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