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Date:   Thu, 28 Apr 2022 11:22:33 -0700 (PDT)
Subject:     Re: [PATCH V12 00/20] riscv: Add COMPAT mode support for 64BIT
In-Reply-To: <CAJF2gTR6=RGJgcYT_yBHep0=zdpU_M7OfsV=d9_DxPeacKN=Gw@mail.gmail.com>
CC:     guoren@kernel.org, Arnd Bergmann <arnd@arndb.de>,
        Greg KH <gregkh@linuxfoundation.org>,
        Christoph Hellwig <hch@lst.de>, nathan@kernel.org,
        naresh.kamboju@linaro.org, linux-arch@vger.kernel.org,
        linux-kernel@vger.kernel.org, linux-riscv@lists.infradead.org,
        linux-s390@vger.kernel.org, sparclinux@vger.kernel.org,
        linuxppc-dev@lists.ozlabs.org, linux-parisc@vger.kernel.org,
        linux-mips@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
        x86@kernel.org, heiko@sntech.de, guoren@linux.alibaba.com
From:   Palmer Dabbelt <palmer@dabbelt.com>
To:     guoren@kernel.org
Message-ID: <mhng-ab858def-1533-4cec-9ee9-f6c3f712fd93@palmer-ri-x1c9>
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On Thu, 28 Apr 2022 05:25:19 PDT (-0700), guoren@kernel.org wrote:
> Hi Palmer,
>
> I see you have taken v12 into your riscv-compat branch and added
> asm/signal32.h. Do you need me help put compat_sigcontext &
> compat_ucontext & compat_rt_sigframe into signal32.h? And could we
> rename signal32.h to compat_signal.h to match compat_signal.c?
>
> In the end, thx for taking care of compat patch series.

No problem.  I was just trying to get something clean through all the 
autobuilders before making it look good, I think it didn't fail this 
time so I'll do a bit more refactoring.  Shouldn't be too much longer at 
this point.

>
>
> On Tue, Apr 5, 2022 at 3:13 PM <guoren@kernel.org> wrote:
>>
>> From: Guo Ren <guoren@linux.alibaba.com>
>>
>> Currently, most 64-bit architectures (x86, parisc, powerpc, arm64,
>> s390, mips, sparc) have supported COMPAT mode. But they all have
>> history issues and can't use standard linux unistd.h. RISC-V would
>> be first standard __SYSCALL_COMPAT user of include/uapi/asm-generic
>> /unistd.h.
>>
>> The patchset are based on v5.18-rc1, you can compare rv64-compat
>> v.s. rv32-native in qemu with following steps:
>>
>>  - Prepare rv32 rootfs & fw_jump.bin by buildroot.org
>>    $ git clone git://git.busybox.net/buildroot
>>    $ cd buildroot
>>    $ make qemu_riscv32_virt_defconfig O=qemu_riscv32_virt_defconfig
>>    $ make -C qemu_riscv32_virt_defconfig
>>    $ make qemu_riscv64_virt_defconfig O=qemu_riscv64_virt_defconfig
>>    $ make -C qemu_riscv64_virt_defconfig
>>    (Got fw_jump.bin & rootfs.ext2 in qemu_riscvXX_virt_defconfig/images)
>>
>>  - Prepare Linux rv32 & rv64 Image
>>    $ git clone git@github.com:c-sky/csky-linux.git -b riscv_compat_v12 linux
>>    $ cd linux
>>    $ echo "CONFIG_STRICT_KERNEL_RWX=n" >> arch/riscv/configs/defconfig
>>    $ echo "CONFIG_STRICT_MODULE_RWX=n" >> arch/riscv/configs/defconfig
>>    $ make ARCH=riscv CROSS_COMPILE=riscv32-buildroot-linux-gnu- O=../build-rv32/ rv32_defconfig
>>    $ make ARCH=riscv CROSS_COMPILE=riscv32-buildroot-linux-gnu- O=../build-rv32/ Image
>>    $ make ARCH=riscv CROSS_COMPILE=riscv64-buildroot-linux-gnu- O=../build-rv64/ defconfig
>>    $ make ARCH=riscv CROSS_COMPILE=riscv64-buildroot-linux-gnu- O=../build-rv64/ Image
>>
>>  - Prepare Qemu:
>>    $ git clone https://gitlab.com/qemu-project/qemu.git -b master linux
>>    $ cd qemu
>>    $ ./configure --target-list="riscv64-softmmu riscv32-softmmu"
>>    $ make
>>
>> Now let's compare rv64-compat with rv32-native memory footprint with almost the same
>> defconfig, rootfs, opensbi in one qemu.
