[PATCH for-v7.5 1/5] srcu: Select IRQ_WORK for Tiny SRCU

[PATCH for-v7.5 1/5] srcu: Select IRQ_WORK for Tiny SRCU

[Joel Fernandes]

Tiny SRCU uses irq_work_queue() to start grace periods and
irq_work_sync() to wait for pending work. However, TINY_SRCU does not
select IRQ_WORK, so configurations that do not otherwise enable it
fail to link with undefined references to these functions.

Guenter reported this failure with csky tinyconfig on the 6.12 and
6.6 stable trees. Current kernels enable IRQ_WORK indirectly through
SLUB, but Tiny SRCU should declare its own dependency.

Select IRQ_WORK from TINY_SRCU to ensure that its irq_work calls are
supported independently of other configuration options.

Fixes: a6fc88b22bc8 ("srcu: Use irq_work to start GP in tiny SRCU")
Reported-by: Guenter Roeck <linux@roeck-us.net>
Closes: https://lore.kernel.org/r/49da816c-8082-46f1-bb12-f0d6187bb06a@roeck-us.net/
Suggested-by: Guenter Roeck <linux@roeck-us.net>
Cc: stable@vger.kernel.org
Signed-off-by: Joel Fernandes <jfern@kernel.org>
---
 kernel/rcu/Kconfig | 1 +
 1 file changed, 1 insertion(+)

diff --git a/kernel/rcu/Kconfig b/kernel/rcu/Kconfig
index bc9483c0b5d8..b6d3597758fc 100644
--- a/kernel/rcu/Kconfig
+++ b/kernel/rcu/Kconfig
@@ -56,6 +56,7 @@ config RCU_EXPERT
 config TINY_SRCU
 	bool
 	default y if TINY_RCU
+	select IRQ_WORK
 	help
 	  This option selects the single-CPU non-preemptible version of SRCU.
 
-- 
2.54.0