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authorAdhemerval Zanella <adhemerval.zanella@linaro.org>2020-06-26 16:06:49 -0300
committerAdhemerval Zanella <adhemerval.zanella@linaro.org>2020-12-10 17:42:37 -0300
commit720480934ab9107714f1ffc29222dfb5d3bc5b1d (patch)
tree3851a6f8fe50b3548e667651805dadb7c242f43b /sysdeps/unix/sysv/linux/brk.c
parent880433de13fa31e52587720f81b762a6c7797e4e (diff)
downloadglibc-720480934ab9107714f1ffc29222dfb5d3bc5b1d.tar.gz
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>
Diffstat (limited to 'sysdeps/unix/sysv/linux/brk.c')
-rw-r--r--sysdeps/unix/sysv/linux/brk.c45
1 files changed, 45 insertions, 0 deletions
diff --git a/sysdeps/unix/sysv/linux/brk.c b/sysdeps/unix/sysv/linux/brk.c
new file mode 100644
index 0000000000..0b6d6d0b70
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/brk.c
@@ -0,0 +1,45 @@
+/* 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)