This patch adds the -fsanitize=bounds-strict option Martin U. wanted; it is
actually based on his earlier patch, I did only some small adjustments.
Bootstrapped/regtested on x86_64-linux, ok for trunk?
2015-04-29 Marek Polacek <pola...@redhat.com>
Martin Uecker <uec...@eecs.berkeley.edu>
* c-ubsan.c (ubsan_instrument_bounds): Don't skip instrumenting
flexible member array-like members if SANITIZE_BOUNDS_STRICT.
* doc/invoke.texi: Document -fsanitize=bounds-strict.
* flag-types.h (enum sanitize_code): Add SANITIZE_BOUNDS_STRICT, or it
into SANITIZE_NONDEFAULT.
* opts.c (common_handle_option): Handle -fsanitize=bounds-strict.
* c-c++-common/ubsan/bounds-10.c: New test.
diff --git gcc/c-family/c-ubsan.c gcc/c-family/c-ubsan.c
index a14426f..dbbdc5b 100644
--- gcc/c-family/c-ubsan.c
+++ gcc/c-family/c-ubsan.c
@@ -301,9 +301,11 @@ ubsan_instrument_bounds (location_t loc, tree array, tree
*index,
bound = fold_build2 (PLUS_EXPR, TREE_TYPE (bound), bound,
build_int_cst (TREE_TYPE (bound), 1));
- /* Detect flexible array members and suchlike. */
+ /* Detect flexible array members and suchlike, unless
+ -fsanitize=bounds-strict. */
tree base = get_base_address (array);
- if (TREE_CODE (array) == COMPONENT_REF
+ if ((flag_sanitize & SANITIZE_BOUNDS_STRICT) == 0
+ && TREE_CODE (array) == COMPONENT_REF
&& base && (TREE_CODE (base) == INDIRECT_REF
|| TREE_CODE (base) == MEM_REF))
{
diff --git gcc/doc/invoke.texi gcc/doc/invoke.texi
index 7d2f6e5..d050ba6 100644
--- gcc/doc/invoke.texi
+++ gcc/doc/invoke.texi
@@ -5728,6 +5728,13 @@ This option enables instrumentation of array bounds.
Various out of bounds
accesses are detected. Flexible array members, flexible array member-like
arrays, and initializers of variables with static storage are not instrumented.
+@item -fsanitize=bounds-strict
+@opindex fsanitize=bounds-strict
+This option enables strict instrumentation of array bounds. Most out of bounds
+accesses are detected, including flexible array members and flexible array
+member-like arrays. Initializers of variables with static storage are not
+instrumented.
+
@item -fsanitize=alignment
@opindex fsanitize=alignment
diff --git gcc/flag-types.h gcc/flag-types.h
index bfdce44..2f820a5 100644
--- gcc/flag-types.h
+++ gcc/flag-types.h
@@ -238,6 +238,7 @@ enum sanitize_code {
SANITIZE_RETURNS_NONNULL_ATTRIBUTE = 1UL << 19,
SANITIZE_OBJECT_SIZE = 1UL << 20,
SANITIZE_VPTR = 1UL << 21,
+ SANITIZE_BOUNDS_STRICT = 1UL << 22,
SANITIZE_UNDEFINED = SANITIZE_SHIFT | SANITIZE_DIVIDE | SANITIZE_UNREACHABLE
| SANITIZE_VLA | SANITIZE_NULL | SANITIZE_RETURN
| SANITIZE_SI_OVERFLOW | SANITIZE_BOOL | SANITIZE_ENUM
@@ -246,6 +247,7 @@ enum sanitize_code {
| SANITIZE_RETURNS_NONNULL_ATTRIBUTE
| SANITIZE_OBJECT_SIZE | SANITIZE_VPTR,
SANITIZE_NONDEFAULT = SANITIZE_FLOAT_DIVIDE | SANITIZE_FLOAT_CAST
+ | SANITIZE_BOUNDS_STRICT
};
/* flag_vtable_verify initialization levels. */
diff --git gcc/opts.c gcc/opts.c
index 39c190d..8c6716b 100644
--- gcc/opts.c
+++ gcc/opts.c
@@ -1584,6 +1584,8 @@ common_handle_option (struct gcc_options *opts,
{ "float-cast-overflow", SANITIZE_FLOAT_CAST,
sizeof "float-cast-overflow" - 1 },
{ "bounds", SANITIZE_BOUNDS, sizeof "bounds" - 1 },
+ { "bounds-strict", SANITIZE_BOUNDS | SANITIZE_BOUNDS_STRICT,
+ sizeof "bounds-strict" - 1 },
{ "alignment", SANITIZE_ALIGNMENT, sizeof "alignment" - 1 },
{ "nonnull-attribute", SANITIZE_NONNULL_ATTRIBUTE,
sizeof "nonnull-attribute" - 1 },
diff --git gcc/testsuite/c-c++-common/ubsan/bounds-10.c
gcc/testsuite/c-c++-common/ubsan/bounds-10.c
index e69de29..a6187b5 100644
--- gcc/testsuite/c-c++-common/ubsan/bounds-10.c
+++ gcc/testsuite/c-c++-common/ubsan/bounds-10.c
@@ -0,0 +1,16 @@
+/* { dg-do run } */
+/* { dg-options "-fsanitize=bounds-strict" } */
+
+struct V { int l; int a[1]; };
+
+int
+main (void)
+{
+ /* For strict, do instrument last array in a struct. */
+ struct V *v = (struct V *) __builtin_malloc (sizeof (struct V) + 10);
+ v->a[1] = 1;
+
+ return 0;
+}
+
+/* { dg-output "index 1 out of bounds for type 'int \\\[1\\\]'" } */
Marek
