diff options
Diffstat (limited to 'libgcc')
| -rw-r--r-- | libgcc/ChangeLog | 13 | ||||
| -rw-r--r-- | libgcc/Makefile.in | 17 | ||||
| -rw-r--r-- | libgcc/config.host | 2 | ||||
| -rw-r--r-- | libgcc/configure | 16 | ||||
| -rw-r--r-- | libgcc/configure.ac | 10 | ||||
| -rw-r--r-- | libgcc/vtv_end.c | 66 | ||||
| -rw-r--r-- | libgcc/vtv_end_preinit.c | 71 | ||||
| -rw-r--r-- | libgcc/vtv_start.c | 65 | ||||
| -rw-r--r-- | libgcc/vtv_start_preinit.c | 73 |
9 files changed, 332 insertions, 1 deletions
diff --git a/libgcc/ChangeLog b/libgcc/ChangeLog index ab4d2c1b049..af42e3e4555 100644 --- a/libgcc/ChangeLog +++ b/libgcc/ChangeLog @@ -1,3 +1,16 @@ +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. + 2013-08-01 Maxim Kuvyrkov <maxim@kugelworks.com> * config/aarch64/sfp-machine.h, config/aarch64/sync-cache.c, diff --git a/libgcc/Makefile.in b/libgcc/Makefile.in index 958be5ec86f..63fd626da40 100644 --- a/libgcc/Makefile.in +++ b/libgcc/Makefile.in @@ -39,6 +39,7 @@ enable_shared = @enable_shared@ double_type_size = @double_type_size@ long_double_type_size = @long_double_type_size@ decimal_float = @decimal_float@ +enable_vtable_verify = @enable_vtable_verify@ enable_decimal_float = @enable_decimal_float@ fixed_point = @fixed_point@ @@ -971,6 +972,22 @@ crtendS$(objext): $(srcdir)/crtstuff.c # This is a version of crtbegin for -static links. crtbeginT$(objext): $(srcdir)/crtstuff.c $(crt_compile) $(CRTSTUFF_T_CFLAGS) -c $< -DCRT_BEGIN -DCRTSTUFFT_O + +ifeq ($(enable_vtable_verify),yes) +# These are used in vtable verification; see comments in source files for +# more details. +vtv_start$(objext): $(srcdir)/vtv_start.c + $(crt_compile) $(CRTSTUFF_T_CFLAGS_S) -c $(srcdir)/vtv_start.c + +vtv_end$(objext): $(srcdir)/vtv_end.c + $(crt_compile) $(CRTSTUFF_T_CFLAGS_S) -c $(srcdir)/vtv_end.c + +vtv_start_preinit$(objext): $(srcdir)/vtv_start_preinit.c + $(crt_compile) $(CRTSTUFF_T_CFLAGS_S) -c $(srcdir)/vtv_start_preinit.c + +vtv_end_preinit$(objext): $(srcdir)/vtv_end_preinit.c + $(crt_compile) $(CRTSTUFF_T_CFLAGS_S) -c $(srcdir)/vtv_end_preinit.c +endif endif ifeq ($(CUSTOM_CRTIN),) diff --git a/libgcc/config.host b/libgcc/config.host index 9c47e1b4233..f75ae9a571c 100644 --- a/libgcc/config.host +++ b/libgcc/config.host @@ -197,7 +197,7 @@ case ${host} in ;; *-*-linux* | frv-*-*linux* | *-*-kfreebsd*-gnu | *-*-knetbsd*-gnu | *-*-gnu* | *-*-kopensolaris*-gnu) tmake_file="$tmake_file t-crtstuff-pic t-libgcc-pic t-eh-dw2-dip t-slibgcc t-slibgcc-gld t-slibgcc-elf-ver t-linux" - extra_parts="crtbegin.o crtbeginS.o crtbeginT.o crtend.o crtendS.o" + extra_parts="crtbegin.o crtbeginS.o crtbeginT.o crtend.o crtendS.o vtv_start.o vtv_end.o vtv_start_preinit.o vtv_end_preinit.o" ;; *-*-lynxos*) tmake_file="$tmake_file t-lynx $cpu_type/t-crtstuff t-crtstuff-pic t-libgcc-pic" diff --git a/libgcc/configure b/libgcc/configure index bb36889ae56..29fa46f597a 100644 --- a/libgcc/configure +++ b/libgcc/configure @@ -608,6 +608,7 @@ build_os build_vendor build_cpu build +enable_vtable_verify enable_shared libgcc_topdir target_alias @@ -655,6 +656,7 @@ with_target_subdir with_cross_host with_ld enable_shared +enable_vtable_verify enable_version_specific_runtime_libs with_slibdir enable_maintainer_mode @@ -1288,6 +1290,7 @@ Optional Features: --disable-FEATURE do not include FEATURE (same as --enable-FEATURE=no) --enable-FEATURE[=ARG] include FEATURE [ARG=yes] --disable-shared don't provide a shared libgcc + --enable-vtable-verify Enable vtable verification feature --enable-version-specific-runtime-libs Specify that runtime libraries should be installed