linux-kernel - [PATCH] staging: vchiq: replace usage of found with dedicated list iterator variable

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Date:   Thu, 24 Mar 2022 08:30:24 +0100
From:   Jakob Koschel <jakobkoschel@...il.com>
To:     Nicolas Saenz Julienne <nsaenz@...nel.org>
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        Stefan Wahren <stefan.wahren@...e.com>,
        Gaston Gonzalez <gascoar@...il.com>,
        Ojaswin Mujoo <ojaswin98@...il.com>,
        bcm-kernel-feedback-list@...adcom.com,
        linux-rpi-kernel@...ts.infradead.org,
        linux-arm-kernel@...ts.infradead.org,
        linux-staging@...ts.linux.dev, linux-kernel@...r.kernel.org,
        Mike Rapoport <rppt@...nel.org>,
        "Brian Johannesmeyer" <bjohannesmeyer@...il.com>,
        Cristiano Giuffrida <c.giuffrida@...nl>,
        "Bos, H.J." <h.j.bos@...nl>, Jakob Koschel <jakobkoschel@...il.com>
Subject: [PATCH] staging: vchiq: replace usage of found with dedicated list iterator variable

To move the list iterator variable into the list_for_each_entry_*()
macro in the future it should be avoided to use the list iterator
variable after the loop body.

To *never* use the list iterator variable after the loop it was
concluded to use a separate iterator variable instead of a
found boolean [1].

This removes the need to use a found variable and simply checking if
the variable was set, can determine if the break/goto was hit.

Link: https://lore.kernel.org/all/CAHk-=wgRr_D8CB-D9Kg-c=EHreAsk5SqXPwr9Y7k9sA6cWXJ6w@mail.gmail.com/
Signed-off-by: Jakob Koschel <jakobkoschel@...il.com>
---
 .../vc04_services/interface/vchiq_arm/vchiq_arm.c   | 13 ++++++-------
 .../vc04_services/interface/vchiq_arm/vchiq_dev.c   | 13 ++++++-------
 2 files changed, 12 insertions(+), 14 deletions(-)

diff --git a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c
index 3a2e4582db8e..f27ff246a672 100644
--- a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c
+++ b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c
@@ -908,8 +908,7 @@ vchiq_blocking_bulk_transfer(unsigned int handle, void *data, unsigned int size,
 	struct vchiq_instance *instance;
 	struct vchiq_service *service;
 	enum vchiq_status status;
-	struct bulk_waiter_node *waiter = NULL;
-	bool found = false;
+	struct bulk_waiter_node *waiter = NULL, *iter;
 
 	service = find_service_by_handle(handle);
 	if (!service)
@@ -920,16 +919,16 @@ vchiq_blocking_bulk_transfer(unsigned int handle, void *data, unsigned int size,
 	vchiq_service_put(service);
 
 	mutex_lock(&instance->bulk_waiter_list_mutex);
-	list_for_each_entry(waiter, &instance->bulk_waiter_list, list) {
-		if (waiter->pid == current->pid) {
-			list_del(&waiter->list);
-			found = true;
+	list_for_each_entry(iter, &instance->bulk_waiter_list, list) {
+		if (iter->pid == current->pid) {
+			list_del(&iter->list);
+			waiter = iter;
 			break;
 		}
 	}
 	mutex_unlock(&instance->bulk_waiter_list_mutex);
 
-	if (found) {
+	if (waiter) {
 		struct vchiq_bulk *bulk = waiter->bulk_waiter.bulk;
 
 		if (bulk) {
diff --git a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_dev.c b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_dev.c
index 2325844b0880..5102750dbabc 100644
--- a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_dev.c
+++ b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_dev.c
@@ -290,8 +290,7 @@ static int vchiq_irq_queue_bulk_tx_rx(struct vchiq_instance *instance,
 				      enum vchiq_bulk_mode __user *mode)
 {
 	struct vchiq_service *service;
-	struct bulk_waiter_node *waiter = NULL;
-	bool found = false;
+	struct bulk_waiter_node *waiter = NULL, *iter;
 	void *userdata;
 	int status = 0;
 	int ret;
@@ -310,16 +309,16 @@ static int vchiq_irq_queue_bulk_tx_rx(struct vchiq_instance *instance,
 		userdata = &waiter->bulk_waiter;
 	} else if (args->mode == VCHIQ_BULK_MODE_WAITING) {
 		mutex_lock(&instance->bulk_waiter_list_mutex);
-		list_for_each_entry(waiter, &instance->bulk_waiter_list,
+		list_for_each_entry(iter, &instance->bulk_waiter_list,
 				    list) {
-			if (waiter->pid == current->pid) {
-				list_del(&waiter->list);
-				found = true;
+			if (iter->pid == current->pid) {
+				list_del(&iter->list);
+				waiter = iter;
 				break;
 			}
 		}
 		mutex_unlock(&instance->bulk_waiter_list_mutex);
-		if (!found) {
+		if (!waiter) {
 			vchiq_log_error(vchiq_arm_log_level,
 					"no bulk_waiter found for pid %d", current->pid);
 			ret = -ESRCH;

base-commit: f443e374ae131c168a065ea1748feac6b2e76613
-- 
2.25.1