From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: ARC-Seal: i=1; a=rsa-sha256; t=1520604142; cv=none; d=google.com; s=arc-20160816; b=KFzLCOfy3DzeGfc18WoEbaoz1Cj5YQQji7Un7DIyUAyr6D9uwocsFUToxv9Y7LkFIs UydLc9CKhMXWO8R7xv5fDJNUceqGyCjyPyH5hEN1/1mye7304ZhOxWotNe7G5RLxyOw+ Luu84W5sW5vu04/lTmTRNHkoawRHEkHqA3urLKICl0ynjOECMtGyyzEMPurcvg2oC8z0 HWI0qlvn3IDPsPZRNOPLoA/krae0MlKJIgnBakV3DBUWVE4yvUepvHTm6kJCEmbEv8An gkVVEWa7juFlGfAr4PrnxII78u+32Qup3cfGQvoi0Z8JiGzlFrp1I+gBiZB9RDaJjqMz IdoQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=references:in-reply-to:references:in-reply-to:message-id:date :subject:cc:to:from:dkim-signature:arc-authentication-results; bh=bFC+dOL1kofLW/Fz0q3F9Mambpm3ECJQAGpTBpsRBqY=; b=Sn7zWiTD/4GisjeJleW8Nh6JqUE1AJTc2dPUZZdlQ7IJnGI4hIy7DvUtRqjm0WPMgY AeNt6zKnR27KmvDBXOPRvM4g4HFZgBD2Dlf3c+pIQ+xiRojkLp1QKffsMdUj4W2LoMl5 jekgGGjbnZIr5hkUPWrlZQVaYdAlJGLd5HpUTkEuCxEXnFOCBpJParPVP3x4gb6gr2mL DizFJKlm8KoLHIQyH4miXlfXlr5F9KErCKUciruROHoOPo3Pd0I/JzsGuEIv6DmGW1Ej YTiwwBUjHSx8MFvbgrSIMwQvQzEkKZ8S60x8BZ1221KlfP0RHH73h6vj8RiC9SGHkh6+ D0zg== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@google.com header.s=20161025 header.b=KlhatkzH; spf=pass (google.com: domain of andreyknvl@google.com designates 209.85.220.65 as permitted sender) smtp.mailfrom=andreyknvl@google.com; dmarc=pass (p=REJECT sp=REJECT dis=NONE) header.from=google.com Authentication-Results: mx.google.com; dkim=pass header.i=@google.com header.s=20161025 header.b=KlhatkzH; spf=pass (google.com: domain of andreyknvl@google.com designates 209.85.220.65 as permitted sender) smtp.mailfrom=andreyknvl@google.com; dmarc=pass (p=REJECT sp=REJECT dis=NONE) header.from=google.com X-Google-Smtp-Source: AG47ELur63iUzTcj/SxULK7/n9/IiOYomFoFueFSfoU9XvqGgqC5/NqRiMXXZBMSOAU5srV8yEvX2w== From: Andrey Konovalov To: Catalin Marinas , Will Deacon , Mark Rutland , Robin Murphy , Al Viro , Philippe Ombredanne , Greg Kroah-Hartman , Thomas Gleixner , Kate Stewart , Andrew Morton , "Kirill A . Shutemov" , Ingo Molnar , "Aneesh Kumar K . V" , Minchan Kim , Michal Hocko , Shaohua Li , Andrea Arcangeli , Anshuman Khandual , Mike Rapoport , Vlastimil Babka , Naoya Horiguchi , Shakeel Butt , Joonsoo Kim , Hugh Dickins , Mel Gorman , =?UTF-8?q?J=C3=A9r=C3=B4me=20Glisse?= , Mike Kravetz , Zi Yan , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, Richard Henderson , Ivan Kokshaysky , Matt Turner , Vineet Gupta , Russell King , Mark Salter , Aurelien Jacquiot , Mikael Starvik , Jesper Nilsson , Tony Luck , Fenghua Yu , Geert Uytterhoeven , James Hogan , Michal Simek , Ralf Baechle , David Howells , Ley Foon Tan , Jonas Bonn , Stefan Kristiansson , Stafford Horne , "James E . J . Bottomley" , Helge Deller , Benjamin Herrenschmidt , Paul Mackerras , Michael Ellerman , Palmer Dabbelt , Albert Ou , Chen Liqin , Lennox Wu , Yoshinori Sato , Rich Felker , "David S . Miller" , Ingo Molnar , x86@kernel.org, Chris Zankel , Max Filippov , Arnd Bergmann , linux-alpha@vger.kernel.org, linux-snps-arc@lists.infradead.org, adi-buildroot-devel@lists.sourceforge.net, linux-c6x-dev@linux-c6x.org, linux-cris-kernel@axis.com, linux-ia64@vger.kernel.org, linux-m68k@lists.linux-m68k.org, linux-metag@vger.kernel.org, linux-mips@linux-mips.org, linux-am33-list@redhat.com, nios2-dev@lists.rocketboards.org, openrisc@lists.librecores.org, linux-parisc@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-riscv@lists.infradead.org, linux-sh@vger.kernel.org, sparclinux@vger.kernel.org, linux-xtensa@linux-xtensa.org, linux-arch@vger.kernel.org Cc: Dmitry Vyukov , Kostya Serebryany , Evgeniy Stepanov , Lee Smith , Ramana Radhakrishnan , Jacob Bramley , Ruben Ayrapetyan , Andrey Konovalov Subject: [RFC PATCH 4/6] mm, arm64: untag user addresses in mm/gup.c Date: Fri, 9 Mar 2018 15:02:02 +0100 Message-Id: X-Mailer: git-send-email 2.16.2.395.g2e18187dfd-goog In-Reply-To: References: In-Reply-To: References: X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-THRID: =?utf-8?q?1594469008964660820?= X-GMAIL-MSGID: =?utf-8?q?1594469008964660820?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: 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 1b46e6e74881..4d820c4792d7 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); @@ -1746,6 +1754,8 @@ 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; @@ -1798,6 +1808,8 @@ 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; -- 2.16.2.395.g2e18187dfd-goog