From 30f3041a7d4ddd47fdb2c000ea1b8548225bb79d Mon Sep 17 00:00:00 2001 From: David Bryant Date: Tue, 22 Nov 2022 16:00:02 -0600 Subject: Rewrote a cumbersome sentence to make it clearer. Capitalized the names of packages. Clarified verbiage in re PIE & ASLR. Improved the description of SSP, and tightened it up. Clarified the instructions for running tests concurrently. Modified descriptions of tests that fail. Patched up punctuation. Spelled "set up" correctly: "setup" is a noun. The phrasal verb used here is spelled as two words. Use the word "directives" to describe "#include" and similar preprocessor instructions. Add periods to some otherwise complete sentences. --- chapter08/gcc.xml | 70 +++++++++++++++++++++++++++---------------------------- 1 file changed, 35 insertions(+), 35 deletions(-) diff --git a/chapter08/gcc.xml b/chapter08/gcc.xml index a36720374..4b5c2dd61 100644 --- a/chapter08/gcc.xml +++ b/chapter08/gcc.xml @@ -80,8 +80,8 @@ cd build --disable-bootstrap \ --with-system-zlib - Note that for other programming languages there are some prerequisites that - are not yet available. See the + GCC supports seven different computer languages, but the + prerequisites for most of them have not yet been installed. See the BLFS Book GCC page for instructions on how to build all of GCC's supported languages. @@ -91,8 +91,8 @@ cd build LD=ld - This parameter makes the configure script use the ld installed - by the binutils built earlier in this chapter, rather than + This parameter makes the configure script use the ld program installed + by the Binutils package built earlier in this chapter, rather than the cross-built version which would otherwise be used. @@ -101,7 +101,7 @@ cd build --with-system-zlib This switch tells GCC to link to the system installed copy of - the zlib library, rather than its own internal copy. + the Zlib library, rather than its own internal copy. @@ -109,21 +109,21 @@ cd build - PIE (position-independent executable) is a technique to produce + PIE (position-independent executables) are binary programs that can be loaded anywhere in memory. Without PIE, the security feature named ASLR (Address Space Layout Randomization) - can be applied for the shared libraries, but not the executable - itself. Enabling PIE allows ASLR for the executables in addition to + can be applied for the shared libraries, but not for the executables + themselves. Enabling PIE allows ASLR for the executables in addition to the shared libraries, and mitigates some attacks based on fixed addresses of sensitive code or data in the executables. SSP (Stack Smashing Protection) is a technique to ensure - that the parameter stack is not corrupted. Stack corruption can - for example alter the return address of a subroutine, - which would allow transferring control to some dangerous code + that the parameter stack is not corrupted. Stack corruption can, + for example, alter the return address of a subroutine, + thus transferring control to some dangerous code (existing in the program or shared libraries, or injected by the - attacker somehow) instead of the original one. + attacker somehow). @@ -133,10 +133,10 @@ cd build In this section, the test suite for GCC is considered - important, but it takes a long time. First time builders are - encouraged to not skip it. The time to run the tests can be - reduced significantly by adding -jx to the make command below - where x is the number of cores on your system. + important, but it takes a long time. First-time builders are + encouraged to run the test suite. The time to run the tests can be + reduced significantly by adding -jx to the make -k check command below, + where x is the number of CPU cores on your system. One set of tests in the GCC test suite is known to exhaust the default @@ -149,23 +149,23 @@ cd build chown -Rv tester . su tester -c "PATH=$PATH make -k check" - To receive a summary of the test suite results, run: + To extract a summary of the test suite results, run: ../contrib/test_summary - For only the summaries, pipe the output through + To filter out only the summaries, pipe the output through grep -A7 Summ. Results can be compared with those located at