NAME¶
hardened-cc - gcc wrapper to enforce hardening toolchain improvements
SYNOPSIS¶
export DEB_BUILD_HARDENING=1
gcc ...
DESCRIPTION¶
The
hardened-cc wrapper is normally used by calling
gcc as usual
when
DEB_BUILD_HARDENING is set to 1. It will configure the necessary
toolchain hardening features. By default, all features are enabled. If a given
feature does not work correctly and needs to be disabled, the corresponding
environment variables mentioned below can be set to 0.
ENVIRONMENT¶
- DEB_BUILD_HARDENING=1
- Enable hardening features.
- DEB_BUILD_HARDENING_DEBUG=1
- Print the full resulting gcc command line to STDERR before calling
gcc.
- DEB_BUILD_HARDENING_OUTPUT=/some/path/debug.log
- Instead of using STDERR for debugging, redirect to the given path. Some
builds are very sensitive to unexpected STDERR output.
- DEB_BUILD_HARDENING_STACKPROTECTOR=0
- Disable stack overflow protection. See README.Debian for details.
- DEB_BUILD_HARDENING_RELRO=0
- Disable read-only linker sections. See README.Debian for details.
- DEB_BUILD_HARDENING_FORTIFY=0
- Don't fortify several standard functions. See README.Debian for
details.
- DEB_BUILD_HARDENING_PIE=0
- Don't build position independent executables. See README.Debian for
details.
- DEB_BUILD_HARDENING_FORMAT=0
- Disable unsafe format string usage errors. See README.Debian for details.
NOTES¶
System-wide settings can be added to
/etc/hardening-wrapper.conf, one per
line.
The real
gcc symlinks are renamed
gcc.real, and a diversion is
registered with
dpkg-divert(1). Thus
hardened-cc's idea of the
default
gcc is dictated by whatever package installed
/usr/bin/gcc.
SEE ALSO¶
hardened-ld(1) gcc(1)