# Copyright (C) 2016-2021 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 # . # Allowed attributes for tunables: # # type: Defaults to STRING # minval: Optional minimum acceptable value # maxval: Optional maximum acceptable value # env_alias: An alias environment variable # security_level: Specify security level of the tunable for AT_SECURE binaries. # Valid values are: # # SXID_ERASE: (default) Do not read and do not pass on to # child processes. # SXID_IGNORE: Do not read, but retain for non-AT_SECURE # subprocesses. # NONE: Read all the time. glibc { malloc { check { type: INT_32 minval: 0 maxval: 3 env_alias: MALLOC_CHECK_ } top_pad { type: SIZE_T env_alias: MALLOC_TOP_PAD_ security_level: SXID_IGNORE } perturb { type: INT_32 minval: 0 maxval: 0xff env_alias: MALLOC_PERTURB_ security_level: SXID_IGNORE } mmap_threshold { type: SIZE_T env_alias: MALLOC_MMAP_THRESHOLD_ security_level: SXID_IGNORE } trim_threshold { type: SIZE_T env_alias: MALLOC_TRIM_THRESHOLD_ security_level: SXID_IGNORE } mmap_max { type: INT_32 env_alias: MALLOC_MMAP_MAX_ security_level: SXID_IGNORE minval: 0 } arena_max { type: SIZE_T env_alias: MALLOC_ARENA_MAX minval: 1 security_level: SXID_IGNORE } arena_test { type: SIZE_T env_alias: MALLOC_ARENA_TEST minval: 1 security_level: SXID_IGNORE } tcache_max { type: SIZE_T } tcache_count { type: SIZE_T } tcache_unsorted_limit { type: SIZE_T } mxfast { type: SIZE_T minval: 0 security_level: SXID_IGNORE } } cpu { hwcap_mask { type: UINT_64 env_alias: LD_HWCAP_MASK default: HWCAP_IMPORTANT } } elision { enable { type: INT_32 minval: 0 maxval: 1 } skip_lock_busy { type: INT_32 default: 3 minval: 0 } skip_lock_internal_abort { type: INT_32 default: 3 minval: 0 } skip_lock_after_retries { type: INT_32 default: 3 minval: 0 } tries { type: INT_32 default: 3 minval: 0 } skip_trylock_internal_abort { type: INT_32 default: 3 minval: 0 } } rtld { nns { type: SIZE_T minval: 1 maxval: 16 default: 4 } optional_static_tls { type: SIZE_T minval: 0 default: 512 } } mem { tagging { type: INT_32 minval: 0 maxval: 255 security_level: SXID_IGNORE } } rtld { dynamic_sort { type: INT_32 minval: 1 maxval: 2 default: 2 } } }