mod/file2alias: make modalias generation safe for cross compiling

Use the target compiler to compute the offsets for the fields of the
device_id structures, so that it won't be broken by different alignments
between the host and target ABIs.

This also fixes missing endian corrections for some modaliases.

Signed-off-by: Andreas Schwab <schwab@linux-m68k.org>
Signed-off-by: Michal Marek <mmarek@suse.cz>

6 files changed, 582 insertions, 318 deletions

diff --git a/scripts/Makefile.modpost b/scripts/Makefile.modpost
index a1cb0222ebe6..cf82c832458f 100644
--- a/scripts/Makefile.modpost
+++ b/scripts/Makefile.modpost
@@ -66,10 +66,6 @@ modules   := $(patsubst %.o,%.ko, $(wildcard $(__modules:.ko=.o)))
 # Stop after building .o files if NOFINAL is set. Makes compile tests quicker
 _modpost: $(if $(KBUILD_MODPOST_NOFINAL), $(modules:.ko:.o),$(modules))
 
-ifneq ($(KBUILD_BUILDHOST),$(ARCH))
-        cross_build := 1
-endif
-
 # Step 2), invoke modpost
 #  Includes step 3,4
 modpost = scripts/mod/modpost                    \
@@ -80,8 +76,7 @@ modpost = scripts/mod/modpost                    \
  $(if $(KBUILD_EXTRA_SYMBOLS), $(patsubst %, -e %,$(KBUILD_EXTRA_SYMBOLS))) \
  $(if $(KBUILD_EXTMOD),-o $(modulesymfile))      \
  $(if $(CONFIG_DEBUG_SECTION_MISMATCH),,-S)      \
- $(if $(KBUILD_EXTMOD)$(KBUILD_MODPOST_WARN),-w) \
- $(if $(cross_build),-c)
+ $(if $(KBUILD_EXTMOD)$(KBUILD_MODPOST_WARN),-w)
 
 quiet_cmd_modpost = MODPOST $(words $(filter-out vmlinux FORCE, $^)) modules
       cmd_modpost = $(modpost) -s
diff --git a/scripts/mod/.gitignore b/scripts/mod/.gitignore
index e9b7abe7b95b..33bae0df4de5 100644
--- a/scripts/mod/.gitignore
+++ b/scripts/mod/.gitignore
@@ -1,4 +1,5 @@
 elfconfig.h
 mk_elfconfig
 modpost
+devicetable-offsets.h
 
diff --git a/scripts/mod/Makefile b/scripts/mod/Makefile
index ff954f8168c1..9415b5663364 100644
--- a/scripts/mod/Makefile
+++ b/scripts/mod/Makefile
@@ -3,9 +3,44 @@ always		:= $(hostprogs-y) empty.o
 
 modpost-objs    := modpost.o file2alias.o sumversion.o
 
+devicetable-offsets-file := devicetable-offsets.h
+
+define sed-y
+        "/^->/{s:->#\(.*\):/* \1 */:; \
+        s:^->\([^ ]*\) [\$$#]*\([-0-9]*\) \(.*\):#define \1 \2 /* \3 */:; \
+        s:^->\([^ ]*\) [\$$#]*\([^ ]*\) \(.*\):#define \1 \2 /* \3 */:; \
+        s:->::; p;}"
+endef
+
+quiet_cmd_offsets = GEN     $@
+define cmd_offsets
+        (set -e; \
+         echo "#ifndef __DEVICEVTABLE_OFFSETS_H__"; \
+         echo "#define __DEVICEVTABLE_OFFSETS_H__"; \
+         echo "/*"; \
+         echo " * DO NOT MODIFY."; \
+         echo " *"; \
+         echo " * This file was generated by Kbuild"; \
+         echo " *"; \
+         echo " */"; \
+         echo ""; \
+         sed -ne $(sed-y) $<; \
+         echo ""; \
+         echo "#endif" ) > $@
+endef
+
+# We use internal kbuild rules to avoid the "is up to date" message from make
+scripts/mod/devicetable-offsets.s: scripts/mod/devicetable-offsets.c FORCE
+        $(Q)mkdir -p $(dir $@)
+        $(call if_changed_dep,cc_s_c)
+
+$(obj)/$(devicetable-offsets-file): scripts/mod/devicetable-offsets.s
+        $(call cmd,offsets)
+
 # dependencies on generated files need to be listed explicitly
 
