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authorctice <ctice@138bc75d-0d04-0410-961f-82ee72b054a4>2013-08-07 03:38:59 +0000
committerctice <ctice@138bc75d-0d04-0410-961f-82ee72b054a4>2013-08-07 03:38:59 +0000
commitb710ec859aae2bc828140010517b8b5855ace5ef (patch)
tree2799c94bc06794956a20aaa9db224f64c5e35e4d /libgcc/vtv_start.c
parent4abac0f08bce5ceb85a67ab4554d61a29248859a (diff)
downloadgcc-b710ec859aae2bc828140010517b8b5855ace5ef.tar.gz
Commit the vtable verification feature. This feature is designed to
detect, at run time, if/when the vtable pointer in a C++ object has been corrupted, before allowing virtual calls through that pointer. If pointer corruption is detected, execution of the program is halted. libstdc++-v3 ChangeLog: 2013-08-06 Caroline Tice <cmtice@google.com> * fragment.am: Add XTEMPLATE_FLAGS. * configure.ac: Add definitions for --enable-vtable-verify. * acinclude.m4: Add --enable-vtable-verify and --disable-vtable-verify; define --enable-vtable-verify; define VTV_CXXFLAGS, VTV_PCH_CXXFLAGS and VTV_CXXLINKFLAGS. * config/abi/pre/gnu.ver: Export symbols for vtable verification. * libsupc++/Makefile.am: Define vtv_sources and add it to libsupc___la_SOURCES and libsupc__convenience_la_SOURCES. * libsupc++/vtv_stubs.cc: New file. * include/Makefile.am: Add VTV_PCH_CXXFLAGS to PCHFLAGS. * src/Makefile.am: Add VTV_CXXFLAGS to AM_CXXFLAGS; add VTV_CXXLINKFLAGS to CXXLINK. * src/c++98/Makefile.am: Comment out XTEMPLATE_FLAGS; add VTV_CXXFLAGS to AM_CXXFLAGS; add VTV_CXXXLINKFLAGS to CXXLINK. * src/C++11/Makefile.am: Ditto. * doc/xml/manual/configure.xml: Add entry for --enable-vtable-verify. * scripts/testsuite_flags.in: Add cxxvtvflags to Usage; cause cxxvtvflags to use VTV_CXXFLAGS and VTV_CXXLINKFLAGS. * testsuite/lib/libstdc++.exp: Add cxxvtvflags; add code to locate libvtv if --enable-vtable-verify was used; set cxxvtvflags; add cxxvtvflags to cxx_final. * testsuite/18_support/bad_exception/23591_thread-1.c: Add -fvtable-verify=none to compiler flags. * testsuite/17_intro/freestanding.cc: Add -fvtable-verify=none to compiler flags. * configure: Regenerated. * Makefile.in: Regenerated. * python/Makefile.in: Regenerated. * include/Makefile.in: Regenerated. * libsupc++/Makefile.in: Regenerated. * config.h.in: Regenerated. * po/Makefile.in: Regenerated. * src/Makefile.in: Regenerated. * src/c++98/Makefile.in: Regenerated. * src/c++11/Makefile.in: Regenerated. * doc/Makefile.in: Regenerated. * testsuite/Makefile.in: Regenerated. top level ChangeLog: 2013-08-06 Caroline Tice <cmtice@google.com> * configure.ac: Add target-libvtv to target_libraries; disable libvtv on non-linux systems; add target-libvtv to noconfigdirs; add libsupc++/.libs to C++ library search paths. * configure: Regenerated. * Makefile.def: Add libvtv to target_modules; make libvtv depend on libstdc++ and libgcc. * Makefile.in: Regenerated. include/ChangeLog: 2013-08-06 Caroline Tice <cmtice@google.com> * vtv-change-permission.h: New file. contrib/ChangeLog: 2013-08-06 Caroline Tice4 <cmtice@google.com> * gcc_update: Add libvtv files. libgcc/ChangeLog: 2013-08-06 Caroline Tice <cmtice@google.com> config.host (extra_parts): Add vtv_start.o, vtv_end.o vtv_start_preinit.o and vtv_end_preinit.o. configure.ac: Add code to check/set enable_vtable_verify. Makefile.in: Add rules to build vtv_*.o, if enable_vtable_verify is true. vtv_start_preinit.c: New file. vtv_end_preinit.c: New file. vtv_start.c: New file. vtv_end.c: New file. configure: Regenerated. gcc/ChangeLog: 2013-08-06 Caroline Tice <cmtice@google.com> * gcc.c (VTABLE_VERIFICATION_SPEC): New definition. (LINK_COMMAND_SPEC): Add VTABLE_VERIFICATION_SPEC. * tree-pass.h: Add pass_vtable_verify. * varasm.c (assemble_variable): Add code to properly set the comdat section and name for the .vtable_map_vars section. (assemble_vtyv_preinit_initializer): New function. (default_sectin_type_flags): Make sure .vtable_map_vars section has LINK_ONCE flag. * output.h: Add function decl for assemble_vtv_preinit_initializer. * vtable-verify.c: New file. * vtable-verify.h: