From: Catalin Marinas <catalin.marinas@arm.com>
To: Arnd Bergmann <arnd@arndb.de>
Cc: linux-doc@vger.kernel.org,
Andrew Pinski <Andrew.Pinski@caviumnetworks.com>,
heiko.carstens@de.ibm.com, Yury Norov <ynorov@caviumnetworks.com>,
Hanjun Guo <guohanjun@huawei.com>,
joseph@codesourcery.com, linux-arch@vger.kernel.org,
linux-s390@vger.kernel.org, "jijun (D)" <jijun2@huawei.com>,
Prasun.Kapoor@caviumnetworks.com, schwab@suse.de, agraf@suse.de,
pinskia@gmail.com, klimov.linux@gmail.com, broonie@kernel.org,
"Zhangjian (Bamvor)" <bamvor.zhangjian@huawei.com>,
linux-arm-kernel@lists.infradead.org, Nathan_Lynch@mentor.com,
linux-kernel@vger.kernel.org, Andrew Pinski <apinski@cavium.com>,
schwidefsky@de.ibm.com, christoph.muellner@theobroma-systems.com
Subject: Re: [PATCH 20/25] arm64:ilp32: add sys_ilp32.c and a separate table (in entry.S) to use it
Date: Thu, 12 May 2016 10:17:58 +0100 [thread overview]
Message-ID: <20160512091758.GB11226@e104818-lin.cambridge.arm.com> (raw)
In-Reply-To: <4989778.Fs81NJurjH@wuerfel>
On Wed, May 11, 2016 at 09:30:07PM +0200, Arnd Bergmann wrote:
> On Wednesday 11 May 2016 17:59:01 Catalin Marinas wrote:
> > On Wed, May 11, 2016 at 12:55:01PM +0200, Arnd Bergmann wrote:
> > > On Wednesday 11 May 2016 11:04:38 Yury Norov wrote:
> > > > On Wed, May 11, 2016 at 10:04:16AM +0800, Zhangjian (Bamvor) wrote:
> > > > [...]
> > > >
> > > > > >>Ok, I will test the ltp syscall test.
> > > > > >>With this changes, the issue I mentioned should be fixed. But we still
> > > > > >>use mmap2 syscall for ILP32 application when we pass the offset instead
> > > > > >>of page offset. Is it correct?
> > > > > >
> > > > > >I don't remember. It's probably not important whether we have the shift
> > > > > >in there, as long as it's independent of the actual kernel page size and
> > > > > >user space and kernel agree on the calling conventions.
> > > > > Well. I am ok with where to shift the pages size because we get the same
> > > > > result. I was just thinking if we should get rid of the name of mmap2 in our
> > > > > ILP32 porting. Actually, it is mmap but we name it as mmap2. User may confused
> > > > > if they do not know the implementations.
> > > > >
> > > >
> > > > This is what generic unistd.h does. If you want to change it, you'd
> > > > change each arch that uses generic unistd.h.
> > >
> > > Generic unistd.h has this:
> > >
> > > #ifdef __SYSCALL_COMPAT
> > > #define __SC_COMP_3264(_nr, _32, _64, _comp) __SYSCALL(_nr, _comp)
> > > #else
> > > #define __SC_COMP_3264(_nr, _32, _64, _comp) __SC_3264(_nr, _32, _64)
> > > #endif
> > >
> > > #define __NR3264_mmap 222
> > > __SC_3264(__NR3264_mmap, sys_mmap2, sys_mmap)
> > >
> > >
> > > #if __BITS_PER_LONG == 64 && !defined(__SYSCALL_COMPAT)
> > > #define __NR_mmap __NR3264_mmap
> > > #else
> > > #define __NR_mmap2 __NR3264_mmap
> > > #endif
> > >
> > > So by default we get __NR_mmap2 and sys_mmap2 on 32-bit ABIs, but
> > > __NR_mmap and sys_mmap on 64-bit ABIs, as it should be.
> > >
> > > The problem is that arch/arm64/kernel/sys_ilp32.c now overrides
> > > this to use __NR_mmap2 with sys_mmap, so we have a mismatch. I think
> > > we should either override both the implementation and the number,
> > > or neither of them.
> >
> > I would vote for "neither of them" (so we use __NR_mmap2 and sys_mmap2)
> > to keep it close to new 32-bit architectures, even though we would have
> > some shifts by 12 in both glibc and kernel.
>
> I don't think the shifts are a problem, the main downside would be
> the limit to 44 bits of file offsets (16TB files), but it's also
> unclear if that is a practical problem at all. If it is, we run
> into the same problem on all other 32-bit architectures too.
I hope people are seriously thinking of moving to an LP64 ABI if they
have such large file offset needs.
