From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrey Konovalov Subject: [PATCH 4/6] mm, arm64: untag user addresses in mm/gup.c Date: Wed, 18 Apr 2018 20:53:13 +0200 Message-ID: <0db34d04fa16be162336106e3b4a94f3dacc0af4.1524077494.git.andreyknvl__44781.9629022435$1524077514$gmane$org@google.com> References: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: In-Reply-To: References: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=m.gmane.org@lists.infradead.org To: Catalin Marinas , Will Deacon , Jonathan Corbet , Mark Rutland , Robin Murphy , Al Viro , Andrey Konovalov , James Morse , Kees Cook , Bart Van Assche , Kate Stewart , Greg Kroah-Hartman , Thomas Gleixner , Philippe Ombredanne , Andrew Morton , Ingo Molnar , "Kirill A . Shutemov" , Dan Williams , "Aneesh Kumar K . V" , Zi Yan , linux-arm-kernel@lists.infradead.org, linux-doc@vger.kernel.orglin Cc: Jacob Bramley , Ruben Ayrapetyan , Lee Smith , Kostya Serebryany , Dmitry Vyukov , Ramana Radhakrishnan , Evgeniy Stepanov List-Id: linux-mm.kvack.org mm/gup.c provides a kernel interface that accepts user addresses and manipulates user pages directly (for example get_user_pages, that is used by the futex syscall). Here we also need to handle the case of tagged user pointers. Untag addresses passed to this interface. Signed-off-by: Andrey Konovalov --- mm/gup.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/mm/gup.c b/mm/gup.c index 76af4cfeaf68..fb375de7d40d 100644 --- a/mm/gup.c +++ b/mm/gup.c @@ -386,6 +386,8 @@ struct page *follow_page_mask(struct vm_area_struct *vma, struct page *page; struct mm_struct *mm = vma->vm_mm; + address = untagged_addr(address); + *page_mask = 0; /* make this handle hugepd */ @@ -647,6 +649,8 @@ static long __get_user_pages(struct task_struct *tsk, struct mm_struct *mm, if (!nr_pages) return 0; + start = untagged_addr(start); + VM_BUG_ON(!!pages != !!(gup_flags & FOLL_GET)); /* @@ -801,6 +805,8 @@ int fixup_user_fault(struct task_struct *tsk, struct mm_struct *mm, struct vm_area_struct *vma; int ret, major = 0; + address = untagged_addr(address); + if (unlocked) fault_flags |= FAULT_FLAG_ALLOW_RETRY; @@ -854,6 +860,8 @@ static __always_inline long __get_user_pages_locked(struct task_struct *tsk, long ret, pages_done; bool lock_dropped; + start = untagged_addr(start); + if (locked) { /* if VM_FAULT_RETRY can be returned, vmas become invalid */ BUG_ON(vmas); @@ -1751,6 +1759,8 @@ int __get_user_pages_fast(unsigned long start, int nr_pages, int write, unsigned long flags; int nr = 0; + start = untagged_addr(start); + start &= PAGE_MASK; addr = start; len = (unsigned long) nr_pages << PAGE_SHIFT; @@ -1803,6 +1813,8 @@ int get_user_pages_fast(unsigned long start, int nr_pages, int write, unsigned long addr, len, end; int nr = 0, ret = 0; + start = untagged_addr(start); + start &= PAGE_MASK; addr = start; len = (unsigned long) nr_pages << PAGE_SHIFT; -- 2.17.0.484.g0c8726318c-goog