Enable AddressSanitizer by default in gcc

Question

To be able to debug and fuzz a whole Linux distribution, I would like to set ASAN (AddressSanitizer, https://en.wikipedia.org/wiki/AddressSanitizer) as default option to gcc. So normally to achieve what I want, generally, I set the following variables before to compile a linux package:

CFLAGS="-fsanitize=address,undefined -Wformat -Werror=format-security -Werror=array-bounds -g" 
CXXFLAGS="-fsanitize=address,undefined -Wformat -Werror=format-security -Werror=array-bounds -g" 
LDFLAGS="-fsanitize=address,undefined"

and try to compile and run my code. I would like to have it default to gcc.

One option to do it is using spec files: https://gcc.gnu.org/onlinedocs/gcc/Spec-Files.html. However I didn't find a way to set a "catch all rules" to compile and link all my c/c++ code with AddressSanitizer.

My questions are:

Any example how to do it using spec files?
Is that the best approach to do it?
Any other alternative approach?

yugr · Accepted Answer · 2017-02-18 09:27:23Z

2

First of all, be sure to take a look at existing whole-distro Asan enablings in Tizen (also here) and Gentoo.

In general there are two main approaches:

customize your build system to enable Asan by default, usually using CFLAGS and CXXFLAGS; this won't always work because many packages ignore them (I think that's what Hanno Boeck did in Gentoo)
replace /usr/bin/gcc, /usr/bin/g++ and /usr/bin/cc (and may x86_64-linux-gnu-gcc, x86_64-linux-gnu-g++) with wrappers which would add Asan flags and redirect calls to original executables (this is the approach we eventually took in Tizen and found it very successful)

As a side note, I'd suggest to add the following options

CFLAGS += -fsanitize-recover=address,undefined

otherwise boot will fail at too early stages. Also look at suggested settings ASAN_OPTIONS in above links, it took people long time to figure them out.

answered Feb 18, 2017 at 9:27

yugr

22.7k4 gold badges66 silver badges111 bronze badges

Sign up to request clarification or add additional context in comments.

4 Comments

VP. Over a year ago

hi, could you point me to a gcc wrapper example? I found for example github.com/gawen947/gcc-wrapper which I could look into, however if you have something already in mind, it would be better..

yugr Over a year ago

@VP. Well, it's really just a primitive shell wrapper which calls "true" gcc with -fanitize=address -fsanitize-recover=address -fno-common etc.. Gcc wrappers is a common practice (see e.g. pbuilder instructions) but I'm afraid I don't have a link specific to Asan.

VP. Over a year ago

Ok, I did something like export MYFLAGS="..."; exec /usr/bin/gcc-6 $@ but it didnt work somehow.. thank you by the great input!

yugr Over a year ago

@VP. FYI I just I checked the Tizen article, it has example wrapper (Fig. 5). You are welcome.

Collectives™ on Stack Overflow

Enable AddressSanitizer by default in gcc

1 Answer 1

4 Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

4 Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related