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, 95 insertions, 0 deletions

diff --git a/lib/argv_split.c b/lib/argv_split.c
new file mode 100644
index 000000000..e28db8e3b
--- /dev/null
+++ b/lib/argv_split.c
@@ -0,0 +1,95 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Helper function for splitting a string into an argv-like array.
+ */
+
+#include <linux/kernel.h>
+#include <linux/ctype.h>
+#include <linux/string.h>
+#include <linux/slab.h>
+#include <linux/export.h>
+
+static int count_argc(const char *str)
+{
+	int count = 0;
+	bool was_space;
+
+	for (was_space = true; *str; str++) {
+		if (isspace(*str)) {
+			was_space = true;
+		} else if (was_space) {
+			was_space = false;
+			count++;
+		}
+	}
+
+	return count;
+}
+
+/**
+ * argv_free - free an argv
+ * @argv: the argument vector to be freed
+ *
+ * Frees an argv and the strings it points to.
+ */
+void argv_free(char **argv)
+{
+	argv--;
+	kfree(argv[0]);
+	kfree(argv);
+}
+EXPORT_SYMBOL(argv_free);
+
+/**
+ * argv_split - split a string at whitespace, returning an argv
+ * @gfp: the GFP mask used to allocate memory
+ * @str: the string to be split
+ * @argcp: returned argument count
+ *
+ * Returns: an array of pointers to strings which are split out from
+ * @str.  This is performed by strictly splitting on white-space; no
+ * quote processing is performed.  Multiple whitespace characters are
+ * considered to be a single argument separator.  The returned array
+ * is always NULL-terminated.  Returns NULL on memory allocation
+ * failure.
+ *
+ * The source string at `str' may be undergoing concurrent alteration via
+ * userspace sysctl activity (at least).  The argv_split() implementation
+ * attempts to handle this gracefully by taking a local copy to work on.
+ */
+char **argv_split(gfp_t gfp, const char *str, int *argcp)
+{
+	char *argv_str;
+	bool was_space;
+	char **argv, **argv_ret;
+	int argc;
+
+	argv_str = kstrndup(str, KMALLOC_MAX_SIZE - 1, gfp);
+	if (!argv_str)
+		return NULL;
+
+	argc = count_argc(argv_str);
+	argv = kmalloc_array(argc + 2, sizeof(*argv), gfp);
+	if (!argv) {
+		kfree(argv_str);
+		return NULL;
+	}
+
+	*argv = argv_str;
+	argv_ret = ++argv;
+	for (was_space = true; *argv_str; argv_str++) {
+		if (isspace(*argv_str)) {
+			was_space = true;
+			*argv_str = 0;
+		} else if (was_space) {
+			was_space = false;
+			*argv++ = argv_str;
+		}
+	}
+	*argv = NULL;
+
+	if (argcp)
+		*argcp = argc;
+	return argv_ret;
+}
+EXPORT_SYMBOL(argv_split);