When multiple built-in modules (especially drivers) provide the same
capability, they're prioritized by link order specified by the order
listed in Makefile.  This implicit ordering is lost for loadable
modules.

When driver modules are loaded by udev, what comes first in
modules.alias file is selected.  However, the order in this file is
indeterministic (depends on filesystem listing order of installed
modules).  This causes confusion.

The solution is two-parted.  This patch updates kbuild such that it
generates and installs modules.order which contains the name of
modules ordered according to Makefile.  The second part is update to
depmod such that it generates output files according to this file.

Note that both obj-y and obj-m subdirs can contain modules and
ordering information between those two are lost from beginning.
Currently obj-y subdirs are put before obj-m subdirs.

Sam Ravnborg cleaned up Makefile modifications and suggested using awk
to remove duplicate lines from modules.order instead of using separate
C program.

Signed-off-by: Tejun Heo <htejun@gmail.com>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Cc: Bill Nottingham <notting@redhat.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Cc: Jon Masters <jonathan@jonmasters.org>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>

Introduce ccflags-y, asflags-y and ldflags-y so we soon can
deprecate use of EXTRA_CFLAGS, EXTRA_AFLAGS and EXTRA_LDFLAGS.
This patch does not touch any in-tree users - thats next round.
Lets get this committed first and then fix the users of the
soon to be deprecated variants next.

The rationale behind this change is to introduce support for
makefile fragments like:

ccflags-$(CONFIG_WHATEVER_DEBUG) := -DDEBUG

As a replacement for the uglier:
ifeq ($(CONFIG_WHATEVER_DEBUG),y)
        EXTRA_CFLAGS := -DDEBUG
endif

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>

The variable CPPFLAGS is a wellknown variable and the usage by
kbuild may result in unexpected behaviour.

This patch replace use of CPPFLAGS with KBUILD_CPPFLAGS all over the
tree and enabling one to use:
make CPPFLAGS=...
to specify additional CPP commandline options.

Patch was tested on following architectures:
alpha, arm, i386, x86_64, mips, sparc, sparc64, ia64, m68k, s390

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>

The variable AFLAGS is a wellknown variable and the usage by
kbuild may result in unexpected behaviour.
On top of that several people over time has asked for a way to
pass in additional flags to gcc.

This patch replace use of AFLAGS with KBUILD_AFLAGS all over
the tree.

Patch was tested on following architectures:
alpha, arm, i386, x86_64, mips, sparc, sparc64, ia64, m68k, s390

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>

The variable CFLAGS is a wellknown variable and the usage by
kbuild may result in unexpected behaviour.
On top of that several people over time has asked for a way to
pass in additional flags to gcc.

This patch replace use of CFLAGS with KBUILD_CFLAGS all over the
tree and enabling one to use:
make CFLAGS=...
to specify additional gcc commandline options.

One usecase is when trying to find gcc bugs but other
use cases has been requested too.

Patch was tested on following architectures:
alpha, arm, i386, x86_64, mips, sparc, sparc64, ia64, m68k

Test was simple to do a defconfig build, apply the patch and check
that nothing got rebuild.

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>

These checks has been present for several kernel releases (> 5).
So lets just get rid of them.
With this we no longer check for use of:
EXTRA_TARGETS, O_TARGET, L_TARGET, list-multi, export-objs

There were three remaining in-tree users of O_TARGET in some
unmaintained sh64 code - mail sent to the maintainer + list.

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>

Previously kbuild choked over the following:
obj-y += ../../../arch/i386/kernel/bootflag.o

This has resulted in some rather ugly workarounds in
current x86_64 tree.
This patch fixes kbuild to allow the above and enable
potential cleanups in x86_64 and maybe in other places.

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>

kbuild used $¤(*F to get filename of target without extension.
This was used in several places all over kbuild, but introducing
make -rR broke his for all cases where we specified full path to
target/prerequsite. It is assumed that make -rR disables old style
suffix-rules which is why is suddenly failed.

ia64 was impacted by this change because several div* routines in
arch/ia64/lib are build using explicit paths and then kbuild failed.

Thanks to David Mosberger-Tang <David.Mosberger@acm.org> for an explanation
what was the root-cause and for testing on ia64.

This patch also fixes two uses of $(*F) in arch/um

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>

This reverts commit e5c44fd88c146755da6941d047de4d97651404a9.

Thanks to Daniel Ritz and Michal Piotrowski for noticing the problem.

Daniel says:

  "[The] reason is a recent change that made modules always shows as
   module.mod.  it breaks modprobe and probably many scripts..besides
   lsmod looking horrible

   stuff like this in modprobe.conf:
        install pcmcia_core /sbin/modprobe --ignore-install pcmcia_core; /sbin/modprobe pcmcia
   makes modprobe fork/exec endlessly calling itself...until oom
   interrupts it"

Signed-off-by: Linus Torvalds <torvalds@osdl.org>

make failed to supply the filename when using make -rR and using $(*F)
to get target filename without extension.
This bug was not reproduceable in small scale but using:
$(basename $(notdir $@)) fixes it with same functionality.

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>