Re: [PATCH 15/30] Linux: consolidate sendfile implementation

[Carlos O'Donell <carlos@redhat.com>]

On 10/19/22 18:14, Adhemerval Zanella via Libc-alpha wrote:
> This is similar to other LFS consolidation, where the non-LFS is only
> built if __OFF_T_MATCHES_OFF64_T is not defined and the LFS version
> is aliased to non-LFS name if __OFF_T_MATCHES_OFF64_T is defined.
> 
> For non-LFS variant, use sendfile syscall if defined, otherwise use
> sendfile64 plus the offset overflow check (as generic implementation).

LGTM.

No regressions on x86_64 and i686.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Tested-by: Carlos O'Donell <carlos@redhat.com>

> 
> Checked on x86_64-linux-gnu.
> ---
>  .../sysv/linux/mips/mips64/n64/sendfile64.c   |  1 -
>  .../sysv/linux/mips/mips64/n64/syscalls.list  |  3 --
>  .../{generic/wordsize-32 => }/sendfile.c      | 15 ++++++--
>  sysdeps/unix/sysv/linux/sendfile64.c          | 37 +++++++++++++++++++
>  sysdeps/unix/sysv/linux/syscalls.list         |  2 -
>  .../unix/sysv/linux/wordsize-64/sendfile64.c  |  1 -
>  .../unix/sysv/linux/wordsize-64/syscalls.list |  1 -
>  7 files changed, 49 insertions(+), 11 deletions(-)
>  delete mode 100644 sysdeps/unix/sysv/linux/mips/mips64/n64/sendfile64.c
>  delete mode 100644 sysdeps/unix/sysv/linux/mips/mips64/n64/syscalls.list
>  rename sysdeps/unix/sysv/linux/{generic/wordsize-32 => }/sendfile.c (77%)
>  create mode 100644 sysdeps/unix/sysv/linux/sendfile64.c
>  delete mode 100644 sysdeps/unix/sysv/linux/wordsize-64/sendfile64.c
> 
> diff --git a/sysdeps/unix/sysv/linux/mips/mips64/n64/sendfile64.c b/sysdeps/unix/sysv/linux/mips/mips64/n64/sendfile64.c
> deleted file mode 100644
> index 4c451bd093..0000000000
> --- a/sysdeps/unix/sysv/linux/mips/mips64/n64/sendfile64.c
> +++ /dev/null
> @@ -1 +0,0 @@
> -/* sendfile64 is alias of sendfile syscall.  */

OK. Remove.

> diff --git a/sysdeps/unix/sysv/linux/mips/mips64/n64/syscalls.list b/sysdeps/unix/sysv/linux/mips/mips64/n64/syscalls.list
> deleted file mode 100644
> index 0924f245d4..0000000000
> --- a/sysdeps/unix/sysv/linux/mips/mips64/n64/syscalls.list
> +++ /dev/null
> @@ -1,3 +0,0 @@
> -# File name	Caller	Syscall name	# args	Strong name	Weak names
> -
> -sendfile	-	sendfile	i:iipi	sendfile	sendfile64

OK. Remove.

> diff --git a/sysdeps/unix/sysv/linux/generic/wordsize-32/sendfile.c b/sysdeps/unix/sysv/linux/sendfile.c
> similarity index 77%
> rename from sysdeps/unix/sysv/linux/generic/wordsize-32/sendfile.c
> rename to sysdeps/unix/sysv/linux/sendfile.c
> index 4fdf979324..c8bc890944 100644
> --- a/sysdeps/unix/sysv/linux/generic/wordsize-32/sendfile.c
> +++ b/sysdeps/unix/sysv/linux/sendfile.c

OK. Moved.

> @@ -1,4 +1,5 @@
> -/* Copyright (C) 2011-2022 Free Software Foundation, Inc.
> +/* Transfer data between file descriptors.  Linux version.
> +   Copyright (C) 2011-2022 Free Software Foundation, Inc.
>     This file is part of the GNU C Library.
>  
>     The GNU C Library is free software; you can redistribute it and/or
> @@ -20,11 +21,16 @@
>  #include <errno.h>
>  #include <sysdep.h>
>  
> +#ifndef __OFF_T_MATCHES_OFF64_T
> +
>  /* Send COUNT bytes from file associated with IN_FD starting at OFFSET to
>     descriptor OUT_FD.  */
>  ssize_t
>  sendfile (int out_fd, int in_fd, off_t *offset, size_t count)
>  {
> +# ifdef __NR_sendfile
> +  return INLINE_SYSCALL_CALL (sendfile, out_fd, in_fd, offset, count);

OK. Consolidated. Call sendfile if we have it.

