Add sancov plugin
The sancov gcc plugin inserts a __sanitizer_cov_trace_pc() call at the start of basic blocks. This plugin is a helper plugin for the kcov feature. It supports all gcc versions with plugin support (from gcc-4.5 on). It is based on the gcc commit "Add fuzzing coverage support" by Dmitry Vyukov (https://gcc.gnu.org/viewcvs/gcc?limit_changes=0&view=revision&revision=231296). Signed-off-by: Emese Revfy <re.emese@gmail.com> Acked-by: Kees Cook <keescook@chromium.org> Signed-off-by: Michal Marek <mmarek@suse.com>
This commit is contained in:
Emese Revfy
Michal Marek
parent
0dae776c6b
commit
543c37cb16
7 changed files with 184 additions and 10 deletions
10
Makefile
10
Makefile
|
|
@ -369,7 +369,7 @@ LDFLAGS_MODULE =
|
|||
CFLAGS_KERNEL =
|
||||
AFLAGS_KERNEL =
|
||||
CFLAGS_GCOV = -fprofile-arcs -ftest-coverage -fno-tree-loop-im -Wno-maybe-uninitialized
|
||||
CFLAGS_KCOV = -fsanitize-coverage=trace-pc
|
||||
CFLAGS_KCOV := $(call cc-option,-fsanitize-coverage=trace-pc,)
|
||||
|
||||
|
||||
# Use USERINCLUDE when you must reference the UAPI directories only.
|
||||
|
|
@ -691,14 +691,6 @@ endif
|
|||
endif
|
||||
KBUILD_CFLAGS += $(stackp-flag)
|
||||
|
||||
ifdef CONFIG_KCOV
|
||||
ifeq ($(call cc-option, $(CFLAGS_KCOV)),)
|
||||
$(warning Cannot use CONFIG_KCOV: \
|
||||
-fsanitize-coverage=trace-pc is not supported by compiler)
|
||||
CFLAGS_KCOV =
|
||||
endif
|
||||
endif
|
||||
|
||||
ifeq ($(cc-name),clang)
|
||||
KBUILD_CPPFLAGS += $(call cc-option,-Qunused-arguments,)
|
||||
KBUILD_CPPFLAGS += $(call cc-option,-Wno-unknown-warning-option,)
|
||||
|
|
|
|||
|
|
@ -384,6 +384,15 @@ config GCC_PLUGIN_CYC_COMPLEXITY
|
|||
N = the number of nodes
|
||||
P = the number of connected components (exit nodes).
|
||||
|
||||
config GCC_PLUGIN_SANCOV
|
||||
bool
|
||||
depends on GCC_PLUGINS
|
||||
help
|
||||
This plugin inserts a __sanitizer_cov_trace_pc() call at the start of
|
||||
basic blocks. It supports all gcc versions with plugin support (from
|
||||
gcc-4.5 on). It is based on the commit "Add fuzzing coverage support"
|
||||
by Dmitry Vyukov <dvyukov@google.com>.
|
||||
|
||||
config HAVE_CC_STACKPROTECTOR
|
||||
bool
|
||||
help
|
||||
|
|
|
|||
|
|
@ -8,6 +8,8 @@ PURGATORY_OBJS = $(addprefix $(obj)/,$(purgatory-y))
|
|||
LDFLAGS_purgatory.ro := -e purgatory_start -r --no-undefined -nostdlib -z nodefaultlib
|
||||
targets += purgatory.ro
|
||||
|
||||
KCOV_INSTRUMENT := n
|
||||
|
||||
# Default KBUILD_CFLAGS can have -pg option set when FTRACE is enabled. That
|
||||
# in turn leaves some undefined symbols like __fentry__ in purgatory and not
|
||||
# sure how to relocate those. Like kexec-tools, use custom flags.
|
||||
|
|
|
|||
|
|
@ -708,6 +708,8 @@ config KCOV
|
|||
bool "Code coverage for fuzzing"
|
||||
depends on ARCH_HAS_KCOV
|
||||
select DEBUG_FS
|
||||
select GCC_PLUGINS
|
||||
select GCC_PLUGIN_SANCOV
|
||||
help
|
||||
KCOV exposes kernel code coverage information in a form suitable
|
||||
for coverage-guided fuzzing (randomized testing).
|
||||
|
|
|
|||
|
|
@ -2,10 +2,26 @@ ifdef CONFIG_GCC_PLUGINS
|
|||
__PLUGINCC := $(call cc-ifversion, -ge, 0408, $(HOSTCXX), $(HOSTCC))
|
||||
PLUGINCC := $(shell $(CONFIG_SHELL) $(srctree)/scripts/gcc-plugin.sh "$(__PLUGINCC)" "$(HOSTCXX)" "$(CC)")
|
||||
|
||||
SANCOV_PLUGIN := -fplugin=$(objtree)/scripts/gcc-plugins/sancov_plugin.so
|
||||
|
||||
gcc-plugin-$(CONFIG_GCC_PLUGIN_CYC_COMPLEXITY) += cyc_complexity_plugin.so
|
||||
|
||||
ifdef CONFIG_GCC_PLUGIN_SANCOV
|
||||
ifeq ($(CFLAGS_KCOV),)
