From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (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 D7E62DDD7 for ; Tue, 21 May 2024 03:49:42 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.133.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1716263384; cv=none; b=OpvUkIHby271rUXn51ua6CBsJDeaKKbu1Q07uz8211mmCZSwbC6dA4DbIFrl2NRWhP6SdlrF+4uoFZqLEOqhEnTyKkHQs3LF6dN40Rdu06/9LsxIhSaK2uodABrZxWkTdt5QR9u50MqR1/BHRXU+eD/B1BXNhg5MOj7/zHK3/2s= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1716263384; c=relaxed/simple; bh=buDMIUMP/mQLrTA7c6+3ac8cH8jaRMOdz9QqlsfD4Sc=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=ffYj5CYkjYPpAu9MULJqYL/QfNVQbjwUXd47UkWU4rlRFuKhAhKgwWlvFxlXzSPItoC8D/mevrXP9XFPQAC4o+hFeqn1nwdLNOcvgjjOLVhSMQYcGBRywy+hHdTxrqSeKNEOlCiwJAfC0KCJI35TGz700ELymedfn2pG8aLcMrI= 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=BiOsVNjU; arc=none smtp.client-ip=170.10.133.124 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="BiOsVNjU" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1716263381; 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=84fW/dirVXf5VBFqyibcvwX/hKqHiB6YLgeewDy6EUw=; b=BiOsVNjU0y534mFtW16/6vRDnCpzdFKp7giz/Kf17T3BXaZpo1mZtEZQeEDgEGU04QwASP qB6kwb5aQyIH/G2J0qXPDIXOpKUmZqGy9IWmJ3Gm7wI29TQs3VdgXA8ot+KGf7RRHUjYLe +qjOueU/D1eO0alaxBl4b6D0FWdFgus= Received: from mimecast-mx02.redhat.com (mx-ext.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-582-hZPXxrt6Ov2PCqM5ZY3_8w-1; Mon, 20 May 2024 23:48:55 -0400 X-MC-Unique: hZPXxrt6Ov2PCqM5ZY3_8w-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.rdu2.redhat.com [10.11.54.5]) (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 D43F43C0BE36; Tue, 21 May 2024 03:48:54 +0000 (UTC) Received: from localhost (unknown [10.72.116.65]) by smtp.corp.redhat.com (Postfix) with ESMTPS id E60157412; Tue, 21 May 2024 03:48:53 +0000 (UTC) Date: Tue, 21 May 2024 11:48:49 +0800 From: Baoquan He To: Coiby Xu Cc: kexec@lists.infradead.org, Ondrej Kozina , Milan Broz , Thomas Staudt , Daniel P =?iso-8859-1?Q?=2E_Berrang=E9?= , Kairui Song , Jan Pazdziora , Pingfan Liu , Dave Young , linux-kernel@vger.kernel.org, x86@kernel.org, Dave Hansen , Vitaly Kuznetsov , Vivek Goyal Subject: Re: [PATCH v3 4/7] crash_dump: reuse saved dm crypt keys for CPU/memory hot-plugging Message-ID: References: <20240425100434.198925-1-coxu@redhat.com> <20240425100434.198925-5-coxu@redhat.com> Precedence: bulk X-Mailing-List: linux-kernel@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: <20240425100434.198925-5-coxu@redhat.com> X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.5 On 04/25/24 at 06:04pm, Coiby Xu wrote: > When there is CPU/memory hot-plugging, the kdump kernel image and initrd > will be reloaded. The user space can write the "reuse" command to > /sys/kernel/crash_dm_crypt_key so the stored keys can be re-saved again. > > Note currently only x86 (commit ea53ad9cf73b ("x86/crash: add x86 crash > hotplug support")) and ppc (WIP) supports the new infrastructure > (commit 247262756121 ("crash: add generic infrastructure for crash > hotplug support")). If the new infrastructure get extended to all arches, > this patch can be dropped. > > Signed-off-by: Coiby Xu > --- > kernel/crash_dump_dm_crypt.c | 30 ++++++++++++++++++++++++++---- > 1 file changed, 26 insertions(+), 4 deletions(-) > > diff --git a/kernel/crash_dump_dm_crypt.c b/kernel/crash_dump_dm_crypt.c > index b9997fb53351..6ac1fabdb6cb 100644 > --- a/kernel/crash_dump_dm_crypt.c > +++ b/kernel/crash_dump_dm_crypt.c > @@ -10,12 +10,13 @@ > // The key scription has the format: cryptsetup:UUID 11+36+1(NULL)=48 > #define KEY_DESC_LEN 48 > > -static char *STATE_STR[] = {"fresh", "initialized", "recorded", "loaded"}; > +static char *STATE_STR[] = {"fresh", "initialized", "recorded", "loaded", "reuse"}; > enum STATE_ENUM { > FRESH = 0, > INITIALIZED, > RECORDED, > LOADED, > + REUSE, > } state; > > static unsigned int key_count; > @@ -90,12 +91,31 @@ static int record_key_desc(const char *buf, struct dm_crypt_key *dm_key) > return 0; > } > > +static void get_keys_from_kdump_reserved_memory(void) > +{ > + struct keys_header *keys_header_loaded; > + > + arch_kexec_unprotect_crashkres(); I don't see the corresponging arch_kexec_protect_crashkres() in the following flow. Aren't they a pair when used? > + > + keys_header_loaded = kmap_local_page(pfn_to_page( > + kexec_crash_image->dm_crypt_keys_addr >> PAGE_SHIFT)); > + > + memcpy(keys_header, keys_header_loaded, keys_header_size); > + kunmap_local(keys_header_loaded); > + state = RECORDED; > +} > + > static int process_cmd(const char *buf, size_t count) > { > if (strncmp(buf, "init ", 5) == 0) > return init(buf); > else if (strncmp(buf, "record ", 7) == 0) > return record_key_desc(buf, &keys_header->keys[key_count]); > + else if (!strcmp(buf, "reuse")) { > + state = REUSE; > + get_keys_from_kdump_reserved_memory(); > + return 0; > + } > > return -EINVAL; > } > @@ -175,9 +195,11 @@ int crash_load_dm_crypt_keys(struct kimage *image) > } > > image->dm_crypt_keys_addr = 0; > - r = build_keys_header(); > - if (r) > - return r; > + if (state != REUSE) { > + r = build_keys_header(); > + if (r) > + return r; > + } > > kbuf.buffer = keys_header; > kbuf.bufsz = keys_header_size; > -- > 2.44.0 >