Message ID | 875zj6d9p8.fsf@oldenburg2.str.redhat.com |
---|---|
State | New |
Headers | show |
Series | x86: Assume --enable-cet if GCC defaults to CET [BZ #25225] | expand |
On Tue, Nov 26, 2019 at 5:54 AM Florian Weimer <fweimer@redhat.com> wrote: > > 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. > > ----- > configure | 23 ++++++++++++++++++++++- > configure.ac | 9 ++++++++- > 2 files changed, 30 insertions(+), 2 deletions(-) > > diff --git a/configure b/configure > index 2f44b66656..b959d2d988 100755 > --- a/configure > +++ b/configure > @@ -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 > > > diff --git a/configure.ac b/configure.ac > index e69c88c543..49b900c1ed 100644 > --- a/configure.ac > +++ b/configure.ac > @@ -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 > LGTM. Thanks.
diff --git a/configure b/configure index 2f44b66656..b959d2d988 100755 --- a/configure +++ b/configure @@ -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 diff --git a/configure.ac b/configure.ac index e69c88c543..49b900c1ed 100644 --- a/configure.ac +++ b/configure.ac @@ -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