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Re: [PATCH] Add -fsanitize=pointer-{compare,subtract}.
- From: Martin Liška <mliska at suse dot cz>
- To: Jakub Jelinek <jakub at redhat dot com>
- Cc: gcc-patches at gcc dot gnu dot org
- Date: Tue, 21 Nov 2017 12:59:46 +0100
- Subject: Re: [PATCH] Add -fsanitize=pointer-{compare,subtract}.
- Authentication-results: sourceware.org; auth=none
- References: <20171011142214.GL14653@tucnak> <d805088c-4d10-d836-bea8-1dffb6458ab8@suse.cz> <20171012113430.GT14653@tucnak> <4f727889-e597-5aa8-7ada-6f74c332c153@suse.cz> <20171013111719.GG14653@tucnak> <8216fdf0-5a3a-260d-81ac-e81eed58a3ca@suse.cz> <20171013131308.GH14653@tucnak> <27d314e3-4f42-e634-193d-daa7f3b8235b@suse.cz> <20171016122156.GT14653@tucnak> <ad265f59-39f6-648a-7247-90f6b9f8e7e4@suse.cz> <20171016134515.GV14653@tucnak> <26f388e4-8b2f-acab-b7d3-70768f7f1c42@suse.cz>
On 10/16/2017 10:39 PM, Martin Liška wrote:
> Hi.
>
> All nits included in mainline review request I've just done:
> https://reviews.llvm.org/D38971
>
> Martin
Hi.
There's updated version of patch where I added new test-cases and it's rebased
with latest version of libsanitizer changes. This is subject for libsanitizer review process.
Martin
>From 100b723b9b7fb10dedb2154f30e1ebd6ef885ab4 Mon Sep 17 00:00:00 2001
From: marxin <mliska@suse.cz>
Date: Wed, 8 Nov 2017 13:16:17 +0100
Subject: [PATCH] Add -fsanitize=pointer-{compare,subtract}.
gcc/ChangeLog:
2017-11-21 Martin Liska <mliska@suse.cz>
* doc/invoke.texi: Document the options.
* flag-types.h (enum sanitize_code): Add
SANITIZE_POINTER_COMPARE and SANITIZE_POINTER_SUBTRACT.
* ipa-inline.c (sanitize_attrs_match_for_inline_p): Add handling
of SANITIZE_POINTER_COMPARE and SANITIZE_POINTER_SUBTRACT.
* opts.c: Define new sanitizer options.
* sanitizer.def (BUILT_IN_ASAN_POINTER_COMPARE): Likewise.
(BUILT_IN_ASAN_POINTER_SUBTRACT): Likewise.
gcc/c/ChangeLog:
2017-11-21 Martin Liska <mliska@suse.cz>
* c-typeck.c (pointer_diff): Add new argument and instrument
pointer subtraction.
(build_binary_op): Similar for pointer comparison.
gcc/cp/ChangeLog:
2017-11-21 Martin Liska <mliska@suse.cz>
* typeck.c (pointer_diff): Add new argument and instrument
pointer subtraction.
(cp_build_binary_op): Create compound expression if doing an
instrumentation.
gcc/testsuite/ChangeLog:
2017-11-21 Martin Liska <mliska@suse.cz>
* c-c++-common/asan/pointer-compare-1.c: New test.
* c-c++-common/asan/pointer-compare-2.c: New test.
* c-c++-common/asan/pointer-subtract-1.c: New test.
* c-c++-common/asan/pointer-subtract-2.c: New test.
* c-c++-common/asan/pointer-subtract-3.c: New test.
* c-c++-common/asan/pointer-subtract-4.c: New test.
---
gcc/c/c-typeck.c | 31 ++++++--
gcc/cp/typeck.c | 39 ++++++++--
gcc/doc/invoke.texi | 22 ++++++
gcc/flag-types.h | 2 +
gcc/ipa-inline.c | 8 ++-
gcc/opts.c | 15 ++++
gcc/sanitizer.def | 4 ++
.../c-c++-common/asan/pointer-compare-1.c | 83 ++++++++++++++++++++++
.../c-c++-common/asan/pointer-compare-2.c | 76 ++++++++++++++++++++
.../c-c++-common/asan/pointer-subtract-1.c | 41 +++++++++++
.../c-c++-common/asan/pointer-subtract-2.c | 33 +++++++++
.../c-c++-common/asan/pointer-subtract-3.c | 40 +++++++++++
.../c-c++-common/asan/pointer-subtract-4.c | 40 +++++++++++
libsanitizer/asan/asan_descriptions.cc | 20 ++++++
libsanitizer/asan/asan_descriptions.h | 4 ++
libsanitizer/asan/asan_report.cc | 53 ++++++++++++--
libsanitizer/asan/asan_thread.cc | 25 ++++++-
libsanitizer/asan/asan_thread.h | 3 +
18 files changed, 521 insertions(+), 18 deletions(-)
create mode 100644 gcc/testsuite/c-c++-common/asan/pointer-compare-1.c
create mode 100644 gcc/testsuite/c-c++-common/asan/pointer-compare-2.c
create mode 100644 gcc/testsuite/c-c++-common/asan/pointer-subtract-1.c
create mode 100644 gcc/testsuite/c-c++-common/asan/pointer-subtract-2.c
create mode 100644 gcc/testsuite/c-c++-common/asan/pointer-subtract-3.c
create mode 100644 gcc/testsuite/c-c++-common/asan/pointer-subtract-4.c
diff --git a/gcc/c/c-typeck.c b/gcc/c/c-typeck.c
index 4bdc48a9ea3..5dac9bdf08b 100644
--- a/gcc/c/c-typeck.c
+++ b/gcc/c/c-typeck.c
@@ -96,7 +96,7 @@ static tree lookup_field (tree, tree);
static int convert_arguments (location_t, vec<location_t>, tree,
vec<tree, va_gc> *, vec<tree, va_gc> *, tree,
tree);
-static tree pointer_diff (location_t, tree, tree);
+static tree pointer_diff (location_t, tree, tree, tree *);
static tree convert_for_assignment (location_t, location_t, tree, tree, tree,
enum impl_conv, bool, tree, tree, int);
static tree valid_compound_expr_initializer (tree, tree);
@@ -3778,10 +3778,11 @@ parser_build_binary_op (location_t location, enum tree_code code,
}
/* Return a tree for the difference of pointers OP0 and OP1.
