x86/alternative: Report missing return thunk details

stable inclusion
from stable-v5.10.134
commit c0a3a9eb262a5e86a36fd5fc4f9fc38470713f13
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I5ZVR7

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=c0a3a9eb262a5e86a36fd5fc4f9fc38470713f13



--------------------------------

commit 65cdf0d6 upstream.

Debugging missing return thunks is easier if we can see where they're
happening.

Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/lkml/Ys66hwtFcGbYmoiZ@hirez.programming.kicks-ass.net/


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>
Reviewed-by: Wei Li <liwei391@huawei.com>