public inbox for linux-kernel@vger.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>,
	linux-usb@vger.kernel.org
Subject: [PATCH 4/5] usb: gadget: Remove snprintf() from sysfs call-backs and replace with sysfs_emit()
Date: Thu, 30 Nov 2023 10:54:38 +0000	[thread overview]
Message-ID: <20231130105459.3208986-5-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: linux-usb@vger.kernel.org
Signed-off-by: Lee Jones <lee@kernel.org>
---
 drivers/usb/gadget/configfs.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/usb/gadget/configfs.c b/drivers/usb/gadget/configfs.c
index 4c639e9ddedc0..b7d2a1313a684 100644
--- a/drivers/usb/gadget/configfs.c
+++ b/drivers/usb/gadget/configfs.c
@@ -812,7 +812,7 @@ static ssize_t gadget_string_s_show(struct config_item *item, char *page)
 	struct gadget_string *string = to_gadget_string(item);
 	int ret;
 
-	ret = snprintf(page, sizeof(string->string), "%s\n", string->string);
+	ret = sysfs_emit(page, "%s\n", string->string);
 	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 ` Lee Jones [this message]
2023-11-30 10:54 ` [PATCH 5/5] usb: gadget: f_tcm: Remove snprintf() from sysfs call-backs and replace with sysfs_emit() Lee Jones

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=20231130105459.3208986-5-lee@kernel.org \
    --to=lee@kernel.org \
    --cc=gregkh@linuxfoundation.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-usb@vger.kernel.org \
    /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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox