• Paul E. McKenney's avatar
    rcu: Check for illegal use of RCU from offlined CPUs · c0d6d01b
    Paul E. McKenney authored
    Although it is legal to use RCU during early boot, it is anything
    but legal to use RCU at runtime from an offlined CPU.  After all, RCU
    explicitly ignores offlined CPUs.  This commit therefore adds checks
    for runtime use of RCU from offlined CPUs.
    
    These checks are not perfect, in particular, they can be subverted
    through use of things like rcu_dereference_raw().  Note that it is not
    possible to put checks in rcu_read_lock() and friends due to the fact
    that these primitives are used in code that might be used under either
    RCU or lock-based protection, which means that checking rcu_read_lock()
    gets you fat piles of false positives.
    Signed-off-by: default avatarPaul E. McKenney <paul.mckenney@linaro.org>
    Signed-off-by: default avatarPaul E. McKenney <paulmck@linux.vnet.ibm.com>
    c0d6d01b
rcupdate.c 9.67 KB