- The resulting tree has type int. */
+ The resulting tree has type int. If POINTER_SUBTRACT sanitization is
+ enabled, assign to INSTRUMENT_EXPR call to libsanitizer. */
static tree
-pointer_diff (location_t loc, tree op0, tree op1)
+pointer_diff (location_t loc, tree op0, tree op1, tree *instrument_expr)
{
tree restype = ptrdiff_type_node;
tree result, inttype;
@@ -3825,6 +3826,17 @@ pointer_diff (location_t loc, tree op0, tree op1)
pedwarn (loc, OPT_Wpointer_arith,
"pointer to a function used in subtraction");
+ if (sanitize_flags_p (SANITIZE_POINTER_SUBTRACT))
+ {
+ gcc_assert (current_function_decl != NULL_TREE);
+
+ op0 = save_expr (op0);
+ op1 = save_expr (op1);
+
+ tree tt = builtin_decl_explicit (BUILT_IN_ASAN_POINTER_SUBTRACT);
+ *instrument_expr = build_call_expr_loc (loc, tt, 2, op0, op1);
+ }
+
/* First do the subtraction as integers;
then drop through to build the divide operator.
Do not do default conversions on the minus operator
@@ -11185,7 +11197,7 @@ build_binary_op (location_t location, enum tree_code code,
if (code0 == POINTER_TYPE && code1 == POINTER_TYPE
&& comp_target_types (location, type0, type1))
{
- ret = pointer_diff (location, op0, op1);
+ ret = pointer_diff (location, op0, op1, &instrument_expr);
goto return_build_binary_op;
}
/* Handle pointer minus int. Just like pointer plus int. */
@@ -11735,6 +11747,17 @@ build_binary_op (location_t location, enum tree_code code,
result_type = type1;
pedwarn (location, 0, "comparison between pointer and integer");
}
+
+ if ((code0 == POINTER_TYPE || code1 == POINTER_TYPE)
+ && sanitize_flags_p (SANITIZE_POINTER_COMPARE))
+ {
+ op0 = save_expr (op0);
+ op1 = save_expr (op1);
+
+ tree tt = builtin_decl_explicit (BUILT_IN_ASAN_POINTER_COMPARE);
+ instrument_expr = build_call_expr_loc (location, tt, 2, op0, op1);
+ }
+
if ((TREE_CODE (TREE_TYPE (orig_op0)) == BOOLEAN_TYPE
|| truth_value_p (TREE_CODE (orig_op0)))
^ (TREE_CODE (TREE_TYPE (orig_op1)) == BOOLEAN_TYPE
diff --git a/gcc/cp/typeck.c b/gcc/cp/typeck.c
index 9130c10f390..e2474267436 100644
--- a/gcc/cp/typeck.c
+++ b/gcc/cp/typeck.c
@@ -54,7 +54,7 @@ static tree rationalize_conditional_expr (enum tree_code, tree,
static int comp_ptr_ttypes_real (tree, tree, int);
static bool comp_except_types (tree, tree, bool);
static bool comp_array_types (const_tree, const_tree, bool);
-static tree pointer_diff (location_t, tree, tree, tree, tsubst_flags_t);
+static tree pointer_diff (location_t, tree, tree, tree, tsubst_flags_t, tree *);
static tree get_delta_difference (tree, tree, bool, bool, tsubst_flags_t);
static void casts_away_constness_r (tree *, tree *, tsubst_flags_t);
static bool casts_away_constness (tree, tree, tsubst_flags_t);
@@ -4318,8 +4318,16 @@ cp_build_binary_op (location_t location,
if (code0 == POINTER_TYPE && code1 == POINTER_TYPE
&& same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (type0),
TREE_TYPE (type1)))
- return pointer_diff (location, op0, op1,
- common_pointer_type (type0, type1), complain);
+ {
+ result = pointer_diff (location, op0, op1,
+ common_pointer_type (type0, type1), complain,
+ &instrument_expr);
+ if (instrument_expr != NULL)
+ result = build2 (COMPOUND_EXPR, TREE_TYPE (result),
+ instrument_expr, result);
+
+ return result;
+ }
/* In all other cases except pointer - int, the usual arithmetic
rules apply. */
else if (!(code0 == POINTER_TYPE && code1 == INTEGER_TYPE))
@@ -5008,6 +5016,17 @@ cp_build_binary_op (location_t location,
else
return error_mark_node;
}
+
+ if ((code0 == POINTER_TYPE || code1 == POINTER_TYPE)
+ && sanitize_flags_p (SANITIZE_POINTER_COMPARE))
+ {
+ op0 = save_expr (op0);
+ op1 = save_expr (op1);
+
+ tree tt = builtin_decl_explicit (BUILT_IN_ASAN_POINTER_COMPARE);
+ instrument_expr = build_call_expr_loc (location, tt, 2, op0, op1);
+ }
+
break;
case UNORDERED_EXPR:
@@ -5363,11 +5382,12 @@ cp_pointer_int_sum (location_t loc, enum tree_code resultcode, tree ptrop,
}
/* Return a tree for the difference of pointers OP0 and OP1.
