From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Date: Fri, 30 Aug 2024 05:35:58 +0000 (+0200)
Subject: 6.1-stable patches
X-Git-Tag: v4.19.321~77
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=caf0a142a06d96391fb90353b0a21e0f526a1afc;p=thirdparty%2Fkernel%2Fstable-queue.git

6.1-stable patches

added patches:
	of-add-cleanup.h-based-auto-release-via-__free-device_node-markings.patch
---

diff --git a/queue-6.1/of-add-cleanup.h-based-auto-release-via-__free-device_node-markings.patch b/queue-6.1/of-add-cleanup.h-based-auto-release-via-__free-device_node-markings.patch
new file mode 100644
index 00000000000..3cff72d3ad9
--- /dev/null
+++ b/queue-6.1/of-add-cleanup.h-based-auto-release-via-__free-device_node-markings.patch
@@ -0,0 +1,66 @@
+From 9448e55d032d99af8e23487f51a542d51b2f1a48 Mon Sep 17 00:00:00 2001
+From: Jonathan Cameron <Jonathan.Cameron@huawei.com>
+Date: Sun, 25 Feb 2024 14:27:11 +0000
+Subject: of: Add cleanup.h based auto release via __free(device_node) markings
+
+From: Jonathan Cameron <Jonathan.Cameron@huawei.com>
+
+commit 9448e55d032d99af8e23487f51a542d51b2f1a48 upstream.
+
+The recent addition of scope based cleanup support to the kernel
+provides a convenient tool to reduce the chances of leaking reference
+counts where of_node_put() should have been called in an error path.
+
+This enables
+	struct device_node *child __free(device_node) = NULL;
+
+	for_each_child_of_node(np, child) {
+		if (test)
+			return test;
+	}
+
+with no need for a manual call of of_node_put().
+A following patch will reduce the scope of the child variable to the
+for loop, to avoid an issues with ordering of autocleanup, and make it
+obvious when this assigned a non NULL value.
+
+In this simple example the gains are small but there are some very
+complex error handling cases buried in these loops that will be
+greatly simplified by enabling early returns with out the need
+for this manual of_node_put() call.
+
+Note that there are coccinelle checks in
+scripts/coccinelle/iterators/for_each_child.cocci to detect a failure
+to call of_node_put(). This new approach does not cause false positives.
+Longer term we may want to add scripting to check this new approach is
+done correctly with no double of_node_put() calls being introduced due
+to the auto cleanup. It may also be useful to script finding places
+this new approach is useful.
+
+Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
+Reviewed-by: Rob Herring <robh@kernel.org>
+Link: https://lore.kernel.org/r/20240225142714.286440-2-jic23@kernel.org
+Signed-off-by: Rob Herring <robh@kernel.org>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ include/linux/of.h |    2 ++
+ 1 file changed, 2 insertions(+)
+
+--- a/include/linux/of.h
++++ b/include/linux/of.h
+@@ -13,6 +13,7 @@
+  */
+ #include <linux/types.h>
+ #include <linux/bitops.h>
++#include <linux/cleanup.h>
+ #include <linux/errno.h>
+ #include <linux/kobject.h>
+ #include <linux/mod_devicetable.h>
+@@ -128,6 +129,7 @@ static inline struct device_node *of_nod
+ }
+ static inline void of_node_put(struct device_node *node) { }
+ #endif /* !CONFIG_OF_DYNAMIC */
++DEFINE_FREE(device_node, struct device_node *, if (_T) of_node_put(_T))
+ 
+ /* Pointer for first entry in chain of all nodes. */
+ extern struct device_node *of_root;
diff --git a/queue-6.1/series b/queue-6.1/series
index 48799a651a4..c514f20aa7d 100644
--- a/queue-6.1/series
+++ b/queue-6.1/series
@@ -4,3 +4,4 @@ btrfs-run-delayed-iputs-when-flushing-delalloc.patch
 smb-client-avoid-dereferencing-rdata-null-in-smb2_new_read_req.patch
 pinctrl-rockchip-correct-rk3328-iomux-width-flag-for-gpio2-b-pins.patch
 pinctrl-single-fix-potential-null-dereference-in-pcs_get_function.patch
+of-add-cleanup.h-based-auto-release-via-__free-device_node-markings.patch