From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (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 3740B69941 for ; Fri, 9 Feb 2024 10:29:40 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.129.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1707474582; cv=none; b=dhfgl1QbDYHWlTHhb3ugj/kgyyqlIclTUgFcrINL523e+LK+qdnOc/FBi0zRqXOkcKyYkoKOXABEoE0rM93DfwfZBaLqCwP6E9k2G5IR7CEGVxrsOV8m0mwVXEiSa969yQ1nVBKVMajVW4X20TAIGsIUjYALWhJyVsbdl6phxeA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1707474582; c=relaxed/simple; bh=HHUvxWEQeOWIogeQUKI+8xGetAxWcmQWvB4EKQ6xgDY=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=g6x0Bebz311DDAb+MFsuI0VwQZPltud3WPFH3tsyFsSg43j15R09jNrXapbMvMvPuOPF2U8bw5ZpnqFo81Ept9m5P6Entb9ZzVM4lGPGPcsFvfHFERB8jIAdrf3/eDBrcsIaCq87yj/gzgBevw+IUrOleCyLyUOpbfKT80Gpuys= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=fyi28AK3; arc=none smtp.client-ip=170.10.129.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="fyi28AK3" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1707474579; 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=HHUvxWEQeOWIogeQUKI+8xGetAxWcmQWvB4EKQ6xgDY=; b=fyi28AK36G7IH7pDM6lP9xgOS5jFFcyCHImkYFc4xfuy5keSGMiweqHBBeDM8+oghBKjbx OlfgfgTjNvR6tG0zwgT0Sroe8Q2U5gAKLTT6zYkp6Z0wOXmEuMpbrlS2WKC6DQ98unCMYG 09qUrZjCkayB4Mu40XWB375R4PU2dj0= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-41-EERUOpjmM0WcW_tGN8tCrg-1; Fri, 09 Feb 2024 05:29:36 -0500 X-MC-Unique: EERUOpjmM0WcW_tGN8tCrg-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.rdu2.redhat.com [10.11.54.4]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 0F5E5185A781; Fri, 9 Feb 2024 10:29:36 +0000 (UTC) Received: from dhcp-27-174.brq.redhat.com (unknown [10.45.226.84]) by smtp.corp.redhat.com (Postfix) with SMTP id 509E82026D06; Fri, 9 Feb 2024 10:29:34 +0000 (UTC) Received: by dhcp-27-174.brq.redhat.com (nbSMTP-1.00) for uid 1000 oleg@redhat.com; Fri, 9 Feb 2024 11:28:19 +0100 (CET) Date: Fri, 9 Feb 2024 11:28:17 +0100 From: Oleg Nesterov To: Christian Brauner Cc: Andy Lutomirski , "Eric W. Biederman" , Tycho Andersen , linux-api@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] pidfd: change pidfd_send_signal() to respect PIDFD_THREAD Message-ID: <20240209102816.GA3282@redhat.com> References: <20240207114549.GA12697@redhat.com> <20240208-fragt-prospekt-7866333b15f0@brauner> <20240208135344.GD19801@redhat.com> <20240208143407.GF19801@redhat.com> Precedence: bulk X-Mailing-List: linux-api@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20240208143407.GF19801@redhat.com> User-Agent: Mutt/1.5.24 (2015-08-30) X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.4 On 02/08, Oleg Nesterov wrote: > > Is prepare_kill_siginfo() correct when we send a signal to the child > pid namespace? si_pid = task_tgid_vnr(current) doesn't look right Yes, but iiuc send_signal_locked() should fixup si_pid/si_uid, so it is not buggy. > And why do we need it at all? Can't sys_kill() and pidfd_send_signal() > just use SEND_SIG_NOINFO? Probably yes. And even do_tkill() can use SEND_SIG_NOINFO if we change __send_signal_locked() to check the type before ".si_code = SI_USER". but then TP_STORE_SIGINFO() needs some changes... I'll try to do this later, I do not want to mix this change with the PIDFD_THREAD changes. Oleg.