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 */ 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 35