- The resulting tree has type int. */
+ The resulting tree has type int. If POINTER_SUBTRACT sanitization is
+ enabled, assign to INSTRUMENT_EXPR call to libsanitizer. */
static tree
pointer_diff (location_t loc, tree op0, tree op1, tree ptrtype,
- tsubst_flags_t complain)
+ tsubst_flags_t complain, tree *instrument_expr)
{
tree result;
tree restype = ptrdiff_type_node;
@@ -5401,6 +5421,15 @@ pointer_diff (location_t loc, tree op0, tree op1, tree ptrtype,
return error_mark_node;
}
+ if (sanitize_flags_p (SANITIZE_POINTER_SUBTRACT))
+ {
+ op0 = save_expr (op0);
+ op1 = save_expr (op1);
+
+ tree tt = builtin_decl_explicit (BUILT_IN_ASAN_POINTER_SUBTRACT);
+ *instrument_expr = build_call_expr_loc (loc, tt, 2, op0, op1);
+ }
+
/* First do the subtraction as integers;
then drop through to build the divide operator. */
diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
index 2ef88e081f9..4f6f6cd30ce 100644
--- a/gcc/doc/invoke.texi
+++ b/gcc/doc/invoke.texi
@@ -10984,6 +10984,28 @@ Enable AddressSanitizer for Linux kernel.
See @uref{https://github.com/google/kasan/wiki} for more details.
The option cannot be combined with @option{-fcheck-pointer-bounds}.
+@item -fsanitize=pointer-compare
+@opindex fsanitize=pointer-compare
+Instrument comparison operation (<, <=, >, >=) with pointer operands.
+The option must be combined with either @option{-fsanitize=kernel-address} or
+@option{-fsanitize=address}
+The option cannot be combined with @option{-fsanitize=thread}
+and/or @option{-fcheck-pointer-bounds}.
+Note: By default the check is disabled at run time. To enable it,
+add @code{detect_invalid_pointer_pairs=1} to the environment variable
+@env{ASAN_OPTIONS}.
+
+@item -fsanitize=pointer-subtract
+@opindex fsanitize=pointer-subtract
+Instrument subtraction with pointer operands.
+The option must be combined with either @option{-fsanitize=kernel-address} or
+@option{-fsanitize=address}
+The option cannot be combined with @option{-fsanitize=thread}
+and/or @option{-fcheck-pointer-bounds}.
+Note: By default the check is disabled at run time. To enable it,
+add @code{detect_invalid_pointer_pairs=1} to the environment variable
+@env{ASAN_OPTIONS}.
+
@item -fsanitize=thread
@opindex fsanitize=thread
Enable ThreadSanitizer, a fast data race detector.
