srcu: Add FORCE_NEED_SRCU_NMI_SAFE Kconfig for testing

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>
This commit is contained in:
Paul E. McKenney 2025-01-10 11:26:23 -08:00 committed by Boqun Feng
parent 38b43eca66
commit 536e8b9b80

View File

@ -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