This is a note to let you know that I've just added the patch titled
interconnect: Teach lockdep about icc_bw_lock order
to the 5.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
interconnect-teach-lockdep-about-icc_bw_lock-order.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 13619170303878e1dae86d9a58b039475c957fcf Mon Sep 17 00:00:00 2001
From: Rob Clark <robdclark@xxxxxxxxxxxx>
Date: Mon, 7 Aug 2023 10:11:41 -0700
Subject: interconnect: Teach lockdep about icc_bw_lock order
From: Rob Clark <robdclark@xxxxxxxxxxxx>
commit 13619170303878e1dae86d9a58b039475c957fcf upstream.
Teach lockdep that icc_bw_lock is needed in code paths that could
deadlock if they trigger reclaim.
Signed-off-by: Rob Clark <robdclark@xxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20230807171148.210181-8-robdclark@xxxxxxxxx
Signed-off-by: Georgi Djakov <djakov@xxxxxxxxxx>
Cc: Guenter Roeck <linux@xxxxxxxxxxxx>
Cc: Jon Hunter <jonathanh@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/interconnect/core.c | 10 +++++++++-
1 file changed, 9 insertions(+), 1 deletion(-)
--- a/drivers/interconnect/core.c
+++ b/drivers/interconnect/core.c
@@ -1135,13 +1135,21 @@ void icc_sync_state(struct device *dev)
}
}
}
+ mutex_unlock(&icc_bw_lock);
mutex_unlock(&icc_lock);
}
EXPORT_SYMBOL_GPL(icc_sync_state);
static int __init icc_init(void)
{
- struct device_node *root = of_find_node_by_path("/");
+ struct device_node *root;
+
+ /* Teach lockdep about lock ordering wrt. shrinker: */
+ fs_reclaim_acquire(GFP_KERNEL);
+ might_lock(&icc_bw_lock);
+ fs_reclaim_release(GFP_KERNEL);
+
+ root = of_find_node_by_path("/");
providers_count = of_count_icc_providers(root);
of_node_put(root);
Patches currently in stable-queue which might be from robdclark@xxxxxxxxxxxx are
queue-5.15/interconnect-fix-locking-for-runpm-vs-reclaim.patch
queue-5.15/interconnect-teach-lockdep-about-icc_bw_lock-order.patch
