Re: [PATCH 2/3] Consolidate Linux select implementation

[Siddhesh Poyarekar <siddhesh at gotplt dot org>]

On Thursday 20 April 2017 11:26 PM, Adhemerval Zanella wrote:
> This patch consolidates the select Linux syscall implementation on
> sysdeps/unix/sysv/linux/select.c.  The changes are:
> 
>   1. Remove select from auto-generation syscalls.list on the architecture
>      that uses __NR_select.
>   2. Remove generic implementation add a default one that handle all
>      current cases (with the expection of alpha).  The new default
>      implementation will either use __NR_select if available of fallback
>      to __NR_pselect6 otherwise.
>   3. Add a alpha outlier implementation which requires old compatibility
>      symbols.
> 
> Checked on i686-linux-gnu, x86_64-linux-gnu, x86_64-linux-gnux32,
> arch64-linux-gnu, arm-linux-gnueabihf, and powerpc64le-linux-gnu.
> 
> 	* sysdeps/unix/sysv/linux/alpha/Makefile (sysdep_routines): Add
> 	osf_select.
> 	* sysdeps/unix/sysv/linux/alpha/select.c: New file.
> 	* sysdeps/unix/sysv/linux/alpha/syscalls.list: Remove select and
> 	osf_select from auto-generation list.
> 	* sysdeps/unix/sysv/linux/syscalls.list: Likewise.
> 	* sysdeps/unix/sysv/linux/sparc/sparc64/syscalls.list: Likewise.
> 	* sysdeps/unix/sysv/linux/generic/select.c: Remove file.
> 	* sysdeps/unix/sysv/linux/select.c: New file.
> ---
>  ChangeLog                                          | 10 ++++
>  sysdeps/unix/sysv/linux/alpha/Makefile             |  2 +-
>  sysdeps/unix/sysv/linux/alpha/select.c             | 53 ++++++++++++++++++++++
>  sysdeps/unix/sysv/linux/alpha/syscalls.list        |  2 -
>  sysdeps/unix/sysv/linux/{generic => }/select.c     | 19 ++++++--
>  .../unix/sysv/linux/sparc/sparc64/syscalls.list    |  2 -
>  sysdeps/unix/sysv/linux/syscalls.list              |  1 -
>  7 files changed, 78 insertions(+), 11 deletions(-)
>  create mode 100644 sysdeps/unix/sysv/linux/alpha/select.c
>  rename sysdeps/unix/sysv/linux/{generic => }/select.c (82%)
> 
> diff --git a/sysdeps/unix/sysv/linux/alpha/Makefile b/sysdeps/unix/sysv/linux/alpha/Makefile
> index 37bdd5a..47bd189 100644
> --- a/sysdeps/unix/sysv/linux/alpha/Makefile
> +++ b/sysdeps/unix/sysv/linux/alpha/Makefile
> @@ -13,7 +13,7 @@ sysdep_routines += ieee_get_fp_control ieee_set_fp_control \
>  		   ioperm
>  
>  # Support old timeval32 entry points
> -sysdep_routines += osf_select osf_gettimeofday osf_settimeofday \
> +sysdep_routines += osf_gettimeofday osf_settimeofday \
>  		   osf_getitimer osf_setitimer osf_utimes \
>  		   osf_getrusage osf_wait4
>  
> diff --git a/sysdeps/unix/sysv/linux/alpha/select.c b/sysdeps/unix/sysv/linux/alpha/select.c
> new file mode 100644
> index 0000000..bb0298f
> --- /dev/null
> +++ b/sysdeps/unix/sysv/linux/alpha/select.c
> @@ -0,0 +1,53 @@
> +/* Linux/alpha select implementation.
> +   Copyright (C) 2017 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
> +   <http://www.gnu.org/licenses/>.  */
> +
> +#include <sys/time.h>
> +#include <sys/types.h>
> +#include <sys/select.h>
> +#include <errno.h>
> +#include <sysdep-cancel.h>
> +#include <shlib-compat.h>
> +
> +int
> +__new_select (int nfds, fd_set *readfds, fd_set *writefds, fd_set *exceptfds,
> +	      struct timeval *timeout)
> +{
> +  return SYSCALL_CANCEL (select, nfds, readfds, writefds, exceptfds, timeout);
> +}
> +strong_alias (__new_select, __select)
> +libc_hidden_def (__select)
> +
> +default_symbol_version (__new_select, select, GLIBC_2.1);
> +
> +strong_alias (__new_select, __new_select_private);
> +symbol_version (__new_select_private, __select, GLIBC_2.1);
> +
> +/* Old timeval32 compat calls.  */
> +#if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_1)
> +int
> +__select_tv32 (int nfds, fd_set *readfds, fd_set *writefds, fd_set *exceptfds,
> +	       struct timeval *timeout)
> +{
> +  return SYSCALL_CANCEL (osf_select, nfds, readfds, writefds, exceptfds,
> +                        timeout);
> +}
> +strong_alias (__select_tv32, __select_tv32_1)
> +
> +compat_symbol (libc, __select_tv32, __select, GLIBC_2_0);
> +compat_symbol (libc, __select_tv32_1, select, GLIBC_2_0);
> +#endif
> diff --git a/sysdeps/unix/sysv/linux/alpha/syscalls.list b/sysdeps/unix/sysv/linux/alpha/syscalls.list
> index aa21b10..12cd021 100644
> --- a/sysdeps/unix/sysv/linux/alpha/syscalls.list
> +++ b/sysdeps/unix/sysv/linux/alpha/syscalls.list
> @@ -23,7 +23,6 @@ pciconfig_write	EXTRA	pciconfig_write	5	pciconfig_write
>  pciconfig_iobase EXTRA	pciconfig_iobase 3	__pciconfig_iobase pciconfig_iobase
>  
>  # support old timeval32 entry points
> -osf_select	-	osf_select	C:5	__select_tv32  __select@GLIBC_2.0 select@GLIBC_2.0
>  osf_gettimeofday -	osf_gettimeofday 2	__gettimeofday_tv32  __gettimeofday@GLIBC_2.0 gettimeofday@GLIBC_2.0
>  osf_settimeofday -	osf_settimeofday 2	__settimeofday_tv32  settimeofday@GLIBC_2.0
>  osf_getitimer	-	osf_getitimer	2	__getitimer_tv32  getitimer@GLIBC_2.0
> @@ -33,7 +32,6 @@ osf_getrusage	-	osf_getrusage	2	__getrusage_tv32  getrusage@GLIBC_2.0
>  osf_wait4	-	osf_wait4	4	__wait4_tv32  wait4@GLIBC_2.0
>  
>  # support new timeval64 entry points
> -select		-	select		C:5	__GI___select select@@GLIBC_2.1 __select@@GLIBC_2.1
>  gettimeofday	-	gettimeofday	2	__GI___gettimeofday gettimeofday@@GLIBC_2.1 __gettimeofday@@GLIBC_2.1
>  settimeofday	-	settimeofday	2	__settimeofday settimeofday@@GLIBC_2.1
>  getitimer	-	getitimer	2	__getitimer getitimer@@GLIBC_2.1
> diff --git a/sysdeps/unix/sysv/linux/generic/select.c b/sysdeps/unix/sysv/linux/select.c
> similarity index 82%
> rename from sysdeps/unix/sysv/linux/generic/select.c
> rename to sysdeps/unix/sysv/linux/select.c
> index 7743ea3..6e03450 100644
> --- a/sysdeps/unix/sysv/linux/generic/select.c
> +++ b/sysdeps/unix/sysv/linux/select.c
> @@ -1,6 +1,6 @@
> -/* Copyright (C) 2011-2017 Free Software Foundation, Inc.
> +/* Linux select implementation.
> +   Copyright (C) 2017 Free Software Foundation, Inc.
>     This file is part of the GNU C Library.
> -   Contributed by Chris Metcalf <cmetcalf@tilera.com>, 2011.
>  
>     The GNU C Library is free software; you can redistribute it and/or
>     modify it under the terms of the GNU Lesser General Public
> @@ -28,11 +28,19 @@
>     after waiting the interval specified therein.  Returns the number of ready
>     descriptors, or -1 for errors.  */
>  
> +#ifdef __NR__newselect
> +# undef __NR_select
> +# define __RN_select __NR__newselect

