Re: [PATCH v2] Consolidate sched_getcpu

[Adhemerval Zanella <adhemerval dot zanella at linaro dot org>]

I will commit this patch soon if noone opposes it.

On 05-06-2015 15:58, Adhemerval Zanella wrote:
> This is an update patch for my previous one [1] to consolidates 
> sched_getcpu implementations across all arches (except tile, 
> which requires its own).  This patch removes the powerpc, x86_64
> and x32 specific files and change the default linux one to use 
> INLINE_VSYSCALL where possible (for ports that implements it).
> 
> Tested on powerpc64, i386, x86_64, and x32.
> 
> [1] https://sourceware.org/ml/libc-alpha/2015-04/msg00290.html
> 
> Changes from previous version:
> 
> * Do not remove __syscall_clock_gettime for x86_64 (it will be
>   in another cleanup).
> 
> --
> 
> 	* sysdeps/unix/sysv/linux/powerpc/powerpc32/sysdep.h
> 	(HAVE_GETCPU_VSYSCALL): Define.
> 	* sysdeps/unix/sysv/linux/powerpc/powerpc64/sysdep.h
> 	(HAVE_GETCPU_VSYSCALL): Likewise.
> 	* sysdeps/unix/sysv/linux/powerpc/sched_getcpu.c: Remove file.
> 	* sysdeps/unix/sysv/linux/sched_getcpu.c
> 	(HAVE_VSYSCALL) [HAVE_GETCPU_VSYSCALL]: Define.
> 	(sched_getcpu): Use INLINE_VSYSCALL instead of INLINE_SYSCALL.
> 	* sysdeps/unix/sysv/linux/x86/libc-vdso.h (getcpu): Add vDSO
> 	prototype.
> 	* sysdeps/unix/sysv/linux/x86_64/init-first.c
> 	(__vdso_platform_setup): Remove vsyscall getcpu fallback.
> 	* sysdeps/unix/sysv/linux/x86_64/sched_getcpu.S: Remove file.
> 	* sysdeps/unix/sysv/linux/x86_64/sysdep.h (HAVE_GETCPU_VSYSCALL):
> 	Define.
> 	* sysdeps/unix/sysv/linux/x86_64/x32/Makefile: Remove file.
> 	* sysdeps/unix/sysv/linux/x86_64/x32/init-first.c: Likewise.
> 	* sysdeps/unix/sysv/linux/x86_64/x32/sched_getcpu-static.c: Likewise.
> 	* sysdeps/unix/sysv/linux/x86_64/x32/sched_getcpu.S: Likewise.
> 
> ---
> 
> diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc32/sysdep.h b/sysdeps/unix/sysv/linux/powerpc/powerpc32/sysdep.h
> index cbce324..dc56bea 100644
> --- a/sysdeps/unix/sysv/linux/powerpc/powerpc32/sysdep.h
> +++ b/sysdeps/unix/sysv/linux/powerpc/powerpc32/sysdep.h
> @@ -165,6 +165,7 @@
>  /* List of system calls which are supported as vsyscalls.  */
>  # define HAVE_CLOCK_GETRES_VSYSCALL	1
>  # define HAVE_CLOCK_GETTIME_VSYSCALL	1
> +# define HAVE_GETCPU_VSYSCALL		1
>  
>  
>  # define LOADARGS_0(name, dummy)					      \
> diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc64/sysdep.h b/sysdeps/unix/sysv/linux/powerpc/powerpc64/sysdep.h
> index a727f38..e2014cc 100644
> --- a/sysdeps/unix/sysv/linux/powerpc/powerpc64/sysdep.h
> +++ b/sysdeps/unix/sysv/linux/powerpc/powerpc64/sysdep.h
> @@ -80,6 +80,7 @@
>  /* List of system calls which are supported as vsyscalls.  */
>  #define HAVE_CLOCK_GETRES_VSYSCALL	1
>  #define HAVE_CLOCK_GETTIME_VSYSCALL	1
> +#define HAVE_GETCPU_VSYSCALL		1
>  
>  /* Define a macro which expands inline into the wrapper code for a system
>     call. This use is for internal calls that do not need to handle errors
> diff --git a/sysdeps/unix/sysv/linux/powerpc/sched_getcpu.c b/sysdeps/unix/sysv/linux/powerpc/sched_getcpu.c
> deleted file mode 100644
> index f93be01..0000000
> --- a/sysdeps/unix/sysv/linux/powerpc/sched_getcpu.c
> +++ /dev/null
> @@ -1,29 +0,0 @@
> -/* Copyright (C) 2013-2015 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 <sched.h>
> -#include <sysdep.h>
> -#include <sysdep-vdso.h>
> -
> -int
