On Mar 13, 2024, at 15:19, Qing Zhao <qing.z...@oracle.com> wrote:
On Mar 11, 2024, at 13:15, Siddhesh Poyarekar <siddh...@gotplt.org> wrote:
On 2024-02-16 14:47, Qing Zhao wrote:
gcc/c-family/ChangeLog:
* c-ubsan.cc (get_bound_from_access_with_size): New function.
(ubsan_instrument_bounds): Handle call to .ACCESS_WITH_SIZE.
gcc/testsuite/ChangeLog:
* gcc.dg/ubsan/flex-array-counted-by-bounds-2.c: New test.
* gcc.dg/ubsan/flex-array-counted-by-bounds-3.c: New test.
* gcc.dg/ubsan/flex-array-counted-by-bounds.c: New test.
---
gcc/c-family/c-ubsan.cc | 42 +++++++++++++++++
.../ubsan/flex-array-counted-by-bounds-2.c | 45 ++++++++++++++++++
.../ubsan/flex-array-counted-by-bounds-3.c | 34 ++++++++++++++
.../ubsan/flex-array-counted-by-bounds.c | 46 +++++++++++++++++++
4 files changed, 167 insertions(+)
create mode 100644 gcc/testsuite/gcc.dg/ubsan/flex-array-counted-by-bounds-2.c
create mode 100644 gcc/testsuite/gcc.dg/ubsan/flex-array-counted-by-bounds-3.c
create mode 100644 gcc/testsuite/gcc.dg/ubsan/flex-array-counted-by-bounds.c
diff --git a/gcc/c-family/c-ubsan.cc b/gcc/c-family/c-ubsan.cc
index 940982819ddf..164b29845b3a 100644
--- a/gcc/c-family/c-ubsan.cc
+++ b/gcc/c-family/c-ubsan.cc
@@ -376,6 +376,40 @@ ubsan_instrument_return (location_t loc)
return build_call_expr_loc (loc, t, 1, build_fold_addr_expr_loc (loc, data));
}
+/* Get the tree that represented the number of counted_by, i.e, the maximum
+ number of the elements of the object that the call to .ACCESS_WITH_SIZE
+ points to, this number will be the bound of the corresponding array. */
+static tree
+get_bound_from_access_with_size (tree call)
+{
+ if (!is_access_with_size_p (call))
+ return NULL_TREE;
+
+ tree ref_to_size = CALL_EXPR_ARG (call, 1);
+ unsigned int type_of_size = TREE_INT_CST_LOW (CALL_EXPR_ARG (call, 2));
Again for consistency, this should probably be class_of_size.
Okay, I will update this consistently with the change relate to the 3rd
argument.
+ tree type = TREE_TYPE (CALL_EXPR_ARG (call, 3));
+ tree size = fold_build2 (MEM_REF, type, unshare_expr (ref_to_size),
+ build_int_cst (ptr_type_node, 0));
+ /* If size is negative value, treat it as zero. */
+ if (!TYPE_UNSIGNED (type))
+ {
+ tree cond = fold_build2 (LT_EXPR, boolean_type_node,
+ unshare_expr (size), build_zero_cst (type));
+ size = fold_build3 (COND_EXPR, type, cond,
+ build_zero_cst (type), size);
+ }
+
+ /* Only when type_of_size is 1,i.e, the number of the elements of
+ the object type, return the size. */
+ if (type_of_size != 1)
+ return NULL_TREE;
+ else
+ size = fold_convert (sizetype, size);
+
+ return size;
+}
+
+
/* Instrument array bounds for ARRAY_REFs. We create special builtin,
that gets expanded in the sanopt pass, and make an array dimension
of it. ARRAY is the array, *INDEX is an index to the array.
@@ -401,6 +435,14 @@ ubsan_instrument_bounds (location_t loc, tree array, tree
*index,
&& COMPLETE_TYPE_P (type)
&& integer_zerop (TYPE_SIZE (type)))
bound = build_int_cst (TREE_TYPE (TYPE_MIN_VALUE (domain)), -1);
+ else if (INDIRECT_REF_P (array)
+ && is_access_with_size_p ((TREE_OPERAND (array, 0))))
+ {
+ bound = get_bound_from_access_with_size ((TREE_OPERAND (array, 0)));
+ bound = fold_build2 (MINUS_EXPR, TREE_TYPE (bound),
+ bound,
+ build_int_cst (TREE_TYPE (bound), 1));
+ }
This will wrap if bound == 0, maybe that needs to be special-cased. And maybe
also add a test for it below.
Will check on this to see whether a new testing is needed.
Checked, the current code can handle the case when bound==0 correctly.
I just add a new testing case for this.
thanks.
Qing
Thanks a lot for the review.