--
Catalin
next prev parent reply other threads:[~2016-05-12 9:18 UTC|newest]
Thread overview: 132+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-04-05 22:08 [RFC6 PATCH v6 00/21] ILP32 for ARM64 Yury Norov
2016-04-05 22:08 ` [PATCH 01/25] all: syscall wrappers: add documentation Yury Norov
2016-04-05 22:08 ` [PATCH 02/25] all: introduce COMPAT_WRAPPER option and enable it for s390 Yury Norov
2016-04-05 22:08 ` [PATCH 03/25] all: s390: move wrapper infrastructure to generic headers Yury Norov
2016-04-05 22:08 ` [PATCH 04/25] all: s390: move compat_wrappers.c from arch/s390/kernel to kernel/ Yury Norov
2016-04-05 22:08 ` [PATCH 05/25] all: wrap needed syscalls in generic unistd Yury Norov
2016-04-05 22:08 ` [PATCH 06/25] compat ABI: use non-compat openat and open_by_handle_at variants Yury Norov
2016-04-05 22:08 ` [PATCH 07/25] 32-bit ABI: introduce ARCH_32BIT_OFF_T config option Yury Norov
2016-04-05 22:08 ` [PATCH 08/25] arm64: ilp32: add documentation on the ILP32 ABI for ARM64 Yury Norov
2016-04-05 22:08 ` [PATCH 09/25] arm64: ensure the kernel is compiled for LP64 Yury Norov
2016-04-05 22:08 ` [PATCH 10/25] arm64: rename COMPAT to AARCH32_EL0 in Kconfig Yury Norov
2016-04-14 3:20 ` Zhangjian (Bamvor)
2016-04-22 15:28 ` Catalin Marinas
2016-04-05 22:08 ` [PATCH 11/25] arm64: change some CONFIG_COMPAT over to use CONFIG_AARCH32_EL0 instead Yury Norov
2016-04-05 22:08 ` [PATCH 12/25] arm64: compat: change config dependences to aarch32 Yury Norov
2016-04-22 15:58 ` Catalin Marinas
2016-04-22 21:59 ` Yury Norov
2016-04-23 2:33 ` Zhangjian (Bamvor)
2016-04-05 22:08 ` [PATCH 13/25] arm64:uapi: set __BITS_PER_LONG correctly for ILP32 and LP64 Yury Norov
2016-04-05 22:08 ` [PATCH 14/25] thread: move thread bits accessors to separated file Yury Norov
2016-04-05 22:08 ` [PATCH 15/25] arm64: introduce is_a32_task and is_a32_thread (for AArch32 compat) Yury Norov
2016-05-06 12:02 ` Zhangjian (Bamvor)
2016-04-05 22:08 ` [PATCH 16/25] arm64: ilp32: add is_ilp32_compat_{task,thread} and TIF_32BIT_AARCH64 Yury Norov
2016-04-05 22:08 ` [PATCH 17/25] arm64: introduce binfmt_elf32.c Yury Norov
2016-04-05 22:08 ` [PATCH 18/25] arm64: ilp32: introduce binfmt_ilp32.c Yury Norov
2016-04-22 16:51 ` Catalin Marinas
2016-04-22 17:41 ` Arnd Bergmann
2016-04-05 22:08 ` [PATCH 19/25] arm64: ptrace: handle ptrace_request differently for aarch32 and ilp32 Yury Norov
2016-04-22 17:10 ` Catalin Marinas
2016-04-22 21:40 ` Yury Norov
2016-04-25 16:57 ` Catalin Marinas
2016-04-05 22:08 ` [PATCH 20/25] arm64:ilp32: add sys_ilp32.c and a separate table (in entry.S) to use it Yury Norov
2016-04-25 17:26 ` Catalin Marinas
2016-04-25 18:19 ` Yury Norov
2016-04-25 18:47 ` Yury Norov
2016-04-26 10:08 ` Catalin Marinas
2016-04-26 16:57 ` Catalin Marinas
2016-04-28 19:19 ` Yury Norov
2016-04-28 20:43 ` Arnd Bergmann
2016-04-28 22:21 ` Yury Norov
2016-04-28 22:43 ` Arnd Bergmann
2016-04-29 13:13 ` Yury Norov
2016-04-29 15:45 ` Arnd Bergmann
2016-05-06 12:16 ` Zhangjian (Bamvor)
2016-05-06 12:37 ` Yury Norov
2016-05-10 7:42 ` Zhangjian (Bamvor)
2016-05-10 7:55 ` Zhangjian (Bamvor)
2016-05-10 8:36 ` Arnd Bergmann
2016-05-10 9:47 ` Zhangjian (Bamvor)
2016-05-10 11:48 ` Arnd Bergmann
