[PATCH v2] driver/core: Fix build error when SRCU and lockdep disabled

From: Joel Fernandes (Google)
Date: Mon Aug 12 2019 - 17:49:30 EST


Check if lockdep lock checking is disabled. If so, then do not define
device_links_read_lock_held(). It is used only from places where lockdep
checking is enabled.

Also fix a bug where I was not checking dep_map. Previously, I did not
test !SRCU configs so this got missed. Now it is sorted.

Link: https://lore.kernel.org/lkml/201908080026.WSAFx14k%25lkp@xxxxxxxxx/
Fixes: c9e4d3a2fee8 ("acpi: Use built-in RCU list checking for acpi_ioremaps list")
(Based on RCU's dev branch)

Cc: kernel-team@xxxxxxxxxxx
Cc: kbuild test robot <lkp@xxxxxxxxx>,
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>,
Cc: Josh Triplett <josh@xxxxxxxxxxxxxxxx>,
Cc: Lai Jiangshan <jiangshanlai@xxxxxxxxx>,
Cc: linux-doc@xxxxxxxxxxxxxxx,
Cc: Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxxxx>,
Cc: "Paul E. McKenney" <paulmck@xxxxxxxxxxxxx>,
Cc: "Rafael J. Wysocki" <rafael@xxxxxxxxxx>,
Cc: rcu@xxxxxxxxxxxxxxx,
Cc: Steven Rostedt <rostedt@xxxxxxxxxxx>,

Reported-by: kbuild test robot <lkp@xxxxxxxxx>
Signed-off-by: Joel Fernandes (Google) <joel@xxxxxxxxxxxxxxxxx>
---
drivers/base/core.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/base/core.c b/drivers/base/core.c
index 32cf83d1c744..c22271577c84 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -97,10 +97,12 @@ void device_links_read_unlock(int not_used)
up_read(&device_links_lock);
}

+#ifdef CONFIG_DEBUG_LOCK_ALLOC
int device_links_read_lock_held(void)
{
- return lock_is_held(&device_links_lock);
+ return lock_is_held(&(device_links_lock.dep_map));
}
+#endif
#endif /* !CONFIG_SRCU */

/**
--
2.23.0.rc1.153.gdeed80330f-goog