linux: Consolidate brk implementation

It removes all the arch-specific assembly implementation.  The
outliers are alpha, where its kernel ABI explict return -ENOMEM
in case of failure; and i686, where it can't use
"call *%gs:SYSINFO_OFFSET" during statup in static PIE.

Also some ABIs exports an additional ___brk_addr symbol and to
handle it an internal HAVE_INTERNAL_BRK_ADDR_SYMBOL is added.

Checked on x86_64-linux-gnu, i686-linux-gnu, adn with builsd for
the affected ABIs.

Reviewed-by: Tulio Magno Quites Machado Filho <tuliom@linux.ibm.com>

3 files changed, 10 insertions, 55 deletions

diff --git a/sysdeps/unix/sysv/linux/s390/brk.c b/sysdeps/unix/sysv/linux/s390/brk.c
deleted file mode 100644
index ca3a730f83..0000000000
--- a/sysdeps/unix/sysv/linux/s390/brk.c
+++ /dev/null
@@ -1,55 +0,0 @@
-/*
-   Copyright (C) 2000-2020 Free Software Foundation, Inc.
-   Contributed by Martin Schwidefsky (schwidefsky@de.ibm.com).
-   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 <errno.h>
-#include <unistd.h>
-#include <sysdep.h>
-
-void *__curbrk = 0;
-
-/* Old braindamage in GCC's crtstuff.c requires this symbol in an attempt
-   to work around different old braindamage in the old Linux/x86 ELF
-   dynamic linker.  Sigh.  */
-weak_alias (__curbrk, ___brk_addr)
-
-int
-__brk (void *addr)
-{
-  void *newbrk;
-
-  {
-    register void *__addr __asm__("2") = addr;
-
-    __asm__ ("svc  %b1\n\t"		/* call sys_brk */
-	     : "=d" (__addr)
-	     : "I" (SYS_ify(brk)), "r" (__addr)
-	     : "cc", "memory" );
-    newbrk = __addr;
-  }
-  __curbrk = newbrk;
-
-  if (newbrk < addr)
-    {
-      __set_errno (ENOMEM);
-      return -1;
-    }
-
-  return 0;
-}
-weak_alias (__brk, brk)
diff --git a/sysdeps/unix/sysv/linux/s390/s390-32/sysdep.h b/sysdeps/unix/sysv/linux/s390/s390-32/sysdep.h
index 26b0410cf3..26836620f2 100644
--- a/sysdeps/unix/sysv/linux/s390/s390-32/sysdep.h
+++ b/sysdeps/unix/sysv/linux/s390/s390-32/sysdep.h
@@ -175,6 +175,11 @@
 #define ret_ERRVAL							      \
     br      14
 
+#else
+
+# undef HAVE_INTERNAL_BRK_ADDR_SYMBOL
+# define HAVE_INTERNAL_BRK_ADDR_SYMBOL 1
+
 #endif /* __ASSEMBLER__ */
 
 /* Pointer mangling support.  */
diff --git a/sysdeps/unix/sysv/linux/s390/s390-64/sysdep.h b/sysdeps/unix/sysv/linux/s390/s390-64/sysdep.h
index 39831a2ec2..7211dadbfd 100644
--- a/sysdeps/unix/sysv/linux/s390/s390-64/sysdep.h
+++ b/sysdeps/unix/sysv/linux/s390/s390-64/sysdep.h
@@ -173,6 +173,11 @@
 #define ret_ERRVAL							      \
     br	    14
 
+#else
+
+# undef HAVE_INTERNAL_BRK_ADDR_SYMBOL
+# define HAVE_INTERNAL_BRK_ADDR_SYMBOL 1
+
 #endif /* __ASSEMBLER__ */
 
 /* Pointer mangling support.  */