glibc/sysdeps/unix/sysv/linux/malloc-sysdep.h

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/* System-specific malloc support functions. Linux version.
Copyright (C) 2012-2023 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
Prefer https to http for gnu.org and fsf.org URLs Also, change sources.redhat.com to sourceware.org. This patch was automatically generated by running the following shell script, which uses GNU sed, and which avoids modifying files imported from upstream: sed -ri ' s,(http|ftp)(://(.*\.)?(gnu|fsf|sourceware)\.org($|[^.]|\.[^a-z])),https\2,g s,(http|ftp)(://(.*\.)?)sources\.redhat\.com($|[^.]|\.[^a-z]),https\2sourceware.org\4,g ' \ $(find $(git ls-files) -prune -type f \ ! -name '*.po' \ ! -name 'ChangeLog*' \ ! -path COPYING ! -path COPYING.LIB \ ! -path manual/fdl-1.3.texi ! -path manual/lgpl-2.1.texi \ ! -path manual/texinfo.tex ! -path scripts/config.guess \ ! -path scripts/config.sub ! -path scripts/install-sh \ ! -path scripts/mkinstalldirs ! -path scripts/move-if-change \ ! -path INSTALL ! -path locale/programs/charmap-kw.h \ ! -path po/libc.pot ! -path sysdeps/gnu/errlist.c \ ! '(' -name configure \ -execdir test -f configure.ac -o -f configure.in ';' ')' \ ! '(' -name preconfigure \ -execdir test -f preconfigure.ac ';' ')' \ -print) and then by running 'make dist-prepare' to regenerate files built from the altered files, and then executing the following to cleanup: chmod a+x sysdeps/unix/sysv/linux/riscv/configure # Omit irrelevant whitespace and comment-only changes, # perhaps from a slightly-different Autoconf version. git checkout -f \ sysdeps/csky/configure \ sysdeps/hppa/configure \ sysdeps/riscv/configure \ sysdeps/unix/sysv/linux/csky/configure # Omit changes that caused a pre-commit check to fail like this: # remote: *** error: sysdeps/powerpc/powerpc64/ppc-mcount.S: trailing lines git checkout -f \ sysdeps/powerpc/powerpc64/ppc-mcount.S \ sysdeps/unix/sysv/linux/s390/s390-64/syscall.S # Omit change that caused a pre-commit check to fail like this: # remote: *** error: sysdeps/sparc/sparc64/multiarch/memcpy-ultra3.S: last line does not end in newline git checkout -f sysdeps/sparc/sparc64/multiarch/memcpy-ultra3.S
2019-09-07 05:40:42 +00:00
<https://www.gnu.org/licenses/>. */
#include <fcntl.h>
#include <not-cancel.h>
/* The Linux kernel overcommits address space by default and if there is not
enough memory available, it uses various parameters to decide the process to
kill. It is however possible to disable or curb this overcommit behavior
by setting the proc sysctl vm.overcommit_memory to the value '2' and with
that, a process is only allowed to use the maximum of a pre-determined
fraction of the total address space. In such a case, we want to make sure
that we are judicious with our heap usage as well, and explicitly give away
the freed top of the heap to reduce our commit charge. See the proc(5) man
page to know more about overcommit behavior.
Other than that, we also force an unmap in a secure exec. */
static inline bool
check_may_shrink_heap (void)
{
static int may_shrink_heap = -1;
if (__builtin_expect (may_shrink_heap >= 0, 1))
return may_shrink_heap;
may_shrink_heap = __libc_enable_secure;
if (__builtin_expect (may_shrink_heap == 0, 1))
{
Consolidate non cancellable open call This patch consolidates all the non cancellable open calls to use the __open_nocancel identifier. For non cancellable targets it will be just a macro to call the default respective symbol while on Linux will be a internal one. To be consistent with the following non cancellable openat call, a new __open64_nocancel is also added (although not currently used). Checked on x86_64-linux-gnu, x86_64-linux-gnu-x32, and i686-linux-gnu. * sysdeps/generic/not-cancel.h (open_not_cancel): Remove macro. (open_not_cancel_2): Likewise. (open_nocancel): New macro. (open64_nocancel): Likewise. * sysdeps/unix/sysv/linux/not-cancel.h (open_not_cancel): Remove macro. (open_not_cancel_2): Likewise. (__open_nocancel): New prototype. (__open64_nocancel): Likewise. * sysdeps/unix/sysv/linux/Versions (libc) [GLIBC_PRIVATE]: Add __open_nocancel. * sysdeps/unix/sysv/linux/open.c (__open_nocancel): New function. * sysdeps/unix/sysv/linux/open64.c (__open64_nocancel): Likewise. * catgets/open_catalog.c (__open_catalog): Replace open_not_cancel{_2} with __open_nocancel. * csu/check_fds.c (check_one_fd): Likewise. * gmon/gmon.c (write_gmon): Likewise. * iconv/gconv_cache.c (__gconv_load_cached): Likewise. * intl/loadmsgcat.c (open): Likewise. * libio/fileops.c (_IO_file_open): Likewise. * locale/loadarchive.c (_nl_load_locale_from_archive): Likewise. * locale/loadlocale.c (_nl_load_locale): Likewise. * login/utmp_file.c (setutent_file): Likewise. * misc/daemon.c (daemon): Likewise. * nss/nss_db/db-open.c (internal_setent): Likewise. * sysdeps/mach/hurd/opendir.c (__opendirat): Likewise. * sysdeps/posix/libc_fatal.c (__libc_message): Likewise. * sysdeps/posix/opendir.c (tryopen_o_directory): Likewise. (__opendir): Likewise. * sysdeps/posix/spawni.c (__spawni_child): Likewise. * sysdeps/unix/sysv/linux/fips-private.h (fips_enable_p): Likewise. * sysdeps/unix/sysv/linux/gethostid.c (sethostid): Likewise. (gethostid): Likewise. * sysdeps/unix/sysv/linux/getloadavg.c (getloadavg): Likewise. * sysdeps/unix/sysv/linux/getlogin_r.c (__getlogin_r_loginuid): Likewise. * sysdeps/unix/sysv/linux/getsysstats.c (__get_nprocs): Likewise. * sysdeps/unix/sysv/linux/grantpt.c (__close_all_fds): Likewise. * sysdeps/unix/sysv/linux/i386/smp.h (is_smp_system): Likewise. * sysdeps/unix/sysv/linux/ia64/has_cpuclock.c (has_cpuclock): Likewise. * sysdeps/unix/sysv/linux/libc_fatal.c (backtrace_and_maps): Likewise. * sysdeps/unix/sysv/linux/malloc-sysdep.h (check_may_shrink_heap): Likewise. * sysdeps/unix/sysv/linux/powerpc/get_clockfreq.c (__get_clockfreq): Likewise. * sysdeps/unix/sysv/linux/pthread_getname.c (pthread_getname_np): Likewise. * sysdeps/unix/sysv/linux/pthread_setname.c (pthread_setname_np): Likewise. * sysdeps/unix/sysv/linux/spawni.c (__spawni_child): Likewise. * sysdeps/unix/sysv/linux/sysconf.c (__sysconf): Likewise.
2017-07-03 14:11:24 +00:00
int fd = __open_nocancel ("/proc/sys/vm/overcommit_memory",
O_RDONLY | O_CLOEXEC);
if (fd >= 0)
{
char val;
Consolidate non cancellable read call This patch consolidates all the non cancellable read calls to use the __read_nocancel identifier. For non cancellable targets it will be just a macro to call the default respective symbol while on Linux will be a internal one. Also, since it is used on libcrypto it is also exported in GLIBC_PRIVATE namespace. Checked on x86_64-linux-gnu, x86_64-linux-gnu-x32, and i686-linux-gnu. * sysdeps/generic/not-cancel.h (read_not_cancel): Remove macro. (__read_nocancel): New macro. * sysdeps/unix/sysv/linux/Versions (libc) [GLIBC_PRIVATE]: Add __read_nocancel. * sysdeps/unix/sysv/linux/not-cancel.h (__read_nocancel): Remove macro. (__read_nocancel): New prototype. * sysdeps/unix/sysv/linux/read.c (__read_nocancel): New function. * catgets/open_catalog.c (__open_catalog): Replace read_not_cancel with __read_nocancel. * intl/loadmsgcat.c (read): Likewise. * libio/fileops.c (_IO_file_read): Likewise. * locale/loadlocale.c (_nl_load_locale): Likewise. * login/utmp_file.c (getutent_r_file): Likewise. (internal_getut_r): Likewise. (getutline_r_file): Likewise. * sysdeps/unix/sysv/linux/fips-private.h (fips_enable_p): Likewise. * sysdeps/unix/sysv/linux/gethostid.c (gethostid): Likewise. * sysdeps/unix/sysv/linux/getloadavg.c (getloadavg): Likewise. * sysdeps/unix/sysv/linux/getlogin_r.c (__getlogin_r_loginuid): Likewise. * sysdeps/unix/sysv/linux/getsysstats.c (next_line): Likewise. * sysdeps/unix/sysv/linux/i386/smp.h (is_smp_system): Likewise. * sysdeps/unix/sysv/linux/ia64/has_cpuclock.c (has_cpuclock): Likewise. * sysdeps/unix/sysv/linux/libc_fatal.c (backtrace_and_maps): Likewise. * sysdeps/unix/sysv/linux/malloc-sysdep.h (check_may_shrink_heap): Likewise. * sysdeps/unix/sysv/linux/pthread_getname.c (pthread_getname_np): Likewise. * sysdeps/unix/sysv/linux/sysconf.c (__sysconf): Likewise.
