From mboxrd@z Thu Jan 1 00:00:00 1970 From: Catalin Marinas Subject: Re: [PATCH v15 05/17] arms64: untag user pointers passed to memory syscalls Date: Mon, 27 May 2019 15:37:20 +0100 Message-ID: <20190527143719.GA59948@MBP.local> References: <00eb4c63fefc054e2c8d626e8fedfca11d7c2600.1557160186.git.andreyknvl@google.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <00eb4c63fefc054e2c8d626e8fedfca11d7c2600.1557160186.git.andreyknvl@google.com> Sender: linux-kernel-owner@vger.kernel.org To: Andrey Konovalov Cc: linux-arm-kernel@lists.infradead.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, amd-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, linux-rdma@vger.kernel.org, linux-media@vger.kernel.org, kvm@vger.kernel.org, linux-kselftest@vger.kernel.org, Vincenzo Frascino , Will Deacon , Mark Rutland , Andrew Morton , Greg Kroah-Hartman , Kees Cook , Yishai Hadas , Felix Kuehling , Alexander Deucher , Christian Koenig , Mauro Carvalho Chehab , Jens Wiklander List-Id: linux-rdma@vger.kernel.org On Mon, May 06, 2019 at 06:30:51PM +0200, Andrey Konovalov wrote: > This patch is a part of a series that extends arm64 kernel ABI to allow to > pass tagged user pointers (with the top byte set to something else other > than 0x00) as syscall arguments. > > This patch allows tagged pointers to be passed to the following memory > syscalls: brk, get_mempolicy, madvise, mbind, mincore, mlock, mlock2, > mmap, mmap_pgoff, mprotect, mremap, msync, munlock, munmap, > remap_file_pages, shmat and shmdt. > > This is done by untagging pointers passed to these syscalls in the > prologues of their handlers. > > Signed-off-by: Andrey Konovalov Actually, I don't think any of these wrappers get called (have you tested this patch?). Following commit 4378a7d4be30 ("arm64: implement syscall wrappers"), I think we have other macro names for overriding the sys_* ones. -- Catalin