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, 34 insertions, 0 deletions

diff --git a/lib/memcat_p.c b/lib/memcat_p.c
new file mode 100644
index 000000000..b810fbc66
--- /dev/null
+++ b/lib/memcat_p.c
@@ -0,0 +1,34 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <linux/slab.h>
+
+/*
+ * Merge two NULL-terminated pointer arrays into a newly allocated
+ * array, which is also NULL-terminated. Nomenclature is inspired by
+ * memset_p() and memcat() found elsewhere in the kernel source tree.
+ */
+void **__memcat_p(void **a, void **b)
+{
+	void **p = a, **new;
+	int nr;
+
+	/* count the elements in both arrays */
+	for (nr = 0, p = a; *p; nr++, p++)
+		;
+	for (p = b; *p; nr++, p++)
+		;
+	/* one for the NULL-terminator */
+	nr++;
+
+	new = kmalloc_array(nr, sizeof(void *), GFP_KERNEL);
+	if (!new)
+		return NULL;
+
+	/* nr -> last index; p points to NULL in b[] */
+	for (nr--; nr >= 0; nr--, p = p == b ? &a[nr] : p - 1)
+		new[nr] = *p;
+
+	return new;
+}
+EXPORT_SYMBOL_GPL(__memcat_p);
+