From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from linux.microsoft.com (linux.microsoft.com [13.77.154.182]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 4C02B262A6; Sun, 20 Apr 2025 12:30:38 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=13.77.154.182 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1745152239; cv=none; b=ej4QO4NvnDU8CXiQYbBn4dTl3hD3/Ne7DJ1jD67TWWcY/KAD5UWEwhCPUAJJj/1ZCPGP/f8geXZESsQn9Z5nhMT0fU0YH9dNyeEpp9LTqE0E/yPPN4kQjIN9ComxfzR0PEE1M+v7pQuTB3dRDuLOekd4dTImgHsxgfVG8fpOxaA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1745152239; c=relaxed/simple; bh=5b5/FWnIrEzpCy0kn9VAxmzU7MFyxemO188s/rptvTI=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=kpoIazUldV5PlOIffrzJCILO42umcV/DSzBLul69zKEpbu5SPjU3D5FdL4r/Qgsu3sufbZGL8Qit3F6ny0CiE2rUYN8q7/jx//MKHOuMSwhrS1VFv6a6ZM70VqbVKon0e3YQzOfpz50hj/05GL4N7Hf7Lkt0IjJV274OGDtgHcU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.microsoft.com; spf=pass smtp.mailfrom=linux.microsoft.com; dkim=pass (1024-bit key) header.d=linux.microsoft.com header.i=@linux.microsoft.com header.b=V4Np+vMs; arc=none smtp.client-ip=13.77.154.182 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.microsoft.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.microsoft.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.microsoft.com header.i=@linux.microsoft.com header.b="V4Np+vMs" Received: from [100.70.200.26] (unknown [20.110.218.7]) by linux.microsoft.com (Postfix) with ESMTPSA id C47DB2052525; Sun, 20 Apr 2025 05:30:35 -0700 (PDT) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com C47DB2052525 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1745152237; bh=QfQcgycMxq4nFFdzo1bb4Mu23pE71kIy82/gI3Q5HR8=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=V4Np+vMsDXuWmgqdQ24dSBKB/bda0EoaXO8SXIxFdLnBzuuvLGiSX/cekoo3Hwt1o 1dztDlj5ZtHUC6mkUaJwEeOWc//MQYrhn1kmFDTtX0EDpakTFURgS0JngBVI+clV2A LBPBfKqpczgqlm1OR0izf5GVEK+quBc6jq6LbZEk= Message-ID: <95d249ef-bfb3-431f-b633-8b3de383e067@linux.microsoft.com> Date: Sun, 20 Apr 2025 05:30:33 -0700 Precedence: bulk X-Mailing-List: linux-security-module@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v12 3/9] kexec: define functions to map and unmap segments To: Baoquan He 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 References: <20250416021028.1403-1-chenste@linux.microsoft.com> <20250416021028.1403-4-chenste@linux.microsoft.com> Content-Language: en-US From: steven chen In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 4/17/2025 9:36 PM, Baoquan He wrote: > 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. Hi Baoquan, From my understanding, if there is no change from the original author patch, need to add From tag and Signed-off-by tag; otherwise, if there are changes, Signed-off-by can be used. Thanks, Steven >> 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 >>