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On Firefox Updates

02.04.2008

When Mozilla Firefox(TM) aka www/firesomething version 1.5.0.10 came out over a year ago, I tried porting it (of course). However, not only did the build not finish, it filled the entire filesystem before failing. At the time, I was updating from something like 1.5.0.4 so I did not know which version exactly caused the problem. Thus, I made incremental updates up to 1.5.0.8, where I seemingly lost interest. Now, with a faster build machine, I continued the updates, discovering that 1.5.0.10 is really the version that fails.

A diff between firefox-1.5.0.9-source.tar.bz2 and firefox-1.5.0.10-source.tar.bz2 is 10 MiB. Most of that is in CVS directories, which are included in their fucking releases, believe it or not. If you leave out those changes, the diff is still 5 MiB and 155000 lines, of which 90% are in security/. Mind you, the whole source tarball, from calling the directory mozilla instead of adding a version number to including CVS directories to using several different build systems, leaving unused configure scripts in the tree, etc., positively REEKS of a flagrant disrespect for those that build from source. All this seems to be meant to encourage you to use official Mozilla builds—which is fine if you happen to be on one of the few supported platforms: Windows, Mac OS X, and Linux i386. We are not.

Anyway: in their infinite wisdom, the Firefox developers chose to upgrade the included NSS libraries (Netscape Security) from 3.10.x to 3.11.4 in a minor security update. This version sports extensive internal restructurations—another nice way of saying "fuck you, porters". Thank you, Mozilla project. Of course, the NSS update is not explicitly mentioned in the release notes.

This tech note says: "The low-level freebl cryptographic code has been separated from softoken on all platforms. Even on platforms for which there is only one implementation of freebl, there is now a separate freebl shared library. The freebl library implements a private interface internal to NSS." This new library is the core of the problem. After the NSS libraries are built, they are cryptographically signed by a program called shlibsign which, in turn, dumps core, generating a 3 GiB core dump in my case!

I had suspected a problem related to our security features, especially W^X. The page about Building on Fedora Core 5 says: "For those with SELinux in enforcing mode, you are likely to run into problems both with the shlibsign during the build process and with the running the final build related to SELinux denying execmod permission ..." However, with some difficulty, I managed to build a debug version of everything for analyis with gdb. During the start of shlibsign, one of the init procedures loads the native freebl (?) module, which promptly loads itself. On and on, until memory exhaustion.

This comment in security/nss/lib/freebl/Makefile provided a clue to the solution:

# The blapi functions are defined not only in the freebl shared
# libraries but also in the shared libraries linked with loader.c
# (libsoftokn3.so and libssl3.so).  We need to use GNU ld's
# -Bsymbolic option or the equivalent option for other linkers
# to bind the blapi function references in FREEBLVector vector
# (ldvector.c) to the blapi functions defined in the freebl
# shared libraries.
ifeq (,$(filter-out BSD_OS FreeBSD Linux NetBSD, $(OS_TARGET)))
    MKSHLIB += -Wl,-Bsymbolic
endif

Adding MirBSD to the OS list fixes the build. And it works!

Now, firefox 1.5 is old and unsupported. So why was this update important? It makes further updates possible. The same bug was holding up my long-finished firesomething-2.0 port. I already have a package for firefox 2.0.0.13 but the port needs just a little more work. I am also confident I will be able to provide a working port for firesomething 3 when released.

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