treewide: refresh kmalloc_obj() conversionsgrafted

This is another run of the Coccinelle script for converting kmalloc()
family of allocations to kmalloc_obj() via the existing rules in
scripts/coccinelle/api/kmalloc_objs.cocci

This catches both the set of kmalloc() uses added since the first
kmalloc_obj() conversions in v7.0 and adds a large group missed in the
first pass due to Coccinelle not interacting well with the cleanup.h
scoped_...() family of macros[1]. I worked around this with spatch's
"--macro-file" argument to a file with all the scoped_...() macros mapped
to Coccinelle's YACFE_ITERATOR[2] as that was the closest viable control
flow indicator I could find.

Build tested allmodconfig on x86, arm64, arm, loongarch, mips, powerpc,
riscv, and s390 with no new warnings.

Link: https://lore.kernel.org/lkml/202609021314.8A9C0B8@keescook/ [1]
Link: https://github.com/coccinelle/coccinelle/blob/master/standard.h [2]
Signed-off-by: Kees Cook <kees+treewide@kernel.org>

1 files changed, 52 insertions, 0 deletions

diff --git a/include/net/netns/generic.h b/include/net/netns/generic.h
new file mode 100644
index 000000000..00c399ede
--- /dev/null
+++ b/include/net/netns/generic.h
@@ -0,0 +1,52 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * generic net pointers
+ */
+
+#ifndef __NET_GENERIC_H__
+#define __NET_GENERIC_H__
+
+#include <linux/bug.h>
+#include <linux/rcupdate.h>
+#include <net/net_namespace.h>
+
+/*
+ * Generic net pointers are to be used by modules to put some private
+ * stuff on the struct net without explicit struct net modification
+ *
+ * The rules are simple:
+ * 1. set pernet_operations->id.  After register_pernet_device you
+ *    will have the id of your private pointer.
+ * 2. set pernet_operations->size to have the code allocate and free
+ *    a private structure pointed to from struct net.
+ * 3. do not change this pointer while the net is alive;
+ * 4. do not try to have any private reference on the net_generic object.
+ *
+ * After accomplishing all of the above, the private pointer can be
+ * accessed with the net_generic() call.
+ */
+
+struct net_generic {
+	union {
+		struct {
+			unsigned int len;
+			struct rcu_head rcu;
+		} s;
+
+		DECLARE_FLEX_ARRAY(void *, ptr);
+	};
+};
+
+static inline void *net_generic(const struct net *net, unsigned int id)
+{
+	struct net_generic *ng;
+	void *ptr;
+
+	rcu_read_lock();
+	ng = rcu_dereference(net->gen);
+	ptr = ng->ptr[id];
+	rcu_read_unlock();
+
+	return ptr;
+}
+#endif