1*fb6c29d0Slogin #include <common/string.h> 2*fb6c29d0Slogin #include <common/glib.h> 3*fb6c29d0Slogin 4*fb6c29d0Slogin /** 5*fb6c29d0Slogin * @brief 拷贝整个字符串 6*fb6c29d0Slogin * 7*fb6c29d0Slogin * @param dst 目标地址 8*fb6c29d0Slogin * @param src 源地址 9*fb6c29d0Slogin * @return char* 目标字符串 10*fb6c29d0Slogin */ 11*fb6c29d0Slogin char *strcpy(char *dst, const char *src) 12*fb6c29d0Slogin { 13*fb6c29d0Slogin while (*src) 14*fb6c29d0Slogin { 15*fb6c29d0Slogin *(dst++) = *(src++); 16*fb6c29d0Slogin } 17*fb6c29d0Slogin *dst = 0; 18*fb6c29d0Slogin 19*fb6c29d0Slogin return dst; 20*fb6c29d0Slogin } 21*fb6c29d0Slogin 22*fb6c29d0Slogin long strnlen(const char *src, unsigned long maxlen) 23*fb6c29d0Slogin { 24*fb6c29d0Slogin 25*fb6c29d0Slogin if (src == NULL) 26*fb6c29d0Slogin return 0; 27*fb6c29d0Slogin register int __res = 0; 28*fb6c29d0Slogin while (src[__res] != '\0' && __res < maxlen) 29*fb6c29d0Slogin { 30*fb6c29d0Slogin ++__res; 31*fb6c29d0Slogin } 32*fb6c29d0Slogin return __res; 33*fb6c29d0Slogin } 34*fb6c29d0Slogin 35*fb6c29d0Slogin /* 36*fb6c29d0Slogin 比较字符串 FirstPart and SecondPart 37*fb6c29d0Slogin FirstPart = SecondPart => 0 38*fb6c29d0Slogin FirstPart > SecondPart => 1 39*fb6c29d0Slogin FirstPart < SecondPart => -1 40*fb6c29d0Slogin */ 41*fb6c29d0Slogin 42*fb6c29d0Slogin int strcmp(const char *FirstPart, const char *SecondPart) 43*fb6c29d0Slogin { 44*fb6c29d0Slogin register int __res; 45*fb6c29d0Slogin __asm__ __volatile__("cld \n\t" 46*fb6c29d0Slogin "1: \n\t" 47*fb6c29d0Slogin "lodsb \n\t" 48*fb6c29d0Slogin "scasb \n\t" 49*fb6c29d0Slogin "jne 2f \n\t" 50*fb6c29d0Slogin "testb %%al, %%al \n\t" 51*fb6c29d0Slogin "jne 1b \n\t" 52*fb6c29d0Slogin "xorl %%eax, %%eax \n\t" 53*fb6c29d0Slogin "jmp 3f \n\t" 54*fb6c29d0Slogin "2: \n\t" 55*fb6c29d0Slogin "movl $1, %%eax \n\t" 56*fb6c29d0Slogin "jl 3f \n\t" 57*fb6c29d0Slogin "negl %%eax \n\t" 58*fb6c29d0Slogin "3: \n\t" 59*fb6c29d0Slogin : "=a"(__res) 60*fb6c29d0Slogin : "D"(FirstPart), "S"(SecondPart) 61*fb6c29d0Slogin :); 62*fb6c29d0Slogin return __res; 63*fb6c29d0Slogin } 64*fb6c29d0Slogin 65*fb6c29d0Slogin char *strncpy(char *dst, const char *src, long count) 66*fb6c29d0Slogin { 67*fb6c29d0Slogin __asm__ __volatile__("cld \n\t" 68*fb6c29d0Slogin "1: \n\t" 69*fb6c29d0Slogin "decq %2 \n\t" 70*fb6c29d0Slogin "js 2f \n\t" 71*fb6c29d0Slogin "lodsb \n\t" 72*fb6c29d0Slogin "stosb \n\t" 73*fb6c29d0Slogin "testb %%al, %%al \n\t" 74*fb6c29d0Slogin "jne 1b \n\t" 75*fb6c29d0Slogin "rep \n\t" 76*fb6c29d0Slogin "stosb \n\t" 77*fb6c29d0Slogin "2: \n\t" 78*fb6c29d0Slogin : 79*fb6c29d0Slogin : "S"(src), "D"(dst), "c"(count) 80*fb6c29d0Slogin : "ax", "memory"); 81*fb6c29d0Slogin return dst; 82*fb6c29d0Slogin } 83*fb6c29d0Slogin 84*fb6c29d0Slogin long strncpy_from_user(char *dst, const char *src, unsigned long size) 85*fb6c29d0Slogin { 86*fb6c29d0Slogin if (!verify_area((uint64_t)src, size)) 87*fb6c29d0Slogin return 0; 88*fb6c29d0Slogin 89*fb6c29d0Slogin strncpy(dst, src, size); 90*fb6c29d0Slogin return size; 91*fb6c29d0Slogin } 92*fb6c29d0Slogin 93*fb6c29d0Slogin /** 94*fb6c29d0Slogin * @brief 测量来自用户空间的字符串的长度，会检验地址空间是否属于用户空间 95*fb6c29d0Slogin * @param src 96*fb6c29d0Slogin * @param maxlen 97*fb6c29d0Slogin * @return long 98*fb6c29d0Slogin */ 99*fb6c29d0Slogin long strnlen_user(const char *src, unsigned long maxlen) 100*fb6c29d0Slogin { 101*fb6c29d0Slogin 102*fb6c29d0Slogin unsigned long size = strlen(src); 103*fb6c29d0Slogin // 地址不合法 104*fb6c29d0Slogin if (!verify_area((uint64_t)src, size)) 105*fb6c29d0Slogin return 0; 106*fb6c29d0Slogin 107*fb6c29d0Slogin return size <= maxlen ? size : maxlen; 108*fb6c29d0Slogin } 109*fb6c29d0Slogin 110