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>

36 files changed, 60 insertions, 745 deletions

diff --git a/sysdeps/unix/sysv/linux/aarch64/sysdep.h b/sysdeps/unix/sysv/linux/aarch64/sysdep.h
index 319a7c7ac5..e526328ea4 100644
--- a/sysdeps/unix/sysv/linux/aarch64/sysdep.h
+++ b/sysdeps/unix/sysv/linux/aarch64/sysdep.h
@@ -234,6 +234,9 @@
 # define INTERNAL_SYSCALL_NCS(number, nr, args...)	\
 	INTERNAL_SYSCALL_RAW (number, nr, args)
 
+#undef HAVE_INTERNAL_BRK_ADDR_SYMBOL
+#define HAVE_INTERNAL_BRK_ADDR_SYMBOL 1
+
 #endif	/* __ASSEMBLER__ */
 
 /* Pointer mangling is supported for AArch64.  */
diff --git a/sysdeps/unix/sysv/linux/alpha/brk.S b/sysdeps/unix/sysv/linux/alpha/brk.S
deleted file mode 100644
index 5596b346d8..0000000000
--- a/sysdeps/unix/sysv/linux/alpha/brk.S
+++ /dev/null
@@ -1,83 +0,0 @@
-/* Copyright (C) 1993-2020 Free Software Foundation, Inc.
-   This file is part of the GNU C Library.
-   Contributed by Brendan Kehoe <brendan@zen.org>, 1993.
-
-   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/>.  */
-
-/* __brk is a special syscall under Linux since it never returns an
-   error.  Instead, the error condition is indicated by returning the old
-   break value (instead of the new, requested one).  */
-
-#include <sysdep.h>
-#include <errno.h>
-
-#ifdef PIC
-.section .bss
-	.align 3
-	.globl __curbrk
-__curbrk: .skip 8
-	.type __curbrk,@object
-	.size __curbrk,8
-#else
-.comm __curbrk, 8
-#endif
-
-	.text
-	.align	4
-	.globl	__brk
-	.ent	__brk
-	.usepv	__brk, std
-
-	cfi_startproc
-__brk:
-	ldgp	gp, 0(t12)
-	subq	sp, 16, sp
-	cfi_adjust_cfa_offset (16)
-#ifdef PROF
-	.set noat
-	lda	AT, _mcount
-	jsr	AT, (AT), _mcount
-	.set at
-#endif
-
-	/* Save the requested brk across the system call.  */
-	stq	a0, 0(sp)
-
-	ldiq	v0, __NR_brk
-	call_pal PAL_callsys
-
-	ldq	a0, 0(sp)
-	addq	sp, 16, sp
-	cfi_adjust_cfa_offset (-16)
-
-	/* Be prepared for an OSF-style brk.  */
-	bne	a3, SYSCALL_ERROR_LABEL
-	beq	v0, $ok
-
-	/* Correctly handle the brk(0) query case.  */
-	cmoveq	a0, v0, a0
-	xor	a0, v0, t0
-	lda	v0, ENOMEM
-	bne	t0, SYSCALL_ERROR_LABEL
-
-	/* Update __curbrk and return cleanly.  */
-	lda	v0, 0
-$ok:	stq	a0, __curbrk
-	ret
-
-PSEUDO_END(__brk)
-	cfi_endproc
-
-weak_alias (__brk, brk)
diff --git a/sysdeps/unix/sysv/linux/arm/brk.c b/sysdeps/unix/sysv/linux/alpha/brk.c
index d4878939ae..d105a50724 100644
--- a/sysdeps/unix/sysv/linux/arm/brk.c
+++ b/sysdeps/unix/sysv/linux/alpha/brk.c
@@ -1,5 +1,5 @@
-/* brk system call for Linux/ARM.
-   Copyright (C) 1995-2020 Free Software Foundation, Inc.
+/* Change data segment size.  Linux/Alpha.
+   Copyright (C) 2020 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
@@ -20,17 +20,14 @@
 #include <unistd.h>
 #include <sysdep.h>
 
