{
struct insn insn;
void *addr;
- int bytes, size = MAX_INSN_SIZE;
+ int bytes_read, bytes_left;
int ret = X86_BR_NONE;
int ext, to_plm, from_plm;
u8 buf[MAX_INSN_SIZE];
return X86_BR_NONE;
/* may fail if text not present */
- bytes = copy_from_user_nmi(buf, (void __user *)from, size);
- if (bytes != 0)
+ bytes_left = copy_from_user_nmi(buf, (void __user *)from,
+ MAX_INSN_SIZE);
+ bytes_read = MAX_INSN_SIZE - bytes_left;
+ if (!bytes_read)
return X86_BR_NONE;
addr = buf;
* Ensure we don't blindy read any address by validating it is
* a known text address.
*/
- if (kernel_text_address(from))
+ if (kernel_text_address(from)) {
addr = (void *)from;
- else
+ /*
+ * Assume we can get the maximum possible size
+ * when grabbing kernel data. This is not
+ * _strictly_ true since we could possibly be
+ * executing up next to a memory hole, but
+ * it is very unlikely to be a problem.
+ */
+ bytes_read = MAX_INSN_SIZE;
+ } else {
return X86_BR_NONE;
+ }
}
/*
#ifdef CONFIG_X86_64
is64 = kernel_ip((unsigned long)addr) || !test_thread_flag(TIF_IA32);
#endif
- insn_init(&insn, addr, is64);
+ insn_init(&insn, addr, bytes_read, is64);
insn_get_opcode(&insn);
+ if (!insn.opcode.got)
+ return X86_BR_ABORT;
switch (insn.opcode.bytes[0]) {
case 0xf: