Messages in this thread | | | Date | Thu, 1 Jun 2017 19:29:45 +0200 | From | Borislav Petkov <> | Subject | Re: [RFC PATCH] x86/ldt: Rename ldr_struct.size to .n_entries |
| |
On Wed, May 31, 2017 at 03:20:01PM -0700, Andy Lutomirski wrote: > num_bytes, perhaps?
Better idea: entries_size.
I can read it very easily this way:
static int read_ldt(void __user *ptr, unsigned long bytecount) { struct mm_struct *mm = current->mm; unsigned long entries_size; int retval;
mutex_lock(&mm->context.lock);
if (!mm->context.ldt) { retval = 0; goto out_unlock; }
if (bytecount > LDT_ENTRY_SIZE * LDT_ENTRIES) bytecount = LDT_ENTRY_SIZE * LDT_ENTRIES;
entries_size = mm->context.ldt->n_entries * LDT_ENTRY_SIZE; if (entries_size > bytecount) entries_size = bytecount;
if (copy_to_user(ptr, mm->context.ldt->entries, entries_size)) { retval = -EFAULT; goto out_unlock; }
if (entries_size != bytecount) { /* Zero-fill the rest and pretend we read bytecount bytes. */ if (clear_user(ptr + entries_size, bytecount - entries_size)) { retval = -EFAULT; goto out_unlock; } } retval = bytecount;
out_unlock: mutex_unlock(&mm->context.lock); return retval; }
> > old_ldt = mm->context.ldt; > > - oldsize = old_ldt ? old_ldt->size : 0; > > + oldsize = old_ldt ? old_ldt->n_entries : 0; > > how about old_n_entries?
Yes, and new_n_entries too:
old_ldt = mm->context.ldt; old_n_entries = old_ldt ? old_ldt->n_entries : 0; new_n_entries = max(ldt_info.entry_number + 1, old_n_entries);
Thanks.
-- Regards/Gruss, Boris.
Good mailing practices for 400: avoid top-posting and trim the reply.
| |