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#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/time.h>
#include <time.h>
int
main (int argc, char *argv[])
{
unsigned char prefix_arr[] = {
0x2e, /* cs segment override */
0x36, /* ss segment override */
0x3e, /* ds segment override */
0x26, /* es segment override */
0x64, /* fs segment override */
0x65, /* gs segment override */
0x67, /* adress size override */
0xf2, /* repne/repnz prefix */
0xf3, /* repe/repz prefix */
/* 0xf0,*/ /* lock prefix */
/* 0x66,*/ /* operand size override */
};
unsigned char code[64];
int n, i,
clen,
cwlk;
unsigned long ef_should,
ef_is;
srandom (time (NULL));
for (n = 0 ; n < 32 ; ++n) {
clen = random () % 14;
clen += 1;
memset (code, '\x00', sizeof (code));
for (cwlk = 0 ; clen > 0 ; --clen, ++cwlk) {
code[cwlk] = prefix_arr[random () %
(sizeof (prefix_arr) / sizeof (prefix_arr[0]))];
}
code[cwlk++] = 0x9c; /* pushf */
code[cwlk++] = 0x5a; /* popl %edx */
code[cwlk] = 0xc3; /* ret */
printf ("%4d (%2d):", n, cwlk);
for (i = 0 ; i < cwlk ; ++i)
printf (" %02x", code[i]);
printf ("\n");
printf ("\tef 0x%08lx got 0x%08lx\n", ef_should, ef_is);
__asm__ __volatile__ ("
pushf
popl %%eax
pushl $0x41414141
call *%%edx
addl $4, %%esp"
: "=a" (ef_should), "=d" (ef_is)
: "d" ((unsigned long) code)
);
if (ef_should != ef_is) {
printf ("\tATTENTION: difference detected.\n");
exit (EXIT_FAILURE);
}
}
exit (EXIT_SUCCESS);
}
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