From: "Paul E. McKenney" paulmck@kernel.org
The srcu_read_lock_nmisafe() and srcu_read_unlock_nmisafe() functions map to __srcu_read_lock() and __srcu_read_unlock() on systems like x86 that have NMI-safe this_cpu_inc() operations. This makes the underlying __srcu_read_lock_nmisafe() and __srcu_read_unlock_nmisafe() functions difficult to test on (for example) x86 systems, allowing bugs to creep in.
This commit therefore creates a FORCE_NEED_SRCU_NMI_SAFE Kconfig that forces those underlying functions to be used even on systems where they are not needed, thus providing better testing coverage.
Signed-off-by: Paul E. McKenney paulmck@kernel.org Signed-off-by: Boqun Feng boqun.feng@gmail.com --- kernel/rcu/Kconfig | 11 +++++++++++ 1 file changed, 11 insertions(+)
diff --git a/kernel/rcu/Kconfig b/kernel/rcu/Kconfig index b9b6bc55185d..c8e540af3a35 100644 --- a/kernel/rcu/Kconfig +++ b/kernel/rcu/Kconfig @@ -65,6 +65,17 @@ config TREE_SRCU help This option selects the full-fledged version of SRCU.
+config FORCE_NEED_SRCU_NMI_SAFE + bool "Force selection of NEED_SRCU_NMI_SAFE" + depends on !TINY_SRCU + select NEED_SRCU_NMI_SAFE + default n + help + This option forces selection of the NEED_SRCU_NMI_SAFE + Kconfig option, allowing testing of srcu_read_lock_nmisafe() + and srcu_read_unlock_nmisafe() on architectures (like x86) + that select the ARCH_HAS_NMI_SAFE_THIS_CPU_OPS Kconfig option. + config NEED_SRCU_NMI_SAFE def_bool HAVE_NMI && !ARCH_HAS_NMI_SAFE_THIS_CPU_OPS && !TINY_SRCU