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[PATCH] Consolidate sched_getcpu

From: Adhemerval Zanella <adhemerval dot zanella at linaro dot org>
To: GNU C Library <libc-alpha at sourceware dot org>
Date: Thu, 23 Apr 2015 18:21:27 -0300
Subject: [PATCH] Consolidate sched_getcpu
Authentication-results: sourceware.org; auth=none
Hi

This patch consolidates the 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).

For x86 is add some more cleanups:

* There is no need for __syscall_clock_gettime anymore, since the
  VSYSCALL_INLINE will call the syscall version directly.  So the
  fallback mechanism could be removed.

* The x86_64 fallback mechanism is to use the vsyscall, which is
  nowadays is not a recommended interface to access the kernel.
  The patch removes it and a subsequent patch removes all vsyscall
  usage.

* x86_64 and x32 can use the same init-first.c now.

* There is no need to specific static file for sched_getcpu for x32.

Tested on i686, x86_64, and x32. I also check the build for ppc32
and ppc64le.

--

	* 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): Define if
	HAVE_GETCPU_VSYSCALL and include sysdep-vdso.
	(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
	(__syscall_clock_gettime): Remove prototype.
	(__vdso_platform_setup): Remove vsyscall getcpu fallback.
	* sysdeps/unix/sysv/linux/x86_64/sched_getcpu.S: Remove file.
	* sysdeps/unix/sysv/linux/x86_64/syscalls.list
	(__syscall_clock_gettime): Remove defintion.
	* 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 8bd42ec..f52f1a9 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 1bad856..e2205f9 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..d83b04b 100644
--- a/sysdeps/unix/sysv/linux/x86_64/init-first.c
+++ b/sysdeps/unix/sysv/linux/x86_64/init-first.c
@@ -27,25 +27,16 @@ long int (*VDSO_SYMBOL(clock_gettime)) (clockid_t, struct timespec *)
 long int (*VDSO_SYMBOL(getcpu)) (unsigned *, unsigned *, void *)
   attribute_hidden;
 
-extern long int __syscall_clock_gettime (clockid_t, struct timespec *);
-
-
 static inline void
 __vdso_platform_setup (void)
 {
   PREPARE_VERSION (linux26, "LINUX_2.6", 61765110);
 
   void *p = _dl_vdso_vsym ("__vdso_clock_gettime", &linux26);
-  if (p == NULL)
-    p = __syscall_clock_gettime;
   PTR_MANGLE (p);
   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/syscalls.list b/sysdeps/unix/sysv/linux/x86_64/syscalls.list
index 2e4135f..b4f2075 100644
--- a/sysdeps/unix/sysv/linux/x86_64/syscalls.list
+++ b/sysdeps/unix/sysv/linux/x86_64/syscalls.list
@@ -14,7 +14,6 @@ semop		-	semop		i:ipi	__semop		semop
 semtimedop	-	semtimedop	i:ipip	semtimedop
 semget		-	semget		i:iii	__semget	semget
 semctl		-	semctl		i:iiii	__semctl	semctl
-syscall_clock_gettime	EXTRA	clock_gettime	Ei:ip		__syscall_clock_gettime
 
 
 # proper socket implementations:
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
--
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