>>
>>  - Run rv64 with rv32 rootfs in compat mode:
>>    $ ./build/qemu-system-riscv64 -cpu rv64 -M virt -m 64m -nographic -bios qemu_riscv64_virt_defconfig/images/fw_jump.bin -kernel build-rv64/Image -drive file qemu_riscv32_virt_defconfig/images/rootfs.ext2,format=raw,id=hd0 -device virtio-blk-device,drive=hd0 -append "rootwait root=/dev/vda ro console=ttyS0 earlycon=sbi" -netdev user,id=net0 -device virtio-net-device,netdev=net0
>>
>> QEMU emulator version 6.2.50 (v6.2.0-29-g196d7182c8)
>> OpenSBI v0.9
>> [    0.000000] Linux version 5.16.0-rc6-00017-g750f87086bdd-dirty (guoren@guoren-Z87-HD3) (riscv64-unknown-linux-gnu-gcc (GCC) 10.2.0, GNU ld (GNU Binutils) 2.37) #96 SMP Tue Dec 28 21:01:55 CST 2021
>> [    0.000000] OF: fdt: Ignoring memory range 0x80000000 - 0x80200000
>> [    0.000000] Machine model: riscv-virtio,qemu
>> [    0.000000] earlycon: sbi0 at I/O port 0x0 (options '')
>> [    0.000000] printk: bootconsole [sbi0] enabled
>> [    0.000000] efi: UEFI not found.
>> [    0.000000] Zone ranges:
>> [    0.000000]   DMA32    [mem 0x0000000080200000-0x0000000083ffffff]
>> [    0.000000]   Normal   empty
>> [    0.000000] Movable zone start for each node
>> [    0.000000] Early memory node ranges
>> [    0.000000]   node   0: [mem 0x0000000080200000-0x0000000083ffffff]
>> [    0.000000] Initmem setup node 0 [mem 0x0000000080200000-0x0000000083ffffff]
>> [    0.000000] SBI specification v0.2 detected
>> [    0.000000] SBI implementation ID=0x1 Version=0x9
>> [    0.000000] SBI TIME extension detected
>> [    0.000000] SBI IPI extension detected
>> [    0.000000] SBI RFENCE extension detected
>> [    0.000000] SBI v0.2 HSM extension detected
>> [    0.000000] riscv: ISA extensions acdfhimsu
>> [    0.000000] riscv: ELF capabilities acdfim
>> [    0.000000] percpu: Embedded 17 pages/cpu s30696 r8192 d30744 u69632
>> [    0.000000] Built 1 zonelists, mobility grouping on.  Total pages: 15655
>> [    0.000000] Kernel command line: rootwait root=/dev/vda ro console=ttyS0 earlycon=sbi
>> [    0.000000] Dentry cache hash table entries: 8192 (order: 4, 65536 bytes, linear)
>> [    0.000000] Inode-cache hash table entries: 4096 (order: 3, 32768 bytes, linear)
>> [    0.000000] mem auto-init: stack:off, heap alloc:off, heap free:off
>> [    0.000000] Virtual kernel memory layout:
>> [    0.000000]       fixmap : 0xffffffcefee00000 - 0xffffffceff000000   (2048 kB)
>> [    0.000000]       pci io : 0xffffffceff000000 - 0xffffffcf00000000   (  16 MB)
>> [    0.000000]      vmemmap : 0xffffffcf00000000 - 0xffffffcfffffffff   (4095 MB)
>> [    0.000000]      vmalloc : 0xffffffd000000000 - 0xffffffdfffffffff   (65535 MB)
>> [    0.000000]       lowmem : 0xffffffe000000000 - 0xffffffe003e00000   (  62 MB)
>> [    0.000000]       kernel : 0xffffffff80000000 - 0xffffffffffffffff   (2047 MB)
>> [    0.000000] Memory: 52788K/63488K available (6184K kernel code, 888K rwdata, 1917K rodata, 294K init, 297K bss, 10700K reserved, 0K cma-reserved)
>> [    0.000000] SLUB: HWalign=64, Order=0-3, MinObjects=0, CPUs=1, Nodes=1
>> [    0.000000] rcu: Hierarchical RCU implementation.
