From: Johan Hovold <johan+linaro@kernel.org>
Date: Mon, 6 Mar 2023 08:56:30 +0100
Subject: [PATCH] interconnect: fix icc_provider_del() error handling
References: bsc#1012628
Patch-mainline: 6.2.8
Git-commit: e0e7089bf9a87bc5e3997422e4e24563424f9018

commit e0e7089bf9a87bc5e3997422e4e24563424f9018 upstream.

The interconnect framework currently expects that providers are only
removed when there are no users and after all nodes have been removed.

There is currently nothing that guarantees this to be the case and the
framework does not do any reference counting, but refusing to remove the
provider is never correct as that would leave a dangling pointer to a
resource that is about to be released in the global provider list (e.g.
accessible through debugfs).

Replace the current sanity checks with WARN_ON() so that the provider is
always removed.

Fixes: 11f1ceca7031 ("interconnect: Add generic on-chip interconnect API")
Cc: stable@vger.kernel.org      # 5.1: 680f8666baf6: interconnect: Make icc_provider_del() return void
Reviewed-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
Tested-by: Luca Ceresoli <luca.ceresoli@bootlin.com> # i.MX8MP MSC SM2-MB-EP1 Board
Link: https://lore.kernel.org/r/20230306075651.2449-3-johan+linaro@kernel.org
Signed-off-by: Georgi Djakov <djakov@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
---
 drivers/interconnect/core.c | 14 ++------------
 1 file changed, 2 insertions(+), 12 deletions(-)

diff --git a/drivers/interconnect/core.c b/drivers/interconnect/core.c
index 25debded..fe81b401 100644
--- a/drivers/interconnect/core.c
+++ b/drivers/interconnect/core.c
@@ -1061,18 +1061,8 @@ EXPORT_SYMBOL_GPL(icc_provider_add);
 void icc_provider_del(struct icc_provider *provider)
 {
 	mutex_lock(&icc_lock);
-	if (provider->users) {
-		pr_warn("interconnect provider still has %d users\n",
-			provider->users);
-		mutex_unlock(&icc_lock);
-		return;
-	}
-
-	if (!list_empty(&provider->nodes)) {
-		pr_warn("interconnect provider still has nodes\n");
-		mutex_unlock(&icc_lock);
-		return;
-	}
+	WARN_ON(provider->users);
+	WARN_ON(!list_empty(&provider->nodes));
 
 	list_del(&provider->provider_list);
 	mutex_unlock(&icc_lock);
-- 
2.35.3