From patchwork Mon Nov 7 22:02:10 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Haitao Huang X-Patchwork-Id: 13035351 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 471C7C43219 for ; Mon, 7 Nov 2022 22:02:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232564AbiKGWCX (ORCPT ); Mon, 7 Nov 2022 17:02:23 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44880 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232900AbiKGWCP (ORCPT ); Mon, 7 Nov 2022 17:02:15 -0500 Received: from mga11.intel.com (mga11.intel.com [192.55.52.93]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 90CE51117E for ; Mon, 7 Nov 2022 14:02:13 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1667858533; x=1699394533; h=from:to:subject:date:message-id:in-reply-to:references: mime-version:content-transfer-encoding; bh=+lRX+IOTZ0tF30rHW7Qkc+fzUL8nxG9qXboKVS9c/lo=; b=cxM0MhpoOWILBZqcN9zgHdm7Mw39iZI9ECGwZVEKDNMmAWT8zIptWRHW A1RNmBsiBYFk2BIxe4zsy/Ojbohot7qDCBKvctbtflMPnL6e6Mp/tSwjo yHERDk2jB6aKFlAYfs+fyCBZYfcOWLgRfnDFiPUuzvr/iJtfjnCJUwV7L AWwYZNYvbR0sI0vcM9dhllg8ZvqhmpgaosY9AzEnrwmsLICCNocDAwzRL y9/n5qhugUcue7kA1MzyO5CJa3gWY2kQcpznykp512CRgt5ZZZX+fBVXI iGEtlJy0xgB3NETzyPf1nqVGU1TfrAFCdPqY0eaY3Tfa9Wk40z4mY+28j A==; X-IronPort-AV: E=McAfee;i="6500,9779,10524"; a="308158026" X-IronPort-AV: E=Sophos;i="5.96,145,1665471600"; d="scan'208";a="308158026" Received: from orsmga007.jf.intel.com ([10.7.209.58]) by fmsmga102.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 07 Nov 2022 14:02:12 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6500,9779,10524"; a="630643324" X-IronPort-AV: E=Sophos;i="5.96,145,1665471600"; d="scan'208";a="630643324" Received: from b4969161e530.jf.intel.com ([10.165.56.46]) by orsmga007.jf.intel.com with ESMTP; 07 Nov 2022 14:02:12 -0800 From: Haitao Huang To: linux-sgx@vger.kernel.org, jarkko@kernel.org, dave.hansen@linux.intel.com, reinette.chatre@intel.com, vijay.dhanraj@intel.com Subject: [RFC PATCH v3 2/4] x86/sgx: Implement support for MADV_WILLNEED Date: Mon, 7 Nov 2022 14:02:10 -0800 Message-Id: <20221107220212.257422-3-haitao.huang@linux.intel.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20221107220212.257422-2-haitao.huang@linux.intel.com> References: <20221107220212.257422-1-haitao.huang@linux.intel.com> <20221107220212.257422-2-haitao.huang@linux.intel.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-sgx@vger.kernel.org Support madvise(..., MADV_WILLNEED) by adding EPC pages with EAUG in the newly added fops->fadvise() callback implementation, sgx_fadvise(). Change the return type and values of the sgx_encl_eaug_page function so that more specific error codes are returned for different treatment by the page fault handler and the fadvise callback. On any error, sgx_fadvise() will discontinue further operations and return as normal. The page fault handler allows a PF retried by returning VM_FAULT_NOPAGE in handling -EBUSY returned from sgx_encl_eaug_page. Signed-off-by: Haitao Huang --- arch/x86/kernel/cpu/sgx/driver.c | 76 ++++++++++++++++++++++++++++++++ arch/x86/kernel/cpu/sgx/encl.c | 46 ++++++++++++------- arch/x86/kernel/cpu/sgx/encl.h | 4 +- 3 files changed, 108 insertions(+), 18 deletions(-) diff --git a/arch/x86/kernel/cpu/sgx/driver.c b/arch/x86/kernel/cpu/sgx/driver.c index aa9b8b868867..dec2e9691ae3 100644 --- a/arch/x86/kernel/cpu/sgx/driver.c +++ b/arch/x86/kernel/cpu/sgx/driver.c @@ -2,6 +2,7 @@ /* Copyright(c) 2016-20 Intel Corporation. */ #include +#include #include #include #include @@ -9,6 +10,7 @@ #include #include "driver.h" #include "encl.h" +#include "encls.h" u64 sgx_attributes_reserved_mask; u64 sgx_xfrm_reserved_mask = ~0x3; @@ -97,10 +99,83 @@ static int sgx_mmap(struct file *file, struct vm_area_struct *vma) vma->vm_ops = &sgx_vm_ops; vma->vm_flags |= VM_PFNMAP | VM_DONTEXPAND | VM_DONTDUMP | VM_IO; vma->vm_private_data = encl; + vma->vm_pgoff = PFN_DOWN(vma->vm_start - encl->base); return 0; } +/* + * Add new pages to the enclave sequentially with ENCLS[EAUG] for the WILLNEED advice. + * Only do this to existing VMAs in the same enclave and reject the request otherwise. + */ +static int sgx_fadvise(struct file *file, loff_t offset, loff_t len, int advice) +{ + struct sgx_encl *encl = file->private_data; + struct vm_area_struct *vma = NULL; + unsigned long start, end, pos; + int ret = -EINVAL; + + /* Only support WILLNEED */ + if (advice != POSIX_FADV_WILLNEED) + return -EINVAL; + if (!encl) + return -EINVAL; + if (!cpu_feature_enabled(X86_FEATURE_SGX2)) + return -EINVAL; + + if (offset + len < offset) + return -EINVAL; + if (encl->base + offset < encl->base) + return -EINVAL; + start = offset + encl->base; + end = start + len; + if (end < start) + return -EINVAL; + if (end > encl->base + encl->size) + return -EINVAL; + + if (!test_bit(SGX_ENCL_INITIALIZED, &encl->flags)) + return -EINVAL; + + mmap_read_lock(current->mm); + + vma = find_vma(current->mm, start); + if (!vma) + goto unlock; + if (vma->vm_private_data != encl) + goto unlock; + + pos = start; + if (pos < vma->vm_start || end > vma->vm_end) { + /* Don't allow any gaps */ + goto unlock; + } + + /* Here: vm_start <= pos < end <= vm_end */ + while (pos < end) { + if (xa_load(&encl->page_array, PFN_DOWN(pos))) + continue; + if (signal_pending(current)) { + if (pos == start) + ret = -ERESTARTSYS; + else + ret = -EINTR; + goto unlock; + } + ret = sgx_encl_eaug_page(vma, encl, pos); + /* It's OK to not finish */ + if (ret) + break; + pos = pos + PAGE_SIZE; + cond_resched(); + } + ret = 0; + +unlock: + mmap_read_unlock(current->mm); + return ret; +} + static unsigned long sgx_get_unmapped_area(struct file *file, unsigned long addr, unsigned long len, @@ -133,6 +208,7 @@ static const struct file_operations sgx_encl_fops = { .compat_ioctl = sgx_compat_ioctl, #endif .mmap = sgx_mmap, + .fadvise = sgx_fadvise, .get_unmapped_area = sgx_get_unmapped_area, }; diff --git a/arch/x86/kernel/cpu/sgx/encl.c b/arch/x86/kernel/cpu/sgx/encl.c index 1abc5e7f2660..c57e60d5a0aa 100644 --- a/arch/x86/kernel/cpu/sgx/encl.c +++ b/arch/x86/kernel/cpu/sgx/encl.c @@ -305,11 +305,11 @@ struct sgx_encl_page *sgx_encl_load_page(struct sgx_encl *encl, * on a SGX2 system then the EPC can be added dynamically via the SGX2 * ENCLS[EAUG] instruction. * - * Returns: Appropriate vm_fault_t: VM_FAULT_NOPAGE when PTE was installed - * successfully, VM_FAULT_SIGBUS or VM_FAULT_OOM as error otherwise. + * Returns: 0 when PTE was installed successfully, -EBUSY for waiting on + * reclaimer to free EPC, -ENOMEM for out of RAM, -EFAULT as error otherwise. */ -vm_fault_t sgx_encl_eaug_page(struct vm_area_struct *vma, - struct sgx_encl *encl, unsigned long addr) +int sgx_encl_eaug_page(struct vm_area_struct *vma, + struct sgx_encl *encl, unsigned long addr) { vm_fault_t