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 B8622EAD0 for ; Tue, 4 Jun 2024 13:53:05 +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=1717509187; cv=none; b=YDljWl5wqEztySnCGevepH2iGH96n3raYStBUrnU/+u5Brf4jwxIF5gHVgwhGktC/qk5p38D+s2TMdkB3g/ijnwfZG+GUfe2wHUwt7j1TYmcKpjZkAeROD3H3hXfaO0IImMnN7Nf49ggKNqCtmMp7nCn2TL5NxIMdZApRVO/AmE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1717509187; c=relaxed/simple; bh=/XFAEfCczlibUE70QLgqPgMQ8f45nxN8l1BnMdzrpK8=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=fV4YJ9JWWIIU7TEHtdM8jAyn1vrXmtuHyZTUu+VCGtrdVaQG+3df/iXVfL96WMbJz0Tc20ADmjED12X5migSi4kKocQfv77Tyf99/ch02k72pmxmY3jtFVlLmTm0ZtSKuiLGmFci4toT3x+aij+F/mjTVzJwuUdwsp1h0THcWlE= 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=igiEY8Bb; 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="igiEY8Bb" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1717509184; 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=R0VxfhH1OEgJBZVeakcTEgY15FfwsO+wwN+9uT42qak=; b=igiEY8Bb8kRddFmq0fDyPI/AskDDrNVuOfiJtav+tgxSlOmQ5osNJkmQi9lMHLwgaazP7Y CQVMD3zIfqTRteOBDhrE72vn1mZ1fYeQJP+aLsmm8RLX4Jf/IUbrvnZ0O1gqMIHCk+DhiK 7MKAnsLZrcLO3uOc0ef87OI/LijKneg= 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-298-GvTqAB9lMauck_M8KHLNIg-1; Tue, 04 Jun 2024 09:53:01 -0400 X-MC-Unique: GvTqAB9lMauck_M8KHLNIg-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.rdu2.redhat.com [10.11.54.6]) (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 D423B85A5B6; Tue, 4 Jun 2024 13:53:00 +0000 (UTC) Received: from localhost (unknown [10.72.116.9]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 9C0212166B35; Tue, 4 Jun 2024 13:52:59 +0000 (UTC) Date: Tue, 4 Jun 2024 21:52:56 +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 v4 4/7] crash_dump: reuse saved dm crypt keys for CPU/memory hot-plugging Message-ID: References: <20240523050451.788754-1-coxu@redhat.com> <20240523050451.788754-5-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: <20240523050451.788754-5-coxu@redhat.com> X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.6 On 05/23/24 at 01:04pm, 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. I am confused, what is the new infrastructure? And why this patch can be dropped if 'the new infrastructure' is extended to all arches. > > 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 89fec768fba8..b4dc881cc867 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"}; > static 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(); > + > + 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; Is the logic here wrong? Isn't it we return when it's REUSE. If not REUSE, we need build_keys_header(), then add buffer? > + } > > kbuf.buffer = keys_header; > kbuf.bufsz = keys_header_size; > -- > 2.45.0 >