Rainer Orth<ro@CeBiTec.Uni-Bielefeld.DE> writes:
>Now that init priority support on Solaris is on mainline, porting libvtv
>proved to be relatively easy, though it discovered a couple of quirks on
>a non-gld non-x86 platform.
This patch has now remained unreviewed for a week. With both Jeff and
Richi fine with it going into mainline even this late, it would be nice
if Caroline could find the time to review it.
Linux/x86_64 testing found one minor issue, explained below. I'm
attaching the updated patch.
>A considerable part of the patch lives in Solaris-specific files and
>thus doesn't need approval, though some changes require explanation:
>
>* In gcc.c (LINK_COMMAND_SPEC), VTABLE_VERIFICATION_SPEC was before
> %{L*}. The spec includes -lvtv. Solaris ld, other than GNU ld, heeds
> the relative order of -L and -l switches, so the libvtv testcases
> wouldn't link manually, but did inside a testsuite run where
> LD_LIBRARY_PATH points ld at the correct directory.
>
>* Solaris/SPARC uses an 8 kB page size, so a couple of cases where uses
> of VTV_PAGE_SIZE had been replaced with hardcoded values of 4096 had
> to be reverted.
>
>* Inside libgcc, the vtv_*.c files are compiled with
> -finhibit-size-directive, whereas in libvtv that flag is absent. This
> caused all testcases to fail due to a linker warning:
>
>FAIL: libvtv.cc/bb_tests.cc -O0 -fvtable-verify=std (test for excess errors)
>Excess errors:
>ld: warning: symbol '_vtable_map_vars_end' has differing sizes:
> (file/var/gcc/gcc-6.0.0-20151111/12-gcc-vtv/sparc-sun-solaris2.12/./libvtv/.libs/libvtv.so value=0x1000; file /var/gcc/gcc-6.0.0-20151111/12-gcc-vtv/gcc/vtv_end.o value=0x0);
> /var/gcc/gcc-6.0.0-20151111/12-gcc-vtv/gcc/vtv_end.o definition taken
>
>* Like Cygwin, Solaris has no obstack functions in libc, so I'm now
> using a common conditional for that.
>
>* libvtv requires constructor priority support and dl_iterate_phdr. The
> former needs either a recent (Solaris 12 only so far) ld or gld, the
> latter came in Solaris 11 only.
>
>* Unlike glibc systems, Solaris has no __fortify_fail in libc; some of
> this can probably provided using libbacktrace, which I haven't yet
> done.
>
>* It also lacks program_invocation_name, but the functionality can be
> provided via getexecname() instead.
>
>* On Solaris 12/SPARC with Solaris as, the .vtable_map_vars section
> wouldn't be pagesize aligned (I'm still looking how to fix this; it
> works out of the box for .bss), so the section length calclated in
> read_section_offset_and_length would be negative, leading to all sorts
> of havoc. For the moment, I'm using gas instead to avoid this.
>
>* The patch also fixes a number of typos noticed during testing.
>I'm still investigating what causes those timeouts, it seems to be a
>scalability issue in libc.
>
>While I realize that we are past stage1, maybe the fact that this patch
>is for an off-by-default feature and well localized still could allow it
>into mainline at this point?
On x86_64-pc-linux-gnu, initial testing found all libvtv testcases
failing initially like this:
FAIL: libvtv.cc/bb_tests.cc -O0 -fvtable-verify=std (test for excess errors)
Excess errors:
vtv_end.c:(.text.startup+0x0): multiple definition of `__VLTprotect'
/var/gcc/gcc-6.0.0-20151111/3.19.8-gcc-gas-gld-vtv/x86_64-pc-linux-gnu/./libvtv/.libs/libvtv.a(vtv_end.o):/var/gcc/gcc-6.0.0-20151111/3.19.8-gcc-gas-gld-vtv/x86_64-pc-linux-gnu/libvtv/vtv_end.c:59: first defined here
It turned out that while the libvtv.so.0 and libvtv.so symlinks were
built, libvtv.so.0.0.0 proper was not. I'd overlooked this aucotonf
warning:
ro@lokon 1503 > autoconf
configure.ac:109: warning: AC_COMPILE_IFELSE was called before AC_USE_SYSTEM_EXTENSIONS
/vol/src/gnu/autoconf/autoconf-2.64/lib/autoconf/specific.m4:332: AC_GNU_SOURCE is expanded from...
configure.ac:109: the top level
As expected, adding the macro to configure.ac fixed both the warning and
the libvtv.so.0.0.0 build, so Linux/x86_64 results are all fine again.
Thanks.
Rainer
2015-08-20 Rainer Orth<ro@CeBiTec.Uni-Bielefeld.DE>
libstdc++-v3:
* acinclude.m4 (GLIBCXX_ENABLE_VTABLE_VERIFY) <solaris2*>: Use
-Wl,-R in VTV_CXXLINKFLAGS.
* configure: Regenerate.
* testsuite/18_support/bad_exception/23591_thread-1.c: Use
-fvtable-verify=none on Solaris 12+.
libgcc:
* Makefile.in (VTV_CFLAGS): New variable.
(vtv_start$(objext), vtv_end$(objext), vtv_end$(objext))
(vtv_start_preinit$(objext), vtv_end_preinit$(objext)): Use it.
* config.host (*-*-solaris2*): Add t-crtstuff-pic to tmake_file.
Add vtv_start.o, vtv_end.o, vtv_start_preinit.o, vtv_end_preinit.o
to extra_parts if $enable_vtable_verify = yes.
libvtv:
* configure.tgt (*-*-solaris2.[1-9]*): Declare supported.
* configure.ac: Call AC_USE_SYSTEM_EXTENSIONS.
<*-*-solaris2*>: Check for init priority support.
Check for getexecname, __fortify_fail, _obstack_begin.
(VTV_NO_OBSTACK): New conditional.
* configure: Regenerate.
* Makefile.am [VTV_NO_OBSTACK] (obstack.c): Use new condition.
* Makefile.in: Regenerate.
* vtv_rts.cc [HAVE_GETEXECNAME] (program_invocation_name): New
variable.
(read_section_offset_and_length) [HAVE_GETEXECNAME]: Set it.
(dl_iterate_phdr_callback) [HAVE_GETEXECNAME]: Set it.
(__fortify_fail): Wrap in HAVE___FORTIFY_FAIL
[!HAVE___FORTIFY_FAIL]: Provide non-Cygwin implementation.
(read_section_offset_and_length): Assert sh_size >= VTV_PAGE_SIZE.
(iterate_modules): Fix typo.
Use VTV_PAGE_SIZE.
(dl_iterate_phdr_callback): Fix typo.
Use VTV_PAGE_SIZE.
(__VLTChangePermission): Fix typos.
include:
* vtv-change-permission.h (VTV_PAGE_SIZE) [__sun__ && __svr4__ &&
__sparc__]: Define.
gcc:
* config/sol2.h (SUPPORTS_INIT_PRIORITY): Move up.
(STARTFILE_VTV_SPEC, ENDFILE_VTV_SPEC): Define.
(STARTFILE_SPEC): Use %(startfile_vtv).
(ENDFILE_SPEC): Use %(endfile_vtv).
(SUBTARGET_EXTRA_SPECS): Handle STARTFILE_VTV_SPEC,
ENDFILE_VTV_SPEC.
* gcc.c (LINK_COMMAND_SPEC): Move VTABLE_VERIFICATION_SPEC after %{L*}.