From patchwork Fri Oct 20 01:18:54 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jakub Kicinski X-Patchwork-Id: 13429957 X-Patchwork-Delegate: kuba@kernel.org Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 75909ECE for ; Fri, 20 Oct 2023 01:19:00 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="E9iKs/1I" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E2A1EC433CA; Fri, 20 Oct 2023 01:18:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1697764740; bh=4nxRFy7uAeXFMKE//Wszpq3lf9oOTfgFd8lrOhnblBk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=E9iKs/1IdZwt0/pcOsobUvDNteQpksrGPkVz996DCJIj008LpMgFifuzFblCXGv9q xYWtbIek8fr4UFPJmY7rI32b5tqYjTlFjsKcdRar9BvaEF+QO+y0WcOEGaDO2lQv0F WXKvjP3Uvj05H/V2iMv5Qvo93gcUCjUSJxWKJFELcS8822Cxf0TuVoTo7BX0xl3k5O x2um2Bq1AYVvCc39i7cDAURFAg9T94kkugaMNxhckyQ3N9ZZElIA8AdTnfFDr0YSJ7 FdqAUpjkpj0PZ4d6ACPPKgewHqKSsoZUg8XKweSLzL/b3YxDj+gfMSPU5pN/0b+XLP lp3IkqSfsj1Pw== From: Jakub Kicinski To: davem@davemloft.net Cc: netdev@vger.kernel.org, edumazet@google.com, pabeni@redhat.com, johannes.berg@intel.com, mpe@ellerman.id.au, j@w1.fi, jiri@resnulli.us Subject: [PATCH net-next 4/6] net: trust the bitmap in __dev_alloc_name() Date: Thu, 19 Oct 2023 18:18:54 -0700 Message-ID: <20231020011856.3244410-5-kuba@kernel.org> X-Mailer: git-send-email 2.41.0 In-Reply-To: <20231020011856.3244410-1-kuba@kernel.org> References: <20231020011856.3244410-1-kuba@kernel.org> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Patchwork-Delegate: kuba@kernel.org Prior to restructuring __dev_alloc_name() handled both printf and non-printf names. In a clever attempt at code reuse it always prints the name into a buffer and checks if it's a duplicate. Trust the bitmap, and return an error if its full. Signed-off-by: Jakub Kicinski --- net/core/dev.c | 15 ++++----------- 1 file changed, 4 insertions(+), 11 deletions(-) diff --git a/net/core/dev.c b/net/core/dev.c index bbfb02b4a228..d2698b4bbad4 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -1119,18 +1119,11 @@ static int __dev_alloc_name(struct net *net, const char *name, char *res) i = find_first_zero_bit(inuse, max_netdevices); bitmap_free(inuse); + if (i == max_netdevices) + return -ENFILE; - snprintf(buf, IFNAMSIZ, name, i); - if (!netdev_name_in_use(net, buf)) { - strscpy(res, buf, IFNAMSIZ); - return i; - } - - /* It is possible to run out of possible slots - * when the name is long and there isn't enough space left - * for the digits, or if all bits are used. - */ - return -ENFILE; + snprintf(res, IFNAMSIZ, name, i); + return i; } /* Returns negative errno or allocated unit id (see __dev_alloc_name()) */