> +# else
>    __off64_t off64;
>    int rc;
>  
> @@ -38,9 +44,12 @@ sendfile (int out_fd, int in_fd, off_t *offset, size_t count)
>        off64 = *offset;
>      }
>  
> -  rc = INLINE_SYSCALL (sendfile64, 4, out_fd, in_fd,
> -                       offset ? &off64 : NULL, count);
> +  rc = INLINE_SYSCALL_CALL (sendfile64, out_fd, in_fd, offset ? &off64 : NULL,
> +			    count);

OK. Otherwise call sendfile64.

>    if (offset)
>      *offset = off64;
>    return rc;
> +# endif
>  }
> +
> +#endif
> diff --git a/sysdeps/unix/sysv/linux/sendfile64.c b/sysdeps/unix/sysv/linux/sendfile64.c
> new file mode 100644
> index 0000000000..d9d2a4a4c2
> --- /dev/null
> +++ b/sysdeps/unix/sysv/linux/sendfile64.c
> @@ -0,0 +1,37 @@
> +/* Transfer data between file descriptors.  Linux version.

OK. New consolidated version.

> +   Copyright (C) 2022 Free Software Foundation, Inc.
> +   This file is part of the GNU C Library.
> +
> +   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/>.  */
> +
> +#include <sys/sendfile.h>
> +#include <stddef.h>
> +#include <errno.h>
> +#include <sysdep.h>
> +
> +/* Send COUNT bytes from file associated with IN_FD starting at OFFSET to
> +   descriptor OUT_FD.  */
> +ssize_t
> +sendfile64 (int out_fd, int in_fd, off64_t *offset, size_t count)
> +{
> +#ifndef __NR_sendfile64
> +# define __NR_sendfile64 __NR_sendfile
> +#endif
> +  return INLINE_SYSCALL_CALL (sendfile64, out_fd, in_fd, offset, count);

OK.

> +}
> +
> +#ifdef __OFF_T_MATCHES_OFF64_T
> +strong_alias (sendfile64, sendfile)

OK. Alias.

> +#endif
> diff --git a/sysdeps/unix/sysv/linux/syscalls.list b/sysdeps/unix/sysv/linux/syscalls.list
> index 6420049e8b..b9f45463c5 100644
> --- a/sysdeps/unix/sysv/linux/syscalls.list
> +++ b/sysdeps/unix/sysv/linux/syscalls.list
> @@ -62,8 +62,6 @@ sched_primin	-	sched_get_priority_min	i:i	__sched_get_priority_min	sched_get_pri
>  sched_setp	-	sched_setparam	i:ip	__sched_setparam	sched_setparam
>  sched_sets	-	sched_setscheduler	i:iip	__sched_setscheduler	sched_setscheduler
>  sched_yield	-	sched_yield	i:	__sched_yield	sched_yield
> -sendfile	-	sendfile	i:iipU	sendfile
> -sendfile64	-	sendfile64	i:iipU	sendfile64

OK. Remove. We have C files for these.

>  setfsgid	EXTRA	setfsgid	i:i	setfsgid
>  setfsuid	EXTRA	setfsuid	i:i	setfsuid
>  setpgid		-	setpgid		i:ii	__setpgid	setpgid
> diff --git a/sysdeps/unix/sysv/linux/wordsize-64/sendfile64.c b/sysdeps/unix/sysv/linux/wordsize-64/sendfile64.c
> deleted file mode 100644
> index 4c451bd093..0000000000
> --- a/sysdeps/unix/sysv/linux/wordsize-64/sendfile64.c
> +++ /dev/null
> @@ -1 +0,0 @@
> -/* sendfile64 is alias of sendfile syscall.  */

OK.

> diff --git a/sysdeps/unix/sysv/linux/wordsize-64/syscalls.list b/sysdeps/unix/sysv/linux/wordsize-64/syscalls.list
> index 3232f11f51..db80696e41 100644
> --- a/sysdeps/unix/sysv/linux/wordsize-64/syscalls.list
> +++ b/sysdeps/unix/sysv/linux/wordsize-64/syscalls.list
> @@ -1,4 +1,3 @@
>  # File name	Caller	Syscall name	# args	Strong name	Weak names
>  
> -sendfile	-	sendfile	i:iipi	sendfile	sendfile64

OK. Have C files.

>  personality	EXTRA	personality	i:i	__personality	personality

-- 
Cheers,
Carlos.