All of lore.kernel.org
 help / color / mirror / Atom feed
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	[thread overview]
Message-ID: <20231130105459.3208986-6-lee@kernel.org> (raw)
In-Reply-To: <20231130105459.3208986-1-lee@kernel.org>

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


      parent reply	other threads:[~2023-11-30 10:55 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-11-30 10:54 [PATCH 0/5] usb: Replace {v}snprintf() variants with safer alternatives Lee Jones
2023-11-30 10:54 ` [PATCH 1/5] usb: atm: Remove snprintf() from sysfs call-backs and replace with sysfs_emit() Lee Jones
2023-11-30 10:54 ` [PATCH 2/5] usb: cdnsp: Replace snprintf() with the safer scnprintf() variant Lee Jones
2023-11-30 10:54 ` [PATCH 3/5] usb: fotg210-hcd: " Lee Jones
2023-11-30 14:40   ` David Laight
2023-11-30 14:48   ` Linus Walleij
2023-11-30 10:54 ` [PATCH 4/5] usb: gadget: Remove snprintf() from sysfs call-backs and replace with sysfs_emit() Lee Jones
2023-11-30 10:54 ` Lee Jones [this message]

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20231130105459.3208986-6-lee@kernel.org \
    --to=lee@kernel.org \
    --cc=d.bogdanov@yadro.com \
    --cc=gregkh@linuxfoundation.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-usb@vger.kernel.org \
    --cc=martin.petersen@oracle.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.