m68k: Remove vDSO support

Although defined in initial TLS/NPTL ABI for m68k and ColdFire [1], kernel
support was never pushed upstream.  This patch removes the unused m68k
vDSO support.

Checked with a build against m68k and m68k-coldfire and some basic
tests on ARAnyM.

	* sysdeps/unix/sysv/linux/m68k/Makefile (sysdep_routines,
	sysdep-rtld-routines): Remove rules.
	* sysdeps/unix/sysv/linux/m68k/Versions (libc) [GLIBC_PRIVATE]:
	Remove __vdso_atomic_cmpxchg_32 and __vdso_atomic_barrier.
	(ld) [GLIBC_PRIVATE]: __rtld___vdso_read_tp,
	__rtld___vdso_atomic_cmpxchg_32, and __rtld___vdso_atomic_barrier.
	* sysdeps/unix/sysv/linux/m68k/coldfire/atomic-machine.h
	(atomic_compare_and_exchange_val_acq, atomic_full_barrier): Remove
	vDSO path for SHARED.
	* sysdeps/unix/sysv/linux/m68k/init-first.c: Remove file.
	* sysdeps/unix/sysv/linux/m68k/libc-m68k-vdso.c: Likewise.
	* sysdeps/unix/sysv/linux/m68k/m68k-helpers.S: Likewise.
	* sysdeps/unix/sysv/linux/m68k/m68k-vdso.c: Likewise.
	* sysdeps/unix/sysv/linux/m68k/m68k-vdso.h: Likewise.
	* sysdeps/unix/sysv/linux/m68k/m68k-helpers.c: New file.

[1] https://lists.debian.org/debian-68k/2007/11/msg00071.html

9 files changed, 27 insertions, 321 deletions

diff --git a/sysdeps/unix/sysv/linux/m68k/Makefile b/sysdeps/unix/sysv/linux/m68k/Makefile
index ce1f696a6f..be40fae68a 100644
--- a/sysdeps/unix/sysv/linux/m68k/Makefile
+++ b/sysdeps/unix/sysv/linux/m68k/Makefile
@@ -18,8 +18,6 @@ endif
 
 ifeq ($(subdir),elf)
 sysdep-dl-routines += dl-static
-sysdep_routines += dl-vdso libc-m68k-vdso
-sysdep-rtld-routines += m68k-vdso
 sysdep-others += lddlibc4
 install-bin += lddlibc4
 endif
diff --git a/sysdeps/unix/sysv/linux/m68k/Versions b/sysdeps/unix/sysv/linux/m68k/Versions
index 7ecc96ea97..8e72cd18cb 100644
--- a/sysdeps/unix/sysv/linux/m68k/Versions
+++ b/sysdeps/unix/sysv/linux/m68k/Versions
@@ -40,15 +40,4 @@ libc {
   GLIBC_2.12 {
     __m68k_read_tp;
   }
-  GLIBC_PRIVATE {
-    __vdso_atomic_cmpxchg_32; __vdso_atomic_barrier;
-  }
-}
-
-ld {
-  GLIBC_PRIVATE {
-    __rtld___vdso_read_tp;
-    __rtld___vdso_atomic_cmpxchg_32;
-    __rtld___vdso_atomic_barrier;
-  }
 }
diff --git a/sysdeps/unix/sysv/linux/m68k/coldfire/atomic-machine.h b/sysdeps/unix/sysv/linux/m68k/coldfire/atomic-machine.h
index 7465a98fef..0a2aa9ffa5 100644
--- a/sysdeps/unix/sysv/linux/m68k/coldfire/atomic-machine.h
+++ b/sysdeps/unix/sysv/linux/m68k/coldfire/atomic-machine.h
@@ -21,7 +21,6 @@
 
 #include <stdint.h>
 #include <sysdep.h>
-#include <m68k-vdso.h>
 
 /* Coldfire has no atomic compare-and-exchange operation, but the
    kernel provides userspace atomicity operations.  Use them.  */
@@ -43,33 +42,7 @@ typedef uintmax_t uatomic_max_t;
 #define ATOMIC_EXCHANGE_USES_CAS 1
 
