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 E89CA1CF8B for ; Fri, 18 Apr 2025 04:37:00 +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=1744951022; cv=none; b=o4Ph/Tfa8UmHigr/+vgoDoJvsAxhuMiLIACwXvD1LZWx34f2mSxTDmxvq7k859dRON3QrDmnqUGsb1G+6BRVsatENVh3khiMnwJIy/YH7XFYTdLdRDp2J6ksidbEVcLCRddwBp9+aXootVEwMFi7rQ4TZUP+SJYA5RlSc0iwC7U= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744951022; c=relaxed/simple; bh=hWlkTaA4ioMW1UIH7YWVCFR0z6HkDhnLtYuqDWJKnSk=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=A4AlV1hiCJs0xrpTX3d+vpsDKZD3ls/2R74TYnzGIHDlKcjIRJsZAsORv1SXEaOrjUxUSnLiE752Af8A1lwniteLoW9t0rl2d+do69fW1n/PoNmr1HObN6bBTPdj1NZ5hOkcEFCMAP7AP5LT0tOVVN9ThmAK64HpF4HzACygJs0= 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=Dvc3G21B; arc=none smtp.client-ip=170.10.129.124 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="Dvc3G21B" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1744951019; 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=r4z2rRRUuOwywXorABV6PjT0ToaPZLx/d2Fez8DE9Oc=; b=Dvc3G21Bbz4FNVjG3TDyowB1qg1/TaZ2ba8BpYkVRstfgPv5h84RCbD0vRlDkTJGZEiHMr O4iql/Nw2U6LXv/Aj0iEryojq2qydifNGcmPJKlHqdqLFXu5ciFggQScqVRHPWAmsqfRJf mZzj7vm5IXeyvycjBjqJHJP774NvJnU= Received: from mx-prod-mc-04.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-359-BAv6iW8rOyy94eXYbPoNlw-1; Fri, 18 Apr 2025 00:36:58 -0400 X-MC-Unique: BAv6iW8rOyy94eXYbPoNlw-1 X-Mimecast-MFC-AGG-ID: BAv6iW8rOyy94eXYbPoNlw_1744951016 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-04.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 4CDFA1956048; Fri, 18 Apr 2025 04:36:55 +0000 (UTC) Received: from localhost (unknown [10.72.112.106]) by mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id D250119560A3; Fri, 18 Apr 2025 04:36:52 +0000 (UTC) Date: Fri, 18 Apr 2025 12:36:48 +0800 From: Baoquan He To: steven chen Cc: zohar@linux.ibm.com, stefanb@linux.ibm.com, roberto.sassu@huaweicloud.com, roberto.sassu@huawei.com, eric.snowberg@oracle.com, ebiederm@xmission.com, paul@paul-moore.com, code@tyhicks.com, bauermann@kolabnow.com, linux-integrity@vger.kernel.org, kexec@lists.infradead.org, linux-security-module@vger.kernel.org, linux-kernel@vger.kernel.org, madvenka@linux.microsoft.com, nramas@linux.microsoft.com, James.Bottomley@hansenpartnership.com, vgoyal@redhat.com, dyoung@redhat.com Subject: Re: [PATCH v12 3/9] kexec: define functions to map and unmap segments Message-ID: References: <20250416021028.1403-1-chenste@linux.microsoft.com> <20250416021028.1403-4-chenste@linux.microsoft.com> Precedence: bulk X-Mailing-List: linux-security-module@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: <20250416021028.1403-4-chenste@linux.microsoft.com> X-Scanned-By: MIMEDefang 3.0 on 10.30.177.17 On 04/15/25 at 07:10pm, steven chen wrote: > From: Steven Chen ^^^^^^ > > Implement kimage_map_segment() to enable IMA to map the measurement log > list to the kimage structure during the kexec 'load' stage. This function > gathers the source pages within the specified address range, and maps them > to a contiguous virtual address range. > > This is a preparation for later usage. > > Implement kimage_unmap_segment() for unmapping segments using vunmap(). > > From: Tushar Sugandhi ^^^^^^ > Signed-off-by: Tushar Sugandhi ^^^^^^^ > Cc: Eric Biederman > Cc: Baoquan He > Cc: Vivek Goyal > Cc: Dave Young > Signed-off-by: steven chen ^^^^^ The signing on this patch is a little confusing. I can't see who is the real author, who is the co-author, between you and Tushar. You may need to refer to Documentation/process/5.Posting.rst to make that clear. > Acked-by: Baoquan He > --- > include/linux/kexec.h | 6 +++++ > kernel/kexec_core.c | 54 +++++++++++++++++++++++++++++++++++++++++++ > 2 files changed, 60 insertions(+) > > diff --git a/include/linux/kexec.h b/include/linux/kexec.h > index f0e9f8eda7a3..7d6b12f8b8d0 100644 > --- a/include/linux/kexec.h > +++ b/include/linux/kexec.h > @@ -467,13 +467,19 @@ extern bool kexec_file_dbg_print; > #define kexec_dprintk(fmt, arg...) \ > do { if (kexec_file_dbg_print) pr_info(fmt, ##arg); } while (0) > > +extern void *kimage_map_segment(struct kimage *image, unsigned long addr, unsigned long size); > +extern void kimage_unmap_segment(void *buffer); > #else /* !CONFIG_KEXEC_CORE */ > struct pt_regs; > struct task_struct; > +struct kimage; > static inline void __crash_kexec(struct pt_regs *regs) { } > static inline void crash_kexec(struct pt_regs *regs) { } > static inline int kexec_should_crash(struct task_struct *p) { return 0; } > static inline int kexec_crash_loaded(void) { return 0; } > +static inline void *kimage_map_segment(struct kimage *image, unsigned long addr, unsigned long size) > +{ return NULL; } > +static inline void kimage_unmap_segment(void *buffer) { } > #define kexec_in_progress false > #endif /* CONFIG_KEXEC_CORE */ > > diff --git a/kernel/kexec_core.c b/kernel/kexec_core.c > index c0bdc1686154..a5e378e1dc7f 100644 > --- a/kernel/kexec_core.c > +++ b/kernel/kexec_core.c > @@ -867,6 +867,60 @@ int kimage_load_segment(struct kimage *image, > return result; > } > > +void *kimage_map_segment(struct kimage *image, > + unsigned long addr, unsigned long size) > +{ > + unsigned long src_page_addr, dest_page_addr = 0; > + unsigned long eaddr = addr + size; > + kimage_entry_t *ptr, entry; > + struct page **src_pages; > + unsigned int npages; > + void *vaddr = NULL; > + int i; > + > + /* > + * Collect the source pages and map them in a contiguous VA range. > + */ > + npages = PFN_UP(eaddr) - PFN_DOWN(addr); > + src_pages = kmalloc_array(npages, sizeof(*src_pages), GFP_KERNEL); > + if (!src_pages) { > + pr_err("Could not allocate ima pages array.\n"); > + return NULL; > + } > + > + i = 0; > + for_each_kimage_entry(image, ptr, entry) { > + if (entry & IND_DESTINATION) { > + dest_page_addr = entry & PAGE_MASK; > + } else if (entry & IND_SOURCE) { > + if (dest_page_addr >= addr && dest_page_addr < eaddr) { > + src_page_addr = entry & PAGE_MASK; > + src_pages[i++] = > + virt_to_page(__va(src_page_addr)); > + if (i == npages) > + break; > + dest_page_addr += PAGE_SIZE; > + } > + } > + } > + > + /* Sanity check. */ > + WARN_ON(i < npages); > + > + vaddr = vmap(src_pages, npages, VM_MAP, PAGE_KERNEL); > + kfree(src_pages); > + > + if (!vaddr) > + pr_err("Could not map ima buffer.\n"); > + > + return vaddr; > +} > + > +void kimage_unmap_segment(void *segment_buffer) > +{ > + vunmap(segment_buffer); > +} > + > struct kexec_load_limit { > /* Mutex protects the limit count. */ > struct mutex mutex; > -- > 2.43.0 >