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67e58f3941
The tunables framework allows us to uniformly manage and expose global variables inside glibc as switches to users. tunables/README has instructions for glibc developers to add new tunables. Tunables support can be enabled by passing the --enable-tunables configure flag to the configure script. This patch only adds a framework and does not pose any limitations on how tunable values are read from the user. It also adds environment variables used in malloc behaviour tweaking to the tunables framework as a PoC of the compatibility interface. * manual/install.texi: Add --enable-tunables option. * INSTALL: Regenerate. * README.tunables: New file. * Makeconfig (CPPFLAGS): Define TOP_NAMESPACE. (before-compile): Generate dl-tunable-list.h early. * config.h.in: Add HAVE_TUNABLES. * config.make.in: Add have-tunables. * configure.ac: Add --enable-tunables option. * configure: Regenerate. * csu/init-first.c (__libc_init_first): Move __libc_init_secure earlier... * csu/init-first.c (LIBC_START_MAIN):... to here. Include dl-tunables.h, libc-internal.h. (LIBC_START_MAIN) [!SHARED]: Initialize tunables for static binaries. * elf/Makefile (dl-routines): Add dl-tunables. * elf/Versions (ld): Add __tunable_set_val to GLIBC_PRIVATE namespace. * elf/dl-support (_dl_nondynamic_init): Unset MALLOC_CHECK_ only when !HAVE_TUNABLES. * elf/rtld.c (process_envvars): Likewise. * elf/dl-sysdep.c [HAVE_TUNABLES]: Include dl-tunables.h (_dl_sysdep_start): Call __tunables_init. * elf/dl-tunable-types.h: New file. * elf/dl-tunables.c: New file. * elf/dl-tunables.h: New file. * elf/dl-tunables.list: New file. * malloc/tst-malloc-usable-static.c: New test case. * malloc/Makefile (tests-static): Add it. * malloc/arena.c [HAVE_TUNABLES]: Include dl-tunables.h. Define TUNABLE_NAMESPACE. (DL_TUNABLE_CALLBACK (set_mallopt_check)): New function. (DL_TUNABLE_CALLBACK_FNDECL): New macro. Use it to define callback functions. (ptmalloc_init): Set tunable values. * scripts/gen-tunables.awk: New file. * sysdeps/mach/hurd/dl-sysdep.c: Include dl-tunables.h. (_dl_sysdep_start): Call __tunables_init.
111 lines
3.1 KiB
C
111 lines
3.1 KiB
C
/* Initialization code run first thing by the ELF startup code. Common version
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Copyright (C) 1995-2016 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, see
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<http://www.gnu.org/licenses/>. */
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#include <ctype.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <fcntl.h>
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#include <unistd.h>
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#include <sysdep.h>
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#include <fpu_control.h>
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#include <sys/param.h>
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#include <sys/types.h>
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#include <libc-internal.h>
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#include <ldsodefs.h>
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/* Set nonzero if we have to be prepared for more than one libc being
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used in the process. Safe assumption if initializer never runs. */
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int __libc_multiple_libcs attribute_hidden = 1;
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/* Remember the command line argument and enviroment contents for
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later calls of initializers for dynamic libraries. */
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int __libc_argc attribute_hidden;
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char **__libc_argv attribute_hidden;
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void
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__libc_init_first (int argc, char **argv, char **envp)
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{
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#ifdef SHARED
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/* For DSOs we do not need __libc_init_first but instead _init. */
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}
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void
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attribute_hidden
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_init (int argc, char **argv, char **envp)
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{
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#endif
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#ifdef USE_NONOPTION_FLAGS
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extern void __getopt_clean_environment (char **);
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#endif
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__libc_multiple_libcs = &_dl_starting_up && !_dl_starting_up;
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/* Make sure we don't initialize twice. */
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if (!__libc_multiple_libcs)
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{
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/* Set the FPU control word to the proper default value if the
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kernel would use a different value. */
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if (__fpu_control != GLRO(dl_fpu_control))
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__setfpucw (__fpu_control);
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}
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/* Save the command-line arguments. */
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__libc_argc = argc;
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__libc_argv = argv;
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__environ = envp;
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#ifndef SHARED
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/* First the initialization which normally would be done by the
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dynamic linker. */
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_dl_non_dynamic_init ();
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#endif
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#ifdef VDSO_SETUP
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VDSO_SETUP ();
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#endif
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__init_misc (argc, argv, envp);
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#ifdef USE_NONOPTION_FLAGS
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/* This is a hack to make the special getopt in GNU libc working. */
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__getopt_clean_environment (envp);
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#endif
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/* Initialize ctype data. */
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__ctype_init ();
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#if defined SHARED && !defined NO_CTORS_DTORS_SECTIONS
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__libc_global_ctors ();
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#endif
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}
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/* This function is defined here so that if this file ever gets into
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ld.so we will get a link error. Having this file silently included
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in ld.so causes disaster, because the _init definition above will
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cause ld.so to gain an init function, which is not a cool thing. */
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extern void _dl_start (void) __attribute__ ((noreturn));
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void
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_dl_start (void)
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{
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abort ();
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}
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