>> [    0.000000] rcu:     RCU restricting CPUs from NR_CPUS=8 to nr_cpu_ids=1.
>> [    0.000000] rcu:     RCU debug extended QS entry/exit.
>> [    0.000000]  Tracing variant of Tasks RCU enabled.
>> [    0.000000] rcu: RCU calculated value of scheduler-enlistment delay is 25 jiffies.
>> [    0.000000] rcu: Adjusting geometry for rcu_fanout_leaf=16, nr_cpu_ids=1
>> [    0.000000] NR_IRQS: 64, nr_irqs: 64, preallocated irqs: 0
>> [    0.000000] riscv-intc: 64 local interrupts mapped
>> [    0.000000] plic: plic@c000000: mapped 53 interrupts with 1 handlers for 2 contexts.
>> ...
>> Welcome to Buildroot
>> buildroot login: root
>> # cat /proc/cpuinfo
>> processor       : 0
>> hart            : 0
>> isa             : rv64imafdcsuh
>> mmu             : sv48
>>
>> # file /bin/busybox
>> /bin/busybox: setuid ELF 32-bit LSB shared object, UCB RISC-V, version 1 (SYSV), dynamically linked, interpreter /lib/ld-linux-riscv32-ilp32d.so.1, for GNU/Linux 5.15.0, stripped
>> # ca[   78.386630] random: fast init done
>> # cat /proc/meminfo
>> MemTotal:          53076 kB
>> MemFree:           40264 kB
>> MemAvailable:      40244 kB
>> Buffers:             236 kB
>> Cached:             1560 kB
>> SwapCached:            0 kB
>> Active:             1700 kB
>> Inactive:            516 kB
>> Active(anon):         40 kB
>> Inactive(anon):      424 kB
>> Active(file):       1660 kB
>> Inactive(file):       92 kB
>> Unevictable:           0 kB
>> Mlocked:               0 kB
>> SwapTotal:             0 kB
>> SwapFree:              0 kB
>> Dirty:                 0 kB
>> Writeback:             0 kB
>> AnonPages:           444 kB
>> Mapped:             1188 kB
>> Shmem:                44 kB
>> KReclaimable:        952 kB
>> Slab:               5744 kB
>> SReclaimable:        952 kB
>> SUnreclaim:         4792 kB
>> KernelStack:         624 kB
>> PageTables:          156 kB
>> NFS_Unstable:          0 kB
>> Bounce:                0 kB
>> WritebackTmp:          0 kB
>> CommitLimit:       26536 kB
>> Committed_AS:       1748 kB
>> VmallocTotal:   67108863 kB
>> VmallocUsed:         652 kB
>> VmallocChunk:          0 kB
>> Percpu:               80 kB
>> #
>>
>>  - Run rv32 with rv32 rootfs:
>>    $ ./build/qemu-system-riscv32 -cpu rv32 -M virt -m 64m -nographic -bios qemu_riscv32_virt_defconfig/images/fw_jump.bin -kernel build-rv32/Image -drive file qemu_riscv32_virt_defconfig/images/rootfs.ext2,format=raw,id=hd0 -device virtio-blk-device,drive=hd0 -append "rootwait root=/dev/vda ro console=ttyS0 earlycon=sbi" -netdev user,id=net0 -device virtio-net-device,netdev=net0
>>
>> QEMU emulator version 6.2.50 (v6.2.0-29-g196d7182c8)
>> OpenSBI v0.9
>> [    0.000000] Linux version 5.16.0-rc6-00017-g750f87086bdd-dirty (guoren@guoren-Z87-HD3) (riscv32-buildroot-linux-gnu-gcc.br_real (Buildroot 2021.11-201-g7600ca7960-dirty) 10.3.0, GNU ld (GNU Binutils) 2.36.1) #7 SMP Tue Dec 28 21:02:21 CST 2021
>> [    0.000000] OF: fdt: Ignoring memory range 0x80000000 - 0x80400000
>> [    0.000000] Machine model: riscv-virtio,qemu
>> [    0.000000] earlycon: sbi0 at I/O port 0x0 (options '')
>> [    0.000000] printk: bootconsole [sbi0] enabled
>> [    0.000000] efi: UEFI not found.
>> [    0.000000] Zone ranges:
>> [    0.000000]   Normal   [mem 0x0000000080400000-0x0000000083ffffff]
>> [    0.000000] Movable zone start for each node
>> [    0.000000] Early memory node ranges
>> [    0.000000]   node   0: [mem 0x0000000080400000-0x0000000083ffffff]
>> [    0.000000] Initmem setup node 0 [mem 0x0000000080400000-0x0000000083ffffff]
>> [    0.000000] SBI specification v0.2 detected
>> [    0.000000] SBI implementation ID=0x1 Version=0x9
>> [    0.000000] SBI TIME extension detected
>> [    0.000000] SBI IPI extension detected
>> [    0.000000] SBI RFENCE extension detected
>> [    0.000000] SBI v0.2 HSM extension detected
>> [    0.000000] riscv: ISA extensions acdfhimsu
>> [    0.000000] riscv: ELF capabilities acdfim
>> [    0.000000] percpu: Embedded 12 pages/cpu s16600 r8192 d24360 u49152
>> [    0.000000] Built 1 zonelists, mobility grouping on.  Total pages: 15240
>> [    0.000000] Kernel command line: rootwait root=/dev/vda ro console=ttyS0 earlycon=sbi
>> [    0.000000] Dentry cache hash table entries: 8192 (order: 3, 32768 bytes, linear)
>> [    0.000000] Inode-cache hash table entries: 4096 (order: 2, 16384 bytes, linear)
>> [    0.000000] mem auto-init: stack:off, heap alloc:off, heap free:off
>> [    0.000000] Virtual kernel memory layout:
>> [    0.000000]       fixmap : 0x9dc00000 - 0x9e000000   (4096 kB)
>> [    0.000000]       pci io : 0x9e000000 - 0x9f000000   (  16 MB)
>> [    0.000000]      vmemmap : 0x9f000000 - 0x9fffffff   (  15 MB)
>> [    0.000000]      vmalloc : 0xa0000000 - 0xbfffffff   ( 511 MB)
>> [    0.000000]       lowmem : 0xc0000000 - 0xc3c00000   (  60 MB)
>> [    0.000000] Memory: 51924K/61440K available (6117K kernel code, 695K rwdata, 1594K rodata, 255K init, 241K bss, 9516K reserved, 0K cma-reserved)
>> [    0.000000] SLUB: HWalign=64, Order=0-3, MinObjects=0, CPUs=1, Nodes=1
>> [    0.000000] rcu: Hierarchical RCU implementation.
>> [    0.000000] rcu:     RCU restricting CPUs from NR_CPUS=8 to nr_cpu_ids=1.
>> [    0.000000] rcu:     RCU debug extended QS entry/exit.
>> [    0.000000]  Tracing variant of Tasks RCU enabled.
>> [    0.000000] rcu: RCU calculated value of scheduler-enlistment delay is 25 jiffies.
>> [    0.000000] rcu: Adjusting geometry for rcu_fanout_leaf=16, nr_cpu_ids=1
>> [    0.000000] NR_IRQS: 64, nr_irqs: 64, preallocated irqs: 0
>> [    0.000000] riscv-intc: 32 local interrupts mapped
>> [    0.000000] plic: plic@c000000: mapped 53 interrupts with 1 handlers for 2 contexts.
>> ...
