The directories for objdump is created by the code
a few lines below:

  [ ! -d "$OBJDIFFD/$dn" ] && mkdir -p "$OBJDIFFD/$dn"
Signed-off-by: NMasahiro Yamada <yamada.m@jp.panasonic.com>
Acked-by: NJason Cooper <jason@lakedaemon.net>
Signed-off-by: NMichal Marek <mmarek@suse.cz>

Signed-off-by: NMasahiro Yamada <yamada.m@jp.panasonic.com>
Acked-by: NJason Cooper <jason@lakedaemon.net>
Signed-off-by: NMichal Marek <mmarek@suse.cz>

This commit is a minor refactoring.

Temporary files for objdiff are stored in .tmp_objdiff directory
which is located at the top directory.

To get the path to this directory,

  SRCTREE=`git rev-parse --show-toplevel`
  TMPD=$SRCTREE/.tmp_objdiff

seems easier to understand than

  GIT_DIR=`git rev-parse --git-dir`
  TMPD=${GIT_DIR%git}tmp_objdiff

Besides, it is not always necessary to create .tmp_objdiff dicrectory.
It should be created only for "record" command.
Signed-off-by: NMasahiro Yamada <yamada.m@jp.panasonic.com>
Acked-by: NJason Cooper <jason@lakedaemon.net>
Signed-off-by: NMichal Marek <mmarek@suse.cz>

objdiff is useful when doing large code cleanups.  For example, when
removing checkpatch warnings and errors from new drivers in the staging
tree.

objdiff can be used in conjunction with a git rebase to confirm that
each commit made no changes to the resulting object code.  It has the
same return values as diff(1).

This was written specifically to support adding the skein and threefish
cryto drivers to the staging tree.  I needed a programmatic way to
confirm that commits changing >90% of the lines didn't inadvertently
change the code.

Temporary files (objdump output) are stored in

  /path/to/linux/.tmp_objdiff

'make mrproper' will remove this directory.
Signed-off-by: NJason Cooper <jason@lakedaemon.net>
Signed-off-by: NMichal Marek <mmarek@suse.cz>