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Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.2.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On 1/16/19 3:41 AM, Arnd Bergmann wrote: > On Tue, Jan 15, 2019 at 3:55 AM Jens Axboe wrote: >> >> diff --git a/arch/x86/entry/syscalls/syscall_32.tbl b/arch/x86/entry/syscalls/syscall_32.tbl >> index 3cf7b533b3d1..194e79c0032e 100644 >> --- a/arch/x86/entry/syscalls/syscall_32.tbl >> +++ b/arch/x86/entry/syscalls/syscall_32.tbl >> @@ -398,3 +398,5 @@ >> 384 i386 arch_prctl sys_arch_prctl __ia32_compat_sys_arch_prctl >> 385 i386 io_pgetevents sys_io_pgetevents __ia32_compat_sys_io_pgetevents >> 386 i386 rseq sys_rseq __ia32_sys_rseq >> +387 i386 io_uring_setup sys_io_uring_setup __ia32_compat_sys_io_uring_setup >> +388 i386 io_uring_enter sys_io_uring_enter __ia32_sys_io_uring_enter >> diff --git a/arch/x86/entry/syscalls/syscall_64.tbl b/arch/x86/entry/syscalls/syscall_64.tbl >> index f0b1709a5ffb..453ff7a79002 100644 >> --- a/arch/x86/entry/syscalls/syscall_64.tbl >> +++ b/arch/x86/entry/syscalls/syscall_64.tbl >> @@ -343,6 +343,8 @@ >> 332 common statx __x64_sys_statx >> 333 common io_pgetevents __x64_sys_io_pgetevents >> 334 common rseq __x64_sys_rseq >> +335 common io_uring_setup __x64_sys_io_uring_setup >> +336 common io_uring_enter __x64_sys_io_uring_enter > > In my series for the y2038 system calls, I'm trying to move to having the > same numbers across all architectures. Unfortunately, that clashes > with newly assigned numbers here, so one of us needs to pick new > numbers. > > If my series gets merged without other changes to the numbers, the next > available numbers on all architectures become 424 and 425. > > Could you use those here? Yeah that's totally fine, I don't really care what the numbers end up being, that side isn't fixed for me. >> +SYSCALL_DEFINE2(io_uring_setup, u32, entries, >> + struct io_uring_params __user *, params) >> +{ >> + return io_uring_setup(entries, params, false); >> +} >> + >> +#ifdef CONFIG_COMPAT >> +COMPAT_SYSCALL_DEFINE2(io_uring_setup, u32, entries, >> + struct io_uring_params __user *, params) >> +{ >> + return io_uring_setup(entries, params, true); >> +} >> +#endif > > The compat syscall has the same calling conventions as the > native one here, so I think you can just use that directly. Not sure I understand what you mean here. I need to know if it's the compat one, hence 'true' vs 'false', so I know what the size of the user pointers/structs are. >> +/* >> + * IO submission data structure (Submission Queue Entry) >> + */ >> +struct io_uring_sqe { >> + __u8 opcode; /* type of operation for this sqe */ >> + __u8 flags; /* as of now unused */ >> + __u16 ioprio; /* ioprio for the request */ >> + __s32 fd; /* file descriptor to do IO on */ >> + __u64 off; /* offset into file */ >> + union { >> + void *addr; /* buffer or iovecs */ >> + __u64 __pad; >> + }; > > It seems a bit unfortunate to keep the pointer field only > almost compatible between 32-bit and 64-bit big-endian > architectures, as that requires an in_compat_syscall() > check whenever we access the pointer from the kernel. > > Could you use a __u64 field to store the pointer itself > instead? I feel like I'm missing something here, we'll still need the compat code on the kernel side for 32-bit app on 64-bit kernel, so what would we solve by making this an __u64? >> diff --git a/kernel/sys_ni.c b/kernel/sys_ni.c >> index ab9d0e3c6d50..ee5e523564bb 100644 >> --- a/kernel/sys_ni.c >> +++ b/kernel/sys_ni.c >> @@ -46,6 +46,8 @@ COND_SYSCALL(io_getevents); >> COND_SYSCALL(io_pgetevents); >> COND_SYSCALL_COMPAT(io_getevents); >> COND_SYSCALL_COMPAT(io_pgetevents); >> +COND_SYSCALL(io_uring_setup); >> +COND_SYSCALL(io_uring_enter); > > Unless you remove the compat_sys_io_uring_setup() definition, > this should also have a corresponding COND_SYSCALL_COMPAT() > entry. Gotcha, thanks! I'll make that change. -- Jens Axboe