and . - In gcc, eleven tests, in the i386 test suite are known to FAIL. + Eleven tests in the i386 test suite for the gcc compiler are known to FAIL. It's because the test files do not account for the --enable-default-pie option. - In g++, four tests related to PR100400 are known to be reported - as both XPASS and FAIL. It's because the test file for this known issue + Four tests related to PR100400 may be reported + as both XPASS and FAIL when testing the g++ compiler; the test file is not well written. A few unexpected failures cannot always be avoided. The GCC developers @@ -187,8 +187,8 @@ su tester -c "PATH=$PATH make -k check" make install The GCC build directory is owned by - tester now and the ownership of the installed header - directory (and its content) will be incorrect. Change the ownership to + tester now, and the ownership of the installed header + directory (and its content) is incorrect. Change the ownership to the root user and group: chown -v -R root:root \ @@ -225,7 +225,7 @@ readelf -l a.out | grep ': /lib' [Requesting program interpreter: /lib64/ld-linux-x86-64.so.2] - Now make sure that we're setup to use the correct start files: + Now make sure that we're set up to use the correct start files: grep -E -o '/usr/lib.*/S?crt[1in].*succeeded' dummy.log @@ -274,7 +274,7 @@ SEARCH_DIR("/usr/local/lib") SEARCH_DIR("/lib") SEARCH_DIR("/usr/lib"); - A 32-bit system may see a few different directories. For example, here + A 32-bit system may use a few other directories. For example, here is the output from an i686 machine: SEARCH_DIR("/usr/i686-pc-linux-gnu/lib32") @@ -307,7 +307,7 @@ SEARCH_DIR("/usr/lib"); at all, then something is seriously wrong. Investigate and retrace the steps to find out where the problem is and correct it. Any - issues will need to be resolved before continuing with the process. + issues should be resolved before continuing with the process. Once everything is working correctly, clean up the test files: @@ -374,7 +374,7 @@ mv -v /usr/lib/*gdb.py /usr/share/gdb/auto-load/usr/lib cpp The C preprocessor; it is used by the compiler to expand the - #include, #define, and similar statements in the source files + #include, #define, and similar directives in the source files cpp @@ -407,7 +407,7 @@ mv -v /usr/lib/*gdb.py /usr/share/gdb/auto-load/usr/lib A wrapper around ar that adds a plugin to the command line. This program is only used to add "link time optimization" and is not useful with the - default build options + default build options. gc-ar @@ -420,7 +420,7 @@ mv -v /usr/lib/*gdb.py /usr/share/gdb/auto-load/usr/lib A wrapper around nm that adds a plugin to the command line. This program is only used to add "link time optimization" and is not useful with the - default build options + default build options. gc-nm @@ -433,7 +433,7 @@ mv -v /usr/lib/*gdb.py /usr/share/gdb/auto-load/usr/lib A wrapper around ranlib that adds a plugin to the command line. This program is only used to add "link time optimization" and is not useful with the - default build options + default build options. gc-ranlib @@ -444,7 +444,7 @@ mv -v /usr/lib/*gdb.py /usr/share/gdb/auto-load/usr/lib gcov A coverage testing tool; it is used to analyze programs to - determine where optimizations will have the most effect + determine where optimizations will have the greatest effect gcov @@ -525,7 +525,7 @@ mv -v /usr/lib/*gdb.py /usr/share/gdb/auto-load/usr/lib libgcov - This library is linked in to a program when GCC is instructed + This library is linked into a program when GCC is instructed to enable profiling libgcov @@ -567,7 +567,7 @@ mv -v /usr/lib/*gdb.py /usr/share/gdb/auto-load/usr/lib liblto_plugin - GCC's LTO plugin allows binutils to process object files + GCC's LTO plugin allows Binutils to process object files produced by GCC with LTO enabled liblto_plugin @@ -589,8 +589,8 @@ mv -v /usr/lib/*gdb.py /usr/share/gdb/auto-load/usr/lib libssp Contains routines supporting GCC's stack-smashing protection - functionality. Normally it's unused because glibc also provides - those routines + functionality. Normally it is not used, because Glibc also provides + those routines. libssp -- cgit v1.2.3-54-g00ecf