in a compiler-specific directory --enable-maintainer-mode enable make rules and dependencies not useful (and @@ -2140,6 +2143,19 @@ fi +# Check whether --enable-vtable-verify was given. +if test "${enable_vtable_verify+set}" = set; then : + enableval=$enable_vtable_verify; case "$enableval" in + yes) enable_vtable_verify=yes ;; + no) enable_vtable_verify=no ;; + *) enable_vtable_verify=no;; + esac +else + enable_vtable_verify=no +fi + + + # Make sure we can run config.sub. $SHELL "$ac_aux_dir/config.sub" sun4 >/dev/null 2>&1 || as_fn_error "cannot run $SHELL $ac_aux_dir/config.sub" "$LINENO" 5 diff --git a/libgcc/configure.ac b/libgcc/configure.ac index 8b7aba5823b..186cd6e9cd7 100644 --- a/libgcc/configure.ac +++ b/libgcc/configure.ac @@ -66,6 +66,16 @@ AC_ARG_ENABLE(shared, ], [enable_shared=yes]) AC_SUBST(enable_shared) +AC_ARG_ENABLE(vtable-verify, +[ --enable-vtable-verify Enable vtable verification feature ], +[case "$enableval" in + yes) enable_vtable_verify=yes ;; + no) enable_vtable_verify=no ;; + *) enable_vtable_verify=no;; + esac], +[enable_vtable_verify=no]) +AC_SUBST(enable_vtable_verify) + GCC_PICFLAG AC_SUBST(PICFLAG) diff --git a/libgcc/vtv_end.c b/libgcc/vtv_end.c new file mode 100644 index 00000000000..83fa101c8e3 --- /dev/null +++ b/libgcc/vtv_end.c @@ -0,0 +1,66 @@ +/* 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. That is defined in vtv_start.c (which + contains nothing else). vtv_start.c gest compiled into + vtv_start.o, and vtv_start.o gets inserted 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. This file defines that symbol (and only this + symbol). 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(100))) void +__VLTprotect (void) +{ + __VLTChangePermission (__VLTP_READ_ONLY); +} + +/* Page-sized variable to mark end of .vtable_map_vars section. */ +char _vtable_map_vars_end[VTV_PAGE_SIZE] + __attribute__ ((__visibility__ ("protected"), used, + section(".vtable_map_vars"))); diff --git a/libgcc/vtv_end_preinit.c b/libgcc/vtv_end_preinit.c new file mode 100644 index 00000000000..53d12b07ea1 --- /dev/null +++ b/libgcc/vtv_end_preinit.c @@ -0,0 +1,71 @@ +/* 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. That is defined in vtv_start.c (which + contains nothing else). vtv_start.c gest compiled into + vtv_start.o, and vtv_start.o gets inserted 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. This file defines that symbol (and only this + symbol). 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" + +void +__VLTProtectPreinit (void) +{ + __VLTChangePermission (__VLTP_READ_ONLY); +} + +/* Page-sized variable to mark end of .vtable_map_vars section. */ +char _vtable_map_vars_end[VTV_PAGE_SIZE] + __attribute__ ((__visibility__ ("protected"), used, + section(".vtable_map_vars"))); + +/* Put the function __VLTProtectPreinit into the .preinit_array + section. */ + +__attribute__ ((section (".preinit_array"))) + typeof (__VLTProtectPreinit) *__preinit_end = __VLTProtectPreinit; 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"))) + = { }; diff --git a/libgcc/vtv_start_preinit.c b/libgcc/vtv_start_preinit.c new file mode 100644 index 00000000000..512c8581a28 --- /dev/null +++ b/libgcc/vtv_start_preinit.c @@ -0,0 +1,73 @@ +/* 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" + +void +__VLTUnprotectPreinit (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"))) + = { }; + + +/* Put the function __VLTUnprotectPreinit into the .preinit_array + section. */ + +__attribute__ ((section (".preinit_array"))) + typeof (__VLTUnprotectPreinit) *__preinit = __VLTUnprotectPreinit; + |