From: David Malcolm <dmalcolm@redhat.com>
To: gcc-patches@gcc.gnu.org
Subject: [committed] analyzer: fix false leaks when writing through unknown ptrs [PR97072]
Date: Tue, 5 Jan 2021 20:59:48 -0500 [thread overview]
Message-ID: <20210106015948.3117342-1-dmalcolm@redhat.com> (raw)
Successfully bootstrapped & regrtested on x86_64-pc-linux-gnu.
Pushed to master as r11-6497-gac3966e315ada63eb379d560a012fa77c3909155.
gcc/analyzer/ChangeLog:
PR analyzer/97072
* region-model-reachability.cc (reachable_regions::init_cluster):
Convert symbolic region handling to a switch statement. Add cases
to handle SK_UNKNOWN and SK_CONJURED.
gcc/testsuite/ChangeLog:
PR analyzer/97072
* gcc.dg/analyzer/pr97072.c: New test.
---
gcc/analyzer/region-model-reachability.cc | 36 +++++++++++++++++------
gcc/testsuite/gcc.dg/analyzer/pr97072.c | 9 ++++++
2 files changed, 36 insertions(+), 9 deletions(-)
create mode 100644 gcc/testsuite/gcc.dg/analyzer/pr97072.c
diff --git a/gcc/analyzer/region-model-reachability.cc b/gcc/analyzer/region-model-reachability.cc
index daf785254ea..a988ffc1439 100644
--- a/gcc/analyzer/region-model-reachability.cc
+++ b/gcc/analyzer/region-model-reachability.cc
@@ -88,20 +88,38 @@ reachable_regions::init_cluster (const region *base_reg)
if (m_store->escaped_p (base_reg))
add (base_reg, true);
- /* If BASE_REG is *INIT_VAL(REG) for some other REG, see if REG is
- unbound and untouched. If so, then add BASE_REG as a root. */
if (const symbolic_region *sym_reg = base_reg->dyn_cast_symbolic_region ())
{
const svalue *ptr = sym_reg->get_pointer ();
- if (const initial_svalue *init_sval = ptr->dyn_cast_initial_svalue ())
+ switch (ptr->get_kind ())
{
- const region *init_sval_reg = init_sval->get_region ();
- const region *other_base_reg = init_sval_reg->get_base_region ();
- const binding_cluster *other_cluster
- = m_store->get_cluster (other_base_reg);
- if (other_cluster == NULL
- || !other_cluster->touched_p ())
+ default:
+ break;
+ case SK_INITIAL:
+ {
+ /* If BASE_REG is *INIT_VAL(REG) for some other REG, see if REG is
+ unbound and untouched. If so, then add BASE_REG as a root. */
+ const initial_svalue *init_sval
+ = as_a <const initial_svalue *> (ptr);
+ const region *init_sval_reg = init_sval->get_region ();
+ const region *other_base_reg = init_sval_reg->get_base_region ();
+ const binding_cluster *other_cluster
+ = m_store->get_cluster (other_base_reg);
+ if (other_cluster == NULL
+ || !other_cluster->touched_p ())
+ add (base_reg, true);
+ }
+ break;
+
+ case SK_UNKNOWN:
+ case SK_CONJURED:
+ {
+ /* If this cluster is due to dereferencing an unknown/conjured
+ pointer, any values written through the pointer could still
+ be live. */
add (base_reg, true);
+ }
+ break;
}
}
}
diff --git a/gcc/testsuite/gcc.dg/analyzer/pr97072.c b/gcc/testsuite/gcc.dg/analyzer/pr97072.c
new file mode 100644
index 00000000000..40241248884
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/analyzer/pr97072.c
@@ -0,0 +1,9 @@
+void unknown_fn_1 (void *);
+
+void test_1 (int co, int y)
+{
+ void *p = __builtin_malloc (1024);
+ void **q;
+ unknown_fn_1 (&q);
+ *q = p;
+}
--
2.26.2
reply other threads:[~2021-01-06 1:59 UTC|newest]
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