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From:   Lee Jones <lee@kernel.org>
To:     lee@kernel.org
Cc:     linux-kernel@vger.kernel.org,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        "Martin K. Petersen" <martin.petersen@oracle.com>,
        Dmitry Bogdanov <d.bogdanov@yadro.com>,
        linux-usb@vger.kernel.org
Subject: [PATCH 5/5] usb: gadget: f_tcm: Remove snprintf() from sysfs call-backs and replace with sysfs_emit()
Date:   Thu, 30 Nov 2023 10:54:39 +0000
Message-ID: <20231130105459.3208986-6-lee@kernel.org>
In-Reply-To: <20231130105459.3208986-1-lee@kernel.org>
References: <20231130105459.3208986-1-lee@kernel.org>
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Since snprintf() has the documented, but still rather strange trait of
returning the length of the data that *would have been* written to the
array if space were available, rather than the arguably more useful
length of data *actually* written, it is usually considered wise to use
something else instead in order to avoid confusion.

In the case of sysfs call-backs, new wrappers exist that do just that.

This patch replaces just one use of snprintf() found in the sysfs
.show() call-back with the new sysfs_emit() helper.

Link: https://lwn.net/Articles/69419/
Link: https://github.com/KSPP/linux/issues/105
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>
Cc: Dmitry Bogdanov <d.bogdanov@yadro.com>
Cc: linux-usb@vger.kernel.org
Signed-off-by: Lee Jones <lee@kernel.org>
---
 drivers/usb/gadget/function/f_tcm.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/usb/gadget/function/f_tcm.c b/drivers/usb/gadget/function/f_tcm.c
index ff33f31bcdf64..37befd6db001a 100644
--- a/drivers/usb/gadget/function/f_tcm.c
+++ b/drivers/usb/gadget/function/f_tcm.c
@@ -1504,8 +1504,8 @@ static ssize_t tcm_usbg_tpg_nexus_show(struct config_item *item, char *page)
 		ret = -ENODEV;
 		goto out;
 	}
-	ret = snprintf(page, PAGE_SIZE, "%s\n",
-			tv_nexus->tvn_se_sess->se_node_acl->initiatorname);
+	ret = sysfs_emit(page, "%s\n",
+			 tv_nexus->tvn_se_sess->se_node_acl->initiatorname);
 out:
 	mutex_unlock(&tpg->tpg_mutex);
 	return ret;
-- 
2.43.0.rc1.413.gea7ed67945-goog