From nobody Mon Oct 6 01:46:44 2025 Received: from fout-a6-smtp.messagingengine.com (fout-a6-smtp.messagingengine.com [103.168.172.149]) (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 CAD47198851 for ; Mon, 28 Jul 2025 01:51:33 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=103.168.172.149 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1753667495; cv=none; b=DPIXWPa6hv7f+8AdOd6HYJEXn5WDdVr7fdThPj6l8CX+wzja/6pivlALB1mcmWqKN59bqcLZcC8NZ2+u663ObytFd8+sfo+proKOONQXik5C6xmRGXDy0kFsSskMBpo4krdzHzv8yNFotmmJFZxZqNMKuz+DiD5HKRg0QlsH07M= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1753667495; c=relaxed/simple; bh=q9otTa9NZdOiCJNQl4OD6xqn9lIKwfmzJlUv8Z4LWuk=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=VIIjAf4gb8HSRuscqm0TPg26rHtdrPUzQloLNz9grntsoezl8Dt9j3sQX3Pfm1CeHegHPj55LeSX0JcLuuHgvblCkY+BFT6q4Mqy+udysjS2lyh6IRGeuU+h8AsmxuUEYiwoZpRI9Va0JtT/dQEHc59Lbjw/2+1inaEPa4MVjOo= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=sakamocchi.jp; spf=pass smtp.mailfrom=sakamocchi.jp; dkim=pass (2048-bit key) header.d=sakamocchi.jp header.i=@sakamocchi.jp header.b=fW6QzVKw; dkim=pass (2048-bit key) header.d=messagingengine.com header.i=@messagingengine.com header.b=IaS1lKkl; arc=none smtp.client-ip=103.168.172.149 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=sakamocchi.jp Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=sakamocchi.jp Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=sakamocchi.jp header.i=@sakamocchi.jp header.b="fW6QzVKw"; dkim=pass (2048-bit key) header.d=messagingengine.com header.i=@messagingengine.com header.b="IaS1lKkl" Received: from phl-compute-03.internal (phl-compute-03.phl.internal [10.202.2.43]) by mailfout.phl.internal (Postfix) with ESMTP id F063EEC00DC; Sun, 27 Jul 2025 21:51:32 -0400 (EDT) Received: from phl-mailfrontend-01 ([10.202.2.162]) by phl-compute-03.internal (MEProxy); Sun, 27 Jul 2025 21:51:32 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=sakamocchi.jp; h=cc:cc:content-transfer-encoding:content-type:date:date:from :from:in-reply-to:in-reply-to:message-id:mime-version:references :reply-to:subject:subject:to:to; s=fm3; t=1753667492; x= 1753753892; bh=D0BMPfPajXGaC45vmNs+dIanSxJ+Y1IlpOlvP9lpPHg=; b=f W6QzVKwaobJ7GUPv3Bp9aaIhJD1rnAem5FFGu2NLmYSEIR3biPmDk+UHFXtkpwYI Y6DP+1ro+l4Ur7zF9YMxYCeNoMr8+5eYGPT6OQB+XF5hb5ibsCytJkJNDzO7c236 fciYzMa8SiGGqbMsltPpl+Xq4dOWxa0DaC4MFpFKwkVMFuAGMXzfTxbCoRRbsoxh 5goqytBsGHCylB+d/lgZtyKwI1bZyScYM4ixWog8iKFQ5XdTsCMeuTZL64DTQSJK 32Zz8Jcc5SRzjPHT+XwkBA8Cs+3u5vD2wDdBl4z3w8wF+OL2153v3+GHSF1TOTWl AunalhuLiUlsKAb7/sZfQ== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:cc:content-transfer-encoding :content-type:date:date:feedback-id:feedback-id:from:from :in-reply-to:in-reply-to:message-id:mime-version:references :reply-to:subject:subject:to:to:x-me-proxy:x-me-sender :x-me-sender:x-sasl-enc; s=fm3; t=1753667492; x=1753753892; bh=D 0BMPfPajXGaC45vmNs+dIanSxJ+Y1IlpOlvP9lpPHg=; b=IaS1lKklM6lBm2WBJ hwQWhfHDqlgA2cfI5r+I+4NuSffHBbcypb6XENoy9LkbmLYVwf8arlWH50gcwUNA kLYKVM+YwMXLxxmUapwr+WbTblh148Z5+SiJe6yXNRvmwR+y0Deysz5iUh8N78yP zUAyA9jy9yM08lxi0nGoiBhf6WCOTRTTleUimsSIe5jxB2qfr4m9KgLVWcZ/KdtI