-/* This must be initialized data because commons can't have aliases.  */
 void *__curbrk = 0;
 
 int
 __brk (void *addr)
 {
-  void *newbrk;
-
-  __curbrk = newbrk = (void *) INLINE_SYSCALL (brk, 1, addr);
-
-  if (newbrk < addr)
+  /* Alpha brk returns -ENOMEM in case of failure.  */
+  __curbrk = (void *) INTERNAL_SYSCALL_CALL (brk, addr);
+  if ((unsigned long) __curbrk == -ENOMEM)
     {
       __set_errno (ENOMEM);
       return -1;
diff --git a/sysdeps/unix/sysv/linux/alpha/dl-brk.S b/sysdeps/unix/sysv/linux/alpha/dl-brk.S
deleted file mode 100644
index eeb96544e3..0000000000
--- a/sysdeps/unix/sysv/linux/alpha/dl-brk.S
+++ /dev/null
@@ -1 +0,0 @@
-#include <brk.S>
diff --git a/sysdeps/unix/sysv/linux/arc/sysdep.h b/sysdeps/unix/sysv/linux/arc/sysdep.h
index 8465a2f623..24d8866d66 100644
--- a/sysdeps/unix/sysv/linux/arc/sysdep.h
+++ b/sysdeps/unix/sysv/linux/arc/sysdep.h
@@ -221,6 +221,9 @@ hidden_proto (__syscall_error)
 # define PTR_MANGLE(var) (void) (var)
 # define PTR_DEMANGLE(var) (void) (var)
 
+# undef HAVE_INTERNAL_BRK_ADDR_SYMBOL
+# define HAVE_INTERNAL_BRK_ADDR_SYMBOL  1
+
 #endif /* !__ASSEMBLER__ */
 
 #endif /* linux/arc/sysdep.h */
diff --git a/sysdeps/unix/sysv/linux/generic/brk.c b/sysdeps/unix/sysv/linux/brk.c
index 40a80ab970..0b6d6d0b70 100644
--- a/sysdeps/unix/sysv/linux/generic/brk.c
+++ b/sysdeps/unix/sysv/linux/brk.c
@@ -1,6 +1,6 @@
-/* Copyright (C) 2011-2020 Free Software Foundation, Inc.
+/* Change data segment.  Linux generic version.
+   Copyright (C) 2020 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
@@ -23,10 +23,12 @@
 /* This must be initialized data because commons can't have aliases.  */
 void *__curbrk = 0;
 
+#if HAVE_INTERNAL_BRK_ADDR_SYMBOL
 /* Old braindamage in GCC's crtstuff.c requires this symbol in an attempt
    to work around different old braindamage in the old Linux ELF dynamic
    linker.  */
 weak_alias (__curbrk, ___brk_addr)
+#endif
 
 int
 __brk (void *addr)
diff --git a/sysdeps/unix/sysv/linux/csky/sysdep.h b/sysdeps/unix/sysv/linux/csky/sysdep.h
index 7e8e89dd42..92216572a6 100644
--- a/sysdeps/unix/sysv/linux/csky/sysdep.h
+++ b/sysdeps/unix/sysv/linux/csky/sysdep.h
@@ -461,6 +461,9 @@ __local_syscall_error:				\
 # define INTERNAL_SYSCALL_NCS(number, nr, args...)		\
   INTERNAL_SYSCALL_RAW##nr (number, args)
 
+#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/dl-brk.c b/sysdeps/unix/sysv/linux/dl-brk.c
deleted file mode 100644
index c37cdfec33..0000000000
--- a/sysdeps/unix/sysv/linux/dl-brk.c
+++ /dev/null
@@ -1,5 +0,0 @@
-/* We can use the normal code but we also know the __curbrk is not exported
-   from ld.so.  */
-extern void *__curbrk attribute_hidden;
-
-#include <brk.c>
diff --git a/sysdeps/unix/sysv/linux/hppa/brk.c b/sysdeps/unix/sysv/linux/hppa/brk.c
deleted file mode 100644
index 89d1fd1835..0000000000
--- a/sysdeps/unix/sysv/linux/hppa/brk.c
+++ /dev/null
@@ -1,41 +0,0 @@
-/* brk system call for Linux/HPPA.
-   Copyright (C) 1995-2020 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
-   <https://www.gnu.org/licenses/>.  */
-
-#include <errno.h>
-#include <unistd.h>
-#include <sysdep.h>
-
-/* This must be initialized data because commons can't have aliases.  */
-void *__curbrk = 0;
-
-int
-__brk (void *addr)
-{
-  void *newbrk;
-
-  __curbrk = newbrk = (void *) INLINE_SYSCALL (brk, 1, addr);
-
-  if (newbrk < addr)
-    {
-      __set_errno (ENOMEM);
-      return -1;
-    }
-
-  return 0;
-}
-weak_alias (__brk, brk)
diff --git a/sysdeps/unix/sysv/linux/i386/brk.c b/sysdeps/unix/sysv/linux/i386/brk.c
index 021b6d37a0..8d7b7d42cc 100644
--- a/sysdeps/unix/sysv/linux/i386/brk.c
+++ b/sysdeps/unix/sysv/linux/i386/brk.c
@@ -21,25 +21,4 @@
 # define I386_USE_SYSENTER 0
 #endif
 
