From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-11.5 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,NICE_REPLY_A, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id CC953C35257 for ; Fri, 2 Oct 2020 15:58:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 91234206FA for ; Fri, 2 Oct 2020 15:58:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388111AbgJBP6T (ORCPT ); Fri, 2 Oct 2020 11:58:19 -0400 Received: from mga12.intel.com ([192.55.52.136]:3614 "EHLO mga12.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726017AbgJBP6T (ORCPT ); Fri, 2 Oct 2020 11:58:19 -0400 IronPort-SDR: 1DFwx49py7rA88vLihJtYVFF5EPGV2+2smjlW8PBnOdYYBAa2B4igq/Ct83wI5zI7GCE+hqSxm b+802xx1DxgQ== X-IronPort-AV: E=McAfee;i="6000,8403,9762"; a="142406480" X-IronPort-AV: E=Sophos;i="5.77,328,1596524400"; d="scan'208";a="142406480" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga008.fm.intel.com ([10.253.24.58]) by fmsmga106.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 02 Oct 2020 08:58:17 -0700 IronPort-SDR: UIER8ztpir42d+P/skPtUqpAth+NDcVX4em72Mfu0y5X2uWzRo8um/fUiNf+rZfjUGFriSSsaT qxiCFOSZqR+w== X-IronPort-AV: E=Sophos;i="5.77,328,1596524400"; d="scan'208";a="295390005" Received: from yyu32-mobl1.amr.corp.intel.com (HELO [10.212.143.131]) ([10.212.143.131]) by fmsmga008-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 02 Oct 2020 08:58:15 -0700 Subject: Re: [PATCH v13 19/26] mm: Re-introduce do_mmap_pgoff() To: Peter Collingbourne Cc: x86@kernel.org, "H. Peter Anvin" , Thomas Gleixner , Ingo Molnar , Linux Kernel Mailing List , 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 , Borislav Petkov , 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 , Dave Martin , Weijiang Yang , Pengfei Xu , Andrew Morton References: <20200925145649.5438-1-yu-cheng.yu@intel.com> <20200925145649.5438-20-yu-cheng.yu@intel.com> From: "Yu, Yu-cheng" Message-ID: <00a409f0-1e2e-0bd7-83e7-f21a47878916@intel.com> Date: Fri, 2 Oct 2020 08:58:14 -0700 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:68.0) Gecko/20100101 Thunderbird/68.12.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 10/1/2020 7:06 PM, Peter Collingbourne wrote: > On Fri, Sep 25, 2020 at 7:57 AM Yu-cheng Yu wrote: >> >> There was no more caller passing vm_flags to do_mmap(), and vm_flags was >> removed from the function's input by: >> >> commit 45e55300f114 ("mm: remove unnecessary wrapper function do_mmap_pgoff()"). >> >> There is a new user now. Shadow stack allocation passes VM_SHSTK to >> do_mmap(). Re-introduce the vm_flags and do_mmap_pgoff(). > > I would prefer to change the callers to pass the additional 0 argument > instead of bringing the wrapper function back, but if we're going to > bring it back then we should fix the naming (both functions take a > pgoff argument, so the previous name do_mmap_pgoff() was just plain > confusing). > > Peter > Thanks for your feedback. Here is the updated patch. I will re-send the whole series later. Yu-cheng ====== From 6a9f1e6bcdb6e599a44d5f58cf4cebd28c4634a2 Mon Sep 17 00:00:00 2001 From: Yu-cheng Yu Date: Wed, 12 Aug 2020 14:01:58 -0700 Subject: [PATCH 19/26] mm: Re-introduce do_mmap_pgoff() There was no more caller passing vm_flags to do_mmap(), and vm_flags was removed from the function's input by: commit 45e55300f114 ("mm: remove unnecessary wrapper function do_mmap_pgoff()"). There is a new user now. Shadow stack allocation passes VM_SHSTK to do_mmap(). Re-introduce vm_flags to do_mmap(), but without the old wrapper do_mmap_pgoff(). Instead, fix all callers of the wrapper by passing a zero vm_flags to do_mmap(). Signed-off-by: Yu-cheng Yu Cc: Peter Collingbourne Cc: Andrew Morton Cc: Oleg Nesterov Cc: linux-mm@kvack.org --- fs/aio.c | 2 +- include/linux/mm.h | 3 ++- ipc/shm.c | 2 +- mm/mmap.c | 10 +++++----- mm/nommu.c | 4 ++-- mm/util.c | 2 +- 6 files changed, 12 insertions(+), 11 deletions(-) diff --git a/fs/aio.c b/fs/aio.c index d5ec30385566..ca8c11665eea 100644 --- a/fs/aio.c +++ b/fs/aio.c @@ -527,7 +527,7 @@ static int aio_setup_ring(struct kioctx *ctx, unsigned int