> -sched_getcpu (void)
> -{
> -  unsigned int cpu;
> -  int r = INLINE_VSYSCALL (getcpu, 3, &cpu, NULL, NULL);
> -
> -  return r == -1 ? r : cpu;
> -}
> diff --git a/sysdeps/unix/sysv/linux/sched_getcpu.c b/sysdeps/unix/sysv/linux/sched_getcpu.c
> index 09f0816..a485d36 100644
> --- a/sysdeps/unix/sysv/linux/sched_getcpu.c
> +++ b/sysdeps/unix/sysv/linux/sched_getcpu.c
> @@ -19,13 +19,17 @@
>  #include <sched.h>
>  #include <sysdep.h>
>  
> +#ifdef HAVE_GETCPU_VSYSCALL
> +# define HAVE_VSYSCALL
> +#endif
> +#include <sysdep-vdso.h>
>  
>  int
>  sched_getcpu (void)
>  {
>  #ifdef __NR_getcpu
>    unsigned int cpu;
> -  int r = INLINE_SYSCALL (getcpu, 3, &cpu, NULL, NULL);
> +  int r = INLINE_VSYSCALL (getcpu, 3, &cpu, NULL, NULL);
>  
>    return r == -1 ? r : cpu;
>  #else
> diff --git a/sysdeps/unix/sysv/linux/x86/libc-vdso.h b/sysdeps/unix/sysv/linux/x86/libc-vdso.h
> index fea9c2b..f3a8f07 100644
> --- a/sysdeps/unix/sysv/linux/x86/libc-vdso.h
> +++ b/sysdeps/unix/sysv/linux/x86/libc-vdso.h
> @@ -29,6 +29,8 @@
>  extern long int (*VDSO_SYMBOL(clock_gettime)) (clockid_t, struct timespec *)
>    attribute_hidden;
>  
> +extern long int (*VDSO_SYMBOL(getcpu)) (unsigned *, unsigned *, void *);
> +
>  #endif
>  
>  #endif /* _LIBC_VDSO_H */
> diff --git a/sysdeps/unix/sysv/linux/x86_64/init-first.c b/sysdeps/unix/sysv/linux/x86_64/init-first.c
> index b7bdbd1..6e2b040 100644
> --- a/sysdeps/unix/sysv/linux/x86_64/init-first.c
> +++ b/sysdeps/unix/sysv/linux/x86_64/init-first.c
> @@ -42,10 +42,6 @@ __vdso_platform_setup (void)
>    VDSO_SYMBOL(clock_gettime) = p;
>  
>    p = _dl_vdso_vsym ("__vdso_getcpu", &linux26);
> -  /* If the vDSO is not available we fall back on the old vsyscall.  */
> -#define VSYSCALL_ADDR_vgetcpu	0xffffffffff600800
> -  if (p == NULL)
> -    p = (void *) VSYSCALL_ADDR_vgetcpu;
>    PTR_MANGLE (p);
>    VDSO_SYMBOL(getcpu) = p;
>  }
> diff --git a/sysdeps/unix/sysv/linux/x86_64/sched_getcpu.S b/sysdeps/unix/sysv/linux/x86_64/sched_getcpu.S
> deleted file mode 100644
> index b87f803..0000000
> --- a/sysdeps/unix/sysv/linux/x86_64/sched_getcpu.S
> +++ /dev/null
> @@ -1,74 +0,0 @@
> -/* Copyright (C) 2007-2015 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 <sysdep.h>
> -#include <tls.h>
> -#define _ERRNO_H	1
> -#include <bits/errno.h>
> -#include <kernel-features.h>
> -
> -/* For the calculation see asm/vsyscall.h.  */
> -#define VSYSCALL_ADDR_vgetcpu	0xffffffffff600800
> -
> -
> -ENTRY (sched_getcpu)
> -	/* Align stack and create local variable for result.  */
> -	sub	$0x8, %rsp
> -	cfi_adjust_cfa_offset(8)
> -
> -	movq	%rsp, %rdi
> -	xorl	%esi, %esi
> -	movl	$VGETCPU_CACHE_OFFSET, %edx
> -	addq	%fs:0, %rdx
> -
> -#ifdef SHARED
> -	movq	__vdso_getcpu(%rip), %rax
> -	PTR_DEMANGLE (%rax)
> -	callq	*%rax
> -#else
> -# ifdef __NR_getcpu
> -	movl	$__NR_getcpu, %eax
> -	syscall
> -#  ifndef __ASSUME_GETCPU_SYSCALL
> -	cmpq	$-ENOSYS, %rax
> -	jne	1f
> -#  endif
> -# endif
> -# ifndef __ASSUME_GETCPU_SYSCALL
> -	movq	$VSYSCALL_ADDR_vgetcpu, %rax
> -	callq	*%rax
> -1:
> -# else
> -#  ifndef __NR_getcpu
> -#   error "cannot happen"
> -#  endif
> -# endif
> -#endif
> -
> -	/* Local variable is result if the call is successful.  */
> -	movl	(%rsp), %edx
> -	/* Restore stack pointer before we might jump to
> -	SYSCALL_ERROR_LABEL which returns to the caller.  */
> -	add	$0x8, %rsp
> -	cfi_adjust_cfa_offset(-8)
> -
> -	cmpq	$-4095, %rax