-#include <errno.h>
-#include <unistd.h>
-#include <sysdep.h>
-
-/* This must be initialized data because commons can't have aliases.  */
-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 ELF dynamic
-   linker.  */
-weak_alias (__curbrk, ___brk_addr)
-
-int
-__brk (void *addr)
-{
-  void *newbrk = (void *) INTERNAL_SYSCALL_CALL (brk, addr);
-  __curbrk = newbrk;
-  if (newbrk < addr)
-    return INLINE_SYSCALL_ERROR_RETURN_VALUE (ENOMEM);
-  return 0;
-}
-weak_alias (__brk, brk)
+#include <sysdeps/unix/sysv/linux/brk.c>
diff --git a/sysdeps/unix/sysv/linux/i386/sysdep.h b/sysdeps/unix/sysv/linux/i386/sysdep.h
index bfb5de3b45..addd13dff1 100644
--- a/sysdeps/unix/sysv/linux/i386/sysdep.h
+++ b/sysdeps/unix/sysv/linux/i386/sysdep.h
@@ -291,6 +291,9 @@ struct libc_do_syscall_args
 # define HAVE_TIME_VSYSCALL             "__vdso_time"
 # define HAVE_CLOCK_GETRES_VSYSCALL     "__vdso_clock_getres"
 
+# undef HAVE_INTERNAL_BRK_ADDR_SYMBOL
+# define HAVE_INTERNAL_BRK_ADDR_SYMBOL 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
    normally.  It will never touch errno.  This returns just what the kernel
diff --git a/sysdeps/unix/sysv/linux/ia64/brk.S b/sysdeps/unix/sysv/linux/ia64/brk.S
deleted file mode 100644
index 734d3467a7..0000000000
--- a/sysdeps/unix/sysv/linux/ia64/brk.S
+++ /dev/null
@@ -1,50 +0,0 @@
-/* brk system call for Linux/ia64
-   Copyright (C) 1999-2020 Free Software Foundation, Inc.
-   This file is part of the GNU C Library.
-   Written by Stéphane Eranian <eranian@hpl.hp.com> and
-	      Jes Sorensen, <Jes.Sorensen@cern.ch>, April 1999.
-
-   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 <sysdep.h>
-
-#include <asm/errno.h>
-
-	.global __curbrk
-	.type __curbrk,@object
-	.size __curbrk,8
-	.data
-	.align	8
-__curbrk:
-	data8	0
-
-weak_alias (__curbrk, ___brk_addr)
-
-LEAF(__brk)
-	.regstk 1, 0, 0, 0
-	DO_CALL(__NR_brk)
-	cmp.ltu	p6, p0 = ret0, in0
-	addl r9 = @ltoff(__curbrk), gp
-	;;
-	ld8 r9 = [r9]
-(p6) 	mov ret0 = ENOMEM
-(p6)	br.cond.spnt.few __syscall_error
-	;;
-	st8 [r9] = ret0
-	mov ret0 = 0
-	ret
-END(__brk)
-
-weak_alias (__brk, brk)
diff --git a/sysdeps/unix/sysv/linux/ia64/dl-brk.S b/sysdeps/unix/sysv/linux/ia64/dl-brk.S
deleted file mode 100644
index eeb96544e3..0000000000
--- a/sysdeps/unix/sysv/linux/ia64/dl-brk.S
+++ /dev/null
@@ -1 +0,0 @@
-#include <brk.S>
diff --git a/sysdeps/unix/sysv/linux/ia64/sysdep.h b/sysdeps/unix/sysv/linux/ia64/sysdep.h
index 03ed52552e..e6bcaabecc 100644
--- a/sysdeps/unix/sysv/linux/ia64/sysdep.h
+++ b/sysdeps/unix/sysv/linux/ia64/sysdep.h
@@ -172,6 +172,9 @@
 
 #else /* not __ASSEMBLER__ */
 
+#undef HAVE_INTERNAL_BRK_ADDR_SYMBOL
+#define HAVE_INTERNAL_BRK_ADDR_SYMBOL 1
+
 #define BREAK_INSN_1(num) "break " #num ";;\n\t"
 #define BREAK_INSN(num) BREAK_INSN_1(num)
 
diff --git a/sysdeps/unix/sysv/linux/m68k/brk.c b/sysdeps/unix/sysv/linux/m68k/brk.c
deleted file mode 100644
index ee88acbdc4..0000000000
--- a/sysdeps/unix/sysv/linux/m68k/brk.c
+++ /dev/null
@@ -1,46 +0,0 @@
-/* brk system call for Linux/m68k.
-   Copyright (C) 1996-2020 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
-   <https://www.gnu.org/licenses/>.  */
-
-#include <errno.h>