diff --git a/gcc/flag-types.h b/gcc/flag-types.h
index 591b74457cd..3073c661872 100644
--- a/gcc/flag-types.h
+++ b/gcc/flag-types.h
@@ -246,6 +246,8 @@ enum sanitize_code {
SANITIZE_BOUNDS_STRICT = 1UL << 23,
SANITIZE_POINTER_OVERFLOW = 1UL << 24,
SANITIZE_BUILTIN = 1UL << 25,
+ SANITIZE_POINTER_COMPARE = 1UL << 26,
+ SANITIZE_POINTER_SUBTRACT = 1UL << 27,
SANITIZE_SHIFT = SANITIZE_SHIFT_BASE | SANITIZE_SHIFT_EXPONENT,
SANITIZE_UNDEFINED = SANITIZE_SHIFT | SANITIZE_DIVIDE | SANITIZE_UNREACHABLE
| SANITIZE_VLA | SANITIZE_NULL | SANITIZE_RETURN
diff --git a/gcc/ipa-inline.c b/gcc/ipa-inline.c
index 687996876ce..6969b5365af 100644
--- a/gcc/ipa-inline.c
+++ b/gcc/ipa-inline.c
@@ -263,8 +263,12 @@ sanitize_attrs_match_for_inline_p (const_tree caller, const_tree callee)
if (!caller || !callee)
return true;
- return sanitize_flags_p (SANITIZE_ADDRESS, caller)
- == sanitize_flags_p (SANITIZE_ADDRESS, callee);
+ return ((sanitize_flags_p (SANITIZE_ADDRESS, caller)
+ == sanitize_flags_p (SANITIZE_ADDRESS, callee))
+ && (sanitize_flags_p (SANITIZE_POINTER_COMPARE, caller)
+ == sanitize_flags_p (SANITIZE_POINTER_COMPARE, callee))
+ && (sanitize_flags_p (SANITIZE_POINTER_SUBTRACT, caller)
+ == sanitize_flags_p (SANITIZE_POINTER_SUBTRACT, callee)));
}
/* Used for flags where it is safe to inline when caller's value is
diff --git a/gcc/opts.c b/gcc/opts.c
index ac383d48ec1..c4dded7ff55 100644
--- a/gcc/opts.c
+++ b/gcc/opts.c
@@ -952,6 +952,19 @@ finish_options (struct gcc_options *opts, struct gcc_options *opts_set,
if (opts->x_dwarf_split_debug_info)
opts->x_debug_generate_pub_sections = 2;
+ if ((opts->x_flag_sanitize
+ & (SANITIZE_USER_ADDRESS | SANITIZE_KERNEL_ADDRESS)) == 0)
+ {
+ if (opts->x_flag_sanitize & SANITIZE_POINTER_COMPARE)
+ error_at (loc,
+ "%<-fsanitize=pointer-compare%> must be combined with "
+ "%<-fsanitize=address%> or %<-fsanitize=kernel-address%>");
+ if (opts->x_flag_sanitize & SANITIZE_POINTER_SUBTRACT)
+ error_at (loc,
+ "%<-fsanitize=pointer-subtract%> must be combined with "
+ "%<-fsanitize=address%> or %<-fsanitize=kernel-address%>");
+ }
+
/* Userspace and kernel ASan conflict with each other. */
if ((opts->x_flag_sanitize & SANITIZE_USER_ADDRESS)
&& (opts->x_flag_sanitize & SANITIZE_KERNEL_ADDRESS))
@@ -1496,6 +1509,8 @@ const struct sanitizer_opts_s sanitizer_opts[] =
SANITIZER_OPT (address, (SANITIZE_ADDRESS | SANITIZE_USER_ADDRESS), true),
SANITIZER_OPT (kernel-address, (SANITIZE_ADDRESS | SANITIZE_KERNEL_ADDRESS),
true),
+ SANITIZER_OPT (pointer-compare, SANITIZE_POINTER_COMPARE, true),
+ SANITIZER_OPT (pointer-subtract, SANITIZE_POINTER_SUBTRACT, true),
SANITIZER_OPT (thread, SANITIZE_THREAD, false),
SANITIZER_OPT (leak, SANITIZE_LEAK, false),
SANITIZER_OPT (shift, SANITIZE_SHIFT, true),
diff --git a/gcc/sanitizer.def b/gcc/sanitizer.def
index 00e7ae031e6..7d224fa081e 100644
--- a/gcc/sanitizer.def
+++ b/gcc/sanitizer.def
@@ -175,6 +175,10 @@ DEF_SANITIZER_BUILTIN(BUILT_IN_ASAN_ALLOCA_POISON, "__asan_alloca_poison",
BT_FN_VOID_PTR_PTRMODE, ATTR_NOTHROW_LEAF_LIST)
DEF_SANITIZER_BUILTIN(BUILT_IN_ASAN_ALLOCAS_UNPOISON, "__asan_allocas_unpoison",
BT_FN_VOID_PTR_PTRMODE, ATTR_NOTHROW_LEAF_LIST)
+DEF_SANITIZER_BUILTIN(BUILT_IN_ASAN_POINTER_COMPARE, "__sanitizer_ptr_cmp",
+ BT_FN_VOID_PTR_PTRMODE, ATTR_NOTHROW_LEAF_LIST)
+DEF_SANITIZER_BUILTIN(BUILT_IN_ASAN_POINTER_SUBTRACT, "__sanitizer_ptr_sub",
+ BT_FN_VOID_PTR_PTRMODE, ATTR_NOTHROW_LEAF_LIST)
/* Thread Sanitizer */
DEF_SANITIZER_BUILTIN(BUILT_IN_TSAN_INIT, "__tsan_init",
diff --git a/gcc/testsuite/c-c++-common/asan/pointer-compare-1.c b/gcc/testsuite/c-c++-common/asan/pointer-compare-1.c
new file mode 100644
index 00000000000..742a6a26f07
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/asan/pointer-compare-1.c
@@ -0,0 +1,83 @@
