From 0187efca598c6e072d1de1a59e3bdefa28d89cfe Mon Sep 17 00:00:00 2001 From: Bruno Haible Date: Sun, 6 Dec 2020 17:59:45 +0100 Subject: [PATCH] doc: Add more details regarding the undefined behaviour sanitizer. * doc/gnulib-readme.texi (High Quality): Describe -fsanitize-undefined-trap-on-error better. --- ChangeLog | 6 ++++++ doc/gnulib-readme.texi | 23 ++++++++++++++++++----- 2 files changed, 24 insertions(+), 5 deletions(-) diff --git a/ChangeLog b/ChangeLog index 5cb643ed75..08cef4d151 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,5 +1,11 @@ 2020-12-06 Bruno Haible + doc: Add more details regarding the undefined behaviour sanitizer. + * doc/gnulib-readme.texi (High Quality): Describe + -fsanitize-undefined-trap-on-error better. + +2020-12-06 Bruno Haible + Do the Windows oldnames workaround through the C++ GNULIB_NAMESPACE. Reported by Daniel R. Hurtmans in . diff --git a/doc/gnulib-readme.texi b/doc/gnulib-readme.texi index a2a59628b1..cde6d7aaba 100644 --- a/doc/gnulib-readme.texi +++ b/doc/gnulib-readme.texi @@ -546,8 +546,21 @@ for your compiler. For example: @end example @noindent -Here, @code{-D_FORTIFY_SOURCE=2} enables extra security hardening -checks in the GNU C library, @code{-fsanitize=undefined} enables GCC's -undefined behavior sanitizer (@code{ubsan}), and -@code{-fsanitize-undefined-trap-on-error} prevents @code{ubsan}'s -linking to unnecessary libraries like @code{libstdc++}. +Here: + +@itemize @bullet +@item +@code{-D_FORTIFY_SOURCE=2} enables extra security hardening checks in +the GNU C library. +@item +@code{-fsanitize=undefined} enables GCC's undefined behavior sanitizer +(@code{ubsan}), and +@item +@code{-fsanitize-undefined-trap-on-error} causes @code{ubsan} to +abort the program (through an ``illegal instruction'' signal). This +measure stops exploit attempts and also allows you to debug the issue. +Without this option, @code{-fsanitize=undefined} causes messages to be +printed, execution continues after an undefined behavior situation, and +GCC links the program against @code{libstdc++} (which you can avoid +through the option @code{-static-libubsan}). +@end itemize -- 2.11.4.GIT