|
||||
# It is needed because of the gcc-plugin.sh and gcc version checks.
|
||||
gcc-plugin-$(CONFIG_GCC_PLUGIN_SANCOV) += sancov_plugin.so
|
||||
|
||||
ifneq ($(PLUGINCC),)
|
||||
CFLAGS_KCOV := $(SANCOV_PLUGIN)
|
||||
else
|
||||
$(warning warning: cannot use CONFIG_KCOV: -fsanitize-coverage=trace-pc is not supported by compiler)
|
||||
endif
|
||||
endif
|
||||
endif
|
||||
|
||||
GCC_PLUGINS_CFLAGS := $(addprefix -fplugin=$(objtree)/scripts/gcc-plugins/, $(gcc-plugin-y))
|
||||
|
||||
export PLUGINCC GCC_PLUGINS_CFLAGS GCC_PLUGIN
|
||||
export PLUGINCC GCC_PLUGINS_CFLAGS GCC_PLUGIN SANCOV_PLUGIN
|
||||
|
||||
ifeq ($(PLUGINCC),)
|
||||
ifneq ($(GCC_PLUGINS_CFLAGS),)
|
||||
|
|
@ -16,6 +32,9 @@ ifdef CONFIG_GCC_PLUGINS
|
|||
$(warning warning: your gcc version does not support plugins, you should upgrade it to gcc 4.5 at least)
|
||||
endif
|
||||
endif
|
||||
else
|
||||
# SANCOV_PLUGIN can be only in CFLAGS_KCOV because avoid duplication.
|
||||
GCC_PLUGINS_CFLAGS := $(filter-out $(SANCOV_PLUGIN), $(GCC_PLUGINS_CFLAGS))
|
||||
endif
|
||||
|
||||
KBUILD_CFLAGS += $(GCC_PLUGINS_CFLAGS)
|
||||
|
|
|
|||
|
|
@ -14,8 +14,14 @@ endif
|
|||
|
||||
export GCCPLUGINS_DIR HOSTLIBS
|
||||
|
||||
ifneq ($(CFLAGS_KCOV), $(SANCOV_PLUGIN))
|
||||
GCC_PLUGIN := $(filter-out $(SANCOV_PLUGIN), $(GCC_PLUGIN))
|
||||
endif
|
||||
|
||||
$(HOSTLIBS)-y := $(GCC_PLUGIN)
|
||||
always := $($(HOSTLIBS)-y)
|
||||
|
||||
cyc_complexity_plugin-objs := cyc_complexity_plugin.o
|
||||
sancov_plugin-objs := sancov_plugin.o
|
||||
|
||||
clean-files += *.so
|
||||
|
|
|
|||
144
scripts/gcc-plugins/sancov_plugin.c
Normal file
144
scripts/gcc-plugins/sancov_plugin.c
Normal file
|
|
@ -0,0 +1,144 @@
|
|||
/*
|
||||
* Copyright 2011-2016 by Emese Revfy <re.emese@gmail.com>
|
||||
* Licensed under the GPL v2, or (at your option) v3
|
||||
*
|
||||
* Homepage:
|
||||
* https://github.com/ephox-gcc-plugins/sancov
|
||||
*
|
||||
* This plugin inserts a __sanitizer_cov_trace_pc() call at the start of basic blocks.
|
||||
* It supports all gcc versions with plugin support (from gcc-4.5 on).
|
||||
* It is based on the commit "Add fuzzing coverage support" by Dmitry Vyukov <dvyukov@google.com>.
|
||||
*
|
||||
* You can read about it more here:
|
||||
* https://gcc.gnu.org/viewcvs/gcc?limit_changes=0&view=revision&revision=231296
|
||||
* http://lwn.net/Articles/674854/
|
||||
* https://github.com/google/syzkaller
|
||||
* https://lwn.net/Articles/677764/
|
||||
*
|
||||
* Usage:
|
||||
* make run
|
||||
*/
|
||||
|
||||
#include "gcc-common.h"
|
||||
|
||||
int plugin_is_GPL_compatible;
|
||||
|
||||
tree sancov_fndecl;
|
||||
|
||||
static struct plugin_info sancov_plugin_info = {
|
||||
.version = "20160402",
|
||||
.help = "sancov plugin\n",
|
||||
};
|
||||
|
||||
static unsigned int sancov_execute(void)
|
||||
{
|
||||
basic_block bb;
|
||||
|
||||
/* Remove this line when this plugin and kcov will be in the kernel.