+// { dg-do run }
+// { dg-shouldfail "asan" }
+// { dg-set-target-env-var ASAN_OPTIONS "detect_invalid_pointer_pairs=1:halt_on_error=0" }
+// { dg-options "-fsanitize=address,pointer-compare -O0" }
+
+int foo(char *p, char *q)
+{
+ return p > q;
+}
+
+char global1[100] = {}, global2[100] = {};
+char small_global[7] = {};
+char large_global[5000] = {};
+
+int
+main ()
+{
+ /* Heap allocated memory. */
+ char *heap1 = (char *)__builtin_malloc(42);
+ char *heap2 = (char *)__builtin_malloc(42);
+
+ // { dg-output "ERROR: AddressSanitizer: invalid-pointer-pair.*" }
+ foo(heap1, heap2);
+ __builtin_free (heap1);
+ __builtin_free (heap2);
+
+ heap1 = (char *)__builtin_malloc(1024);
+ // { dg-output "ERROR: AddressSanitizer: invalid-pointer-pair.*" }
+ foo (heap1, heap1 + 1025);
+ // { dg-output "ERROR: AddressSanitizer: invalid-pointer-pair.*" }
+ foo (heap1 + 1024, heap1 + 1025);
+ __builtin_free (heap1);
+
+ heap1 = (char *)__builtin_malloc(4096);
+ // { dg-output "ERROR: AddressSanitizer: invalid-pointer-pair.*" }
+ foo (heap1, heap1 + 4097);
+ // { dg-output "ERROR: AddressSanitizer: invalid-pointer-pair.*" }
+ foo (heap1, 0);
+
+ /* Global variables. */
+ // { dg-output "ERROR: AddressSanitizer: invalid-pointer-pair.*" }
+ foo(&global1[0], &global2[10]);
+
+ char *p = &small_global[0];
+ foo (p, p); // OK
+ foo (p, p + 7); // OK
+ // { dg-output "ERROR: AddressSanitizer: invalid-pointer-pair.*" }
+ foo (p, p + 8);
+ // { dg-output "ERROR: AddressSanitizer: invalid-pointer-pair.*" }
+ foo (p - 1, p);
+ // { dg-output "ERROR: AddressSanitizer: invalid-pointer-pair.*" }
+ foo (p, p - 1);
+ // { dg-output "ERROR: AddressSanitizer: invalid-pointer-pair.*" }
+ foo (p - 1, p + 8);
+
+ p = &large_global[0];
+ // { dg-output "ERROR: AddressSanitizer: invalid-pointer-pair.*" }
+ foo (p - 1, p);
+ // { dg-output "ERROR: AddressSanitizer: invalid-pointer-pair.*" }
+ foo (p, p - 1);
+ // { dg-output "ERROR: AddressSanitizer: invalid-pointer-pair.*" }
+ foo (p, &global1[0]);
+ // { dg-output "ERROR: AddressSanitizer: invalid-pointer-pair.*" }
+ foo (p, &small_global[0]);
+ // { dg-output "ERROR: AddressSanitizer: invalid-pointer-pair.*" }
+ foo (p, 0);
+
+ /* Stack variables. */
+ // { dg-output "ERROR: AddressSanitizer: invalid-pointer-pair.*" }
+ char stack1, stack2;
+ foo(&stack1, &stack2);
+
+ /* Mixtures. */
+ // { dg-output "ERROR: AddressSanitizer: invalid-pointer-pair.*" }
+ foo(heap1, &stack1);
+ // { dg-output "ERROR: AddressSanitizer: invalid-pointer-pair.*" }
+ foo(heap1, &global1[0]);
+ // { dg-output "ERROR: AddressSanitizer: invalid-pointer-pair.*" }
+ foo(&stack1, &global1[0]);
+ // { dg-output "ERROR: AddressSanitizer: invalid-pointer-pair" }
+ foo(&stack1, 0);
+ return 1;
+}
diff --git a/gcc/testsuite/c-c++-common/asan/pointer-compare-2.c b/gcc/testsuite/c-c++-common/asan/pointer-compare-2.c
new file mode 100644
index 00000000000..996c4812d41
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/asan/pointer-compare-2.c
@@ -0,0 +1,76 @@
+// { dg-do run }
+// { dg-set-target-env-var ASAN_OPTIONS "detect_invalid_pointer_pairs=1 halt_on_error=1" }
+// { dg-options "-fsanitize=address,pointer-compare -O0" }
+
+int foo(char *p)
+{
+ char *p2 = p + 20;
+ return p > p2;
+}
+
+int bar(char *p, char *q)
+{
+ return p <= q;
+}
+
+int baz(char *p, char *q)
+{
+ return p != 0 && p < q;
+}
+
+char global[8192] = {};
+char small_global[7] = {};
+
+int
+main ()
+{
+ /* Heap allocated memory. */
+ char *p = (char *)__builtin_malloc(42);
+ int r = foo(p);
+ __builtin_free (p);
+
+ p = (char *)__builtin_malloc(1024);
+ bar(p, p + 1024);
+ bar(p + 1024, p + 1023);
+ bar(p + 1, p + 1023);
+ __builtin_free (p);
+
+ p = (char *)__builtin_malloc(4096);
+ bar(p, p + 4096);
+ bar(p + 10, p + 100);
+ bar(p + 1024, p + 4096);
