[PATCH v3 03/19] RISC-V: Use 64-bit-time syscall numbers with the 32-bit port

[Maciej W. Rozycki]

On Sun, 12 Jul 2020, Alistair Francis via Libc-alpha wrote:

> This patches adds any required syscall suppression for 32-bit
> off_t/time_t to fixup-asm-unistd.h so arch-syscall.h will have only
> the required definitions.

 This part is not needed; see below.

> sysdep.h redefines only the syscall where the generic implementation
> still does not have actual 64-bit time_t support:
> 
>    /* "workarounds" for generic code needing to handle 64-bit time_t.  */

 I'm not sure why the ARC port developers chose to not to capitalise the 
sentence and use quotation marks here.  It's not like "workarounds" here 
is a metaphor, a quotation, or a keyword (which, oddly, people often don't 
wrap into quotation marks for a change).  Please use:

   /* Workarounds for generic code needing to handle 64-bit time_t.  */

then.  Likewise with the inline comment below.

> diff --git a/sysdeps/unix/sysv/linux/riscv/fixup-asm-unistd.h b/sysdeps/unix/sysv/linux/riscv/fixup-asm-unistd.h
> new file mode 100644
> index 0000000000..bc8b10e283
> --- /dev/null
> +++ b/sysdeps/unix/sysv/linux/riscv/fixup-asm-unistd.h
> @@ -0,0 +1,45 @@
> +/* Regularize <asm/unistd.h> definitions.  RISC-V version.
> +   Copyright (C) 2020 Free Software Foundation, Inc.
> +
> +   The GNU C Library is free software; you can redistribute it and/or
> +   modify it under the terms of the GNU Lesser General Public
> +   License as published by the Free Software Foundation; either
> +   version 2.1 of the License, or (at your option) any later version.
> +
> +   The GNU C Library is distributed in the hope that it will be useful,
> +   but WITHOUT ANY WARRANTY; without even the implied warranty of
> +   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
> +   Lesser General Public License for more details.
> +
> +   You should have received a copy of the GNU Lesser General Public
> +   License along with the GNU C Library; if not, see
> +   <https://www.gnu.org/licenses/>.  */
> +
> +/* Adjustments to RISC-V asm-generic syscall for 64-bit time_t support.  */
> +
> +/* fstat64 and fstatat64 need to be replaced with statx.  */
> +
> +#undef __NR_fstat64
> +#undef __NR_fstatat64
> +
> +/* Replace all other 32-bit time syscalls with 64-bit variants.  */
> +
> +# undef __NR_clock_adjtime
> +# undef __NR_clock_getres
> +# undef __NR_clock_gettime
> +# undef __NR_clock_nanosleep
> +# undef __NR_clock_settime
> +# undef __NR_futex
> +# undef __NR_mq_timedreceive
> +# undef __NR_mq_timedsend
> +# undef __NR_ppoll
> +# undef __NR_pselect6
> +# undef __NR_recvmmsg
> +# undef __NR_rt_sigtimedwait
> +# undef __NR_sched_rr_get_interval
> +# undef __NR_semtimedop
> +# undef __NR_timer_gettime
> +# undef __NR_timer_settime
> +# undef __NR_timerfd_gettime
> +# undef __NR_timerfd_settime
> +# undef __NR_utimensat

 None of these #undef's are required, as none of these syscalls (macros) 
are actually defined in the first place by Linux for RV32.

> diff --git a/sysdeps/unix/sysv/linux/riscv/sysdep.h b/sysdeps/unix/sysv/linux/riscv/sysdep.h
> index 429686cebe..62a9551f50 100644
> --- a/sysdeps/unix/sysv/linux/riscv/sysdep.h
> +++ b/sysdeps/unix/sysv/linux/riscv/sysdep.h
> @@ -22,6 +22,33 @@
>  #include <sysdeps/unix/sysv/linux/generic/sysdep.h>
>  #include <tls.h>
>  
> +#if __WORDSIZE == 32
> +
> +

 Extraneous newline.

> +/* "workarounds" for generic code needing to handle 64-bit time_t.  */
> +
> +/* Fix sysdeps/unix/sysv/linux/clock_getcpuclockid.c.  */
> +#define __NR_clock_getres      __NR_clock_getres_time64
> +/* Fix sysdeps/nptl/lowlevellock-futex.h.  */
> +#define __NR_futex             __NR_futex_time64
> +/* Fix sysdeps/unix/sysv/linux/pause.c.  */
> +#define __NR_ppoll             __NR_ppoll_time64
> +/* Fix sysdeps/unix/sysv/linux/select.c.  */
> +#define __NR_pselect6          __NR_pselect6_time64
> +/* Fix sysdeps/unix/sysv/linux/recvmmsg.c.  */
> +#define __NR_recvmmsg          __NR_recvmmsg_time64
> +/* Fix sysdeps/unix/sysv/linux/sigtimedwait.c.  */
> +#define __NR_rt_sigtimedwait   __NR_rt_sigtimedwait_time64
> +/* Fix sysdeps/unix/sysv/linux/semtimedop.c.  */
> +#define __NR_semtimedop                __NR_semtimedop_time64
> +/* Hack sysdeps/unix/sysv/linux/generic/utimes.c.  */
> +#define __NR_utimensat         __NR_utimensat_time64

 Please use tabs rather than spaces between the LHS and the RHS, and align 
the RHS.  NB `indent -gnu' can help with such boring mechanical stuff.

> +
> +#undef SYS_ify
> +#define SYS_ify(syscall_name)	__NR_##syscall_name

 This has to go along with 02/19, as noted in the review of that change.

  Maciej