On 5/10/2021 7:15 AM, Borislav Petkov wrote:
On Tue, Apr 27, 2021 at 01:43:08PM -0700, Yu-cheng Yu wrote:
@@ -181,6 +184,12 @@ int copy_thread(unsigned long clone_flags, unsigned long sp, unsigned long arg,
if (clone_flags & CLONE_SETTLS)
ret = set_new_tls(p, tls);
+#ifdef CONFIG_X86_64
IS_ENABLED
+ /* Allocate a new shadow stack for pthread */
+ if (!ret)
+ ret = shstk_setup_thread(p, clone_flags, stack_size);
+#endif
+
And why is this addition here...
if (!ret && unlikely(test_tsk_thread_flag(current, TIF_IO_BITMAP)))
io_bitmap_share(p);
... instead of here?
<---
io_bitmap_share() does refcount_inc(¤t->thread.io_bitmap->refcnt),
and the function won't fail. However, shadow stack allocation can fail.
So, maybe leave io_bitmap_share() at the end?
Thanks,
Yu-cheng