+ bar(p + 4095, p + 4096);
+ bar(p + 4095, p + 4094);
+ bar(p + 100, p + 4096);
+ bar(p + 100, p + 4094);
+ __builtin_free (p);
+
+ /* Global variable. */
+ bar(&global[0], &global[1]);
+ bar(&global[1], &global[2]);
+ bar(&global[2], &global[1]);
+ bar(&global[0], &global[100]);
+ bar(&global[1000], &global[7000]);
+ bar(&global[500], &global[10]);
+ p = &global[0];
+ bar(p, p + 8192);
+ p = &global[8000];
+ bar(p, p + 192);
+
+ p = &small_global[0];
+ bar (p, p + 1);
+ bar (p, p + 7);
+ bar (p + 7, p + 1);
+ bar (p + 6, p + 7);
+ bar (p + 7, p + 7);
+
+ /* Stack variable. */
+ char stack[10000];
+ bar(&stack[0], &stack[100]);
+ bar(&stack[1000], &stack[9000]);
+ bar(&stack[500], &stack[10]);
+
+ baz(0, &stack[10]);
+
+ return 0;
+}
diff --git a/gcc/testsuite/c-c++-common/asan/pointer-subtract-1.c b/gcc/testsuite/c-c++-common/asan/pointer-subtract-1.c
new file mode 100644
index 00000000000..6d8adebf783
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/asan/pointer-subtract-1.c
@@ -0,0 +1,41 @@
+// { dg-do run }
+// { dg-shouldfail "asan" }
+// { dg-set-target-env-var ASAN_OPTIONS "detect_invalid_pointer_pairs=1 halt_on_error=0" }
+// { dg-options "-fsanitize=address,pointer-subtract -O0" }
+
+int foo(char *p, char *q)
+{
+ return p - q;
+}
+
+char global1[100] = {}, global2[100] = {};
+
+int
+main ()
+{
+ /* Heap allocated memory. */
+ char *heap1 = (char *)__builtin_malloc(42);
+ char *heap2 = (char *)__builtin_malloc(42);
+
+ // { dg-output "ERROR: AddressSanitizer: invalid-pointer-pair.*" }
+ foo(heap1, heap2);
+
+ /* Global variables. */
+ // { dg-output "ERROR: AddressSanitizer: invalid-pointer-pair.*" }
+ foo(&global1[0], &global2[10]);
+
+ /* Stack variables. */
+ char stack1, stack2;
+ // { dg-output "ERROR: AddressSanitizer: invalid-pointer-pair.*" }
+ foo(&stack1, &stack2);
+
+ /* Mixtures. */
+ // { dg-output "ERROR: AddressSanitizer: invalid-pointer-pair.*" }
+ foo(heap1, &stack1);
+ // { dg-output "ERROR: AddressSanitizer: invalid-pointer-pair.*" }
+ foo(heap1, &global1[0]);
+ // { dg-output "ERROR: AddressSanitizer: invalid-pointer-pair" }
+ foo(&stack1, &global1[0]);
+ return 1;
+}
+
diff --git a/gcc/testsuite/c-c++-common/asan/pointer-subtract-2.c b/gcc/testsuite/c-c++-common/asan/pointer-subtract-2.c
new file mode 100644
index 00000000000..50bd62993fa
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/asan/pointer-subtract-2.c
@@ -0,0 +1,33 @@
+// { dg-do run }
+// { dg-set-target-env-var ASAN_OPTIONS "detect_invalid_pointer_pairs=1 halt_on_error=1" }
+// { dg-options "-fsanitize=address,pointer-subtract -O0" }
+
+int bar(char *p, char *q)
+{
+ return p <= q;
+}
+
+char global[10000] = {};
+
+int
+main ()
+{
+ /* Heap allocated memory. */
+ char *p = (char *)__builtin_malloc(42);
+ int r = bar(p, p - 20);
+ __builtin_free (p);
+
+ /* Global variable. */
+ bar(&global[0], &global[100]);
+ bar(&global[1000], &global[9000]);
+ bar(&global[500], &global[10]);
+ bar(&global[0], &global[10000]);
+
+ /* Stack variable. */
+ char stack[10000];
+ bar(&stack[0], &stack[100]);
+ bar(&stack[1000], &stack[9000]);
+ bar(&stack[500], &stack[10]);
+
+ return 0;
+}
diff --git a/gcc/testsuite/c-c++-common/asan/pointer-subtract-3.c b/gcc/testsuite/c-c++-common/asan/pointer-subtract-3.c
new file mode 100644
index 00000000000..422a9a125e4
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/asan/pointer-subtract-3.c
@@ -0,0 +1,40 @@
+// { dg-do run }
+// { dg-set-target-env-var ASAN_OPTIONS "detect_invalid_pointer_pairs=1:halt_on_error=1" }
+// { dg-options "-fsanitize=address,pointer-subtract -O0" }
+
+#include <unistd.h>
+#include <pthread.h>
+
+char *pointers[2];
+
+void *
+thread_main (void *n)
+{
+ char local;
+
+ unsigned long id = (unsigned long) n;
+ pointers[id] = &local;