vmret = VM_FAULT_SIGBUS; struct sgx_pageinfo pginfo = {0}; @@ -318,10 +318,10 @@ vm_fault_t sgx_encl_eaug_page(struct vm_area_struct *vma, struct sgx_va_page *va_page; unsigned long phys_addr; u64 secinfo_flags; - int ret; + int ret = -EFAULT; if (!test_bit(SGX_ENCL_INITIALIZED, &encl->flags)) - return VM_FAULT_SIGBUS; + return -EFAULT; /* * Ignore internal permission checking for dynamically added pages. @@ -332,21 +332,21 @@ vm_fault_t sgx_encl_eaug_page(struct vm_area_struct *vma, secinfo_flags = SGX_SECINFO_R | SGX_SECINFO_W | SGX_SECINFO_X; encl_page = sgx_encl_page_alloc(encl, addr - encl->base, secinfo_flags); if (IS_ERR(encl_page)) - return VM_FAULT_OOM; + return -ENOMEM; mutex_lock(&encl->lock); epc_page = sgx_alloc_epc_page(encl_page, false); if (IS_ERR(epc_page)) { if (PTR_ERR(epc_page) == -EBUSY) - vmret = VM_FAULT_NOPAGE; + ret = -EBUSY; goto err_out_unlock; } va_page = sgx_encl_grow(encl, false); if (IS_ERR(va_page)) { if (PTR_ERR(va_page) == -EBUSY) - vmret = VM_FAULT_NOPAGE; + ret = -EBUSY; goto err_out_epc; } @@ -359,16 +359,20 @@ vm_fault_t sgx_encl_eaug_page(struct vm_area_struct *vma, * If ret == -EBUSY then page was created in another flow while * running without encl->lock */ - if (ret) + if (ret) { + ret = -EFAULT; goto err_out_shrink; + } pginfo.secs = (unsigned long)sgx_get_epc_virt_addr(encl->secs.epc_page); pginfo.addr = encl_page->desc & PAGE_MASK; pginfo.metadata = 0; ret = __eaug(&pginfo, sgx_get_epc_virt_addr(epc_page)); - if (ret) + if (ret) { + ret = -EFAULT; goto err_out; + } encl_page->encl = encl; encl_page->epc_page = epc_page; @@ -385,10 +389,10 @@ vm_fault_t sgx_encl_eaug_page(struct vm_area_struct *vma, vmret = vmf_insert_pfn(vma, addr, PFN_DOWN(phys_addr)); if (vmret != VM_FAULT_NOPAGE) { mutex_unlock(&encl->lock); - return VM_FAULT_SIGBUS; + return -EFAULT; } mutex_unlock(&encl->lock); - return VM_FAULT_NOPAGE; + return 0; err_out: xa_erase(&encl->page_array, PFN_DOWN(encl_page->desc)); @@ -401,7 +405,7 @@ vm_fault_t sgx_encl_eaug_page(struct vm_area_struct *vma, mutex_unlock(&encl->lock); kfree(encl_page); - return vmret; + return ret; } static vm_fault_t sgx_vma_fault(struct vm_fault *vmf) @@ -431,8 +435,18 @@ static vm_fault_t sgx_vma_fault(struct vm_fault *vmf) * enclave that will be checked for right away. */ if (cpu_feature_enabled(X86_FEATURE_SGX2) && - (!xa_load(&encl->page_array, PFN_DOWN(addr)))) - return sgx_encl_eaug_page(vma, encl, addr); + (!xa_load(&encl->page_array, PFN_DOWN(addr)))) { + switch (sgx_encl_eaug_page(vma, encl, addr)) { + case 0: + case -EBUSY: + return VM_FAULT_NOPAGE; + case -ENOMEM: + return VM_FAULT_OOM; + case -EFAULT: + default: + return VM_FAULT_SIGBUS; + } + } mutex_lock(&encl->lock); diff --git a/arch/x86/kernel/cpu/sgx/encl.h b/arch/x86/kernel/cpu/sgx/encl.h index 557d4abb13fc..5a351e2ece5e 100644 --- a/arch/x86/kernel/cpu/sgx/encl.h +++ b/arch/x86/kernel/cpu/sgx/encl.h @@ -127,7 +127,7 @@ struct sgx_encl_page *sgx_encl_load_page(struct sgx_encl *encl, unsigned long addr); struct sgx_va_page *sgx_encl_grow(struct sgx_encl *encl, bool reclaim); void sgx_encl_shrink(struct sgx_encl *encl, struct sgx_va_page *va_page); -vm_fault_t sgx_encl_eaug_page(struct vm_area_struct *vma, - struct sgx_encl *encl, unsigned long addr); +int sgx_encl_eaug_page(struct vm_area_struct *vma, + struct sgx_encl *encl, unsigned long addr); #endif /* _X86_ENCL_H */