Typo.

Looks OK otherwise.

Siddhesh

> +#endif
> +
>  int
> -__select(int nfds, fd_set *readfds,
> -         fd_set *writefds, fd_set *exceptfds,
> -         struct timeval *timeout)
> +__select (int nfds, fd_set *readfds, fd_set *writefds, fd_set *exceptfds,
> +	  struct timeval *timeout)
>  {
> +#ifdef __NR_select
> +  return SYSCALL_CANCEL (select, nfds, readfds, writefds, exceptfds,
> +			 timeout);
> +#else
>    int result;
>    struct timespec ts, *tsp = NULL;
>  
> @@ -55,6 +63,7 @@ __select(int nfds, fd_set *readfds,
>      }
>  
>    return result;
> +#endif
>  }
>  libc_hidden_def (__select)
>  
> diff --git a/sysdeps/unix/sysv/linux/sparc/sparc64/syscalls.list b/sysdeps/unix/sysv/linux/sparc/sparc64/syscalls.list
> index 1e85118..33082f3 100644
> --- a/sysdeps/unix/sysv/linux/sparc/sparc64/syscalls.list
> +++ b/sysdeps/unix/sysv/linux/sparc/sparc64/syscalls.list
> @@ -1,7 +1,5 @@
>  # File name	Caller	Syscall name	# args	Strong name	Weak names
>  
> -# Override select.S in parent directory:
> -select		-	select		C:5	__select	select
>  bind		-	bind		3	__bind		bind
>  getpeername	-	getpeername	3	__getpeername	getpeername
>  getsockname	-	getsockname	3	__getsockname	getsockname
> diff --git a/sysdeps/unix/sysv/linux/syscalls.list b/sysdeps/unix/sysv/linux/syscalls.list
> index fcefefc..4d550b8 100644
> --- a/sysdeps/unix/sysv/linux/syscalls.list
> +++ b/sysdeps/unix/sysv/linux/syscalls.list
> @@ -63,7 +63,6 @@ sched_rr_gi	-	sched_rr_get_interval	i:ip	__sched_rr_get_interval	sched_rr_get_in
>  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
> -select		-	_newselect	Ci:iPPPP	__select	__libc_select select
>  sendfile	-	sendfile	i:iipi	sendfile
>  sendfile64	-	sendfile64	i:iipi	sendfile64
>  setfsgid	EXTRA	setfsgid	i:i	setfsgid
>