|
||||
if (!strcmp(DECL_NAME_POINTER(current_function_decl), DECL_NAME_POINTER(sancov_fndecl)))
|
||||
return 0;
|
||||
*/
|
||||
|
||||
FOR_EACH_BB_FN(bb, cfun) {
|
||||
const_gimple stmt;
|
||||
gcall *gcall;
|
||||
gimple_stmt_iterator gsi = gsi_after_labels(bb);
|
||||
|
||||
if (gsi_end_p(gsi))
|
||||
continue;
|
||||
|
||||
stmt = gsi_stmt(gsi);
|
||||
gcall = as_a_gcall(gimple_build_call(sancov_fndecl, 0));
|
||||
gimple_set_location(gcall, gimple_location(stmt));
|
||||
gsi_insert_before(&gsi, gcall, GSI_SAME_STMT);
|
||||
}
|
||||
return 0;
|
||||
}
|
||||
|
||||
#define PASS_NAME sancov
|
||||
|
||||
#define NO_GATE
|
||||
#define TODO_FLAGS_FINISH TODO_dump_func | TODO_verify_stmts | TODO_update_ssa_no_phi | TODO_verify_flow
|
||||
|
||||
#include "gcc-generate-gimple-pass.h"
|
||||
|
||||
static void sancov_start_unit(void __unused *gcc_data, void __unused *user_data)
|
||||
{
|
||||
tree leaf_attr, nothrow_attr;
|
||||
tree BT_FN_VOID = build_function_type_list(void_type_node, NULL_TREE);
|
||||
|
||||
sancov_fndecl = build_fn_decl("__sanitizer_cov_trace_pc", BT_FN_VOID);
|
||||
|
||||
DECL_ASSEMBLER_NAME(sancov_fndecl);
|
||||
TREE_PUBLIC(sancov_fndecl) = 1;
|
||||
DECL_EXTERNAL(sancov_fndecl) = 1;
|
||||
DECL_ARTIFICIAL(sancov_fndecl) = 1;
|
||||
DECL_PRESERVE_P(sancov_fndecl) = 1;
|
||||
DECL_UNINLINABLE(sancov_fndecl) = 1;
|
||||
TREE_USED(sancov_fndecl) = 1;
|
||||
|
||||
nothrow_attr = tree_cons(get_identifier("nothrow"), NULL, NULL);
|
||||
decl_attributes(&sancov_fndecl, nothrow_attr, 0);
|
||||
gcc_assert(TREE_NOTHROW(sancov_fndecl));
|
||||
#if BUILDING_GCC_VERSION > 4005
|
||||
leaf_attr = tree_cons(get_identifier("leaf"), NULL, NULL);
|
||||
decl_attributes(&sancov_fndecl, leaf_attr, 0);
|
||||
#endif
|
||||
}
|
||||
|
||||
int plugin_init(struct plugin_name_args *plugin_info, struct plugin_gcc_version *version)
|
||||
{
|
||||
int i;
|
||||
struct register_pass_info sancov_plugin_pass_info;
|
||||
const char * const plugin_name = plugin_info->base_name;
|
||||
const int argc = plugin_info->argc;
|
||||
const struct plugin_argument * const argv = plugin_info->argv;
|
||||
bool enable = true;
|
||||
|
||||
static const struct ggc_root_tab gt_ggc_r_gt_sancov[] = {
|
||||
{
|
||||
.base = &sancov_fndecl,
|
||||
.nelt = 1,
|
||||
.stride = sizeof(sancov_fndecl),
|
||||
.cb = >_ggc_mx_tree_node,
|
||||
.pchw = >_pch_nx_tree_node
|
||||
},
|
||||
LAST_GGC_ROOT_TAB
|
||||
};
|
||||
|
||||
/* BBs can be split afterwards?? */
|
||||
sancov_plugin_pass_info.pass = make_sancov_pass();
|
||||
#if BUILDING_GCC_VERSION >= 4009
|
||||
sancov_plugin_pass_info.reference_pass_name = "asan";
|
||||
#else
|
||||
sancov_plugin_pass_info.reference_pass_name = "nrv";
|
||||
#endif
|
||||
sancov_plugin_pass_info.ref_pass_instance_number = 0;
|
||||
sancov_plugin_pass_info.pos_op = PASS_POS_INSERT_BEFORE;
|
||||
|
||||
if (!plugin_default_version_check(version, &gcc_version)) {
|
||||
error(G_("incompatible gcc/plugin versions"));
|
||||
return 1;
|
||||
}
|
||||
|
||||
for (i = 0; i < argc; ++i) {
|
||||
if (!strcmp(argv[i].key, "no-sancov")) {
|
||||
enable = false;
|
||||
continue;
|
||||
}
|
||||
error(G_("unkown option '-fplugin-arg-%s-%s'"), plugin_name, argv[i].key);
|
||||
}
|
||||
|
||||
register_callback(plugin_name, PLUGIN_INFO, NULL, &sancov_plugin_info);
|
||||
|
||||
if (!enable)
|
||||
return 0;
|
||||
|
||||
#if BUILDING_GCC_VERSION < 6000
|
||||
register_callback(plugin_name, PLUGIN_START_UNIT, &sancov_start_unit, NULL);
|
||||
register_callback(plugin_name, PLUGIN_REGISTER_GGC_ROOTS, NULL, (void *)>_ggc_r_gt_sancov);
|
||||
register_callback(plugin_name, PLUGIN_PASS_MANAGER_SETUP, NULL, &sancov_plugin_pass_info);
|
||||
#endif
|
||||
|
||||
return 0;
|
||||
}
|
||||
Loading…
Reference in a new issue