1 | <?xml version="1.0" encoding="ISO-8859-1"?>
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2 | <!DOCTYPE sect1 PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
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3 | "http://www.oasis-open.org/docbook/xml/4.5/docbookx.dtd" [
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4 | <!ENTITY % general-entities SYSTEM "../general.ent">
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5 | %general-entities;
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6 | ]>
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7 |
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8 | <sect1 id="ch-system-strippingagain">
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9 | <?dbhtml filename="strippingagain.html"?>
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10 |
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11 | <title>Stripping Again</title>
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12 |
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13 | <para>This section is optional. If the intended user is not a
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14 | programmer and does not plan to do
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15 | any debugging on the system software, the system size can be decreased
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16 | by about 90 MB by removing the debugging symbols from binaries and
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17 | libraries. This causes no inconvenience other than not being able to
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18 | debug the software fully anymore.</para>
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19 |
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20 | <para>Most people who use the commands mentioned below do not
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21 | experience any difficulties. However, it is easy to make a typo and
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22 | render the new system unusable, so before running the
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23 | <command>strip</command> commands, it is a good idea to make a
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24 | backup of the LFS system in its current state.</para>
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25 |
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26 | <para>First place the debugging symbols for selected libraries
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27 | in separate files. This debugging information is needed if running
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28 | regression tests that use <ulink
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29 | url='&blfs-book;/general/valgrind.html'>valgrind</ulink> or <ulink
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30 | url='&blfs-book;/general/gdb.html'>gdb</ulink> later in BLFS.
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31 | </para>
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32 |
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33 | <!-- also of interest are libgfortan, libgo, libgomp, and libobjc from gcc -->
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34 |
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35 | <!--<screen><userinput>save_lib="ld-2.25.so libc-2.25.so libpthread-2.25.so libthread_db-1.0.so"-->
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36 | <screen><userinput>save_lib="ld-&glibc-version;.so libc-&glibc-version;.so libpthread-&glibc-version;.so libthread_db-&libthread_db-version;.so"
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37 |
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38 | cd /lib
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39 |
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40 | for LIB in $save_lib; do
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41 | objcopy --only-keep-debug $LIB $LIB.dbg
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42 | strip --strip-unneeded $LIB
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43 | objcopy --add-gnu-debuglink=$LIB.dbg $LIB
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44 | done
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45 |
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46 | save_usrlib="libquadmath.so.&libquadmath-version; libstdc++.so.&libstdcpp-version;
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47 | libmpx.so.&libmpx-version; libmpxwrappers.so.&libmpxwrap-version; libitm.so.&libitm-version;
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48 | libatomic.so.&libatomic-version;" <!-- libcilkrts.so.&libcilkrts-version;-->
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49 |
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50 | cd /usr/lib
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51 |
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52 | for LIB in $save_usrlib; do
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53 | objcopy --only-keep-debug $LIB $LIB.dbg
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54 | strip --strip-unneeded $LIB
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55 | objcopy --add-gnu-debuglink=$LIB.dbg $LIB
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56 | done
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57 |
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58 | unset LIB save_lib save_usrlib</userinput></screen>
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59 |
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60 | <para>Before performing the stripping, take special care to ensure that
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61 | none of the binaries that are about to be stripped are running:</para>
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62 |
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63 | <screen role="nodump"><userinput>exec /tools/bin/bash</userinput></screen>
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64 |
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65 | <!--
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66 | If
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67 | unsure whether the user entered chroot with the command given in
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68 | <xref linkend="ch-system-chroot" role=","/> first use the version
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69 | of bash we created in
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70 | chroot:</para>
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71 |
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72 | <screen role="nodump"><userinput>logout</userinput></screen>
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73 |
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74 | <para>Then reenter it with:</para>
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75 |
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76 | <screen role="nodump"><userinput>chroot $LFS /tools/bin/env -i \
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77 | HOME=/root TERM=$TERM \
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78 | PS1='(lfs chroot) \u:\w\$ ' \
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79 | PATH=/bin:/usr/bin:/sbin:/usr/sbin \
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80 | /tools/bin/bash - -login</userinput></screen>-->
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81 |
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82 | <para>Now the binaries and libraries can be safely stripped:</para>
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83 |
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84 | <screen><userinput>/tools/bin/find /usr/lib -type f -name \*.a \
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85 | -exec /tools/bin/strip --strip-debug {} ';'
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86 |
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87 | /tools/bin/find /lib /usr/lib -type f \( -name \*.so* -a ! -name \*dbg \) \
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88 | -exec /tools/bin/strip --strip-unneeded {} ';'
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89 |
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90 | /tools/bin/find /{bin,sbin} /usr/{bin,sbin,libexec} -type f \
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91 | -exec /tools/bin/strip --strip-all {} ';'</userinput></screen>
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92 |
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93 | <para>A large number of files will be reported as having their file
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94 | format not recognized. These warnings can be safely ignored. These
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95 | warnings indicate that those files are scripts instead of
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96 | binaries.</para>
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97 |
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98 | </sect1>
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