From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf1-f199.google.com (mail-pf1-f199.google.com [209.85.210.199]) by kanga.kvack.org (Postfix) with ESMTP id 3BDE06B1CB2 for ; Mon, 19 Nov 2018 16:54:59 -0500 (EST) Received: by mail-pf1-f199.google.com with SMTP id s14so4876845pfk.16 for ; Mon, 19 Nov 2018 13:54:59 -0800 (PST) Received: from mga11.intel.com (mga11.intel.com. [192.55.52.93]) by mx.google.com with ESMTPS id s8si4586261plq.345.2018.11.19.13.54.58 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 19 Nov 2018 13:54:58 -0800 (PST) From: Yu-cheng Yu Subject: [RFC PATCH v6 04/11] mm/mmap: Add IBT bitmap size to address space limit check Date: Mon, 19 Nov 2018 13:49:27 -0800 Message-Id: <20181119214934.6174-5-yu-cheng.yu@intel.com> In-Reply-To: <20181119214934.6174-1-yu-cheng.yu@intel.com> References: <20181119214934.6174-1-yu-cheng.yu@intel.com> Sender: owner-linux-mm@kvack.org List-ID: 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 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 | 10 ++++++++++ mm/mmap.c | 19 ++++++++++++++++++- 2 files changed, 28 insertions(+), 1 deletion(-) diff --git a/arch/x86/include/asm/mmu_context.h b/arch/x86/include/asm/mmu_context.h index 57c1f6c42bef..97a101267dd5 100644 --- a/arch/x86/include/asm/mmu_context.h +++ b/arch/x86/include/asm/mmu_context.h @@ -341,4 +341,14 @@ 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) +{ + if (current->thread.cet.ibt_enabled) + return current->thread.cet.ibt_bitmap_size; + else + return 0; +} +#endif + #endif /* _ASM_X86_MMU_CONTEXT_H */ diff --git a/mm/mmap.c b/mm/mmap.c index 9560d69fa08c..3de023f3e565 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -3283,13 +3283,30 @@ struct vm_area_struct *copy_vma(struct vm_area_struct **vmap, return NULL; } +#ifndef CONFIG_ARCH_HAS_AS_LIMIT +static inline unsigned long 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