From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wm0-f71.google.com (mail-wm0-f71.google.com [74.125.82.71]) by kanga.kvack.org (Postfix) with ESMTP id 9E1DA6B025E for ; Mon, 24 Oct 2016 05:57:29 -0400 (EDT) Received: by mail-wm0-f71.google.com with SMTP id b80so28287933wme.5 for ; Mon, 24 Oct 2016 02:57:29 -0700 (PDT) Received: from mail-wm0-x242.google.com (mail-wm0-x242.google.com. [2a00:1450:400c:c09::242]) by mx.google.com with ESMTPS id j15si11177483wmd.88.2016.10.24.02.57.28 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 24 Oct 2016 02:57:28 -0700 (PDT) Received: by mail-wm0-x242.google.com with SMTP id d128so8999809wmf.0 for ; Mon, 24 Oct 2016 02:57:28 -0700 (PDT) From: Lorenzo Stoakes Subject: [PATCH] mm: unexport __get_user_pages() Date: Mon, 24 Oct 2016 10:57:25 +0100 Message-Id: <20161024095725.17229-1-lstoakes@gmail.com> Sender: owner-linux-mm@kvack.org List-ID: To: linux-mm@kvack.org Cc: Linus Torvalds , Michal Hocko , Jan Kara , Hugh Dickins , Dave Hansen , Rik van Riel , Mel Gorman , Andrew Morton , Paolo Bonzini , =?UTF-8?q?Radim=20Kr=C4=8Dm=C3=A1=C5=99?= , kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Lorenzo Stoakes This patch unexports the low-level __get_user_pages() function. Recent refactoring of the get_user_pages* functions allow flags to be passed through get_user_pages() which eliminates the need for access to this function from its one user, kvm. We can see that the 2 calls to get_user_pages() which replace __get_user_pages() in kvm_main.c are equivalent by examining their call stacks: get_user_page_nowait(): get_user_pages(start, 1, flags, page, NULL) __get_user_pages_locked(current, current->mm, start, 1, page, NULL, NULL, false, flags | FOLL_TOUCH) __get_user_pages(current, current->mm, start, 1, flags | FOLL_TOUCH | FOLL_GET, page, NULL, NULL) check_user_page_hwpoison(): get_user_pages(addr, 1, flags, NULL, NULL) __get_user_pages_locked(current, current->mm, addr, 1, NULL, NULL, NULL, false, flags | FOLL_TOUCH) __get_user_pages(current, current->mm, addr, 1, flags | FOLL_TOUCH, NULL, NULL, NULL) Signed-off-by: Lorenzo Stoakes --- include/linux/mm.h | 4 ---- mm/gup.c | 3 +-- mm/nommu.c | 2 +- virt/kvm/kvm_main.c | 10 ++++------ 4 files changed, 6 insertions(+), 13 deletions(-) diff --git a/include/linux/mm.h b/include/linux/mm.h index 3a19185..a92c8d7 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -1271,10 +1271,6 @@ extern int access_process_vm(struct task_struct *tsk, unsigned long addr, void * extern int access_remote_vm(struct mm_struct *mm, unsigned long addr, void *buf, int len, unsigned int gup_flags); -long __get_user_pages(struct task_struct *tsk, struct mm_struct *mm, - unsigned long start, unsigned long nr_pages, - unsigned int foll_flags, struct page **pages, - struct vm_area_struct **vmas, int *nonblocking); long get_user_pages_remote(struct task_struct *tsk, struct mm_struct *mm, unsigned long start, unsigned long nr_pages, unsigned int gup_flags, struct page **pages, diff --git a/mm/gup.c b/mm/gup.c index 7aa113c..ec4f827 100644 --- a/mm/gup.c +++ b/mm/gup.c @@ -526,7 +526,7 @@ static int check_vma_flags(struct vm_area_struct *vma, unsigned long gup_flags) * instead of __get_user_pages. __get_user_pages should be used only if * you need some special @gup_flags. */ -long __get_user_pages(struct task_struct *tsk, struct mm_struct *mm, +static long __get_user_pages(struct task_struct *tsk, struct mm_struct *mm, unsigned long start, unsigned long nr_pages, unsigned int gup_flags, struct page **pages, struct vm_area_struct **vmas, int *nonblocking) @@ -631,7 +631,6 @@ long __get_user_pages(struct task_struct *tsk, struct mm_struct *mm, } while (nr_pages); return i; } -EXPORT_SYMBOL(__get_user_pages); bool vma_permits_fault(struct vm_area_struct *vma, unsigned int fault_flags) { diff --git a/mm/nommu.c b/mm/nommu.c index db5fd17..8b8faaf 100644 --- a/mm/nommu.c +++ b/mm/nommu.c @@ -109,7 +109,7 @@ unsigned int kobjsize(const void *objp) return PAGE_SIZE << compound_order(page); } -long __get_user_pages(struct task_struct *tsk, struct mm_struct *mm, +static long __get_user_pages(struct task_struct *tsk, struct mm_struct *mm, unsigned long start, unsigned long nr_pages, unsigned int foll_flags, struct page **pages, struct vm_area_struct **vmas, int *nonblocking) diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 28510e7..2907b7b 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -1346,21 +1346,19 @@ unsigned long kvm_vcpu_gfn_to_hva_prot(struct kvm_vcpu *vcpu, gfn_t gfn, bool *w static int get_user_page_nowait(unsigned long start, int write, struct page **page) { - int flags = FOLL_TOUCH | FOLL_NOWAIT | FOLL_HWPOISON | FOLL_GET; + int flags = FOLL_NOWAIT | FOLL_HWPOISON; if (write) flags |= FOLL_WRITE; - return __get_user_pages(current, current->mm, start, 1, flags, page, - NULL, NULL); + return get_user_pages(start, 1, flags, page, NULL); } static inline int check_user_page_hwpoison(unsigned long addr) { - int rc, flags = FOLL_TOUCH | FOLL_HWPOISON | FOLL_WRITE; + int rc, flags = FOLL_HWPOISON | FOLL_WRITE; - rc = __get_user_pages(current, current->mm, addr, 1, - flags, NULL, NULL, NULL); + rc = get_user_pages(addr, 1, flags, NULL, NULL); return rc == -EHWPOISON; } -- 2.10.1 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. 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