From 885143fa77599c44bfdd4e8e6b6987b7824db6ba Mon Sep 17 00:00:00 2001
From: Jakub Jelinek <jakub@redhat.com>
Date: Thu, 24 Oct 2024 12:45:34 +0200
Subject: [PATCH] asan: Fix up build_check_stmt gsi handling [PR117209]
gsi_safe_insert_before properly updates gsi_bb in gimple_stmt_iterator
in case it splits objects, but unfortunately build_check_stmt was in
some places (but not others) using a copy of the iterator rather than
the iterator passed from callers and so didn't propagate that to callers.
I guess it didn't matter much before when it was just using
gsi_insert_before as that really didn't change the iterator.
The !before_p case is apparently dead code, nothing is calling it with
before_p=false since around 4.9.
2024-10-24 Jakub Jelinek <jakub@redhat.com>
PR sanitizer/117209
* asan.cc (maybe_cast_to_ptrmode): Formatting fix.
(build_check_stmt): Don't copy *iter into gsi, perform all
the updates on iter directly.
* gcc.dg/asan/pr117209.c: New test.
---
gcc/asan.cc | 14 +++++---------
gcc/testsuite/gcc.dg/asan/pr117209.c | 15 +++++++++++++++
2 files changed, 20 insertions(+), 9 deletions(-)
create mode 100644 gcc/testsuite/gcc.dg/asan/pr117209.c
diff --git a/gcc/asan.cc b/gcc/asan.cc
index 5f262d54a3ac..bc92d9c7a792 100644
--- a/gcc/asan.cc
+++ b/gcc/asan.cc
@@ -2610,7 +2610,7 @@ maybe_cast_to_ptrmode (location_t loc, tree len, gimple_stmt_iterator *iter,
if (ptrofftype_p (len))
return len;
gimple *g = gimple_build_assign (make_ssa_name (pointer_sized_int_node),
- NOP_EXPR, len);
+ NOP_EXPR, len);
gimple_set_location (g, loc);
if (before_p)
gsi_safe_insert_before (iter, g);
@@ -2644,16 +2644,13 @@ build_check_stmt (location_t loc, tree base, tree len,
bool is_non_zero_len, bool before_p, bool is_store,
bool is_scalar_access, unsigned int align = 0)
{
- gimple_stmt_iterator gsi = *iter;
gimple *g;
gcc_assert (!(size_in_bytes > 0 && !is_non_zero_len));
gcc_assert (size_in_bytes == -1 || size_in_bytes >= 1);
- gsi = *iter;
-
base = unshare_expr (base);
- base = maybe_create_ssa_name (loc, base, &gsi, before_p);
+ base = maybe_create_ssa_name (loc, base, iter, before_p);
if (len)
{
@@ -2704,12 +2701,11 @@ build_check_stmt (location_t loc, tree base, tree len,
align / BITS_PER_UNIT));
gimple_set_location (g, loc);
if (before_p)
- gsi_safe_insert_before (&gsi, g);
+ gsi_safe_insert_before (iter, g);
else
{
- gsi_insert_after (&gsi, g, GSI_NEW_STMT);
- gsi_next (&gsi);
- *iter = gsi;
+ gsi_insert_after (iter, g, GSI_NEW_STMT);
+ gsi_next (iter);
}
}
diff --git a/gcc/testsuite/gcc.dg/asan/pr117209.c b/gcc/testsuite/gcc.dg/asan/pr117209.c
new file mode 100644
index 000000000000..34c71ba260b3
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/asan/pr117209.c
@@ -0,0 +1,15 @@
+/* PR sanitizer/117209 */
+/* { dg-do compile } */
+/* { dg-options "-fsanitize=address" } */
+
+struct A { char a; };
+void foo (void);
+__attribute__((returns_twice, const)) int bar (struct A);
+
+void
+baz (struct A *x, int *y, int z)
+{
+ if (z)
+ foo ();
+ *y = bar (*x);
+}
--
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