gRxnNHdZNF0cZIf4C4iGiO1uRLHn99AAPyyfTfIvqwMpmaGaCDbOtphOvwxKt8J5 aesS4FgKjAS3KXMR7VgRjpsN4Cepv1AEy3PKpwxpsIk/FVdNMuHO6Yh0qhk4YsaK QyBfQ== X-ME-Sender: X-ME-Received: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgeeffedrtdefgdeltdeltdcutefuodetggdotefrod ftvfcurfhrohhfihhlvgemucfhrghsthforghilhdpuffrtefokffrpgfnqfghnecuuegr ihhlohhuthemuceftddtnecunecujfgurhephffvvefufffkofgjfhgggfestdekredtre dttdenucfhrhhomhepvfgrkhgrshhhihcuufgrkhgrmhhothhouceoohdqthgrkhgrshhh ihesshgrkhgrmhhotggthhhirdhjpheqnecuggftrfgrthhtvghrnhepvdejgfejuedvgf duudekleevtefgtdevhfdtffefiefgveeuteffiedvffekvddtnecuvehluhhsthgvrhfu ihiivgeptdenucfrrghrrghmpehmrghilhhfrhhomhepohdqthgrkhgrshhhihesshgrkh grmhhotggthhhirdhjphdpnhgspghrtghpthhtohepvddpmhhouggvpehsmhhtphhouhht pdhrtghpthhtoheplhhinhhugidufeelgedquggvvhgvlheslhhishhtshdrshhouhhrtg gvfhhorhhgvgdrnhgvthdprhgtphhtthhopehlihhnuhigqdhkvghrnhgvlhesvhhgvghr rdhkvghrnhgvlhdrohhrgh X-ME-Proxy: Feedback-ID: ie8e14432:Fastmail Received: by mail.messagingengine.com (Postfix) with ESMTPA; Sun, 27 Jul 2025 21:51:31 -0400 (EDT) From: Takashi Sakamoto To: linux1394-devel@lists.sourceforge.net Cc: linux-kernel@vger.kernel.org Subject: [PATCH 2/3] firewire: core: call handler for exclusive regions outside RCU read-side critical section Date: Mon, 28 Jul 2025 10:51:24 +0900 Message-ID: <20250728015125.17825-3-o-takashi@sakamocchi.jp> X-Mailer: git-send-email 2.48.1 In-Reply-To: <20250728015125.17825-1-o-takashi@sakamocchi.jp> References: <20250728015125.17825-1-o-takashi@sakamocchi.jp> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" The previous commit added reference counting to ensure safe invocations of address handlers. This commit moves the invocation of handlers for exclusive regins outside of the RCU read-side critical section. The address handler for the requested region is selected within the critical section, then invoked outside of it. Signed-off-by: Takashi Sakamoto --- drivers/firewire/core-transaction.c | 16 +++++++++------- 1 file changed, 9 insertions(+), 7 deletions(-) diff --git a/drivers/firewire/core-transaction.c b/drivers/firewire/core-tr= ansaction.c index 29ca9f3f14ce..a742971c65fa 100644 --- a/drivers/firewire/core-transaction.c +++ b/drivers/firewire/core-transaction.c @@ -935,17 +935,19 @@ static void handle_exclusive_region_request(struct fw= _card *card, scoped_guard(rcu) { handler =3D lookup_enclosing_address_handler(&address_handler_list, offs= et, request->length); - if (handler) { + if (handler) get_address_handler(handler); - handler->address_callback(card, request, tcode, destination, source, - p->generation, offset, request->data, - request->length, handler->callback_data); - put_address_handler(handler); - } } =20 - if (!handler) + if (!handler) { fw_send_response(card, request, RCODE_ADDRESS_ERROR); + return; + } + + // Outside the RCU read-side critical section. Without spinlock. With ref= erence count. + handler->address_callback(card, request, tcode, destination, source, p->g= eneration, offset, + request->data, request->length, handler->callback_data); + put_address_handler(handler); } =20 static void handle_fcp_region_request(struct fw_card *card, --=20 2.48.1