New file. * flag-types.h (enum vtv_priority): Defintions for flag_vtable_verify initialiation levels. * timevar.def (TV_VTABLE_VERIFICATION): New definition. * passes.def: Insert pass_vtable_verify. * aclocal.m4: Reorder includes. * doc/invoke.texi: Add documentation for the flags -fvtable-verify=, -fvtv-debug and -fvtv-counts. * config/gnu-user.h (GNU_USER_TARGET_STARTFILE_SPEC): Add vtv_start*.o, as appropriate, if -fvtable-verify=... is used. (GNU_USER_TARGET_ENDFILE_SPEC): Add vtv_end*.o as appropriate, if -fvtable-verify=... is used. * Makefile.in (OBJS): Add vtable-verify.o to list. (vtable-verify.o): Add new build rule. (GTFILES): Add vtable-verify.c to list. * common.opt (fvtable-verify=): New flag. (vtv_priority): Values for fvtable-verify= flag. (fvtv-counts): New flag. (fvtv-debug): New flag. * tree.h (save_vtable_map_decl): New extern function decl. gcc/cp/ChangeLog: 2013-08-06 Caroline Tice <cmtice@google.com> * Make-lang.in (*CXX_AND_OBJCXX_OBJS): Add vtable-class-hierarchy.o to list. (vtable-class-hierarchy.o): Add build rule. * cp-tree.h (vtv_start_verification_constructor_init_function): New extern function decl. (vtv_finish_verification_constructor_init_function): New extern function decl. (build_vtbl_address): New extern function decl. (get_mangled_vtable_map_var_name): New extern function decl. (vtv_compute_class_hierarchy_transitive_closure): New extern function decl. (vtv_generate_init_routine): New extern function decl. (vtv_save_class_info): New extern function decl. (vtv_recover_class_info): New extern function decl. (vtv_build_vtable_verify_fndecl): New extern function decl. * class.c (finish_struct_1): Add call to vtv_save_class_info if flag_vtable_verify is true. * config-lang.in: Add vtable-class-hierarchy.c to gtfiles list. * vtable-class-hierarchy.c: New file. * mangle.c (get_mangled_vtable_map_var_name): New function. * decl2.c (start_objects): Update function comment. (cp_write_global_declarations): Call vtv_recover_class_info, vtv_compute_class_hierarchy_transitive_closure and vtv_build_vtable_verify_fndecl, before calling finalize_compilation_unit, and call vtv_generate_init_rount after, IFF flag_vtable_verify is true. (vtv_start_verification_constructor_init_function): New function. (vtv_finish_verification_constructor_init_function): New function. * init.c (build_vtbl_address): Remove static qualifier from function. libvtv/ChangeLog: 2013-08-06 Caroline Tice <cmtice@google.com> Initial check-in of new vtable verification feature. * configure.ac : New file. * acinclude.m4 : New file. * Makefile.am : New file. * aclocal.m4 : New file. * configure.tgt : New file. * configure: New file (generated). * Makefile.in: New file (generated). * vtv_set.h : New file. * vtv_utils.cc : New file. * vtv_utils.h : New file. * vtv_malloc.cc : New file. * vtv_rts.cc : New file. * vtv_malloc.h : New file. * vtv_rts.h : New file. * vtv_fail.cc : New file. * vtv_fail.h : New file. * vtv_map.h : New file. * scripts/run-testsuite.sh : New file. * scripts/sum-vtv-counts.c : New file. * testsuite/parts-test-main.h : New file. * testusite/dataentry.cc : New file. * testsuite/temp_deriv.cc : New file. * testsuite/register_pair.cc : New file. * testsuite/virtual_inheritance.cc : New file. * testsuite/field-test.cc : New file. * testsuite/nested_vcall_test.cc : New file. * testsuite/template-list-iostream.cc : New file. * testsuite/register_pair_inserts.cc : New file. * testsuite/register_pair_inserts_mt.cc : New file. * testsuite/event.list : New file. * testsuite/parts-test-extra-parts-views.cc : New file. * testsuite/parts-test-extra-parts-views.h : New file. * testsuite/environment-fail-32.s : New file. * testsuite/parts-test-extra-parts.h : New file. * testsuite/temp_deriv2.cc : New file. * testsuite/dlopen_mt.cc : New file. * testsuite/event.h : New file. * testsuite/template-list.cc : New file. * testsuite/replace-fail.cc : New file. * testsuite/Makefile.am : New file. * testsuite/Makefile.in: New file (generated). * testsuite/mempool_negative.c : New file. * testsuite/parts-test-main.cc : New file. * testsuite/event-private.cc : New file. * testsuite/thunk.cc : New file. * testsuite/event-defintiions.cc : New file. * testsuite/event-private.h : New file. * testsuite/parts-test.list : New file. * testusite/register_pair_mt.cc : New file. * testsuite/povray-derived.cc : New file. * testsuite/event-main.cc : New file. * testsuite/environment.cc : New file. * testsuite/template-list2.cc : New file. * testsuite/thunk_vtable_map_attack.cc : New file. * testsuite/parts-test-extra-parts.cc : New file. * testsuite/environment-fail-64.s : New file. * testsuite/dlopen.cc : New file. * testsuite/so.cc : New file. * testsuite/temp_deriv3.cc : New file. * testsuite/const_vtable.cc : New file. * testsuite/mempool_positive.c : New file. * testsuite/dup_name.cc : New file. git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@201555 138bc75d-0d04-0410-961f-82ee72b054a4
Diffstat (limited to 'libgcc/vtv_start.c')
-rw-r--r--libgcc/vtv_start.c65
1 files changed, 65 insertions, 0 deletions
diff --git a/libgcc/vtv_start.c b/libgcc/vtv_start.c
new file mode 100644
index 00000000000..3efb63dfbb0
--- /dev/null
+++ b/libgcc/vtv_start.c
@@ -0,0 +1,65 @@
+/* Copyright (C) 2012, 2013
+ Free Software Foundation, Inc.
+
+This file is part of GCC.
+
+GCC is free software; you can redistribute it and/or modify it under
+the terms of the GNU General Public License as published by the Free
+Software Foundation; either version 3, or (at your option) any later
+version.
+
+GCC 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 General Public License
+for more details.
+
+Under Section 7 of GPL version 3, you are granted additional
+permissions described in the GCC Runtime Library Exception, version
+3.1, as published by the Free Software Foundation.
+
+You should have received a copy of the GNU General Public License and
+a copy of the GCC Runtime Library Exception along with this program;
+see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
+<http://www.gnu.org/licenses/>. */
+
+/* This file is part of the vtable verification feature (for a
+ detailed description of the feature, see comments in
+ vtable-verify.c). The vtable verification feature creates
+ certain global symbols that need to be read-write sometimes during
+ program execution, and read-only at others. It uses 'mprotect' to
+ change the memory protections of the pages on which these variables
+ are stored. In order to not affect the protections of other
+ program variables, these variables are put into a special named
+ section, ".vtable_map_vars", which is page-aligned at the start,
+ and which is padded with a page-sized amount of zeros at the end.
+ To make this section page aligned, we create a special symbol,
+ "_vtable_map_vars_start" which we make the very first thing that
+ goes into the section. This file defines that symbol (and only
+ that symbol). GCC compiles this file into vtv_start.o, and
+ inserts vtv_start.o into the link line immediately after
+ crtbegin.o, if the program is compiled with -fvtable.verify.
+
+ In order to pad the ".vtable_map_vars" section with a page-sized
+ amount of zeros at the end, there is a second symbol,
+ _vtable_map_vars_end, which is defined in another file, vtv_end.c.
+ This second symbol is a page-sized array of chars, zero-filled, and
+ is the very last thing to go into the section. When the GCC driver
+ inserts vtv_start.o into the link line (just after crtbegin.o) it
+ also inserts vtv_end.o into the link line, just before crtend.o.
+ This has the desired effect of making our section page-aligned and
+ page-size paded, ensuring that no other program data lands on our
+ pages. */
+
+#include "vtv-change-permission.h"
+
+__attribute__ ((constructor(98))) void
+__VLTunprotect (void)
+{
+ __VLTChangePermission (__VLTP_READ_WRITE);
+}
+
+/* Page-aligned symbol to mark beginning of .vtable_map_vars section. */
+char _vtable_map_vars_start []
+__attribute__ ((__visibility__ ("protected"), used, aligned(VTV_PAGE_SIZE),
+ section(".vtable_map_vars")))
+ = { };