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SYSCALL_DEFINE3(silly_copy,
unsigned long *, src,
unsigned long *, dst,
unsigned long, len)
{
unsigned long buf[64]; /* Buffer for chunks */
unsigned long lenleft = len; /* Remaining size */
unsigned long chunklen = sizeof(buf); /* Initial chunk length */
/* Loop handling chunk sizes */
while (lenleft > 0) {
/* Change chunk length on last chunk */
if (lenleft < chunklen) chunklen = lenleft;
/* copy src(user) to buf(kernel) then dst(user) */
if (copy_from_user(buf, src, chunklen)) return -EFAULT;
if (copy_to_user(dst, buf, chunklen)) return -EFAULT;
/* Adjust pointers and remaining size */
src += chunklen; dst += chunklen; lenleft -= chunklen;
}
/* return amount of data copied */
return len;
}
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