+ sleep (1);
+
+ return 0;
+}
+
+int
+main (int argc, char **argv)
+{
+ pthread_t threads[2];
+ pthread_create (&threads[0], 0, thread_main, (void *) 0);
+ pthread_create (&threads[1], 0, thread_main, (void *) 1);
+
+ do
+ {
+ }
+ while (pointers[0] == 0 || pointers[1] == 0);
+
+ unsigned r = pointers[0] - pointers[1];
+
+ pthread_join(threads[0], 0);
+ pthread_join(threads[1], 0);
+
+ return 0;
+}
diff --git a/gcc/testsuite/c-c++-common/asan/pointer-subtract-4.c b/gcc/testsuite/c-c++-common/asan/pointer-subtract-4.c
new file mode 100644
index 00000000000..f64f289c487
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/asan/pointer-subtract-4.c
@@ -0,0 +1,40 @@
+// { dg-do run }
+// { dg-shouldfail "asan" }
+// { dg-set-target-env-var ASAN_OPTIONS "detect_invalid_pointer_pairs=1:halt_on_error=1" }
+// { dg-options "-fsanitize=address,pointer-subtract -O0" }
+
+#include <unistd.h>
+#include <pthread.h>
+
+char *pointer;
+
+void *
+thread_main (void *n)
+{
+ char local;
+ pointer = &local;
+ sleep (1);
+
+ return 0;
+}
+
+int
+main (int argc, char **argv)
+{
+ pthread_t thread;
+ pthread_create (&thread, 0, thread_main, (void *) 0);
+
+ do
+ {
+ }
+ while (pointer == 0);
+
+ char local;
+ char *parent_pointer = &local;
+
+ // { dg-output "ERROR: AddressSanitizer: invalid-pointer-pair" }
+ unsigned r = parent_pointer - pointer;
+ pthread_join(thread, 0);
+
+ return 0;
+}
diff --git a/libsanitizer/asan/asan_descriptions.cc b/libsanitizer/asan/asan_descriptions.cc
index d46962adf27..c856a653742 100644
--- a/libsanitizer/asan/asan_descriptions.cc
+++ b/libsanitizer/asan/asan_descriptions.cc
@@ -333,6 +333,26 @@ void GlobalAddressDescription::Print(const char *bug_type) const {
}
}
+bool GlobalAddressDescription::PointsInsideTheSameVariable(
+ const GlobalAddressDescription &other) const {
+ if (size == 0 || other.size == 0) return false;
+
+ for (uptr i = 0; i < size; i++) {
+ const __asan_global &a = globals[i];
+ for (uptr j = 0; j < other.size; j++) {
+ const __asan_global &b = other.globals[j];
+ if (a.beg == b.beg &&
+ a.beg <= addr &&
+ b.beg <= other.addr &&
+ (addr + access_size) < (a.beg + a.size) &&
+ (other.addr + other.access_size) < (b.beg + b.size))
+ return true;
+ }
+ }
+
+ return false;
+}
+
void StackAddressDescription::Print() const {
Decorator d;
char tname[128];
diff --git a/libsanitizer/asan/asan_descriptions.h b/libsanitizer/asan/asan_descriptions.h
index 0fbb531492a..12d9ac5f70b 100644
--- a/libsanitizer/asan/asan_descriptions.h
+++ b/libsanitizer/asan/asan_descriptions.h
@@ -143,6 +143,10 @@ struct GlobalAddressDescription {
u8 size;
void Print(const char *bug_type = "") const;
+
+ // Returns true when this descriptions points inside the same global variable
+ // as other. Descriptions can have different address within the variable
+ bool PointsInsideTheSameVariable(const GlobalAddressDescription &other) const;
};
bool GetGlobalAddressInformation(uptr addr, uptr access_size,
diff --git a/libsanitizer/asan/asan_report.cc b/libsanitizer/asan/asan_report.cc
index 51bad6e45e3..1f19e726e1e 100644
--- a/libsanitizer/asan/asan_report.cc
+++ b/libsanitizer/asan/asan_report.cc
@@ -295,17 +295,58 @@ static NOINLINE void ReportInvalidPointerPair(uptr pc, uptr bp, uptr sp,
in_report.ReportError(error);
}
+static bool IsInvalidPointerPair(uptr a1, uptr a2) {
+ if (a1 == a2)
+ return false;
+
+ // 256B in shadow memory can be iterated quite fast
+ static const uptr kMaxOffset = 2048;
+
+ uptr left = a1 < a2 ? a1 : a2;
+ uptr right = a1 < a2 ? a2 : a1;
+ uptr offset = right - left;
+ if (offset <= kMaxOffset)
+ return __asan_region_is_poisoned(left, offset);
+
+ AsanThread *t = GetCurrentThread();
+
+ // check whether left is a stack memory pointer
+ if (uptr shadow_offset1 = t->GetStackVariableShadowStart(left)) {
