From patchwork Wed Apr 16 02:10:21 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: steven chen X-Patchwork-Id: 14053060 Received: from linux.microsoft.com (linux.microsoft.com [13.77.154.182]) by smtp.subspace.kernel.org (Postfix) with ESMTP id CF30E229B1C; Wed, 16 Apr 2025 02:10:53 +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=1744769455; cv=none; b=S6zGZ/pEkzW1d37/vlcUMePQaIDjwVWa2I2xkZnMZ41YQcKBKtolFy7HoSmOdsmFv8/aUtdIuQaAcfyOjVyxUspO7wcWzpE5Addv17LEB62Zaeef/+yP27STiv9j3/ZPeN9P2F/fMoXQdI7MP9Njq9y61aqgtP/y1IGRNUKvnJ4= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744769455; c=relaxed/simple; bh=s7yNaylfpj417bzOpQZJj0w5BgLsjb0ywL+Ge21zPu8=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=gPmLJ07SRweTHp4CoQHCeu0J2Mf/9fkaLbedHbc7HUuesPCEJMrM0Z95PdcjqI7VUtYKJ8/RdZVrFEVwxKnAubXaoAqYK7827RqBuffILXReR8Ry5f4JuFGI5DFSlQtiIkc+y21bKk8cCpF7OsV8upYzb/Gyw8Yz9Fol+yzIlec= 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=rFSktBV6; 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="rFSktBV6" Received: from DESKTOP-VOT081N.hsd1.ga.comcast.net (unknown [172.200.70.13]) by linux.microsoft.com (Postfix) with ESMTPSA id 32714210C456; Tue, 15 Apr 2025 19:10:51 -0700 (PDT) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com 32714210C456 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1744769453; bh=odGoNwFTPegS+X19thSA24g/8Sg4lmrdq6snuoq3sPk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=rFSktBV6yzINKqy/QkY3/2u9tIMMz2cXPwXfbftvIU3sDf76LjW8CNpE16USQDwvl ESjISl4k9/eR4B33F8yVOpmfW0o3o/jhDRoQgjmR1BwNn0kuNBnR7qFtJ4ILZDNZa+ 5haoeRyHTtbt8x12D4M1vIblIkg2+lrz6dX933d0= From: steven chen To: 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 Cc: madvenka@linux.microsoft.com, nramas@linux.microsoft.com, James.Bottomley@HansenPartnership.com, bhe@redhat.com, vgoyal@redhat.com, dyoung@redhat.com Subject: [PATCH v12 3/9] kexec: define functions to map and unmap segments Date: Tue, 15 Apr 2025 19:10:21 -0700 Message-ID: <20250416021028.1403-4-chenste@linux.microsoft.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20250416021028.1403-1-chenste@linux.microsoft.com> References: <20250416021028.1403-1-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 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 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;