8.5.1. Installation of Glibc
Some of the Glibc programs use the non-FHS compliant /var/db directory to store their runtime data.
Apply the following patch to make such programs store their runtime
data in the FHS-compliant locations:
patch -Np1 -i ../glibc-2.37-fhs-1.patch
Fix a security issue identified upstream:
sed '/width -=/s/workend - string/number_length/' \
-i stdio-common/vfprintf-process-arg.c
The Glibc documentation recommends building Glibc in a dedicated
build directory:
mkdir -v build
cd build
Ensure that the ldconfig and sln utilities will be installed
into /usr/sbin:
echo "rootsbindir=/usr/sbin" > configparms
Prepare Glibc for compilation:
../configure --prefix=/usr \
--disable-werror \
--enable-kernel=3.2 \
--enable-stack-protector=strong \
--with-headers=/usr/include \
libc_cv_slibdir=/usr/lib
The meaning of the configure options:
-
--disable-werror
-
This option disables the -Werror option passed to GCC. This
is necessary for running the test suite.
-
--enable-kernel=3.2
-
This option tells the build system that this Glibc may be
used with kernels as old as 3.2. This means generating
workarounds in case a system call introduced in a later
version cannot be used.
-
--enable-stack-protector=strong
-
This option increases system security by adding extra code to
check for buffer overflows, such as stack smashing attacks.
-
--with-headers=/usr/include
-
This option tells the build system where to find the kernel
API headers.
-
libc_cv_slibdir=/usr/lib
-
This variable sets the correct library for all systems. We do
not want lib64 to be used.
Compile the package:
make
![[Important]](../images/important.png)
Important
In this section, the test suite for Glibc is considered critical.
Do not skip it under any circumstance.
Generally a few tests do not pass. The test failures listed below
are usually safe to ignore.
make check
You may see some test failures. The Glibc test suite is somewhat
dependent on the host system. A few failures out of over 5000 tests
can generally be ignored. This is a list of the most common issues
seen for recent versions of LFS:
-
io/tst-lchmod is known
to fail in the LFS chroot environment.
-
misc/tst-ttyname is
known to fail in the LFS chroot environment.
-
The stdlib/tst-arc4random-thread test
is known to fail if the host kernel is relatively old.
-
Some tests, for example nss/tst-nss-files-hosts-multi, are
known to fail on relatively slow systems due to an internal
timeout.
Though it is a harmless message, the install stage of Glibc will
complain about the absence of /etc/ld.so.conf. Prevent this warning with:
touch /etc/ld.so.conf
Fix the Makefile to skip an unneeded sanity check that fails in the
LFS partial environment:
sed '/test-installation/s@$(PERL)@echo not running@' -i ../Makefile
Install the package:
make install
Fix a hardcoded path to the executable loader in the ldd script:
sed '/RTLDLIST=/s@/usr@@g' -i /usr/bin/ldd
Install the configuration file and runtime directory for
nscd:
cp -v ../nscd/nscd.conf /etc/nscd.conf
mkdir -pv /var/cache/nscd
Next, install the locales that can make the system respond in a
different language. None of these locales are required, but if some
of them are missing, the test suites of some packages will skip
important test cases.
Individual locales can be installed using the localedef program. E.g., the
second localedef
command below combines the /usr/share/i18n/locales/cs_CZ charset-independent
locale definition with the /usr/share/i18n/charmaps/UTF-8.gz charmap
definition and appends the result to the /usr/lib/locale/locale-archive file. The
following instructions will install the minimum set of locales
necessary for the optimal coverage of tests:
mkdir -pv /usr/lib/locale
localedef -i POSIX -f UTF-8 C.UTF-8 2> /dev/null || true
localedef -i cs_CZ -f UTF-8 cs_CZ.UTF-8
localedef -i de_DE -f ISO-8859-1 de_DE
localedef -i de_DE@euro -f ISO-8859-15 de_DE@euro
localedef -i de_DE -f UTF-8 de_DE.UTF-8
localedef -i el_GR -f ISO-8859-7 el_GR
localedef -i en_GB -f ISO-8859-1 en_GB
localedef -i en_GB -f UTF-8 en_GB.UTF-8
localedef -i en_HK -f ISO-8859-1 en_HK
localedef -i en_PH -f ISO-8859-1 en_PH
localedef -i en_US -f ISO-8859-1 en_US
localedef -i en_US -f UTF-8 en_US.UTF-8
localedef -i es_ES -f ISO-8859-15 es_ES@euro
localedef -i es_MX -f ISO-8859-1 es_MX
localedef -i fa_IR -f UTF-8 fa_IR
localedef -i fr_FR -f ISO-8859-1 fr_FR
localedef -i fr_FR@euro -f ISO-8859-15 fr_FR@euro
localedef -i fr_FR -f UTF-8 fr_FR.UTF-8
localedef -i is_IS -f ISO-8859-1 is_IS
localedef -i is_IS -f UTF-8 is_IS.UTF-8
localedef -i it_IT -f ISO-8859-1 it_IT
localedef -i it_IT -f ISO-8859-15 it_IT@euro
localedef -i it_IT -f UTF-8 it_IT.UTF-8
localedef -i ja_JP -f EUC-JP ja_JP
localedef -i ja_JP -f SHIFT_JIS ja_JP.SJIS 2> /dev/null || true
localedef -i ja_JP -f UTF-8 ja_JP.UTF-8
localedef -i nl_NL@euro -f ISO-8859-15 nl_NL@euro
localedef -i ru_RU -f KOI8-R ru_RU.KOI8-R
localedef -i ru_RU -f UTF-8 ru_RU.UTF-8
localedef -i se_NO -f UTF-8 se_NO.UTF-8
localedef -i ta_IN -f UTF-8 ta_IN.UTF-8
localedef -i tr_TR -f UTF-8 tr_TR.UTF-8
localedef -i zh_CN -f GB18030 zh_CN.GB18030
localedef -i zh_HK -f BIG5-HKSCS zh_HK.BIG5-HKSCS
localedef -i zh_TW -f UTF-8 zh_TW.UTF-8
In addition, install the locale for your own country, language and
character set.