2017-07-03 17:20:46 +00:00
ssize_t n = __read_nocancel (fd, &val, 1);
may_shrink_heap = n > 0 && val == '2';
Consolidate non cancellable close call This patch consolidates all the non cancellable close calls to use the __close_nocancel{_nostatus} identifier. For non cancellable targets it will be just a macro to call the default respective symbol while on Linux will be a internal one. Also, since it is used on libcrypto it is also exported in GLIBC_PRIVATE namespace. Checked on x86_64-linux-gnu, x86_64-linux-gnu-x32, and i686-linux-gnu. * sysdeps/generic/not-cancel.h (close_not_cancel): Remove macro. (close_not_cancel_no_status): Likewise. (__close_nocancel): New macro. (__close_nocancel_no_status): Likewise. * sysdeps/unix/sysv/linux/not-cancel.h (__close_nocancel): Remove macro. (close_not_cancel): Likewise. (close_not_cancel_no_status): Likewise. (__close_nocancel): New prototype. (__close_nocancel_no_status): New function. * sysdeps/unix/sysv/linux/close.c (__close_nocancel): New function. * catgets/open_catalog.c (__open_catalog): Replace close_not_cancel{_no_status) with __close_nocancel{_nostatus}. * gmon/gmon.c (write_gmon): Likewise. * iconv/gconv_cache.c (__gconv_load_cache): Likewise. * intl/loadmsgcat.c (close): Likewise. * io/ftw.c (open_dir_stream): Likewise. (ftw_startup): Likewise. * libio/fileops.c (_IO_file_open): Likewise. (_IO_file_close_mmap): Likewise. (_IO_file_close): Likewise. * libio/iopopen.c (_IO_dup2): Likewise. * locale/loadarchive.c (_nl_load_locale_from_archive): Likewise. * locale/loadlocale.c (_nl_load_locale): Likewise. * login/utmp_file.c (pututline_file): Likewise. (endutent_file): Likewise. * misc/daemon.c (daemon): Likewise. * nscd/nscd_getai.c (__nscd_getai): Likewise. * nscd/nscd_getgr_r.c (nscd_getgr_r): Likewise. * nscd/nscd_gethst_r.c (nscd_gethst_r): Likewise. * nscd/nscd_getpw_r.c (nscd_getpw_r): Likewise. * nscd/nscd_getserv_r.c (nscd_getserv_r): Likewise. * nscd/nscd_helper.c (open_socket): Likewise. (__nscd_open_socket): Likewise. * nscd/nscd_initgroups.c (__nscd_getgrouplist): Likewise. * nscd/nscd_netgroup.c (__nscd_setnetgrent): Likewise. (__nscd_innetgr): Likewise. * nss/nss_db/db-open.c (internal_setent): Likewise. * resolv/res-close.c (__res_iclose): Likewise. * sunrpc/pm_getmaps.c (pmap_getmaps): Likewise. * sysdeps/posix/closedir.c (__closedir): Likewise. * sysdeps/posix/getaddrinfo.c (getaddrinfo): Likewise. * sysdeps/posix/getcwd.c (__getcwd): Likewise. * sysdeps/posix/opendir.c (tryopen_o_directory): Likewise. (opendir_tail): Likewise. * sysdeps/posix/spawni.c (__spawni_child): Likewise. * sysdeps/unix/sysv/linux/check_native.c (__check_native): Likewise. * sysdeps/unix/sysv/linux/check_pf.c (__check_pf): Likewise. * sysdeps/unix/sysv/linux/fips-private.h (fips_enabled_p): Likewise. * sysdeps/unix/sysv/linux/gethostid.c (sethostid): Likewise. (gethostid): Likewise. * sysdeps/unix/sysv/linux/getloadavg.c (getloadavg): Likewise. * sysdeps/unix/sysv/linux/getlogin_r.c (__getlogin_r_loginuid): Likewise. * sysdeps/unix/sysv/linux/getsysstats.c (__get_nprocs): Likewise. * sysdeps/unix/sysv/linux/grantpt.c (close_all_fds): Likewise. * sysdeps/unix/sysv/linux/i386/smp.h (is_smp_system): Likewise. * sysdeps/unix/sysv/linux/ia64/has_cpuclock.c (has_cpuclock): Likewise. * sysdeps/unix/sysv/linux/if_index.c (__if_nametoindex): Likewise. * sysdeps/unix/sysv/linux/libc_fatal.c (backtrace_and_maps): Likewise. * sysdeps/unix/sysv/linux/malloc-sysdep.h (check_may_shrink_heap): Likewise. * sysdeps/unix/sysv/linux/mq_notify.c (init_mq_netlink): Likewise. * sysdeps/unix/sysv/linux/pthread_getname.c (pthread_getname_np): Likewise. * sysdeps/unix/sysv/linux/pthread_setname.c (pthread_setname_np): Likewise. * sysdeps/unix/sysv/linux/spawni.c (__spawni_child): Likewise. * sysdeps/unix/sysv/linux/sysconf.c (__sysconf): Likewise.
2017-07-03 18:22:58 +00:00
__close_nocancel_nostatus (fd);
}
}
return may_shrink_heap;
}
#define HAVE_MREMAP 1