From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.1 (2015-04-28) on archive.lwn.net X-Spam-Level: X-Spam-Status: No, score=-5.8 required=5.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI autolearn=unavailable autolearn_force=no version=3.4.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by archive.lwn.net (Postfix) with ESMTP id 996447D088 for ; Thu, 11 Oct 2018 15:22:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728622AbeJKWtn (ORCPT ); Thu, 11 Oct 2018 18:49:43 -0400 Received: from mga17.intel.com ([192.55.52.151]:21581 "EHLO mga17.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727400AbeJKWtn (ORCPT ); Thu, 11 Oct 2018 18:49:43 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga007.fm.intel.com ([10.253.24.52]) by fmsmga107.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 11 Oct 2018 08:22:05 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.54,368,1534834800"; d="scan'208";a="77271627" Received: from 2b52.sc.intel.com ([143.183.136.147]) by fmsmga007.fm.intel.com with ESMTP; 11 Oct 2018 08:21:44 -0700 From: Yu-cheng Yu To: x86@kernel.org, "H. Peter Anvin" , Thomas Gleixner , Ingo Molnar , linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, linux-mm@kvack.org, linux-arch@vger.kernel.org, linux-api@vger.kernel.org, Arnd Bergmann , Andy Lutomirski , Balbir Singh , Cyrill Gorcunov , Dave Hansen , Eugene Syromiatnikov , Florian Weimer , "H.J. Lu" , Jann Horn , Jonathan Corbet , Kees Cook , Mike Kravetz , Nadav Amit , Oleg Nesterov , Pavel Machek , Peter Zijlstra , Randy Dunlap , "Ravi V. Shankar" , Vedvyas Shanbhogue Cc: Yu-cheng Yu Subject: [PATCH v5 04/11] mm/mmap: Add IBT bitmap size to address space limit check Date: Thu, 11 Oct 2018 08:16:47 -0700 Message-Id: <20181011151654.27221-5-yu-cheng.yu@intel.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20181011151654.27221-1-yu-cheng.yu@intel.com> References: <20181011151654.27221-1-yu-cheng.yu@intel.com> Sender: linux-doc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-doc@vger.kernel.org The indirect branch tracking legacy bitmap takes a large address space. This causes may_expand_vm() failure on the address limit check. For a IBT-enabled task, add the bitmap size to the address limit. Signed-off-by: Yu-cheng Yu --- arch/x86/include/asm/mmu_context.h | 7 +++++++ mm/mmap.c | 19 ++++++++++++++++++- 2 files changed, 25 insertions(+), 1 deletion(-) diff --git a/arch/x86/include/asm/mmu_context.h b/arch/x86/include/asm/mmu_context.h index 8da7c999b7ee..9c726171e5c5 100644 --- a/arch/x86/include/asm/mmu_context.h +++ b/arch/x86/include/asm/mmu_context.h @@ -341,4 +341,11 @@ static inline unsigned long __get_current_cr3_fast(void) return cr3; } +#ifdef CONFIG_X86_INTEL_BRANCH_TRACKING_USER +static inline unsigned long arch_as_limit(void) +{ + return current->thread.cet.ibt_bitmap_size; +} +#endif + #endif /* _ASM_X86_MMU_CONTEXT_H */ diff --git a/mm/mmap.c b/mm/mmap.c index fa581ced3f56..62b3045af005 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -3231,13 +3231,30 @@ struct vm_area_struct *copy_vma(struct vm_area_struct **vmap, return NULL; } +#ifndef CONFIG_ARCH_HAS_AS_LIMIT +static inline int arch_as_limit(void) +{ + return 0; +} +#endif + /* * Return true if the calling process may expand its vm space by the passed * number of pages */ bool may_expand_vm(struct mm_struct *mm, vm_flags_t flags, unsigned long npages) { - if (mm->total_vm + npages > rlimit(RLIMIT_AS) >> PAGE_SHIFT) + unsigned long as_limit = rlimit(RLIMIT_AS); + unsigned long as_limit_plus = as_limit + arch_as_limit(); + + /* as_limit_plus overflowed */ + if (as_limit_plus < as_limit) + as_limit_plus = RLIM_INFINITY; + + if (as_limit_plus > as_limit) + as_limit = as_limit_plus; + + if (mm->total_vm + npages > as_limit >> PAGE_SHIFT) return false; if (is_data_mapping(flags) && -- 2.17.1