diff --git a/Documentation/kbuild/modules.txt b/Documentation/kbuild/modules.txt index 1d247d59ad56..1821c077b435 100644 --- a/Documentation/kbuild/modules.txt +++ b/Documentation/kbuild/modules.txt @@ -486,7 +486,7 @@ Module.symvers contains a list of all exported symbols from a kernel build. 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 @@ Module.symvers contains a list of all exported symbols from a kernel build. 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 2d20640854b7..24b3c8fe6bca 100644 --- a/scripts/Makefile.modpost +++ b/scripts/Makefile.modpost @@ -42,6 +42,13 @@ _modpost: __modpost 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 @@ modpost = scripts/mod/modpost \ $(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)) \