Qing
else
return NULL_TREE;
}
diff --git a/gcc/testsuite/gcc.dg/ubsan/flex-array-counted-by-bounds-2.c
b/gcc/testsuite/gcc.dg/ubsan/flex-array-counted-by-bounds-2.c
new file mode 100644
index 000000000000..148934975ee5
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/ubsan/flex-array-counted-by-bounds-2.c
@@ -0,0 +1,45 @@
+/* test the attribute counted_by and its usage in
+ bounds sanitizer combined with VLA. */
+/* { dg-do run } */
+/* { dg-options "-fsanitize=bounds" } */
+/* { dg-output "index 11 out of bounds for type 'int
\\\[\\\*\\\]\\\[\\\*\\\]'\[^\n\r]*(\n|\r\n|\r)" } */
+/* { dg-output "\[^\n\r]*index 20 out of bounds for type 'int
\\\[\\\*\\\]\\\[\\\*\\\]\\\[\\\*\\\]'\[^\n\r]*(\n|\r\n|\r)" } */
+/* { dg-output "\[^\n\r]*index 11 out of bounds for type 'int
\\\[\\\*\\\]\\\[\\\*\\\]'\[^\n\r]*(\n|\r\n|\r)" } */
+/* { dg-output "\[^\n\r]*index 10 out of bounds for type 'int
\\\[\\\*\\\]'\[^\n\r]*(\n|\r\n|\r)" } */
+
+
+#include <stdlib.h>
+
+void __attribute__((__noinline__)) setup_and_test_vla (int n, int m)
+{
+ struct foo {
+ int n;
+ int p[][n] __attribute__((counted_by(n)));
+ } *f;
+
+ f = (struct foo *) malloc (sizeof(struct foo) + m*sizeof(int[n]));
+ f->n = m;
+ f->p[m][n-1]=1;
+ return;
+}
+
+void __attribute__((__noinline__)) setup_and_test_vla_1 (int n1, int n2, int m)
+{
+ struct foo {
+ int n;
+ int p[][n2][n1] __attribute__((counted_by(n)));
+ } *f;
+
+ f = (struct foo *) malloc (sizeof(struct foo) + m*sizeof(int[n2][n1]));
+ f->n = m;
+ f->p[m][n2][n1]=1;
+ return;
+}
+
+int main(int argc, char *argv[])
+{
+ setup_and_test_vla (10, 11);
+ setup_and_test_vla_1 (10, 11, 20);
+ return 0;
+}
+
diff --git a/gcc/testsuite/gcc.dg/ubsan/flex-array-counted-by-bounds-3.c
b/gcc/testsuite/gcc.dg/ubsan/flex-array-counted-by-bounds-3.c
new file mode 100644
index 000000000000..33bdea1c430b
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/ubsan/flex-array-counted-by-bounds-3.c
@@ -0,0 +1,34 @@
+/* test the attribute counted_by and its usage in bounds
+ sanitizer. when counted_by field is negative value. */
+/* { dg-do run } */
+/* { dg-options "-fsanitize=bounds" } */
+
+#include <stdlib.h>
+
+struct annotated {
+ int b;
+ int c[] __attribute__ ((counted_by (b)));
+} *array_annotated;
+
+void __attribute__((__noinline__)) setup (int annotated_count)
+{
+ array_annotated
+ = (struct annotated *)malloc (sizeof (struct annotated));
+ array_annotated->b = annotated_count;
+
+ return;
+}
+
+void __attribute__((__noinline__)) test (int annotated_index)
+{
+ array_annotated->c[annotated_index] = 2;
+}
+
+int main(int argc, char *argv[])
+{
+ setup (-3);
+ test (2);
+ return 0;
+}
+
+/* { dg-output "24:21: runtime error: index 2 out of bounds for type" } */
diff --git a/gcc/testsuite/gcc.dg/ubsan/flex-array-counted-by-bounds.c
b/gcc/testsuite/gcc.dg/ubsan/flex-array-counted-by-bounds.c
new file mode 100644
index 000000000000..81eaeb3f2681
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/ubsan/flex-array-counted-by-bounds.c
@@ -0,0 +1,46 @@
+/* test the attribute counted_by and its usage in
+ bounds sanitizer. */
+/* { dg-do run } */
+/* { dg-options "-fsanitize=bounds" } */
+
+#include <stdlib.h>
+
+struct flex {
+ int b;
+ int c[];
+} *array_flex;
+
+struct annotated {
+ int b;
+ int c[] __attribute__ ((counted_by (b)));
+} *array_annotated;
+
+void __attribute__((__noinline__)) setup (int normal_count, int
annotated_count)
+{
+ array_flex
+ = (struct flex *)malloc (sizeof (struct flex)
+ + normal_count * sizeof (int));
+ array_flex->b = normal_count;
+
+ array_annotated
+ = (struct annotated *)malloc (sizeof (struct annotated)
+ + annotated_count * sizeof (int));
+ array_annotated->b = annotated_count;
+
+ return;
+}
+
+void __attribute__((__noinline__)) test (int normal_index, int annotated_index)
+{
+ array_flex->c[normal_index] = 1;
+ array_annotated->c[annotated_index] = 2;
+}
+
+int main(int argc, char *argv[])
+{
+ setup (10, 10);
+ test (10, 10);
+ return 0;
+}
+
+/* { dg-output "36:21: runtime error: index 10 out of bounds for type" } */
