From 84b0769e335819050ecdd86301a5f5d41fa5df8b Mon Sep 17 00:00:00 2001 From: Maxim Ostapenko Date: Fri, 2 Dec 2016 07:39:27 +0000 Subject: [PATCH] Add support for ASan odr_indicator. config/ * bootstrap-asan.mk: Replace LSAN_OPTIONS=detect_leaks=0 with ASAN_OPTIONS=detect_leaks=0:use_odr_indicator=1. gcc/ * asan.c (asan_global_struct): Refactor. (create_odr_indicator): New function. (asan_needs_odr_indicator_p): Likewise. (is_odr_indicator): Likewise. (asan_add_global): Introduce odr_indicator_ptr. Pass it into global's constructor. (asan_protect_global): Do not protect odr indicators. gcc/c-family/ * c-attribs.c (asan odr indicator): New attribute. (handle_asan_odr_indicator_attribute): New function. gcc/testsuite/ * c-c++-common/asan/no-redundant-odr-indicators-1.c: New test. From-SVN: r243153 --- config/ChangeLog | 5 ++ config/bootstrap-asan.mk | 2 +- gcc/ChangeLog | 10 +++ gcc/asan.c | 87 +++++++++++++++++-- gcc/c-family/ChangeLog | 5 ++ gcc/c-family/c-attribs.c | 14 +++ gcc/testsuite/ChangeLog | 4 + .../asan/no-redundant-odr-indicators-1.c | 17 ++++ 8 files changed, 135 insertions(+), 9 deletions(-) create mode 100644 gcc/testsuite/c-c++-common/asan/no-redundant-odr-indicators-1.c diff --git a/config/ChangeLog b/config/ChangeLog index 8dcb4831b17..a823d21626b 100644 --- a/config/ChangeLog +++ b/config/ChangeLog @@ -1,3 +1,8 @@ +2016-12-02 Maxim Ostapenko + + * bootstrap-asan.mk: Replace LSAN_OPTIONS=detect_leaks=0 with + ASAN_OPTIONS=detect_leaks=0:use_odr_indicator=1. + 2016-12-01 Matthias Klose * pkg.m4: Remove. diff --git a/config/bootstrap-asan.mk b/config/bootstrap-asan.mk index 70baaf9bb17..e73d4c2cfb8 100644 --- a/config/bootstrap-asan.mk +++ b/config/bootstrap-asan.mk @@ -1,7 +1,7 @@ # This option enables -fsanitize=address for stage2 and stage3. # Suppress LeakSanitizer in bootstrap. -export LSAN_OPTIONS="detect_leaks=0" +export ASAN_OPTIONS=detect_leaks=0:use_odr_indicator=1 STAGE2_CFLAGS += -fsanitize=address STAGE3_CFLAGS += -fsanitize=address diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 75881ee7ace..ef080c77ed3 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,13 @@ +2016-12-02 Maxim Ostapenko + + * asan.c (asan_global_struct): Refactor. + (create_odr_indicator): New function. + (asan_needs_odr_indicator_p): Likewise. + (is_odr_indicator): Likewise. + (asan_add_global): Introduce odr_indicator_ptr. Pass it into global's + constructor. + (asan_protect_global): Do not protect odr indicators. + 2016-12-01 Jeff Law * tree-ssa-threadedge.c diff --git a/gcc/asan.c b/gcc/asan.c index cb5d6158e59..5af95472db9 100644 --- a/gcc/asan.c +++ b/gcc/asan.c @@ -1388,6 +1388,16 @@ asan_needs_local_alias (tree decl) return DECL_WEAK (decl) || !targetm.binds_local_p (decl); } +/* Return true if DECL, a global var, is an artificial ODR indicator symbol + therefore doesn't need protection. */ + +static bool +is_odr_indicator (tree decl) +{ + return (DECL_ARTIFICIAL (decl) + && lookup_attribute ("asan odr indicator", DECL_ATTRIBUTES (decl))); +} + /* Return true if DECL is a VAR_DECL that should be protected by Address Sanitizer, by appending a red zone with protected shadow memory after it and aligning it to at least @@ -1436,7 +1446,8 @@ asan_protect_global (tree decl) || ASAN_RED_ZONE_SIZE * BITS_PER_UNIT > MAX_OFILE_ALIGNMENT || !valid_constant_size_p (DECL_SIZE_UNIT (decl)) || DECL_ALIGN_UNIT (decl) > 2 * ASAN_RED_ZONE_SIZE - || TREE_TYPE (decl) == ubsan_get_source_location_type ()) + || TREE_TYPE (decl) == ubsan_get_source_location_type () + || is_odr_indicator (decl)) return false; rtl = DECL_RTL (decl); @@ -2266,14 +2277,15 @@ asan_dynamic_init_call (bool after_p) static tree asan_global_struct (void) { - static const char *field_names[8] + static const char *field_names[] = { "__beg", "__size", "__size_with_redzone", - "__name", "__module_name", "__has_dynamic_init", "__location", "__odr_indicator"}; - tree fields[8], ret; - int i; + "__name", "__module_name", "__has_dynamic_init", "__location", + "__odr_indicator" }; + tree fields[ARRAY_SIZE (field_names)], ret; + unsigned i; ret = make_node (RECORD_TYPE); - for (i = 0; i < 8; i++) + for (i = 0; i < ARRAY_SIZE (field_names); i++) { fields[i] = build_decl (UNKNOWN_LOCATION, FIELD_DECL, @@ -2295,6 +2307,63 @@ asan_global_struct (void) return ret; } +/* Create and return odr indicator symbol for DECL. + TYPE is __asan_global struct type as returned by asan_global_struct. */ + +static tree +create_odr_indicator (tree decl, tree type) +{ + char *name; + tree uptr = TREE_TYPE (DECL_CHAIN (TYPE_FIELDS (type))); + tree decl_name + = (HAS_DECL_ASSEMBLER_NAME_P (decl) ? DECL_ASSEMBLER_NAME (decl) + : DECL_NAME (decl)); + /* DECL_NAME theoretically might be NULL. Bail out with 0 in this case. */ + if (decl_name == NULL_TREE) + return build_int_cst (uptr, 0); + size_t len = strlen (IDENTIFIER_POINTER (decl_name)) + sizeof ("__odr_asan_"); + name = XALLOCAVEC (char, len); + snprintf (name, len, "__odr_asan_%s", IDENTIFIER_POINTER (decl_name)); +#ifndef NO_DOT_IN_LABEL + name[sizeof ("__odr_asan") - 1] = '.'; +#elif !defined(NO_DOLLAR_IN_LABEL) + name[sizeof ("__odr_asan") - 1] = '$'; +#endif + tree var = build_decl (UNKNOWN_LOCATION, VAR_DECL, get_identifier (name), + char_type_node); + TREE_ADDRESSABLE (var) = 1; + TREE_READONLY (var) = 0; + TREE_THIS_VOLATILE (var) = 1; + DECL_GIMPLE_REG_P (var) = 0; + DECL_ARTIFICIAL (var) = 1; + DECL_IGNORED_P (var) = 1; + TREE_STATIC (var) = 1; + TREE_PUBLIC (var) = 1; + DECL_VISIBILITY (var) = DECL_VISIBILITY (decl); + DECL_VISIBILITY_SPECIFIED (var) = DECL_VISIBILITY_SPECIFIED (decl); + + TREE_USED (var) = 1; + tree ctor = build_constructor_va (TREE_TYPE (var), 1, NULL_TREE, + build_int_cst (unsigned_type_node, 0)); + TREE_CONSTANT (ctor) = 1; + TREE_STATIC (ctor) = 1; + DECL_INITIAL (var) = ctor; + DECL_ATTRIBUTES (var) = tree_cons (get_identifier ("asan odr indicator"), + NULL, DECL_ATTRIBUTES (var)); + make_decl_rtl (var); + varpool_node::finalize_decl (var); + return fold_convert (uptr, build_fold_addr_expr (var)); +} + +/* Return true if DECL, a global var, might be overridden and needs + an additional odr indicator symbol. */ + +static bool +asan_needs_odr_indicator_p (tree decl) +{ + return !DECL_ARTIFICIAL (decl) && !DECL_WEAK (decl) && TREE_PUBLIC (decl); +} + /* Append description of a single global DECL into vector V. TYPE is __asan_global struct type as returned by asan_global_struct. */ @@ -2335,6 +2404,9 @@ asan_add_global (tree decl, tree type, vec *v) assemble_alias (refdecl, DECL_ASSEMBLER_NAME (decl)); } + tree odr_indicator_ptr + = (asan_needs_odr_indicator_p (decl) ? create_odr_indicator (decl, type) + : build_int_cst (uptr, 0)); CONSTRUCTOR_APPEND_ELT (vinner, NULL_TREE, fold_convert (const_ptr_type_node, build_fold_addr_expr (refdecl))); @@ -2382,8 +2454,7 @@ asan_add_global (tree decl, tree type, vec *v) else locptr = build_int_cst (uptr, 0); CONSTRUCTOR_APPEND_ELT (vinner, NULL_TREE, locptr); - /* TODO: support ODR indicators. */ - CONSTRUCTOR_APPEND_ELT (vinner, NULL_TREE, build_int_cst (uptr, 0)); + CONSTRUCTOR_APPEND_ELT (vinner, NULL_TREE, odr_indicator_ptr); init = build_constructor (type, vinner); CONSTRUCTOR_APPEND_ELT (v, NULL_TREE, init); } diff --git a/gcc/c-family/ChangeLog b/gcc/c-family/ChangeLog index 183493d6e3a..58907981b96 100644 --- a/gcc/c-family/ChangeLog +++ b/gcc/c-family/ChangeLog @@ -1,3 +1,8 @@ +2016-12-02 Maxim Ostapenko + + * c-attribs.c (asan odr indicator): New attribute. + (handle_asan_odr_indicator_attribute): New function. + 2016-11-26 Prathamesh Kulkarni * c-common.c (c_common_nodes_and_builtins): Remove initialization of diff --git a/gcc/c-family/c-attribs.c b/gcc/c-family/c-attribs.c index 964efe94bb7..f5adadee3af 100644 --- a/gcc/c-family/c-attribs.c +++ b/gcc/c-family/c-attribs.c @@ -57,6 +57,8 @@ static tree handle_no_address_safety_analysis_attribute (tree *, tree, tree, int, bool *); static tree handle_no_sanitize_undefined_attribute (tree *, tree, tree, int, bool *); +static tree handle_asan_odr_indicator_attribute (tree *, tree, tree, int, + bool *); static tree handle_stack_protect_attribute (tree *, tree, tree, int, bool *); static tree handle_noinline_attribute (tree *, tree, tree, int, bool *); static tree handle_noclone_attribute (tree *, tree, tree, int, bool *); @@ -292,6 +294,9 @@ const struct attribute_spec c_common_attribute_table[] = { "no_sanitize_undefined", 0, 0, true, false, false, handle_no_sanitize_undefined_attribute, false }, + { "asan odr indicator", 0, 0, true, false, false, + handle_asan_odr_indicator_attribute, + false }, { "warning", 1, 1, true, false, false, handle_error_attribute, false }, { "error", 1, 1, true, false, false, @@ -591,6 +596,15 @@ handle_no_sanitize_undefined_attribute (tree *node, tree name, tree, int, return NULL_TREE; } +/* Handle an "asan odr indicator" attribute; arguments as in + struct attribute_spec.handler. */ + +static tree +handle_asan_odr_indicator_attribute (tree *, tree, tree, int, bool *) +{ + return NULL_TREE; +} + /* Handle a "stack_protect" attribute; arguments as in struct attribute_spec.handler. */ diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index dcbdf565208..c000e07cade 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,7 @@ +2016-12-02 Maxim Ostapenko + + * c-c++-common/asan/no-redundant-odr-indicators-1.c: New test. + 2016-12-01 Elizebeth Punnoose PR fortran/77505 diff --git a/gcc/testsuite/c-c++-common/asan/no-redundant-odr-indicators-1.c b/gcc/testsuite/c-c++-common/asan/no-redundant-odr-indicators-1.c new file mode 100644 index 00000000000..9231264e3d9 --- /dev/null +++ b/gcc/testsuite/c-c++-common/asan/no-redundant-odr-indicators-1.c @@ -0,0 +1,17 @@ +/* { dg-do compile } */ +/* { dg-skip-if "" { *-*-* } { "*" } { "-O0" } } */ + +/* Local variables should not have odr indicators. */ +static int a = 2; +/* Thread local variables should not have odr indicators. */ +__thread int b = 3; +/* Externally visible variables should have odr indicators. */ +int c = 1; + +int main () { + return 0; +} + +/* { dg-final { scan-assembler-not "odr_asan\[\.\$\]a" } } */ +/* { dg-final { scan-assembler-not "odr_asan\[\.\$\]b" } } */ +/* { dg-final { scan-assembler "odr_asan\[\.\$\]c" } } */ -- 2.30.2