 /* The only basic operation needed is compare and exchange.  */
-/* For ColdFire we'll have to trap into the kernel mode anyway,
-   so trap from the library rather then from the kernel wrapper.  */
-#ifdef SHARED
-# define atomic_compare_and_exchange_val_acq(mem, newval, oldval)	\
-  ({									\
-    /* Use temporary variables to workaround call-clobberness of 	\
-       the registers.  */						\
-    __typeof (mem) _mem = mem;						\
-    __typeof (oldval) _oldval = oldval;					\
-    __typeof (newval) _newval = newval;					\
-    register uint32_t *_a0 asm ("a0") = (uint32_t *) _mem;		\
-    register uint32_t _d0 asm ("d0") = (uint32_t) _oldval;		\
-    register uint32_t _d1 asm ("d1") = (uint32_t) _newval;		\
-    void *tmp;								\
-									\
-    asm ("movel #_GLOBAL_OFFSET_TABLE_@GOTPC, %2\n\t"			\
-	 "lea (-6, %%pc, %2), %2\n\t"					\
-	 "movel " STR_M68K_VDSO_SYMBOL (__vdso_atomic_cmpxchg_32)	\
-	 "@GOT(%2), %2\n\t"						\
-	 "movel (%2), %2\n\t"						\
-	 "jsr (%2)\n\t"							\
-	 : "+d" (_d0), "+m" (*_a0), "=&a" (tmp)				\
-	 : "a" (_a0), "d" (_d1));					\
-    (__typeof (oldval)) _d0;						\
-  })
-#else
-# define atomic_compare_and_exchange_val_acq(mem, newval, oldval)	\
+#define atomic_compare_and_exchange_val_acq(mem, newval, oldval)	\
   ({									\
     /* Use temporary variables to workaround call-clobberness of 	\
        the registers.  */						\
@@ -86,24 +59,8 @@ typedef uintmax_t uatomic_max_t;
 	 : "a" (_a0), "d" (_d2), "d" (_d1));				\
     (__typeof (oldval)) _d0;						\
   })
-#endif
 
-#ifdef SHARED
-# define atomic_full_barrier()					 \
-  ({								 \
-    void *tmp;							 \
-								 \
-    asm ("movel #_GLOBAL_OFFSET_TABLE_@GOTPC, %0\n\t"		 \
-	 "lea (-6, %pc, %0), %0\n\t"				 \
-	 "movel " STR_M68K_VDSO_SYMBOL (__vdso_atomic_barrier)	 \
-	 "@GOT(%0), %0\n\t"					 \
-	 "movel (%0), %0\n\t"					 \
-	 "jsr (%0)\n\t"						 \
-	 : "=&a" (tmp));					 \
-  })
-#else
 # define atomic_full_barrier()				\
   (INTERNAL_SYSCALL (atomic_barrier, , 0), (void) 0)
-#endif
 
