vppinfra: fix pool free bitmap allocation

Using clib_bitmap_vec_validate makes free bitmap vector
to be x64 times bigger (assuming x86_64) than necessary
when non-zero and possible oom due (u32)(0 - 1) math with
zero alloc.
Fix it with clib_bitmap_validate which takes bit size, not
index and ensure at least one bit is allocated.

Type: fix
Change-Id: I7e191f4e2fb3722a06bb800e1d075f7c7e2dcec9
Signed-off-by: Vladislav Grishenko <themiron@yandex-team.ru>

1 files changed, 56 insertions, 0 deletions

diff --git a/src/vppinfra/test_pool_alloc.c b/src/vppinfra/test_pool_alloc.c
new file mode 100644
index 00000000000..57b78b8ad9e
--- /dev/null
+++ b/src/vppinfra/test_pool_alloc.c
@@ -0,0 +1,56 @@
+/* SPDX-License-Identifier: Apache-2.0
+ * Copyright(c) 2023 Yandex LLC.
+ */
+
+#include <vppinfra/pool.h>
+
+/* can be a very large size */
+#define NELTS 1024
+
+int
+main (int argc, char *argv[])
+{
+  u32 *junk = 0;
+  int i;
+  u32 *tp = 0;
+  u32 *indices = 0;
+
+  clib_mem_init (0, 3ULL << 30);
+
+  vec_validate (indices, NELTS - 1);
+  vec_set_len (indices, 0);
+
+  /* zero size allocation is ok */
+  pool_alloc (tp, 0);
+
+  fformat (stdout, "%d pool elts of empty pool\n", pool_elts (tp));
+
+  pool_validate (tp);
+
+  pool_alloc (tp, NELTS);
+
+  for (i = 0; i < NELTS; i++)
+    {
+      pool_get (tp, junk);
+      vec_add1 (indices, junk - tp);
+      *junk = i;
+    }
+
+  for (i = 0; i < NELTS; i++)
+    {
+      junk = pool_elt_at_index (tp, indices[i]);
+      ASSERT (*junk == i);
+    }
+
+  fformat (stdout, "%d pool elts before deletes\n", pool_elts (tp));
+
+  pool_put_index (tp, indices[12]);
+  pool_put_index (tp, indices[43]);
+
+  fformat (stdout, "%d pool elts after deletes\n", pool_elts (tp));
+
+  pool_validate (tp);
+
+  pool_free (tp);
+  return 0;
+}