x86: Assume --enable-cet if GCC defaults to CET [BZ #25225]

This links in CET support if GCC defaults to CET.  Otherwise, __CET__
is defined, yet CET functionality is not compiled and linked into the
dynamic loader, resulting in a linker failure due to undefined
references to _dl_cet_check and _dl_open_check.
This commit is contained in:
Florian Weimer 2019-11-26 14:48:56 +01:00
parent 7fc8c286e3
commit a0dd512cbc
2 changed files with 30 additions and 2 deletions

23
configure vendored
View File

@ -3777,11 +3777,32 @@ else
fi
cat confdefs.h - <<_ACEOF >conftest.$ac_ext
/* end confdefs.h. */
int
main ()
{
#ifndef __CET__
#error no CET compiler support
#endif
;
return 0;
}
_ACEOF
if ac_fn_c_try_compile "$LINENO"; then :
libc_cv_compiler_default_cet=yes
else
libc_cv_compiler_default_cet=no
fi
rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
# Check whether --enable-cet was given.
if test "${enable_cet+set}" = set; then :
enableval=$enable_cet; enable_cet=$enableval
else
enable_cet=no
enable_cet=$libc_cv_compiler_default_cet
fi

View File

@ -473,11 +473,18 @@ AC_ARG_ENABLE([mathvec],
[build_mathvec=$enableval],
[build_mathvec=notset])
AC_TRY_COMPILE([], [
#ifndef __CET__
# error no CET compiler support
#endif],
[libc_cv_compiler_default_cet=yes],
[libc_cv_compiler_default_cet=no])
AC_ARG_ENABLE([cet],
AC_HELP_STRING([--enable-cet],
[enable Intel Control-flow Enforcement Technology (CET), x86 only]),
[enable_cet=$enableval],
[enable_cet=no])
[enable_cet=$libc_cv_compiler_default_cet])
# We keep the original values in `$config_*' and never modify them, so we
# can write them unchanged into config.make. Everything else uses