2016-05-10 12:39 ` Zhangjian (Bamvor)
2016-05-10 12:50 ` Arnd Bergmann
2016-05-11 2:04 ` Zhangjian (Bamvor)
2016-05-11 8:04 ` Yury Norov
2016-05-11 10:55 ` Arnd Bergmann
2016-05-11 16:59 ` Catalin Marinas
2016-05-11 19:30 ` Arnd Bergmann
2016-05-12 9:17 ` Catalin Marinas [this message]
2016-05-12 9:21 ` Arnd Bergmann
2016-05-12 12:49 ` Zhangjian (Bamvor)
2016-05-12 13:06 ` Arnd Bergmann
2016-05-12 13:19 ` Yury Norov
2016-05-14 12:49 ` Yury Norov
2016-05-11 8:09 ` Arnd Bergmann
2016-05-11 10:12 ` Zhangjian (Bamvor)
2016-05-11 11:16 ` Zhangjian (Bamvor)
2016-05-11 14:50 ` Arnd Bergmann
2016-05-12 3:45 ` Zhangjian (Bamvor)
2016-05-12 8:24 ` Yury Norov
2016-05-12 12:52 ` Zhangjian (Bamvor)
2016-05-12 12:59 ` Yury Norov
2016-05-14 15:03 ` Yury Norov
2016-05-16 17:06 ` Catalin Marinas
2016-05-17 19:05 ` Yury Norov
2016-05-18 11:21 ` Catalin Marinas
2016-05-18 17:58 ` Yury Norov
2016-04-05 22:08 ` [PATCH 21/25] arm64: signal: share lp64 signal routines to ilp32 Yury Norov
2016-04-05 22:08 ` [PATCH 22/25] arm64: signal32: move ilp32 and aarch32 common code to separated file Yury Norov
2016-04-05 22:08 ` [PATCH 23/25] arm64: ilp32: introduce ilp32-specific handlers for sigframe and ucontext Yury Norov
2016-04-05 22:08 ` [PATCH 24/25] arm64:ilp32: add vdso-ilp32 and use for signal return Yury Norov
2016-04-13 9:19 ` Zhangjian (Bamvor)
2016-04-13 15:55 ` Yury Norov
2016-05-03 12:49 ` Zhangjian (Bamvor)
2016-04-29 16:01 ` Catalin Marinas
2016-04-29 17:30 ` Arnd Bergmann
2016-05-03 9:00 ` Catalin Marinas
2016-05-03 9:05 ` Arnd Bergmann
2016-05-03 11:07 ` Zhangjian (Bamvor)
2016-05-03 12:41 ` Zhangjian (Bamvor)
2016-05-04 21:49 ` Yury Norov
2016-05-04 23:23 ` Andrew Pinski
2016-05-05 2:24 ` Zhangjian (Bamvor)
2016-05-05 6:40 ` Andrew Pinski
2016-05-06 14:00 ` Yury Norov
2016-05-09 10:07 ` Zhangjian (Bamvor)
2016-05-05 8:22 ` Yury Norov
2016-04-05 22:08 ` [PATCH 25/25] arm64:ilp32: add ARM64_ILP32 to Kconfig Yury Norov
2016-04-29 16:03 ` Catalin Marinas
2016-04-29 16:08 ` Yury Norov
2016-04-29 16:14 ` Catalin Marinas
2016-04-29 16:26 ` Yury Norov
2016-04-05 22:44 ` [RFC6 PATCH v6 00/21] ILP32 for ARM64 - LTP results Yury Norov
2016-04-23 3:37 ` Zhangjian (Bamvor)
2016-04-27 7:30 ` Andrew Pinski
2016-04-27 21:15 ` Andrew Pinski
2016-04-28 12:16 ` Zhangjian (Bamvor)
2016-04-06 6:51 ` [RFC6 PATCH v6 00/21] ILP32 for ARM64 Geert Uytterhoeven
2016-04-06 12:29 ` Yury Norov
2016-04-07 12:28 ` Geert Uytterhoeven
2016-05-12 0:20 ` Yury Norov
2016-05-12 9:19 ` Arnd Bergmann
2016-05-12 10:30 ` Yury Norov
2016-05-12 13:35 ` Catalin Marinas
2016-05-12 13:44 ` Yury Norov
2016-05-12 14:07 ` Catalin Marinas
2016-05-12 14:20 ` Catalin Marinas
2016-05-12 14:34 ` Yury Norov
2016-05-12 14:54 ` Catalin Marinas
2016-05-12 15:27 ` Yury Norov
2016-05-12 14:24 ` Yury Norov
2016-05-12 15:28 ` Catalin Marinas
2016-05-13 8:11 ` Zhangjian (Bamvor)
2016-05-13 9:28 ` Catalin Marinas
2016-05-13 10:51 ` Yury Norov
2016-05-13 11:03 ` Catalin Marinas
2016-05-13 13:32 ` Catalin Marinas
2016-05-17 12:10 ` Szabolcs Nagy
2016-05-17 15:37 ` Arnd Bergmann
2016-05-17 15:45 ` Joseph Myers
2016-05-17 16:02 ` Andreas Schwab
2016-05-17 22:45 ` Arnd Bergmann
2016-05-17 15:40 ` Joseph Myers
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