1*93048c09SAlexander Shishkin // SPDX-License-Identifier: GPL-2.0
2*93048c09SAlexander Shishkin
3*93048c09SAlexander Shishkin #include <linux/slab.h>
4*93048c09SAlexander Shishkin
5*93048c09SAlexander Shishkin /*
6*93048c09SAlexander Shishkin * Merge two NULL-terminated pointer arrays into a newly allocated
7*93048c09SAlexander Shishkin * array, which is also NULL-terminated. Nomenclature is inspired by
8*93048c09SAlexander Shishkin * memset_p() and memcat() found elsewhere in the kernel source tree.
9*93048c09SAlexander Shishkin */
__memcat_p(void ** a,void ** b)10*93048c09SAlexander Shishkin void **__memcat_p(void **a, void **b)
11*93048c09SAlexander Shishkin {
12*93048c09SAlexander Shishkin void **p = a, **new;
13*93048c09SAlexander Shishkin int nr;
14*93048c09SAlexander Shishkin
15*93048c09SAlexander Shishkin /* count the elements in both arrays */
16*93048c09SAlexander Shishkin for (nr = 0, p = a; *p; nr++, p++)
17*93048c09SAlexander Shishkin ;
18*93048c09SAlexander Shishkin for (p = b; *p; nr++, p++)
19*93048c09SAlexander Shishkin ;
20*93048c09SAlexander Shishkin /* one for the NULL-terminator */
21*93048c09SAlexander Shishkin nr++;
22*93048c09SAlexander Shishkin
23*93048c09SAlexander Shishkin new = kmalloc_array(nr, sizeof(void *), GFP_KERNEL);
24*93048c09SAlexander Shishkin if (!new)
25*93048c09SAlexander Shishkin return NULL;
26*93048c09SAlexander Shishkin
27*93048c09SAlexander Shishkin /* nr -> last index; p points to NULL in b[] */
28*93048c09SAlexander Shishkin for (nr--; nr >= 0; nr--, p = p == b ? &a[nr] : p - 1)
29*93048c09SAlexander Shishkin new[nr] = *p;
30*93048c09SAlexander Shishkin
31*93048c09SAlexander Shishkin return new;
32*93048c09SAlexander Shishkin }
33*93048c09SAlexander Shishkin EXPORT_SYMBOL_GPL(__memcat_p);
34*93048c09SAlexander Shishkin
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