>> Welcome to Buildroot
>> buildroot login: root
>> # cat /proc/cpuinfo
>> processor       : 0
>> hart            : 0
>> isa             : rv32imafdcsuh
>> mmu             : sv32
>>
>> # file /bin/busybox
>> /bin/busybox: setuid ELF 32-bit LSB shared object, UCB RISC-V, version 1 (SYSV), dynamically linked, interpreter /lib/ld-linux-riscv32-ilp32d.so.1, for GNU/Linux 5.15.0, stripped
>> [   79.320589] random: fast init done
>> # cat /proc/meminfo
>> MemTotal:          52176 kB
>> MemFree:           41012 kB
>> MemAvailable:      42176 kB
>> Buffers:             644 kB
>> Cached:             2724 kB
>> SwapCached:            0 kB
>> Active:             3128 kB
>> Inactive:            752 kB
>> Active(anon):         40 kB
>> Inactive(anon):      516 kB
>> Active(file):       3088 kB
>> Inactive(file):      236 kB
>> Unevictable:           0 kB
>> Mlocked:               0 kB
>> SwapTotal:             0 kB
>> SwapFree:              0 kB
>> Dirty:                 4 kB
>> Writeback:             0 kB
>> AnonPages:           556 kB
>> Mapped:             2172 kB
>> Shmem:                44 kB
>> KReclaimable:        656 kB
>> Slab:               3684 kB
>> SReclaimable:        656 kB
>> SUnreclaim:         3028 kB
>> KernelStack:         312 kB
>> PageTables:           88 kB
>> NFS_Unstable:          0 kB
>> Bounce:                0 kB
>> WritebackTmp:          0 kB
>> CommitLimit:       26088 kB
>> Committed_AS:       2088 kB
>> VmallocTotal:     524287 kB
>> VmallocUsed:          12 kB
>> VmallocChunk:          0 kB
>> Percpu:               60 kB
>> #
>>
>>  Some conclusions:
>>  - kernel statics:
>>    64: Memory: 52788K/63488K available (6184K kernel code, 888K rwdata, 1917K rodata, 294K init, 297K bss, 10700K reserved)
>>    32: Memory: 51924K/61440K available (6117K kernel code, 695K rwdata, 1594K rodata, 255K init, 241K bss,  9516K reserved)
>>    rv32 better than rv64:                  1%               22%           17%          13%        19%         11%
>>    The code size is very similar, but data size rv32 would be better.
>>
>>  - rv32 kernel runtime KernelStack, Slab... are smaller,
>>    rv64: MemTotal: 53076 kB,        MemFree: 40264 kB
>>    rv32: MemTotal: 52176 + 2048 kB, MemFree: 41012  + 2048 kB
>>    rv32 better than rv64:       2%                         6%
>>
>>    (Because opensbi problem, we could add another 2MB for rv32.)
>>    Overall in 64MB memory situation, rv64-compat is 6% worse than rv32-native
>>    at memory footprint. If the userspace memory usage increases, I think
>>    the gap will be further reduced.
>>
>> Changes in v12:
>>  - Rebase on 5.18-rc1
>>  - Fixup compile conflicts with 5.18-rc1
>>  - Fixup $(srctree) == $(objtree) compile error reported by Nathan
>>
>> Changes in v11:
>>  - Using arch instead of kconfig for commit subject by Masahiro Yamada
>>
>> Changes in v10:
>>  - Fixup arm64 compile error with compat_statfs definition
>>  - Fixup compat_sys_fadvise64_64 function arguments error cause ltp failure
>>
>> Changes in v9:
>>  - Fixup rv32 call rv64 segment fault
>>  - Ready for 5.18
>>
>> Changes in v8:
>>  - Enhanced elf_check_arch with EI_CLASS
>>  - Fixup SR_UXL doesn't exist in CONFIG_32BIT
>>  - Add Tested-by with Heiko
>>  - Update qemu compile tips with upstream repo
>>
>> Changes in v7:
>>  - Re-construct compat_vdso/Makefile
>>  - Fixup disable COMPAT compile error by csr.h's macro.
