glibc/sysdeps/unix/sysv/linux/brk.c
Adhemerval Zanella 720480934a 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>
2020-12-10 17:42:37 -03:00

46 lines
1.4 KiB
C

/* Change data segment. Linux generic version.
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
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;
#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)
{
__curbrk = (void *) INTERNAL_SYSCALL_CALL (brk, addr);
if (__curbrk < addr)
{
__set_errno (ENOMEM);
return -1;
}
return 0;
}
weak_alias (__brk, brk)