In several cases the section mismatch check triggered false warnings.
Following patch introduce a whitelist to 'false positives' are not warned of.
Two types of patterns are recognised:
1) Typical case when a module parameter is _initdata
2) When a function pointer is assigned to a driver structure

In both patterns we rely on the actual name of the variable assigned
Signed-off-by: NSam Ravnborg <sam@ravnborg.org>

It seems popular to protect your work with copyright, so I decided to do
so for modpost which I patch a great deal atm.
Signed-off-by: NSam Ravnborg <sam@ravnborg.org>

Andrew Morton reported a number of false positives for ia64 - like these:
WARNING: drivers/acpi/button.o - Section mismatch: reference to .init.text: from .IA_64.unwind.init.text after '' (at offset 0x0)
WARNING: drivers/acpi/button.o - Section mismatch: reference to .exit.text: from .IA_64.unwind.exit.text after '' (at offset 0x0)
WARNING: drivers/acpi/processor.o - Section mismatch: reference to .init.text: from .IA_64.unwind after '' (at offset 0x1e8)

They are all false positives - or at least the .c code looks OK.
It is not known why sometimes a section name is appended and sometimes not.

Fix is to accept references from all sections that includes "unwind." in the name.
Signed-off-by: NSam Ravnborg <sam@ravnborg.org>

The kernel now requires that CC be 3.1.0 or higher.  But we shouldn't place
that requirement upon HOSTCC unless we really need to.  Fixes my ia64 problem.
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NSam Ravnborg <sam@ravnborg.org>

Try to look up the symbol that is referenced. Include the symbol
name in the warning message.
Signed-off-by: NSam Ravnborg <sam@ravnborg.org>

Do not try to look up section name until we know it is not a special
section. Otherwise we will address outside legal space and segfault.
Signed-off-by: NSam Ravnborg <sam@ravnborg.org>

Section mismatch is identified as references to .init*
sections from non .init sections. And likewise references
to .exit.* sections outside .exit sections.

.init.* sections are discarded after a module is initialized
and references to .init.* sections are oops candidates.
.exit.* sections are discarded when a module is built-in and
thus references to .exit are also oops candidates.

The checks were possible to do using 'make buildcheck' which
called the two perl scripts: reference_discarded.pl and
reference_init.pl. This patch just moves the same functionality
inside modpost and the scripts are then obsoleted.
They will though be kept for a while so users can do double
checks - but note that some .o files are skipped by the perl scripts
so result is not 1:1.
All credit for the concept goes to Keith Owens who implemented
the original perl scrips - this patch just moves it to modpost.

Compared to the perl script the implmentation in modpost will be run
for each kernel build - thus catching the error much sooner, but
the downside is that the individual .o file are not always identified.
Signed-off-by: NSam Ravnborg <sam@ravnborg.org>

In modpost introduce a check for symbols exported twice.
This check caught only one victim (inet_bind_bucket_create) for
which a patch is already sent to netdev.
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>

Just some light CodingStyle updates - no functional changes.
Signed-off-by: NSam Ravnborg <sam@ravnborg.org>

modpost.c provides warn() and fatal() - so use them all over the place.
Signed-off-by: NSam Ravnborg <sam@ravnborg.org>

This patch fixes a problem when we use well known kernel symbols as module
names.

For example, if module source name is current.c, idle_stack.c or etc.,
we have a bad KBUILD_MODNAME value.
For example, KBUILD_MODNAME will be "get_current()" instead of "current", or
"(init_thread_union.stack)" instead of "idle_task".

The trick is to define a stringify macro on the commandline - named
KBUILD_STR for namespace reasons - and then to stringify the module
name.

There are a few uses of KBUILD_MODNAME throughout the tree but the usage
is for debug and will not be harmed by this change so left untouched for now.

While at it KBUILD_BASENAME was changed too. Any spinlock usage in the
unix module would have created wrong section names without it.
Usage in spinlock.h fixed so it no longer stringify KBUILD_BASENAME.

Original patch from Ustyogov Roman - all bugs introduced by me.
Signed-off-by: NSam Ravnborg <sam@ravnborg.org>

   This is the patch for the following issue:

 In include/linux/module.h, "__crc_" and "__ksymtab_" are hard
coded to be the   prefix for some kinds of symbols (CRC symbol and
ksymtab section). But in script /mod/modpost.c,
MODULE_SYMBOL_PREFIX##"__crc_" is used as the prefix to search CRC
symbols. So if an architecture (such as h8300 or Blackfin) defines
MODULE_SYMBOL_PREFIX as not NULL ("_"), modpost will always warn about
"no invalid crc".
  And it is the same with KSYMTAB_PFX.
Signed-off-by: NLuke Yang <luke.adi@gmail.com>
Signed-off-by: NSam Ravnborg <sam@ravnborg.org>

From: Al Viro <viro@ZenIV.linux.org.uk>

Instead of playing all of these hand-coded assembler aliasing games,
just translate symbol names in the name space ".sym" to "_Sym" at
module load time.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

GLIBC 2.3.4 and later changed the STT_REGISTER macro to
STT_SPARC_REGISTER, so we need to cope with that somehow.

Original patch from fabbione, reposted by Ben Collins.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Recently a change in the glibc elf.h header has been introduced causing
modpost to spawn tons of warnings (like the one below) building the kernel
on sparc:

[SNIP]
*** Warning: "current_thread_info_reg" [net/sunrpc/auth_gss/auth_rpcgss.ko] undefined!
*** Warning: "" [net/sunrpc/auth_gss/auth_rpcgss.ko] undefined!
*** Warning: "" [net/sunrpc/auth_gss/auth_rpcgss.ko] undefined!
[SNIP]

Ben Collins discovered that the STT_REGISTERED definition in glibc did change
and that this change needs to be propagated to modpost.

glibc change:
-#define STT_REGISTER   13              /* Global register reserved to app. */
+#define STT_SPARC_REGISTER     13      /* Global register reserved to app. */

I did and tested this simple patch to maintain compatibility with newer (>= 2.3.4)
and older (<= 2.3.2) glibc.
Signed-off-by: NFabio M. Di Nitto <fabbione@fabbione.net>
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!