1*4882a593Smuzhiyun // SPDX-License-Identifier: GPL-2.0
2*4882a593Smuzhiyun
3*4882a593Smuzhiyun #include <linux/slab.h>
4*4882a593Smuzhiyun
5*4882a593Smuzhiyun /*
6*4882a593Smuzhiyun * Merge two NULL-terminated pointer arrays into a newly allocated
7*4882a593Smuzhiyun * array, which is also NULL-terminated. Nomenclature is inspired by
8*4882a593Smuzhiyun * memset_p() and memcat() found elsewhere in the kernel source tree.
9*4882a593Smuzhiyun */
__memcat_p(void ** a,void ** b)10*4882a593Smuzhiyun void **__memcat_p(void **a, void **b)
11*4882a593Smuzhiyun {
12*4882a593Smuzhiyun void **p = a, **new;
13*4882a593Smuzhiyun int nr;
14*4882a593Smuzhiyun
15*4882a593Smuzhiyun /* count the elements in both arrays */
16*4882a593Smuzhiyun for (nr = 0, p = a; *p; nr++, p++)
17*4882a593Smuzhiyun ;
18*4882a593Smuzhiyun for (p = b; *p; nr++, p++)
19*4882a593Smuzhiyun ;
20*4882a593Smuzhiyun /* one for the NULL-terminator */
21*4882a593Smuzhiyun nr++;
22*4882a593Smuzhiyun
23*4882a593Smuzhiyun new = kmalloc_array(nr, sizeof(void *), GFP_KERNEL);
24*4882a593Smuzhiyun if (!new)
25*4882a593Smuzhiyun return NULL;
26*4882a593Smuzhiyun
27*4882a593Smuzhiyun /* nr -> last index; p points to NULL in b[] */
28*4882a593Smuzhiyun for (nr--; nr >= 0; nr--, p = p == b ? &a[nr] : p - 1)
29*4882a593Smuzhiyun new[nr] = *p;
30*4882a593Smuzhiyun
31*4882a593Smuzhiyun return new;
32*4882a593Smuzhiyun }
33*4882a593Smuzhiyun EXPORT_SYMBOL_GPL(__memcat_p);
34*4882a593Smuzhiyun
35