Alternatively, install all the locales listed in the glibc-2.37/localedata/SUPPORTED file (it includes
every locale listed above and many more) at once with the following
time-consuming command:
make localedata/install-locales
Then use the localedef command to create and
install locales not listed in the glibc-2.37/localedata/SUPPORTED file when you
need them. For instance, the following two locales are needed for
some tests later in this chapter:
localedef -i POSIX -f UTF-8 C.UTF-8 2> /dev/null || true
localedef -i ja_JP -f SHIFT_JIS ja_JP.SJIS 2> /dev/null || true
![[Note]](../images/note.png)
Note
Glibc now uses libidn2 when resolving internationalized domain
names. This is a run time dependency. If this capability is
needed, the instructions for installing libidn2 are in the
BLFS libidn2 page.
8.5.2. Configuring Glibc
8.5.2.1. Adding nsswitch.conf
The /etc/nsswitch.conf file needs
to be created because the Glibc defaults do not work well in a
networked environment.
Create a new file /etc/nsswitch.conf by running the following:
cat > /etc/nsswitch.conf << "EOF"
# Begin /etc/nsswitch.conf
passwd: files
group: files
shadow: files
hosts: files dns
networks: files
protocols: files
services: files
ethers: files
rpc: files
# End /etc/nsswitch.conf
EOF
8.5.2.2. Adding Time Zone Data
Install and set up the time zone data with the following:
tar -xf ../../tzdata2022g.tar.gz
ZONEINFO=/usr/share/zoneinfo
mkdir -pv $ZONEINFO/{posix,right}
for tz in etcetera southamerica northamerica europe africa antarctica \
asia australasia backward; do
zic -L /dev/null -d $ZONEINFO ${tz}
zic -L /dev/null -d $ZONEINFO/posix ${tz}
zic -L leapseconds -d $ZONEINFO/right ${tz}
done
cp -v zone.tab zone1970.tab iso3166.tab $ZONEINFO
zic -d $ZONEINFO -p America/New_York
unset ZONEINFO
The meaning of the zic commands:
-
zic -L
/dev/null ...
-
This creates posix time zones without any leap seconds. It
is conventional to put these in both zoneinfo and zoneinfo/posix. It is necessary to put
the POSIX time zones in zoneinfo, otherwise various test suites
will report errors. On an embedded system, where space is
tight and you do not intend to ever update the time zones,
you could save 1.9 MB by not using the posix directory, but some applications or
test suites might produce some failures.
-
zic -L
leapseconds ...
-
This creates right time zones, including leap seconds. On
an embedded system, where space is tight and you do not
intend to ever update the time zones, or care about the
correct time, you could save 1.9MB by omitting the
right directory.
-
zic ... -p
...
-
This creates the posixrules
file. We use New York because POSIX requires the daylight
savings time rules to be in accordance with US rules.
One way to determine the local time zone is to run the following
script:
tzselect
After answering a few questions about the location, the script
will output the name of the time zone (e.g., America/Edmonton). There are also some
other possible time zones listed in /usr/share/zoneinfo such as Canada/Eastern or EST5EDT that are not identified by the
script but can be used.
Then create the /etc/localtime file
by running:
ln -sfv /usr/share/zoneinfo/<xxx> /etc/localtime
Replace <xxx>
with the name of the time zone selected (e.g., Canada/Eastern).
8.5.2.3. Configuring the
Dynamic Loader
By default, the dynamic loader (/lib/ld-linux.so.2) searches through
/usr/lib for dynamic libraries that
are needed by programs as they are run. However, if there are
libraries in directories other than /usr/lib, these need to be added to the
/etc/ld.so.conf file in order for
the dynamic loader to find them. Two directories that are
commonly known to contain additional libraries are /usr/local/lib and /opt/lib, so add those directories to the
dynamic loader's search path.
Create a new file /etc/ld.so.conf
by running the following:
cat > /etc/ld.so.conf << "EOF"
# Begin /etc/ld.so.conf
/usr/local/lib
/opt/lib
EOF
If desired, the dynamic loader can also search a directory and
include the contents of files found there. Generally the files in
this include directory are one line specifying the desired
library path. To add this capability run the following commands:
cat >> /etc/ld.so.conf << "EOF"
# Add an include directory
include /etc/ld.so.conf.d/*.conf
EOF
mkdir -pv /etc/ld.so.conf.d