
+ msg = strerror (-3);
|
|
+ (void) msg;
|
|
+ TEST_COMPARE (errno, 0);
|
|
+
|
|
+ return 0;
|
|
+}
|
|
+
|
|
+#include <support/test-driver.c>
|