+ uptr shadow_offset2 = t->GetStackVariableShadowStart(right);
+ return shadow_offset2 == 0 || shadow_offset1 != shadow_offset2;
+ }
+
+ // check whether left is a heap memory address
+ HeapAddressDescription hdesc1, hdesc2;
+ if (GetHeapAddressInformation(left, 0, &hdesc1) &&
+ hdesc1.chunk_access.access_type == kAccessTypeInside)
+ return !GetHeapAddressInformation(right, 0, &hdesc2) ||
+ hdesc2.chunk_access.access_type != kAccessTypeInside ||
+ hdesc1.chunk_access.chunk_begin != hdesc2.chunk_access.chunk_begin;
+
+ // check whether left is an address of a global variable
+ GlobalAddressDescription gdesc1, gdesc2;
+ if (GetGlobalAddressInformation(left, 0, &gdesc1))
+ return !GetGlobalAddressInformation(right - 1, 0, &gdesc2) ||
+ !gdesc1.PointsInsideTheSameVariable(gdesc2);
+
+ if (t->GetStackVariableShadowStart(right) ||
+ GetHeapAddressInformation(right, 0, &hdesc2) ||
+ GetGlobalAddressInformation(right - 1, 0, &gdesc2))
+ return true;
+
+ /* At this point we know nothing about both a1 and a2 addresses. */
+ return false;
+}
+
static INLINE void CheckForInvalidPointerPair(void *p1, void *p2) {
if (!flags()->detect_invalid_pointer_pairs) return;
uptr a1 = reinterpret_cast<uptr>(p1);
uptr a2 = reinterpret_cast<uptr>(p2);
- AsanChunkView chunk1 = FindHeapChunkByAddress(a1);
- AsanChunkView chunk2 = FindHeapChunkByAddress(a2);
- bool valid1 = chunk1.IsAllocated();
- bool valid2 = chunk2.IsAllocated();
- if (!valid1 || !valid2 || !chunk1.Eq(chunk2)) {
+
+ if (IsInvalidPointerPair(a1, a2)) {
GET_CALLER_PC_BP_SP;
- return ReportInvalidPointerPair(pc, bp, sp, a1, a2);
+ ReportInvalidPointerPair(pc, bp, sp, a1, a2);
}
}
// ----------------------- Mac-specific reports ----------------- {{{1
diff --git a/libsanitizer/asan/asan_thread.cc b/libsanitizer/asan/asan_thread.cc
index d0fdf6e9847..178909a52b4 100644
--- a/libsanitizer/asan/asan_thread.cc
+++ b/libsanitizer/asan/asan_thread.cc
@@ -315,7 +315,7 @@ bool AsanThread::GetStackFrameAccessByAddr(uptr addr,
access->frame_descr = (const char *)((uptr*)bottom)[1];
return true;
}
- uptr aligned_addr = addr & ~(SANITIZER_WORDSIZE/8 - 1); // align addr.
+ uptr aligned_addr = RoundDownTo(addr, SANITIZER_WORDSIZE / 8); // align addr.
uptr mem_ptr = RoundDownTo(aligned_addr, SHADOW_GRANULARITY);
u8 *shadow_ptr = (u8*)MemToShadow(aligned_addr);
u8 *shadow_bottom = (u8*)MemToShadow(bottom);
@@ -344,6 +344,29 @@ bool AsanThread::GetStackFrameAccessByAddr(uptr addr,
return true;
}
+uptr AsanThread::GetStackVariableShadowStart(uptr addr) {
+ uptr bottom = 0;
+ if (AddrIsInStack(addr)) {
+ bottom = stack_bottom();
+ } else if (has_fake_stack()) {
+ bottom = fake_stack()->AddrIsInFakeStack(addr);
+ CHECK(bottom);
+ } else
+ return 0;
+
+ uptr aligned_addr = RoundDownTo(addr, SANITIZER_WORDSIZE / 8); // align addr.
+ u8 *shadow_ptr = (u8*)MemToShadow(aligned_addr);
+ u8 *shadow_bottom = (u8*)MemToShadow(bottom);
+
+ while (shadow_ptr >= shadow_bottom &&
+ (*shadow_ptr != kAsanStackLeftRedzoneMagic &&
+ *shadow_ptr != kAsanStackMidRedzoneMagic &&
+ *shadow_ptr != kAsanStackRightRedzoneMagic))
+ shadow_ptr--;
+
+ return (uptr)shadow_ptr;
+}
+
bool AsanThread::AddrIsInStack(uptr addr) {
const auto bounds = GetStackBounds();
return addr >= bounds.bottom && addr < bounds.top;
diff --git a/libsanitizer/asan/asan_thread.h b/libsanitizer/asan/asan_thread.h
index f7a91f3e73b..3195edb9f6f 100644
--- a/libsanitizer/asan/asan_thread.h
+++ b/libsanitizer/asan/asan_thread.h
@@ -88,6 +88,9 @@ class AsanThread {
};
bool GetStackFrameAccessByAddr(uptr addr, StackFrameAccess *access);
+ // Return beginning of a stack variable in shadow memory
+ uptr GetStackVariableShadowStart(uptr addr);
+
bool AddrIsInStack(uptr addr);
void DeleteFakeStack(int tid) {
--
2.14.3