analyzer: fix ignored constraints involving casts [PR113619]

gcc/analyzer/ChangeLog:
	PR analyzer/113619
	* region-model.cc (region_model::eval_condition): Fix
	cast-handling from r14-3632-ge7b267444045c5 so that if those give
	an unknown result, we continue trying the constraint manager.

gcc/testsuite/ChangeLog:
	PR analyzer/113619
	* c-c++-common/analyzer/taint-divisor-pr113619.c: New test.

Signed-off-by: David Malcolm <dmalcolm@redhat.com>

diff --git a/gcc/analyzer/region-model.cc b/gcc/analyzer/region-model.cc
index c3a4ec7bcfc5c6442b0a1ec48e88ea6c3276b8c3..902b887fc0741c64a55aa055c620dab34d414967 100644 (file)
--- a/gcc/analyzer/region-model.cc
+++ b/gcc/analyzer/region-model.cc
@@ -4704,17 +4704,27 @@ region_model::eval_condition (const svalue *lhs,
     if (lhs_un_op && CONVERT_EXPR_CODE_P (lhs_un_op->get_op ())
        && rhs_un_op && CONVERT_EXPR_CODE_P (rhs_un_op->get_op ())
        && lhs_type == rhs_type)
-      return eval_condition (lhs_un_op->get_arg (),
-                            op,
-                            rhs_un_op->get_arg ());
-
+      {
+       tristate res = eval_condition (lhs_un_op->get_arg (),
+                                      op,
+                                      rhs_un_op->get_arg ());
+       if (res.is_known ())
+         return res;
+      }
     else if (lhs_un_op && CONVERT_EXPR_CODE_P (lhs_un_op->get_op ())
             && lhs_type == rhs_type)
-      return eval_condition (lhs_un_op->get_arg (), op, rhs);
-
+      {
+       tristate res = eval_condition (lhs_un_op->get_arg (), op, rhs);
+       if (res.is_known ())
+         return res;
+      }
     else if (rhs_un_op && CONVERT_EXPR_CODE_P (rhs_un_op->get_op ())
             && lhs_type == rhs_type)
-      return eval_condition (lhs, op, rhs_un_op->get_arg ());
+      {
+       tristate res = eval_condition (lhs, op, rhs_un_op->get_arg ());
+       if (res.is_known ())
+         return res;
+      }
   }
 
   /* Otherwise, try constraints.

diff --git a/gcc/testsuite/c-c++-common/analyzer/taint-divisor-pr113619.c b/gcc/testsuite/c-c++-common/analyzer/taint-divisor-pr113619.c
new file mode 100644 (file)
index 0000000..15c8812
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/analyzer/taint-divisor-pr113619.c
@@ -0,0 +1,29 @@
+/* Reduced from false positive in Linux kernel's fs/ceph/ioctl.c: */
+
+__extension__ typedef unsigned long long __u64;
+
+struct ceph_ioctl_layout
+{
+  __u64 stripe_unit, object_size;
+};
+static long
+__validate_layout(struct ceph_ioctl_layout* l)
+{
+  if ((l->object_size & ~(~(((1UL) << 12) - 1))) ||
+      (l->stripe_unit & ~(~(((1UL) << 12) - 1))) ||
+      ((unsigned)l->stripe_unit != 0 &&
+       ((unsigned)l->object_size % (unsigned)l->stripe_unit))) /* { dg-bogus "use of attacker-controlled value 'l.stripe_unit' as divisor without checking for zero" "PR analyzer/113619" } */
+    return -22;
+  return 0;
+}
+
+long
+__attribute__((tainted_args))
+ceph_ioctl_set_layout_policy(struct ceph_ioctl_layout l)
+{
+  int err;
+  err = __validate_layout(&l);
+  if (err)
+    return err;
+  return err;
+}