> -	jae	SYSCALL_ERROR_LABEL
> -
> -	movl	%edx, %eax
> -	ret
> -PSEUDO_END(sched_getcpu)
> diff --git a/sysdeps/unix/sysv/linux/x86_64/sysdep.h b/sysdeps/unix/sysv/linux/x86_64/sysdep.h
> index bea3192..5a62cce 100644
> --- a/sysdeps/unix/sysv/linux/x86_64/sysdep.h
> +++ b/sysdeps/unix/sysv/linux/x86_64/sysdep.h
> @@ -255,6 +255,7 @@
>  /* List of system calls which are supported as vsyscalls.  */
>  # define HAVE_CLOCK_GETTIME_VSYSCALL    1
>  # define HAVE_GETTIMEOFDAY_VSYSCALL     1
> +# define HAVE_GETCPU_VSYSCALL		1
>  
>  # define LOAD_ARGS_0()
>  # define LOAD_REGS_0
> diff --git a/sysdeps/unix/sysv/linux/x86_64/x32/Makefile b/sysdeps/unix/sysv/linux/x86_64/x32/Makefile
> index ecbdefb..8c3253b 100644
> --- a/sysdeps/unix/sysv/linux/x86_64/x32/Makefile
> +++ b/sysdeps/unix/sysv/linux/x86_64/x32/Makefile
> @@ -4,7 +4,3 @@ default-abi := x32
>  ifeq ($(subdir),misc)
>  sysdep_routines += arch_prctl
>  endif
> -
> -ifeq ($(subdir),posix)
> -sysdep_routines += getcpu sched_getcpu-static
> -endif
> diff --git a/sysdeps/unix/sysv/linux/x86_64/x32/init-first.c b/sysdeps/unix/sysv/linux/x86_64/x32/init-first.c
> deleted file mode 100644
> index 31ec80f..0000000
> --- a/sysdeps/unix/sysv/linux/x86_64/x32/init-first.c
> +++ /dev/null
> @@ -1,39 +0,0 @@
> -/* Initialization code run first thing by the ELF startup code.  Linux/x32.
> -   Copyright (C) 2012-2015 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/>.  */
> -
> -#ifdef SHARED
> -# include <dl-vdso.h>
> -# include <libc-vdso.h>
> -
> -long int (*__vdso_clock_gettime) (clockid_t, struct timespec *)
> -  attribute_hidden;
> -
> -static inline void
> -_libc_vdso_platform_setup (void)
> -{
> -  PREPARE_VERSION (linux26, "LINUX_2.6", 61765110);
> -
> -  void *p = _dl_vdso_vsym ("__vdso_clock_gettime", &linux26);
> -  PTR_MANGLE (p);
> -  __vdso_clock_gettime = p;
> -}
> -
> -# define VDSO_SETUP _libc_vdso_platform_setup
> -#endif
> -
> -#include <csu/init-first.c>
> diff --git a/sysdeps/unix/sysv/linux/x86_64/x32/sched_getcpu-static.c b/sysdeps/unix/sysv/linux/x86_64/x32/sched_getcpu-static.c
> deleted file mode 100644
> index 38bbf9a..0000000
> --- a/sysdeps/unix/sysv/linux/x86_64/x32/sched_getcpu-static.c
> +++ /dev/null
> @@ -1,3 +0,0 @@
> -#ifndef SHARED
> -#include "../../sched_getcpu.c"
> -#endif
> diff --git a/sysdeps/unix/sysv/linux/x86_64/x32/sched_getcpu.S b/sysdeps/unix/sysv/linux/x86_64/x32/sched_getcpu.S
> deleted file mode 100644
> index 35ad01b..0000000
> --- a/sysdeps/unix/sysv/linux/x86_64/x32/sched_getcpu.S
> +++ /dev/null
> @@ -1,49 +0,0 @@
> -/* Copyright (C) 2012-2015 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/>.  */
> -
> -#ifdef SHARED
> -#include <sysdep.h>
> -#include <tls.h>
> -#define _ERRNO_H	1
> -#include <bits/errno.h>
> -
> -ENTRY (sched_getcpu)
> -	/* Align stack and create local variable for result.  */
> -	sub	$0x8, %esp
> -	cfi_adjust_cfa_offset(8)
> -
> -	mov	%esp, %edi
> -	xor	%esi, %esi
> -	mov	$VGETCPU_CACHE_OFFSET, %edx
> -	add	%fs:0, %edx
> -
> -	call	__getcpu
> -
> -	/* Local variable is result if the call is successful.  */
> -	mov	(%rsp), %edx
> -	/* Restore stack pointer before we might jump to
> -	   SYSCALL_ERROR_LABEL which returns to the caller.  */
> -	add	$0x8, %esp
> -	cfi_adjust_cfa_offset(-8)
> -
> -	cmp	$-4095, %eax
> -	jae	SYSCALL_ERROR_LABEL
> -
> -	mov	%edx, %eax
> -	ret
> -PSEUDO_END(sched_getcpu)
> -#endif
>