// some test code to get the validate_ptr working.

#define __copy_user(to,from,size) \

do { \

int __d0, __d1; \

__asm__ __volatile__( \

"0: rep; movsl\n" \

" movl %3,%0\n" \

"1: rep; movsb\n" \

"2:\n" \

".section .fixup,\"ax\"\n" \

"3: lea 0(%3,%0,4),%0\n" \

" jmp 2b\n" \

".previous\n" \

".section __ex_table,\"a\"\n" \

" .align 4\n" \

" .long 0b,3b\n" \

" .long 1b,2b\n" \

".previous" \

: "=&c"(size), "=&D" (__d0), "=&S" (__d1) \

: "r"(size & 3), "0"(size / 4), "1"(to), "2"(from) \

: "memory"); \

} while (0)

#define __validate_ptr(ptr, ret) \

__asm__ __volatile__( \

" mov $1, %0\n" \

"0: mov (%1), %1\n" \

"2:\n" \

".section .fixup,\"ax\"\n" \

"3: mov $0, %0\n" \

" jmp 2b\n" \

".previous\n" \

".section __ex_table,\"a\"\n" \

" .align 8\n" \

" .quad 0b,3b\n" \

".previous" \

: "=&a" (ret) \

: "c" (ptr) \

)

int

validate_ptr(void *ptr)

{ int ret;

__validate_ptr(ptr, ret);

return ret;

}

int glob_ptr;

int *xyzzy = &glob_ptr;

int main(int argc, char **argv)

{ char src[10];

char dst[10];

int size = sizeof(src);

int ret;

// __copy_user(dst, src, size);

if (*xyzzy)

printf("hello\n");

getpid(&xyzzy);

ret = validate_ptr(xyzzy);

printf("ret=%d\n", ret);

}