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 211578834 for ; Thu, 6 Nov 2025 03:22:08 +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=1762399331; cv=none; b=MrlsiIfbO42fpByeCvxHtcVEnrCqOLd88JC7HCwuhnsrYBwj3kMkcvKYgQoQYBlgIYCLh5l6FmFyNl5YYDhaDpYJLr4eoU7qY357qQcWOtekNYMTKdKdElr4G4mdDjHtfX9sMBSlrVIwqS0cNt1NawlpfhMxieZ7UyYh3w5rUHk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1762399331; c=relaxed/simple; bh=O38N4sUk/AEMivEXYB5Em6LMlITJb1yd9CiGqmV9h2A=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=nqovW8lAzZxACKjhsdNSm10gAwWtG/Fh2CPCsbyT9p83UTQjkKgOGeOVJBjoi84FMrzV/Itkuh4SaSJzp59V4kJEWHagHLiAuCeMF0SoH0Q1ToXAA40oh8Qoz4miziPSJshFrxFC4c6MyVJztQYSgCbwI7RoiwEzFOQOvBWwP1M= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine 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=gLsFEy5n; arc=none smtp.client-ip=170.10.133.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine 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="gLsFEy5n" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1762399328; 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: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=+rv33evyCdtZ/WOHyRrPfVlUnSklHK0ydY8JP6rULH8=; b=gLsFEy5nExj6zbWRgGCL0LjDPGAMORivV0JkmdLED32WTAze7zRSdeI7WJiAXfzN8Gxtmq GC7yOLruGItMGwANze8MKpCDffUcwUpSTVs00OMhJ+yS1BzdeEI7wI9DuX6XkrgX5chmek HayXuoncEbhaAPf5v337zd2wO23Aymw= Received: from mx-prod-mc-03.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-578-8TnxEnnfP1ut28_PEjFtyg-1; Wed, 05 Nov 2025 22:22:03 -0500 X-MC-Unique: 8TnxEnnfP1ut28_PEjFtyg-1 X-Mimecast-MFC-AGG-ID: 8TnxEnnfP1ut28_PEjFtyg_1762399322 Received: from mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.17]) (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 mx-prod-mc-03.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 44AC919560B2; Thu, 6 Nov 2025 03:22:01 +0000 (UTC) Received: from localhost (unknown [10.72.112.190]) by mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id E67DA1956095; Thu, 6 Nov 2025 03:21:58 +0000 (UTC) Date: Thu, 6 Nov 2025 11:21:54 +0800 From: Baoquan He To: Pingfan Liu Cc: kexec@lists.infradead.org, linux-integrity@vger.kernel.org, Andrew Morton , Mimi Zohar , Roberto Sassu , Alexander Graf , Steven Chen Subject: Re: [PATCH 2/2] kernel/kexec: Fix IMA when allocation happens in CMA area Message-ID: References: <20251105130922.13321-1-piliu@redhat.com> <20251105130922.13321-2-piliu@redhat.com> Precedence: bulk X-Mailing-List: linux-integrity@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: X-Scanned-By: MIMEDefang 3.0 on 10.30.177.17 On 11/06/25 at 10:33am, Pingfan Liu wrote: > Hi Baoquan, > > Thanks for your review. Please see the comment below. > > On Thu, Nov 6, 2025 at 10:04 AM Baoquan He wrote: > > > > Hi Pingfan, > > > > On 11/05/25 at 09:09pm, Pingfan Liu wrote: > > > When I tested kexec with the latest kernel, I ran into the following warning: > > > > > > [ 40.712410] ------------[ cut here ]------------ > > > [ 40.712576] WARNING: CPU: 2 PID: 1562 at kernel/kexec_core.c:1001 kimage_map_segment+0x144/0x198 > > > [...] > > > [ 40.816047] Call trace: > > > [ 40.818498] kimage_map_segment+0x144/0x198 (P) > > > [ 40.823221] ima_kexec_post_load+0x58/0xc0 > > > [ 40.827246] __do_sys_kexec_file_load+0x29c/0x368 > > > [...] > > > [ 40.855423] ---[ end trace 0000000000000000 ]--- > > > > > > This is caused by the fact that kexec allocates the destination directly > > > in the CMA area. In that case, the CMA kernel address should be exported > > > directly to the IMA component, instead of using the vmalloc'd address. > > > > > > Signed-off-by: Pingfan Liu > > > Cc: Andrew Morton > > > Cc: Baoquan He > > > Cc: Alexander Graf > > > Cc: Steven Chen > > > Cc: linux-integrity@vger.kernel.org > > > To: kexec@lists.infradead.org > > > --- > > > kernel/kexec_core.c | 7 ++++++- > > > 1 file changed, 6 insertions(+), 1 deletion(-) > > > > > > diff --git a/kernel/kexec_core.c b/kernel/kexec_core.c > > > index 9a1966207041..abe40286a02c 100644 > > > --- a/kernel/kexec_core.c > > > +++ b/kernel/kexec_core.c > > > @@ -967,6 +967,7 @@ void *kimage_map_segment(struct kimage *image, int idx) > > > kimage_entry_t *ptr, entry; > > > struct page **src_pages; > > > unsigned int npages; > > > + struct page *cma; > > > void *vaddr = NULL; > > > int i; > > > > > > @@ -974,6 +975,9 @@ void *kimage_map_segment(struct kimage *image, int idx) > > > size = image->segment[idx].memsz; > > > eaddr = addr + size; > > > > > > + cma = image->segment_cma[idx]; > > > > Thanks for your fix. But I totally can't get what you are doing. The idx > > passed into kimage_map_segment() could index image->segment[], and can > > index image->segment_cma[], could you reconsider and make the code more > > reasonable? > > > > Since idx can index both image->segment[] and segment_cma[], the > behavior differs based on whether segment_cma[idx] is NULL: > > - If segment_cma[idx] is not NULL, it points directly to the final > target location, eliminating the need for data copying that > traditional kexec relocation requires. > - If segment_cma[idx] is NULL, the segment relies on the traditional > kexec relocation code to copy its data. I see, thanks. While image->segment_cma[idx] records the struct page of the relevant cma area, but not virtual address. Is it OK for IMA later to update? ima_kexec_buffer is supposed to be a virtual address, wondering how IMA behaved in this case.