From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from dvalin.narfation.org (dvalin.narfation.org [213.160.73.56]) (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 78D9348CD5E for ; Tue, 1 Sep 2026 18:18:56 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=213.160.73.56 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788286737; cv=none; b=huVQ/e0fpcvGrBvH+CjEmO4KFQFCagT3rASaFQHHXM3yo4wFvWGyIFrXJsFeTaSkrK+mRQxoqZti5LI54JJaHblsSBU0Jy6Mvr0T2t1Dq3tQ6OVynyU9uD/FU7/zvhgPExz6W8eJEfv9DRD/q/hzB86bkHdS0Q1J2K8Ce7tFM3E= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788286737; c=relaxed/simple; bh=YXqEs328TowbEf5G0SPaV4v6Nvx2fFTpdEhShmlp9ms=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=g2O31hO+RBg6H9zH2A/jv1QFWQokWHOtAxaWt44sXdtqhR/u9gSHYcZnWWayCDMAHz60inu07DTBxyy3Uu2zzZLSB7nRrbEXpSU1HAFkBYTNXycNRkq5D25XCTuvDIx1F/NbCst2E1ZkDy2X0Vte0Eh25RrkSg28/chxRsXJN1c= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=narfation.org; spf=pass smtp.mailfrom=narfation.org; dkim=pass (1024-bit key) header.d=narfation.org header.i=@narfation.org header.b=w6oxEPr/; arc=none smtp.client-ip=213.160.73.56 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=narfation.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=narfation.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=narfation.org header.i=@narfation.org header.b="w6oxEPr/" Received: by dvalin.narfation.org (Postfix) id DE591203D9; Tue, 01 Sep 2026 18:18:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=narfation.org; s=20121; t=1788286730; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=RsvuI7lZ0TZRrrGE3s3xeWRxZcspgFKVyXkTwnTErr8=; b=w6oxEPr/yLRyLmoykG/ykaHijXj0AhyZBNcWzrmpqWYwgCYNIgyPYGOvxMh1VuXjSSQZ21 A4RfgfOkuBqHGMBS5ojfaO51H5LstcswzWF457owhmo+pUsOrmche2kPh2f/UP68fswJ6f PUBqkS5MmknD+2NfATqmWr0rNCW0k08= From: Sven Eckelmann To: netdev@vger.kernel.org, Simon Wunderlich Cc: "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Simon Horman , b.a.t.m.a.n@lists.open-mesh.org, Simon Wunderlich Subject: Re: [PATCH net-next 10/15] batman-adv: tt: simplify NEW flag transition code Date: Tue, 01 Sep 2026 20:18:47 +0200 Message-ID: <5146131.31r3eYUQgx@sven-desktop> In-Reply-To: <20260831135117.574836-11-sw@simonwunderlich.de> References: <20260831135117.574836-1-sw@simonwunderlich.de> <20260831135117.574836-11-sw@simonwunderlich.de> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: multipart/signed; boundary="nextPart4778182.LvFx2qVVIh"; micalg="pgp-sha512"; protocol="application/pgp-signature" --nextPart4778182.LvFx2qVVIh Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8"; protected-headers="v1" From: Sven Eckelmann To: netdev@vger.kernel.org, Simon Wunderlich Date: Tue, 01 Sep 2026 20:18:47 +0200 Message-ID: <5146131.31r3eYUQgx@sven-desktop> In-Reply-To: <20260831135117.574836-11-sw@simonwunderlich.de> MIME-Version: 1.0 https://netdev-ai.bots.linux.dev/sashiko/#/patchset/20260831135117.574836-1= =2Dsw%40simonwunderlich.de?part=3D10 [...] > Discovered by: opus-5, sonnet-5 =C2=B7 Missed by: gpt-5-6-sol, sashiko-ge= mini >=20 > This isn't a bug introduced by this patch, since the removed > batadv_tt_local_set_flags() did the same unlocked read-modify-write under > rcu_read_lock(), but it may be worth noting for the rewritten loop in > batadv_tt_local_transition_new(). >=20 > The loop only holds rcu_read_lock(), so it takes neither the hash bucket > list_lock nor any per-entry lock while doing: >=20 > tt_common_entry->flags &=3D ~BATADV_TT_CLIENT_NEW; >=20 > Can this store be lost against a concurrent RMW on the same u16 from > batadv_tt_local_add() or batadv_tt_local_set_pending() on another CPU, for > example one that is OR-ing BATADV_TT_CLIENT_PENDING or > BATADV_TT_CLIENT_ROAM into the same word? [...] Out-of-scope for this patch. And handled in the patch "batman-adv: tt: transition NEW local entries only under lock" Regards, Sven --nextPart4778182.LvFx2qVVIh Content-Type: application/pgp-signature; name="signature.asc" Content-Description: This is a digitally signed message part. Content-Transfer-Encoding: 7Bit -----BEGIN PGP SIGNATURE----- iHUEABYKAB0WIQS81G/PswftH/OW8cVND3cr0xT1ywUCapcXBwAKCRBND3cr0xT1 y8GTAP9pYtgQ53GhxqBDk6erQWp+KbSDdLPShU2KxvHj7228rQEApSyZSKDsN0tA BBvtJ/3BubEGdI0/mkrs3pHOpE3++Aw= =mchY -----END PGP SIGNATURE----- --nextPart4778182.LvFx2qVVIh--