CasperSecurity
To debug fakeroot, one may try:
Start faked in xterm 1:
$ faked --foreground --debug
51452231:280
# First number here is the 'FAKEROOTKEY', second is the pid of
# faked. Both to be used later.
# Later, when programs go using faked, a _lot_ of debug output
# will be shown here.
Send signals to faked in xterm 2:
#Whenever you want to get info about the internal inode data
#faked is keeping, do:
kill -s USR1 280
And the 'real' program runs (at your choise) in another xterm [3], or gdb
In an xterm, do:
$ LD_PRELOAD=/usr/lib/libfakeroot/libfakeroot.so.0
$ FAKEROOTKEY=51452231 # number output by faked, xterm 1
$ export LD_PRELOAD FAKEROOTKEY
$ my-prog #start anything you like.
Or, if you want to run the programme in a gdb session:
To make specifying the paths easier, put libfakeroot.c, libfakeroot.so.0.0.1
and the binary you want to run in the same directory (libfakeroot.so.0.0.1
is put in ./.libs/libfakeroot.so.0.0.1 by libtool during compilation, copy
it out there).
Then, in gdb do:
$ gdb ./ls #as an example, I run 'ls'.
(gdb) set env LD_PRELOAD=/home/joost/maintain/vpathlib/libfakeroot-0.1/libfakeroot.so.0.0.1
(gdb) set env FAKEROOTKEY=51452231 #number from xterm 1.
# Or wherever you've got your libfakeroot.so.0.0.1
(gdb) break libfakeroot.c:181
Breakpoint 1 at 0x4000ecc8: file libfakeroot.c, line 181.
(gdb) run -al
Starting program: /home/joost/maintain/vpathlib/libfakeroot-0.1/ls -al
Temporarily disabling shared library breakpoints:
1
Breakpoint 1, __lxstat (ver=134556187, file_name=0x0, statbuf=0x80529c8)
at libfakeroot.c:208
208 struct stat *statbuf){
# OK, and there I've found a bug -- ver can only be '0' in the
# current libc6 (glibc2). Unfortunately, it didn't reproduce.