Disable floating point code/linking when possible.
Unless heap profiling is enabled, disable floating point code and don't
link with libm. This, in combination with e.g. EXTRA_CFLAGS=-mno-sse on
x64 systems, makes it possible to completely disable floating point
register use. Some versions of glibc neglect to save/restore
caller-saved floating point registers during dynamic lazy symbol
loading, and the symbol loading code uses whatever malloc the
application happens to have linked/loaded with, the result being
potential floating point register corruption.
diff --git a/configure.ac b/configure.ac
index 7f0fecc..1103cc7 100644
--- a/configure.ac
+++ b/configure.ac
@@ -356,11 +356,6 @@
AC_SUBST([AROUT])
AC_SUBST([CC_MM])
-if test "x$abi" != "xpecoff"; then
- dnl Heap profiling uses the log(3) function.
- LIBS="$LIBS -lm"
-fi
-
JE_COMPILABLE([__attribute__ syntax],
[static __attribute__((unused)) void foo(void){}],
[],
@@ -774,6 +769,12 @@
AC_MSG_ERROR([Heap profiling requires TLS]);
fi
force_tls="1"
+
+ if test "x$abi" != "xpecoff"; then
+ dnl Heap profiling uses the log(3) function.
+ LIBS="$LIBS -lm"
+ fi
+
AC_DEFINE([JEMALLOC_PROF], [ ])
fi
AC_SUBST([enable_prof])