 #endif
diff --git a/sysdeps/unix/sysv/linux/m68k/init-first.c b/sysdeps/unix/sysv/linux/m68k/init-first.c
deleted file mode 100644
index f8f0910839..0000000000
--- a/sysdeps/unix/sysv/linux/m68k/init-first.c
+++ /dev/null
@@ -1,74 +0,0 @@
-/* Initialization code run first thing by the ELF startup code.  Linux/m68k.
-   Copyright (C) 2010-2019 Free Software Foundation, Inc.
-   This file is part of the GNU C Library.
-   Contributed by Maxim Kuvyrkov <maxim@codesourcery.com>, 2010.
-
-   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/>.  */
-
-/* Note: linking in vDSO to a static binary requires changes to
-   the main GLIBC proper.  Not yet implemented.  */
-#ifdef SHARED
-
-#include <dl-vdso.h>
-#include <m68k-vdso.h>
-
-static inline void
-_libc_vdso_platform_setup (void)
-{
-  void *p;
-
-  PREPARE_VERSION (linux26, "LINUX_2.6", 61765110);
-
-  /* It may happen that rtld didn't initialize the vDSO, so fallback
-     to the syscall implementations if _dl_vdso_vsym returns NULL.
-     This may happen when a static executable dlopen's a dynamic library.
-     This really is nothing more than a workaround for rtld/csu
-     deficiency.  Ideally, init code would setup the vDSO for static
-     binaries too.  */
-
-  p = _dl_vdso_vsym ("__kernel_read_tp", &linux26);
-  if (p != NULL)
-    {
-      __vdso_read_tp = p;
-      __rtld___vdso_read_tp = p;
-    }
-  else
-    assert (__vdso_read_tp == (void *) __vdso_read_tp_stub);
-
-  p = _dl_vdso_vsym ("__kernel_atomic_cmpxchg_32", &linux26);
-  if (p != NULL)
-    {
-      __vdso_atomic_cmpxchg_32 = p;
-      __rtld___vdso_atomic_cmpxchg_32 = p;
-    }
-  else
-    assert (__vdso_atomic_cmpxchg_32
-	    == (void *) __vdso_atomic_cmpxchg_32_stub);
-
-  p = _dl_vdso_vsym ("__kernel_atomic_barrier", &linux26);
-  if (p != NULL)
-    {
-      __vdso_atomic_barrier = p;
-      __rtld___vdso_atomic_barrier = p;
-    }
-  else
-    assert (__vdso_atomic_barrier == (void *) __vdso_atomic_barrier_stub);
-}
-
-#define VDSO_SETUP _libc_vdso_platform_setup
-
-#endif /* SHARED */
-
-#include <csu/init-first.c>
diff --git a/sysdeps/unix/sysv/linux/m68k/libc-m68k-vdso.c b/sysdeps/unix/sysv/linux/m68k/libc-m68k-vdso.c
deleted file mode 100644
index 45982e99b9..0000000000
--- a/sysdeps/unix/sysv/linux/m68k/libc-m68k-vdso.c
+++ /dev/null
@@ -1 +0,0 @@
-#include "m68k-vdso.c"
diff --git a/sysdeps/unix/sysv/linux/m68k/m68k-helpers.S b/sysdeps/unix/sysv/linux/m68k/m68k-helpers.S
deleted file mode 100644
index 5e3ffb0a7f..0000000000
--- a/sysdeps/unix/sysv/linux/m68k/m68k-helpers.S
+++ /dev/null
@@ -1,95 +0,0 @@
-/* Copyright (C) 2010-2019 Free Software Foundation, Inc.
-   This file is part of the GNU C Library.
-   Contributed by Maxim Kuvyrkov <maxim@codesourcery.com>, 2010.
-
-   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.
-
-   In addition to the permissions in the GNU Lesser General Public
-   License, the Free Software Foundation gives you unlimited
-   permission to link the compiled version of this file with other
-   programs, and to distribute those programs without any restriction
-   coming from the use of this file. (The GNU Lesser General Public
-   License restrictions do apply in other respects; for example, they
-   cover modification of the file, and distribution when not linked
-   into another program.)
-
-   Note that people who make modified versions of this file are not
-   obligated to grant this special exception for their modified
-   versions; it is their choice whether to do so. The GNU Lesser
-   General Public License gives permission to release a modified
-   version without this exception; this exception also makes it
-   possible to release a modified version which carries forward this
-   exception.
-
-   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 <m68k-vdso.h>
-
-	.text
-
-	.hidden __vdso_read_tp_stub
-ENTRY (__vdso_read_tp_stub)
-	move.l	#__NR_get_thread_area, %d0
-	trap	#0
-	move.l	%d0, %a0
-	rts
-END (__vdso_read_tp_stub)
-
-# ifdef SHARED
-/* GCC will emit calls to this routine.  Linux has an
-   equivalent helper function (which clobbers fewer registers than
-   a normal function call) in a vdso; tail call to the
-   helper.  */
