kbuild: Add new Kbuild variable KBUILD_EXTRA_SYMBOLS
This patch adds a new (Kbuild) Makefile variable KBUILD_EXTRA_SYMBOLS.
The space separated list of file names assigned to KBUILD_EXTRA_SYMBOLS
is used when calling scripts/mod/modpost during stage 2 of the Kbuild
process for non-kernel-tree modules.
Signed-off-by: Richard Hacker <lerichi@gmx.net>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
diff --git a/Documentation/kbuild/modules.txt b/Documentation/kbuild/modules.txt
index 1d247d5..1821c07 100644
--- a/Documentation/kbuild/modules.txt
+++ b/Documentation/kbuild/modules.txt
@@ -486,7 +486,7 @@
Sometimes, an external module uses exported symbols from another
external module. Kbuild needs to have full knowledge on all symbols
to avoid spitting out warnings about undefined symbols.
- Two solutions exist to let kbuild know all symbols of more than
+ Three solutions exist to let kbuild know all symbols of more than
one external module.
The method with a top-level kbuild file is recommended but may be
impractical in certain situations.
@@ -523,6 +523,13 @@
containing the sum of all symbols defined and not part of the
kernel.
+ Use make variable KBUILD_EXTRA_SYMBOLS in the Makefile
+ If it is impractical to copy Module.symvers from another
+ module, you can assign a space separated list of files to
+ KBUILD_EXTRA_SYMBOLS in your Makfile. These files will be
+ loaded by modpost during the initialisation of its symbol
+ tables.
+
=== 8. Tips & Tricks
--- 8.1 Testing for CONFIG_FOO_BAR
diff --git a/scripts/Makefile.modpost b/scripts/Makefile.modpost
index 2d20640..24b3c8f 100644
--- a/scripts/Makefile.modpost
+++ b/scripts/Makefile.modpost
@@ -42,6 +42,13 @@
include include/config/auto.conf
include scripts/Kbuild.include
+
+ifneq ($(KBUILD_EXTMOD),)
+# Include the module's Makefile to find KBUILD_EXTRA_SYMBOLS
+include $(if $(wildcard $(KBUILD_EXTMOD)/Kbuild), \
+ $(KBUILD_EXTMOD)/Kbuild, $(KBUILD_EXTMOD)/Makefile)
+endif
+
include scripts/Makefile.lib
kernelsymfile := $(objtree)/Module.symvers
@@ -69,6 +76,7 @@
$(if $(CONFIG_MODULE_SRCVERSION_ALL),-a,) \
$(if $(KBUILD_EXTMOD),-i,-o) $(kernelsymfile) \
$(if $(KBUILD_EXTMOD),-I $(modulesymfile)) \
+ $(if $(iKBUILD_EXTRA_SYMBOLS), $(patsubst %, -e %,$(EXTRA_SYMBOLS))) \
$(if $(KBUILD_EXTMOD),-o $(modulesymfile)) \
$(if $(CONFIG_DEBUG_SECTION_MISMATCH),,-S) \
$(if $(CONFIG_MARKERS),-K $(kernelmarkersfile)) \
