Re: [PATCH 01/13] syscalls: compat: Fix the missing part for __SYSCALL_COMPAT

[Arnd Bergmann]

On Tue, Dec 21, 2021 at 5:35 PM <guoren@xxxxxxxxxx> wrote:
> diff --git a/include/uapi/asm-generic/unistd.h b/include/uapi/asm-generic/unistd.h
> index 4557a8b6086f..aafe5cfeb27c 100644
> --- a/include/uapi/asm-generic/unistd.h
> +++ b/include/uapi/asm-generic/unistd.h
> @@ -383,7 +383,7 @@ __SYSCALL(__NR_syslog, sys_syslog)
>
>  /* kernel/ptrace.c */
>  #define __NR_ptrace 117
> -__SYSCALL(__NR_ptrace, sys_ptrace)
> +__SC_COMP(__NR_ptrace, sys_ptrace, compat_sys_ptrace)
>

Right. We could merge sys_ptrace and compat_sys_ptrace() by adding
a in_compat_syscall() check, but either way works.

>  /* kernel/sched/core.c */
>  #define __NR_sched_setparam 118
> @@ -779,7 +779,7 @@ __SYSCALL(__NR_rseq, sys_rseq)
>  #define __NR_kexec_file_load 294
>  __SYSCALL(__NR_kexec_file_load,     sys_kexec_file_load)
>  /* 295 through 402 are unassigned to sync up with generic numbers, don't use */
> -#if __BITS_PER_LONG == 32
> +#if defined(__SYSCALL_COMPAT) || __BITS_PER_LONG == 32
>  #define __NR_clock_gettime64 403
>  __SYSCALL(__NR_clock_gettime64, sys_clock_gettime)

This part looks wrong, you expose clock_gettime64 to user space this way, both
in asm/unistd.h and in the table.

         Arnd