cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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strstr_32.c (758B)

      1// SPDX-License-Identifier: GPL-2.0
      2#include <linux/string.h>
      3#include <linux/export.h>
      4
      5char *strstr(const char *cs, const char *ct)
      6{
      7int	d0, d1;
      8register char *__res;
      9__asm__ __volatile__(
     10	"movl %6,%%edi\n\t"
     11	"repne\n\t"
     12	"scasb\n\t"
     13	"notl %%ecx\n\t"
     14	"decl %%ecx\n\t"	/* NOTE! This also sets Z if searchstring='' */
     15	"movl %%ecx,%%edx\n"
     16	"1:\tmovl %6,%%edi\n\t"
     17	"movl %%esi,%%eax\n\t"
     18	"movl %%edx,%%ecx\n\t"
     19	"repe\n\t"
     20	"cmpsb\n\t"
     21	"je 2f\n\t"		/* also works for empty string, see above */
     22	"xchgl %%eax,%%esi\n\t"
     23	"incl %%esi\n\t"
     24	"cmpb $0,-1(%%eax)\n\t"
     25	"jne 1b\n\t"
     26	"xorl %%eax,%%eax\n\t"
     27	"2:"
     28	: "=a" (__res), "=&c" (d0), "=&S" (d1)
     29	: "0" (0), "1" (0xffffffff), "2" (cs), "g" (ct)
     30	: "dx", "di");
     31return __res;
     32}
     33EXPORT_SYMBOL(strstr);