>>  - Optimize coding convention for lo/hi in compat.h
>>
>> Changes in v6:
>>  - Rebase on linux-5.17-rc5
>>  - Optimize hw capability check for elf
>>  - Optimize comment in thread_info.h
>>  - Optimize start_thread with SR_UXL setting
>>  - Optimize vdso.c with direct panic
>>
>> Changes in v5:
>>  - Rebase on linux-5.17-rc2
>>  - Include consolidate the fcntl patches by Christoph Hellwig
>>  - Remove F_GETLK64/F_SETLK64/F_SETLKW64 from asm/compat.h
>>  - Change COMPAT_RLIM_INFINITY from 0x7fffffff to 0xffffffff
>>  - Bring back "Add hw-cap detect in setup_arch patch" in v1
>>
>> Changes in v4:
>>  - Rebase on linux-5.17-rc1
>>  - Optimize compat_sys_call_table implementation with Arnd's advice
>>  - Add reviewed-by for Arnd. Thx :)
>>  - Remove FIXME comment in elf.h
>>  - Optimize Cleanup duplicate definitions in compat.h with Arnd's advice
>>
>> Changes in v3:
>>  - Rebase on newest master (pre linux-5.17-rc1)
>>  - Using newest qemu version v7 for test
>>  - Remove fcntl common modification
>>  - Fixup SET_PERSONALITY in elf.h by Arnd
>>  - Fixup KVM Kconfig
>>  - Update Acked-by & Reviewed-by
>>
>> Changes in v2:
>>  - Add __ARCH_WANT_COMPAT_STAT suggested
>>  - Cleanup fcntl compatduplicate definitions
>>  - Cleanup compat.h
>>  - Move rv32_defconfig into Makefile
>>  - Fixup rv64 rootfs boot failed, remove hw_compat_mode_detect
>>  - Move SYSVIPC_COMPAT into init/Kconfig
>>  - Simplify compat_elf_check
>>
>> Christoph Hellwig (3):
>>   uapi: simplify __ARCH_FLOCK{,64}_PAD a little
>>   uapi: always define F_GETLK64/F_SETLK64/F_SETLKW64 in fcntl.h
>>   compat: consolidate the compat_flock{,64} definition
>>
>> Guo Ren (17):
>>   arch: Add SYSVIPC_COMPAT for all architectures
>>   fs: stat: compat: Add __ARCH_WANT_COMPAT_STAT
>>   asm-generic: compat: Cleanup duplicate definitions
>>   syscalls: compat: Fix the missing part for __SYSCALL_COMPAT
>>   riscv: Fixup difference with defconfig
>>   riscv: compat: Add basic compat data type implementation
>>   riscv: compat: Support TASK_SIZE for compat mode
>>   riscv: compat: syscall: Add compat_sys_call_table implementation
>>   riscv: compat: syscall: Add entry.S implementation
>>   riscv: compat: process: Add UXL_32 support in start_thread
>>   riscv: compat: Add elf.h implementation
>>   riscv: compat: Add hw capability check for elf
>>   riscv: compat: vdso: Add COMPAT_VDSO base code implementation
>>   riscv: compat: vdso: Add setup additional pages implementation
>>   riscv: compat: signal: Add rt_frame implementation
>>   riscv: compat: ptrace: Add compat_arch_ptrace implement
>>   riscv: compat: Add COMPAT Kbuild skeletal support
>>
>>  arch/arm64/Kconfig                            |   4 -
>>  arch/arm64/include/asm/compat.h               |  93 +------
>>  arch/arm64/include/asm/unistd.h               |   1 +
>>  arch/mips/Kconfig                             |   5 -
>>  arch/mips/include/asm/compat.h                |  41 +--
>>  arch/mips/include/asm/unistd.h                |   2 +
>>  arch/mips/include/uapi/asm/fcntl.h            |  30 +--
>>  arch/parisc/Kconfig                           |   4 -
>>  arch/parisc/include/asm/compat.h              |  45 +---
>>  arch/parisc/include/asm/unistd.h              |   1 +
>>  arch/powerpc/Kconfig                          |   5 -
>>  arch/powerpc/include/asm/compat.h             |  50 +---
>>  arch/powerpc/include/asm/unistd.h             |   1 +
>>  arch/riscv/Kconfig                            |  19 ++
>>  arch/riscv/Makefile                           |   9 +
>>  arch/riscv/include/asm/compat.h               | 129 ++++++++++
>>  arch/riscv/include/asm/csr.h                  |   7 +
>>  arch/riscv/include/asm/elf.h                  |  50 +++-
>>  arch/riscv/include/asm/mmu.h                  |   1 +
