From mboxrd@z Thu Jan 1 00:00:00 1970 From: Catalin Marinas Subject: Re: [PATCH 11/18] arm64: ilp32: share aarch32 syscall handlers Date: Mon, 5 Dec 2016 17:12:43 +0000 Message-ID: <20161205171242.GH14429@e104818-lin.cambridge.arm.com> References: <1477081997-4770-1-git-send-email-ynorov@caviumnetworks.com> <1477081997-4770-12-git-send-email-ynorov@caviumnetworks.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from foss.arm.com ([217.140.101.70]:50156 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751451AbcLERMu (ORCPT ); Mon, 5 Dec 2016 12:12:50 -0500 Content-Disposition: inline In-Reply-To: <1477081997-4770-12-git-send-email-ynorov@caviumnetworks.com> Sender: linux-arch-owner@vger.kernel.org List-ID: To: Yury Norov Cc: arnd@arndb.de, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, linux-arch@vger.kernel.org, szabolcs.nagy@arm.com, heiko.carstens@de.ibm.com, cmetcalf@ezchip.com, philipp.tomsich@theobroma-systems.com, joseph@codesourcery.com, zhouchengming1@huawei.com, Prasun.Kapoor@caviumnetworks.com, agraf@suse.de, geert@linux-m68k.org, kilobyte@angband.pl, manuel.montezelo@gmail.com, pinskia@gmail.com, linyongting@huawei.com, klimov.linux@gmail.com, broonie@kernel.org, bamvor.zhangjian@huawei.com, maxim.kuvyrkov@linaro.org, Nathan_Lynch@mentor.com, schwidefsky@de.ibm.com, davem@davemloft.net, christoph.muellner@theobroma-systems.com On Fri, Oct 21, 2016 at 11:33:10PM +0300, Yury Norov wrote: > off_t is passed in register pair just like in aarch32. > In this patch corresponding aarch32 handlers are shared to > ilp32 code. [...] > +/* > + * Note: off_4k (w5) is always in units of 4K. If we can't do the > + * requested offset because it is not page-aligned, we return -EINVAL. > + */ > +ENTRY(compat_sys_mmap2_wrapper) > +#if PAGE_SHIFT > 12 > + tst w5, #~PAGE_MASK >> 12 > + b.ne 1f > + lsr w5, w5, #PAGE_SHIFT - 12 > +#endif > + b sys_mmap_pgoff > +1: mov x0, #-EINVAL > + ret > +ENDPROC(compat_sys_mmap2_wrapper) For compat sys_mmap2, the pgoff argument is in multiples of 4K. This was traditionally used for architectures where off_t is 32-bit to allow mapping files to 2^44. Since off_t is 64-bit with AArch64/ILP32, should we just pass the off_t as a 64-bit value in two different registers (w5 and w6)? -- Catalin