On Tue, Jan 15, 2019 at 3:55 AM Jens Axboe <axboe@xxxxxxxxx> 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?
> +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.
> +/*
> + * 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?
> 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.
Arnd
