Why is lock elision forbidden in suid?

[Tulio Magno Quites Machado Filho]

In a message to libc-alpha from 2013 [1] [2], there has been an agreement
that lock elision should be disabled for suid programs.  However, these
messages don't make it clear why it's necessary.

Are there any other reasons beside the risk of adding new code to critical
programs?

[1] https://sourceware.org/ml/libc-alpha/2013-06/msg00561.html
[2] https://sourceware.org/ml/libc-alpha/2013-06/msg00578.html

-- 
Tulio Magno