/* * Copyright 2013 Tilera Corporation. All Rights Reserved. * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation, version 2. * * This program is distributed in the hope that it will be useful, but * WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or * NON INFRINGEMENT. See the GNU General Public License for * more details. */ #include <linux/types.h> #include <linux/string.h> #include <linux/module.h>
size_t strnlen(const char *s, size_t count) { /* Get an aligned pointer. */ const uintptr_t s_int = (uintptr_t) s; const uint32_t *p = (const uint32_t *)(s_int & -4); size_t bytes_read = sizeof(*p) - (s_int & (sizeof(*p) - 1)); size_t len; uint32_t v, bits; /* Avoid page fault risk by not reading any bytes when count is 0. */ if (count == 0) return 0; /* Read first word, but force bytes before the string to be nonzero. */ v = *p | ((1 << ((s_int << 3) & 31)) - 1); while ((bits = __insn_seqb(v, 0)) == 0) { if (bytes_read >= count) { /* Read COUNT bytes and didn't find the terminator. */ return count; } v = *++p; bytes_read += sizeof(v); } len = ((const char *) p) + (__insn_ctz(bits) >> 3) - s; return (len < count ? len : count); }Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Ken Steele | 180 | 100.00% | 1 | 100.00% |
| Total | 180 | 100.00% | 1 | 100.00% |
| Person | Tokens | Prop | Commits | CommitProp |
| Ken Steele | 195 | 100.00% | 1 | 100.00% |
| Total | 195 | 100.00% | 1 | 100.00% |