-# if IS_IN (rtld)
-/* rtld gets a hidden copy of __m68k_read_tp.  */
-	.hidden __m68k_read_tp
-# endif
-ENTRY (__m68k_read_tp)
-	LOAD_GOT (%a0)
-	move.l	M68K_VDSO_SYMBOL (__vdso_read_tp)@GOT(%a0), %a0
-	move.l	(%a0), %a0
-	jmp	(%a0)
-END (__m68k_read_tp)
-
-/* The following two stubs are for macros in atomic.h, they can't
-   clobber anything.  */
-
-	.hidden __vdso_atomic_cmpxchg_32_stub
-ENTRY (__vdso_atomic_cmpxchg_32_stub)
-	move.l	%d2, -(%sp)
-	cfi_adjust_cfa_offset (4)
-	cfi_rel_offset (%d2, 0)
-	move.l	%d0, %d2
-	move.l	#SYS_ify (atomic_cmpxchg_32), %d0
-	trap	#0
-	move.l	(%sp)+, %d2
-	cfi_adjust_cfa_offset (-4)
-	cfi_restore (%d2)
-	rts
-END (__vdso_atomic_cmpxchg_32_stub)
-
-	.hidden __vdso_atomic_barrier_stub
-ENTRY (__vdso_atomic_barrier_stub)
-	move.l	%d0, -(%sp)
-	cfi_adjust_cfa_offset (4)
-	move.l	#SYS_ify (atomic_barrier), %d0
-	trap	#0
-	move.l	(%sp)+, %d0
-	cfi_adjust_cfa_offset (-4)
-	rts
-END (__vdso_atomic_barrier_stub)
-# else /* !SHARED */
-/* If the vDSO is not available, use a syscall to get TP.  */
-	strong_alias (__vdso_read_tp_stub, __m68k_read_tp)
-# endif /* SHARED */
diff --git a/sysdeps/unix/sysv/linux/m68k/m68k-helpers.c b/sysdeps/unix/sysv/linux/m68k/m68k-helpers.c
new file mode 100644
index 0000000000..df02d560aa
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/m68k/m68k-helpers.c
@@ -0,0 +1,26 @@
+/* Copyright (C) 2019 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>
+
+void *
+__m68k_read_tp (void)
+{
+  INTERNAL_SYSCALL_DECL (err);
+  return (void*) INTERNAL_SYSCALL_CALL (get_thread_area, err);
+}
diff --git a/sysdeps/unix/sysv/linux/m68k/m68k-vdso.c b/sysdeps/unix/sysv/linux/m68k/m68k-vdso.c
deleted file mode 100644
index a1345a3a5b..0000000000
--- a/sysdeps/unix/sysv/linux/m68k/m68k-vdso.c
+++ /dev/null
@@ -1,34 +0,0 @@
-/* Copyright (C) 2010-2019 Free Software Foundation, Inc.
-   This file is part of the GNU C Library.
-   Contributed by Maxim Kuvyrkov <maxim@codesourcery.com>, 2010.
-
-   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 <m68k-vdso.h>
-
-/* Because these pointers are used from other libraries than libc,
-   they are exported at GLIBC_PRIVATE version.
-   We initialize them to syscall implementation so that they will be ready
-   to use from the very beginning.  */
-void * M68K_VDSO_SYMBOL (__vdso_read_tp)
-= (void *) __vdso_read_tp_stub;
-void * M68K_VDSO_SYMBOL (__vdso_atomic_cmpxchg_32)
-= (void *) __vdso_atomic_cmpxchg_32_stub;
-void * M68K_VDSO_SYMBOL (__vdso_atomic_barrier)
-= (void *) __vdso_atomic_barrier_stub;
-
-#endif /* SHARED */
diff --git a/sysdeps/unix/sysv/linux/m68k/m68k-vdso.h b/sysdeps/unix/sysv/linux/m68k/m68k-vdso.h
deleted file mode 100644
index fc71c0f4e1..0000000000
--- a/sysdeps/unix/sysv/linux/m68k/m68k-vdso.h
+++ /dev/null
@@ -1,60 +0,0 @@
-/* Resolve function pointers to VDSO functions.
-   Copyright (C) 2010-2019 Free Software Foundation, Inc.
-   This file is part of the GNU C Library.
-   Contributed by Maxim Kuvyrkov <maxim@codesourcery.com>, 2010.
-
-   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/>.  */
-
-
-#ifndef _M68K_VDSO_H
-#define _M68K_VDSO_H
-
-#ifdef SHARED
-
-# if IS_IN (rtld)
-# define M68K_VDSO_SYMBOL(name) __rtld_##name
-# define STR_M68K_VDSO_SYMBOL(name) "__rtld_" #name
-# else
-# define M68K_VDSO_SYMBOL(name) name
-# define STR_M68K_VDSO_SYMBOL(name) #name
-# endif
-
-# ifndef __ASSEMBLER__
-
-/* We define __rtld_* copies for rtld.
-   We need them visible in libc to initialize.  */
-#  if IS_IN (rtld) || IS_IN (libc)
-extern void *__rtld___vdso_read_tp;
-extern void *__rtld___vdso_atomic_cmpxchg_32;
-extern void *__rtld___vdso_atomic_barrier;
-
-/* These stubs are meant to be invoked only from the assembly.  */
-extern void __vdso_read_tp_stub (void);
-extern void __vdso_atomic_cmpxchg_32_stub (void);
-extern void __vdso_atomic_barrier_stub (void);
-#  endif /* IS_IN (rtld) || IS_IN (libc) */
-
-/* RTLD should only use its own copies.  */
-#  if !IS_IN (rtld)
-extern void *__vdso_read_tp;
-extern void *__vdso_atomic_cmpxchg_32;
-extern void *__vdso_atomic_barrier;
-#  endif /* !IS_IN (rtld) */
-
-# endif /* !__ASSEMBLER__ */
-
-#endif /* SHARED */
-
-#endif /* _M68K_VDSO_H */