[gcc r14-9600] analyzer: fix ignored constraints involving casts [PR113619]

[David Malcolm via Gcc-cvs]

https://gcc.gnu.org/g:7a5a4a4467b2e18ff4fe24f565e120280d3e6ba7

commit r14-9600-g7a5a4a4467b2e18ff4fe24f565e120280d3e6ba7
Author: David Malcolm <dmalc...@redhat.com>
Date:   Thu Mar 21 17:48:38 2024 -0400

    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 <dmalc...@redhat.com>

Diff:
---
 gcc/analyzer/region-model.cc                       | 24 ++++++++++++------
 .../c-c++-common/analyzer/taint-divisor-pr113619.c | 29 ++++++++++++++++++++++
 2 files changed, 46 insertions(+), 7 deletions(-)

diff --git a/gcc/analyzer/region-model.cc b/gcc/analyzer/region-model.cc
index c3a4ec7bcfc..902b887fc07 100644
--- 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
index 00000000000..15c881247ce
--- /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;
+}