>>  arch/riscv/include/asm/pgtable.h              |  13 +-
>>  arch/riscv/include/asm/processor.h            |   6 +-
>>  arch/riscv/include/asm/syscall.h              |   1 +
>>  arch/riscv/include/asm/thread_info.h          |   1 +
>>  arch/riscv/include/asm/unistd.h               |  11 +
>>  arch/riscv/include/asm/vdso.h                 |   9 +
>>  arch/riscv/include/uapi/asm/unistd.h          |   2 +-
>>  arch/riscv/kernel/Makefile                    |   3 +
>>  arch/riscv/kernel/compat_signal.c             | 242 ++++++++++++++++++
>>  arch/riscv/kernel/compat_syscall_table.c      |  19 ++
>>  arch/riscv/kernel/compat_vdso/.gitignore      |   2 +
>>  arch/riscv/kernel/compat_vdso/Makefile        |  78 ++++++
>>  arch/riscv/kernel/compat_vdso/compat_vdso.S   |   8 +
>>  .../kernel/compat_vdso/compat_vdso.lds.S      |   3 +
>>  arch/riscv/kernel/compat_vdso/flush_icache.S  |   3 +
>>  .../compat_vdso/gen_compat_vdso_offsets.sh    |   5 +
>>  arch/riscv/kernel/compat_vdso/getcpu.S        |   3 +
>>  arch/riscv/kernel/compat_vdso/note.S          |   3 +
>>  arch/riscv/kernel/compat_vdso/rt_sigreturn.S  |   3 +
>>  arch/riscv/kernel/entry.S                     |  18 +-
>>  arch/riscv/kernel/process.c                   |  37 +++
>>  arch/riscv/kernel/ptrace.c                    |  87 ++++++-
>>  arch/riscv/kernel/signal.c                    |  13 +-
>>  arch/riscv/kernel/sys_riscv.c                 |   6 +-
>>  arch/riscv/kernel/vdso.c                      | 105 +++++---
>>  arch/riscv/kernel/vdso/vdso.S                 |   6 +-
>>  arch/s390/Kconfig                             |   3 -
>>  arch/s390/include/asm/compat.h                |  99 +------
>>  arch/s390/include/asm/unistd.h                |   1 +
>>  arch/sparc/Kconfig                            |   5 -
>>  arch/sparc/include/asm/compat.h               |  61 ++---
>>  arch/sparc/include/asm/unistd.h               |   1 +
>>  arch/x86/Kconfig                              |   4 -
>>  arch/x86/include/asm/compat.h                 | 104 ++------
>>  arch/x86/include/asm/unistd.h                 |   1 +
>>  fs/open.c                                     |  24 ++
>>  fs/read_write.c                               |  16 ++
>>  fs/stat.c                                     |   2 +-
>>  fs/sync.c                                     |   9 +
>>  include/asm-generic/compat.h                  | 113 ++++++++
>>  include/linux/compat.h                        |  68 +++++
>>  include/uapi/asm-generic/fcntl.h              |  23 +-
>>  include/uapi/asm-generic/unistd.h             |   4 +-
>>  init/Kconfig                                  |   4 +
>>  mm/fadvise.c                                  |  11 +
>>  mm/readahead.c                                |   7 +
>>  tools/include/uapi/asm-generic/fcntl.h        |  21 +-
>>  tools/include/uapi/asm-generic/unistd.h       |   4 +-
>>  67 files changed, 1206 insertions(+), 563 deletions(-)
>>  create mode 100644 arch/riscv/include/asm/compat.h
>>  create mode 100644 arch/riscv/kernel/compat_signal.c
>>  create mode 100644 arch/riscv/kernel/compat_syscall_table.c
>>  create mode 100644 arch/riscv/kernel/compat_vdso/.gitignore
>>  create mode 100644 arch/riscv/kernel/compat_vdso/Makefile
>>  create mode 100644 arch/riscv/kernel/compat_vdso/compat_vdso.S
>>  create mode 100644 arch/riscv/kernel/compat_vdso/compat_vdso.lds.S
>>  create mode 100644 arch/riscv/kernel/compat_vdso/flush_icache.S
>>  create mode 100755 arch/riscv/kernel/compat_vdso/gen_compat_vdso_offsets.sh
>>  create mode 100644 arch/riscv/kernel/compat_vdso/getcpu.S
>>  create mode 100644 arch/riscv/kernel/compat_vdso/note.S
>>  create mode 100644 arch/riscv/kernel/compat_vdso/rt_sigreturn.S
>>
>> --
>> 2.25.1
>>