nr_events) ctx->mmap_base = do_mmap(ctx->aio_ring_file, 0, ctx->mmap_size, PROT_READ | PROT_WRITE, - MAP_SHARED, 0, &unused, NULL); + MAP_SHARED, 0, 0, &unused, NULL); mmap_write_unlock(mm); if (IS_ERR((void *)ctx->mmap_base)) { ctx->mmap_size = 0; diff --git a/include/linux/mm.h b/include/linux/mm.h index e09d13699bbe..e020eea33138 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -2560,7 +2560,8 @@ extern unsigned long mmap_region(struct file *file, unsigned long addr, struct list_head *uf); extern unsigned long do_mmap(struct file *file, unsigned long addr, unsigned long len, unsigned long prot, unsigned long flags, - unsigned long pgoff, unsigned long *populate, struct list_head *uf); + vm_flags_t vm_flags, unsigned long pgoff, unsigned long *populate, + struct list_head *uf); extern int __do_munmap(struct mm_struct *, unsigned long, size_t, struct list_head *uf, bool downgrade); extern int do_munmap(struct mm_struct *, unsigned long, size_t, diff --git a/ipc/shm.c b/ipc/shm.c index e25c7c6106bc..91474258933d 100644 --- a/ipc/shm.c +++ b/ipc/shm.c @@ -1556,7 +1556,7 @@ long do_shmat(int shmid, char __user *shmaddr, int shmflg, goto invalid; } - addr = do_mmap(file, addr, size, prot, flags, 0, &populate, NULL); + addr = do_mmap(file, addr, size, prot, flags, 0, 0, &populate, NULL); *raddr = addr; err = 0; if (IS_ERR_VALUE(addr)) diff --git a/mm/mmap.c b/mm/mmap.c index 574b3f273462..fc04184d2eae 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -1365,11 +1365,11 @@ static inline bool file_mmap_ok(struct file *file, struct inode *inode, */ unsigned long do_mmap(struct file *file, unsigned long addr, unsigned long len, unsigned long prot, - unsigned long flags, unsigned long pgoff, - unsigned long *populate, struct list_head *uf) + unsigned long flags, vm_flags_t vm_flags, + unsigned long pgoff, unsigned long *populate, + struct list_head *uf) { struct mm_struct *mm = current->mm; - vm_flags_t vm_flags; int pkey = 0; *populate = 0; @@ -1431,7 +1431,7 @@ unsigned long do_mmap(struct file *file, unsigned long addr, * to. we assume access permissions have been handled by the open * of the memory object, so we don't do any here. */ - vm_flags = calc_vm_prot_bits(prot, pkey) | calc_vm_flag_bits(flags) | + vm_flags |= calc_vm_prot_bits(prot, pkey) | calc_vm_flag_bits(flags) | mm->def_flags | VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC; if (flags & MAP_LOCKED) @@ -3007,7 +3007,7 @@ SYSCALL_DEFINE5(remap_file_pages, unsigned long, start, unsigned long, size, file = get_file(vma->vm_file); ret = do_mmap(vma->vm_file, start, size, - prot, flags, pgoff, &populate, NULL); + prot, flags, 0, pgoff, &populate, NULL); fput(file); out: mmap_write_unlock(mm); diff --git a/mm/nommu.c b/mm/nommu.c index 75a327149af1..f67d6bcdfc9f 100644 --- a/mm/nommu.c +++ b/mm/nommu.c @@ -1078,6 +1078,7 @@ unsigned long do_mmap(struct file *file, unsigned long len, unsigned long prot, unsigned long flags, + vm_flags_t vm_flags, unsigned long pgoff, unsigned long *populate, struct list_head *uf) @@ -1085,7 +1086,6 @@ unsigned long do_mmap(struct file *file, struct vm_area_struct *vma; struct vm_region *region; struct rb_node *rb; - vm_flags_t vm_flags; unsigned long capabilities, result; int ret; @@ -1104,7 +1104,7 @@ unsigned long do_mmap(struct file *file, /* we've determined that we can make the mapping, now translate what we * now know into VMA flags */ - vm_flags = determine_vm_flags(file, prot, flags, capabilities); + vm_flags |= determine_vm_flags(file, prot, flags, capabilities); /* we're going to need to record the mapping */ region = kmem_cache_zalloc(vm_region_jar, GFP_KERNEL); diff --git a/mm/util.c b/mm/util.c index 5ef378a2a038..beb8b881c080 100644 --- a/mm/util.c +++ b/mm/util.c @@ -503,7 +503,7 @@ unsigned long vm_mmap_pgoff(struct file *file, unsigned long addr, if (!ret) { if (mmap_write_lock_killable(mm)) return -EINTR; - ret = do_mmap(file, addr, len, prot, flag, pgoff, &populate, + ret = do_mmap(file, addr, len, prot, flag, 0, pgoff, &populate, &uf); mmap_write_unlock(mm); userfaultfd_unmap_complete(mm, &uf); -- 2.21.0