From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from lgeamrelo13.lge.com (lgeamrelo13.lge.com [156.147.23.53]) (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 9E14E1624C0 for ; Fri, 16 Jan 2026 05:52:30 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=156.147.23.53 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768542754; cv=none; b=V02yTSnwT+12NwazPLyO74W1eWnY8iFfNOD5IkHIB6wES5uwJ8o2VfBkxus2Hec42940hFWFXW05gI75p8TiIkXLtKIVAltXX2JPCT4bFknvlYcK6UQcy828EqXq6TrJlysrn3jKlMYlq1I6MYuYaNX4j50txs/t1YPIcaCRsDQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768542754; c=relaxed/simple; bh=x5bzaVMNTeQsAAg0uSV7GgbCp9Jj1YV4nV+6Ypp/Rdo=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=X/5vYDkDkbke3cXg2WnLezaS1o/Pty3/AhcCL5fqXj1dS7XevZ80guuguXc6uHoQE9HbWLqWEos1dAfp3CCIwzodnL4fZOTNjCNY74V3Rz6MO9j4k0giaADu8/fuAEgN9RxoXTdyrjePcRmHP0I9lV2JkYqIUCEAzkwGIaIGY64= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=lge.com; spf=pass smtp.mailfrom=lge.com; arc=none smtp.client-ip=156.147.23.53 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=lge.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=lge.com Received: from unknown (HELO lgemrelse7q.lge.com) (156.147.1.151) by 156.147.23.53 with ESMTP; 16 Jan 2026 14:52:23 +0900 X-Original-SENDERIP: 156.147.1.151 X-Original-MAILFROM: jongan.kim@lge.com Received: from unknown (HELO jongan-kim-nissan-cdc.bee-live.svc.cluster.local) (10.159.45.52) by 156.147.1.151 with ESMTP; 16 Jan 2026 14:52:23 +0900 X-Original-SENDERIP: 10.159.45.52 X-Original-MAILFROM: jongan.kim@lge.com From: jongan.kim@lge.com To: aliceryhl@google.com, gregkh@linuxfoundation.org Cc: arve@android.com, brauner@kernel.org, cmllamas@google.com, heesu0025.kim@lge.com, ht.hong@lge.com, jongan.kim@lge.com, jungsu.hwang@lge.com, kernel-team@android.com, linux-kernel@vger.kernel.org, sanghun.lee@lge.com, seulgi.lee@lge.com, sunghoon.kim@lge.com, tkjos@android.com Subject: Re: [PATCH RESEND] binder: handle PID namespace conversion for freeze operation Date: Fri, 16 Jan 2026 14:52:22 +0900 Message-Id: <20260116055222.6069-1-jongan.kim@lge.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: References: Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Alice Ryhl @ 2026-01-15 8:41 UTC wrote: > On Thu, Jan 15, 2026 at 05:06:19PM +0900, jongan.kim@lge.com wrote: > > As Alice mentioned, since only the freeze operation takes a pid as input, it > > receives the local pid of the namespace. This patch converts this pid to the > > global pid of the init namespace for matching pid of binder_procs properly. > > (binder_procs has `task->group_leader->pid`). Are there any concerns or > > problems for this logic? > > This isn't new with your changes ... but it does have a race where the > target process dies and gets replaced by a new process with the same pid > just before you invoke the freeze ioctl. Thanks for sharing! Has this issue been encountered before? I think there may be a potential problem, although it is very unlikely to occur. (It is also very hard to fix and verify the problem I guess...) For now I want to focus on the patch submitted regarding the PID namespace on this thread. Please check if there are any issues with merging this patch into the binder driver. Thanks. // JongAn, Kim