Bug#554873: initramfs-tools: silently ignores errors from modprobe command

[Michael Prokop <mika@debian.org>]

Package: initramfs-tools
Version: 0.93.4
Severity: normal


In /usr/share/initramfs-tools/hook-functions there's:

  for mam_x in $(modprobe --set-version="${version}" --ignore-install \
                 --show-depends "$1" 2>/dev/null | awk ....
                                     ^^^^^^^^^^^

If there doesn't exist an according modules.dep file yet¹ the
initramfs is built without mentioning *any* errors (though modprobe
clearly shows the failure when manually invoking the above
command²), even though essential stuff like filesystem modules might
be missing and the system might not be able to boot at all.


¹ For example because the linux-image in question doesn't execute
"depmod -a $KERNELVERSION" automatically during installation. Then
the original modules.dep might be present but contain stuff like:

  kernel/fs/ext3/ext3.ko: kernel/fs/jbd/....

So it references file with relative paths - leading to ².
After manually invoking "depmod -a $KERNELVERSION" it looks like:

  /lib/modules/$KERNELVERSION/kernel/fs/ext3/ext3.ko: /lib/modules/....

So the absolute paths are being used and works fine then.


² Example when the working directory is NOT /lib/modules/$KERNELVERSION/:

  # modprobe --set-version=$KERNELVERSION --ignore-install --show-depends ext3
  WARNING: Could not open 'kernel/fs/mbcache.ko': No such file or directory
  WARNING: Could not open 'kernel/fs/jbd/jbd.ko': No such file or directory
  FATAL: Could not open 'kernel/fs/ext3/ext3.ko': Noch such file or directory

So clearly an error message, but the 2>/dev/null inside
/usr/share/initramfs-tools/hook-functions just throws that away and
the ext3 + related modules don't become part of the initrd.

Of course when being inside /lib/modules/$KERNELVERSION/ and
executing the command again the correct output is available:

  insmod kernel/fs/mbcache.ko
  insmod kernel/fs/jbd/jbd.ko
  insmod kernel/fs/ext3/ext3.ko

But amusingly update-initramfs then (working directory being
/lib/modules/$KERNELVERSION/) complains with tons of messages like:

  ln: creating symbolic link `/tmp/mkinitramfs_HuFGVJ/kernel/....': File exists

regards,
-mika-