From mboxrd@z Thu Jan 1 00:00:00 1970 From: Vincenzo Frascino Subject: Re: [PATCH v3 18/26] arm64: Introduce asm/vdso/processor.h Date: Mon, 16 Mar 2020 16:05:17 +0000 Message-ID: <53eb7809-9da8-33e5-540f-7546de51b53d@arm.com> References: <20200313154345.56760-1-vincenzo.frascino@arm.com> <20200313154345.56760-19-vincenzo.frascino@arm.com> <20200315182950.GB32205@mbp> <20200316103437.GD3005@mbp> <77a2e91a-58f4-3ba3-9eef-42d6a8faf859@arm.com> <20200316112205.GE3005@mbp> <9a0a9285-8a45-4f65-3a83-813cabd0f0d3@arm.com> <20200316144346.GF3005@mbp> <427064ee-45df-233c-0281-69e3d62ba784@arm.com> <20200316154930.GG3005@mbp> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20200316154930.GG3005@mbp> Content-Language: en-US Sender: linux-mips-owner@vger.kernel.org To: Catalin Marinas Cc: linux-arch@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-mips@vger.kernel.org, clang-built-linux@googlegroups.com, x86@kernel.org, Will Deacon , Arnd Bergmann , Russell King , Paul Burton , Thomas Gleixner , Andy Lutomirski , Ingo Molnar , Borislav Petkov , Stephen Boyd , Mark Salyzyn , Kees Cook , Peter Collingbourne , Dmitry Safonov <0x7f454c46@gmail.com>, Andrei Vagin , Nick Desaulniers , Marc Zyngier Mark List-Id: linux-arch.vger.kernel.org On 3/16/20 3:49 PM, Catalin Marinas wrote: > On Mon, Mar 16, 2020 at 03:33:30PM +0000, Vincenzo Frascino wrote: >> On 3/16/20 2:43 PM, Catalin Marinas wrote[...] [...] > >> To make it more explicit we could make COMPAT_VDSO on arm64 depend on >> ARM64_4K_PAGES. What do you think? > > No, I don't see why we should add this limitation. > Fine by me. >>>> Please find below the list of errors for clock_gettime (similar for the other): >>>> >>>> passing UINTPTR_MAX to clock_gettime (VDSO): terminated by unexpected signal 7 >>>> clock-gettime-monotonic/abi: 1 failures/inconsistencies encountered >>> >>> Ah, so it uses UINTPTR_MAX in the test. Fair enough but I don't think >>> the arm64 check is entirely useful. On arm32, the check was meant to >>> return -EFAULT for addresses beyond TASK_SIZE that may enter into the >>> kernel or module space. On arm64 compat, the kernel space is well above >>> the reach of the 32-bit code. >>> >>> If you want to preserve some compatibility for this specific test, what >>> about checking for wrapping around 0, I think it would make more sense. >>> Something like: >>> >>> if ((u32)ts > UINTPTR_MAX - sizeof(*ts) + 1) >> >> Ok, sounds good to me. But it is something that this patch series inherited, >> hence I would prefer to send a separate patch that introduces what you are >> proposing and removes TASK_SIZE_32 from the headers. How does it sound? > > I'd rather avoid moving TASK_SIZE_32 unnecessarily. Just add a > preparatory patch to your series for arm64 compat vdso and follow with > the rest without moving TASK_SIZE_32 around. > Ok, sounds good. I will test it and repost. -- Regards, Vincenzo From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from foss.arm.com ([217.140.110.172]:51308 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731674AbgCPQEz (ORCPT ); Mon, 16 Mar 2020 12:04:55 -0400 Subject: Re: [PATCH v3 18/26] arm64: Introduce asm/vdso/processor.h References: <20200313154345.56760-1-vincenzo.frascino@arm.com> <20200313154345.56760-19-vincenzo.frascino@arm.com> <20200315182950.GB32205@mbp> <20200316103437.GD3005@mbp> <77a2e91a-58f4-3ba3-9eef-42d6a8faf859@arm.com> <20200316112205.GE3005@mbp> <9a0a9285-8a45-4f65-3a83-813cabd0f0d3@arm.com> <20200316144346.GF3005@mbp> <427064ee-45df-233c-0281-69e3d62ba784@arm.com> <20200316154930.GG3005@mbp> From: Vincenzo Frascino Message-ID: <53eb7809-9da8-33e5-540f-7546de51b53d@arm.com> Date: Mon, 16 Mar 2020 16:05:17 +0000 MIME-Version: 1.0 In-Reply-To: <20200316154930.GG3005@mbp> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-arch-owner@vger.kernel.org List-ID: To: Catalin Marinas Cc: linux-arch@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-mips@vger.kernel.org, clang-built-linux@googlegroups.com, x86@kernel.org, Will Deacon , Arnd Bergmann , Russell King , Paul Burton , Thomas Gleixner , Andy Lutomirski , Ingo Molnar , Borislav Petkov , Stephen Boyd , Mark Salyzyn , Kees Cook , Peter Collingbourne , Dmitry Safonov <0x7f454c46@gmail.com>, Andrei Vagin , Nick Desaulniers , Marc Zyngier , Mark Rutland , Will Deacon Message-ID: <20200316160517.q1AekDSaIzWa2MTjfJJKufsASbpBgdMe4YUL_QB2_Uc@z> On 3/16/20 3:49 PM, Catalin Marinas wrote: > On Mon, Mar 16, 2020 at 03:33:30PM +0000, Vincenzo Frascino wrote: >> On 3/16/20 2:43 PM, Catalin Marinas wrote[...] [...] > >> To make it more explicit we could make COMPAT_VDSO on arm64 depend on >> ARM64_4K_PAGES. What do you think? > > No, I don't see why we should add this limitation. > Fine by me. >>>> Please find below the list of errors for clock_gettime (similar for the other): >>>> >>>> passing UINTPTR_MAX to clock_gettime (VDSO): terminated by unexpected signal 7 >>>> clock-gettime-monotonic/abi: 1 failures/inconsistencies encountered >>> >>> Ah, so it uses UINTPTR_MAX in the test. Fair enough but I don't think >>> the arm64 check is entirely useful. On arm32, the check was meant to >>> return -EFAULT for addresses beyond TASK_SIZE that may enter into the >>> kernel or module space. On arm64 compat, the kernel space is well above >>> the reach of the 32-bit code. >>> >>> If you want to preserve some compatibility for this specific test, what >>> about checking for wrapping around 0, I think it would make more sense. >>> Something like: >>> >>> if ((u32)ts > UINTPTR_MAX - sizeof(*ts) + 1) >> >> Ok, sounds good to me. But it is something that this patch series inherited, >> hence I would prefer to send a separate patch that introduces what you are >> proposing and removes TASK_SIZE_32 from the headers. How does it sound? > > I'd rather avoid moving TASK_SIZE_32 unnecessarily. Just add a > preparatory patch to your series for arm64 compat vdso and follow with > the rest without moving TASK_SIZE_32 around. > Ok, sounds good. I will test it and repost. -- Regards, Vincenzo