If the config option CONFIG_SECTION_MISMATCH is not set and
we see a Section mismatch present the following to the user:

modpost: Found 1 section mismatch(es).
To see additional details select "Enable full Section mismatch analysis"
in the Kernel Hacking menu (CONFIG_SECTION_MISMATCH).

If the option CONFIG_SECTION_MISMATCH is selected
then be verbose in the Section mismatch reporting from mdopost.
Sample outputs:

WARNING: o-x86_64/vmlinux.o(.text+0x7396): Section mismatch in reference from the function discover_ebda() to the variable .init.data:ebda_addr
The function  discover_ebda() references
the variable __initdata ebda_addr.
This is often because discover_ebda lacks a __initdata
annotation or the annotation of ebda_addr is wrong.

WARNING: o-x86_64/vmlinux.o(.data+0x74d58): Section mismatch in reference from the variable pci_serial_quirks to the function .devexit.text:pci_plx9050_exit()
The variable pci_serial_quirks references
the function __devexit pci_plx9050_exit()
If the reference is valid then annotate the
variable with __exit* (see linux/init.h) or name the variable:
*driver, *_template, *_timer, *_sht, *_ops, *_probe, *_probe_one, *_console,

WARNING: o-x86_64/vmlinux.o(__ksymtab+0x630): Section mismatch in reference from the variable __ksymtab_arch_register_cpu to the function .cpuinit.text:arch_register_cpu()
The symbol arch_register_cpu is exported and annotated __cpuinit
Fix this by removing the __cpuinit annotation of arch_register_cpu or drop the export.
Signed-off-by: NSam Ravnborg <sam@ravnborg.org>

Sam Ravnborg pointed out that Documentation/kbuild/makefiles.txt already
says this is what it's for.  This patch makes the reality live up to the
documentation.  This fixes the problem of LDFLAGS_BUILD_ID getting into too
many places.
Signed-off-by: NRoland McGrath <roland@redhat.com>
Signed-off-by: NSam Ravnborg <sam@ravnborg.org>

We already check and warn about section mismatches from vmlinux
(build as vmlinux.o) during first pass so skip the checks
during the 2nd pass where we process modules.
Signed-off-by: NSam Ravnborg <sam@ravnborg.org>

Previously we did do the check on the .o files used to link
vmlinux but that failed to find questionable references across
the .o files.
Create a dedicated vmlinux.o file used only for section mismatch checks
that uses the defualt linker script so section does not get renamed.

The vmlinux.o may later be used as part of the the final link of vmlinux
but for now it is used fo section mismatch only.
For a defconfig build this is instant but for an allyesconfig this
add two minutes to a full build (that anyways takes ~2 hours).
Signed-off-by: NSam Ravnborg <sam@ravnborg.org>

vmlinux does not contain relocation entries which is
used by the section mismatch checks.
Reported by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>

Use the individual objects as inputs to overcome
this limitation.
In modpost check the .o files and skip non-ELF files.
Signed-off-by: NSam Ravnborg <sam@ravnborg.org>

Some people want to do crazy things like pass multiple directories as the
value of $(SUBDIRS) or $M.  Mostly this kinda works, except that
Makefile.modpost constructs a modpost commandline which fails modpost's
argument parsing.  This patch fixes that little wrinkle.
Signed-off-by: NGreg Banks <gnb@melbourne.sgi.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

On request from Al Viro make modpost processing configurable.

KBUILD_MODPOST_WARN can be set to make modpost warn instead of
error out in case on unresolved symbols in final module link.

KBUILD_MODPOST_NOFINAL can be set to avoid the final and timeconsuming
.c file generation and link of .ko files. This is solely useful for
speeding up when doing compile checks with for example allmodconfig
Signed-off-by: NSam Ravnborg <sam@ravnborg.org>

At stage 2 modpost utility is used to check modules.  In case of unresolved
symbols modpost only prints warning.

IMHO it is a good idea to fail compilation process in case of unresolved
symbols (at least in modules coming with kernel), since usually such errors
are left unnoticed, but kernel modules are broken.

- new option '-w' is added to modpost:
  if option is specified, modpost only warns about unresolved symbols

- modpost is called with '-w' for external modules in Makefile.modpost
Signed-off-by: NAndrey Mirkin <amirkin@sw.ru>
Signed-off-by: NKirill Korotaev <dev@openvz.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NSam Ravnborg <sam@ravnborg.org>

Based on patch from: Magnus Damm <magnus@valinux.co.jp>
This has the advantage that all section mismatch checks are run regardless
of modules being enabled or not.

When running modpost on vmlinux output:
MODPOST vmlinux

When running modpost on modules output count of modules like this:
MODPOST 5 modules
Signed-off-by: NSam Ravnborg <sam@ravnborg.org>

Reported by a Fedora user when they tried to build some out of tree module..
Signed-off-by: NDave Jones <davej@redhat.com>
Signed-off-by: NSam 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: NSam Ravnborg <sam@ravnborg.org>

This reverts commit e5c44fd8.

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: NLinus 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: NSam Ravnborg <sam@ravnborg.org>

This fixes one of the worst kbuild warts left - the broken dependencies used
to check and regenerate the .config file.  This was done via an indirect
dependency and the .config itself had an empty command, which can cause make
not to reread the changed .config file.

Instead of this we generate now a new file include/config/auto.conf from
.config, which is used for kbuild and has the proper dependencies.  It's also
the main make target now for all files generated during this step (and thus
replaces include/linux/autoconf.h).

This also means we can now relax the syntax requirements for the .config file
and we don't have to rewrite it all the time, i.e.  silentoldconfig only
writes .config now when it's necessary to keep it in sync with the Kconfig
files and even this can be suppressed by setting the environment variable
KCONFIG_NOSILENTUPDATE, so the update can (and must) be done manually.
Signed-off-by: NRoman Zippel <zippel@linux-m68k.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NSam Ravnborg <sam@ravnborg.org>

Signed-off-by: NUwe Zeisberger <zeisberg@informatik.uni-freiburg.de>
Signed-off-by: NAdrian Bunk <bunk@stusta.de>

The kbuild system takes advantage of an incorrect behavior in GNU make.
Once this behavior is fixed, all files in the kernel rebuild every time,
even if nothing has changed.  This patch ensures kbuild works with both
the incorrect and correct behaviors of GNU make.

For more details on the incorrect behavior, see:

http://lists.gnu.org/archive/html/bug-make/2006-03/msg00003.html

Changes in this patch:
  - Keep all targets that are to be marked .PHONY in a variable, PHONY.
  - Add .PHONY: $(PHONY) to mark them properly.
  - Remove any $(PHONY) files from the $? list when determining whether
    targets are up-to-date or not.
Signed-off-by: NPaul Smith <psmith@gnu.org>
Signed-off-by: NSam Ravnborg <sam@ravnborg.org>

With following patch a second option is enabled to obtain
symbol information from a second external module when a
external module is build.
The recommended approach is to use a common kbuild file but
that may be impractical in certain cases.
With this patch one can copy over a Module.symvers from one
external module to make symbols (and symbol versions) available
for another external module.

Updated documentation in Documentation/kbuild/modules.txt
Signed-off-by: NSam Ravnborg <sam@ravnborg.org>

Signed-off-by: NAdrian Bunk <bunk@stusta.de>

Kbuild.include is a placeholder for definitions originally present in
both the top-level Makefile and scripts/Makefile.build.
There were a slight difference in the filechk definition, so the most videly
used version was kept and usr/Makefile was adopted for this syntax.
Signed-off-by: NSam Ravnborg <sam@ravnborg.org>
---

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!