 $(obj)/modpost.o $(obj)/file2alias.o $(obj)/sumversion.o: $(obj)/elfconfig.h
+$(obj)/file2alias.o: $(obj)/$(devicetable-offsets-file)
 
 quiet_cmd_elfconfig = MKELF   $@
       cmd_elfconfig = $(obj)/mk_elfconfig < $< > $@
diff --git a/scripts/mod/devicetable-offsets.c b/scripts/mod/devicetable-offsets.c
new file mode 100644
index 000000000000..b45260bfeaa0
--- /dev/null
+++ b/scripts/mod/devicetable-offsets.c
@@ -0,0 +1,178 @@
+#include <linux/kbuild.h>
+#include <linux/mod_devicetable.h>
+
+#define DEVID(devid) DEFINE(SIZE_##devid, sizeof(struct devid))
+#define DEVID_FIELD(devid, field) \
+        DEFINE(OFF_##devid##_##field, offsetof(struct devid, field))
+
+int main(void)
+{
+        DEVID(usb_device_id);
+        DEVID_FIELD(usb_device_id, match_flags);
+        DEVID_FIELD(usb_device_id, idVendor);
+        DEVID_FIELD(usb_device_id, idProduct);
+        DEVID_FIELD(usb_device_id, bcdDevice_lo);
+        DEVID_FIELD(usb_device_id, bcdDevice_hi);
+        DEVID_FIELD(usb_device_id, bDeviceClass);
+        DEVID_FIELD(usb_device_id, bDeviceSubClass);
+        DEVID_FIELD(usb_device_id, bDeviceProtocol);
+        DEVID_FIELD(usb_device_id, bInterfaceClass);
+        DEVID_FIELD(usb_device_id, bInterfaceSubClass);
+        DEVID_FIELD(usb_device_id, bInterfaceProtocol);
+        DEVID_FIELD(usb_device_id, bInterfaceNumber);
+
+        DEVID(hid_device_id);
+        DEVID_FIELD(hid_device_id, bus);
+        DEVID_FIELD(hid_device_id, group);
+        DEVID_FIELD(hid_device_id, vendor);
+        DEVID_FIELD(hid_device_id, product);
+
+        DEVID(ieee1394_device_id);
+        DEVID_FIELD(ieee1394_device_id, match_flags);
+        DEVID_FIELD(ieee1394_device_id, vendor_id);
+        DEVID_FIELD(ieee1394_device_id, model_id);
+        DEVID_FIELD(ieee1394_device_id, specifier_id);
+        DEVID_FIELD(ieee1394_device_id, version);
+
+        DEVID(pci_device_id);
+        DEVID_FIELD(pci_device_id, vendor);
+        DEVID_FIELD(pci_device_id, device);
+        DEVID_FIELD(pci_device_id, subvendor);
+        DEVID_FIELD(pci_device_id, subdevice);
+        DEVID_FIELD(pci_device_id, class);
+        DEVID_FIELD(pci_device_id, class_mask);
+
+        DEVID(ccw_device_id);
+        DEVID_FIELD(ccw_device_id, match_flags);
+        DEVID_FIELD(ccw_device_id, cu_type);
+        DEVID_FIELD(ccw_device_id, cu_model);
+        DEVID_FIELD(ccw_device_id, dev_type);
+        DEVID_FIELD(ccw_device_id, dev_model);
+
+        DEVID(ap_device_id);
+        DEVID_FIELD(ap_device_id, dev_type);
+
+        DEVID(css_device_id);
+        DEVID_FIELD(css_device_id, type);
+
+        DEVID(serio_device_id);
+        DEVID_FIELD(serio_device_id, type);
+        DEVID_FIELD(serio_device_id, proto);
+        DEVID_FIELD(serio_device_id, id);
+        DEVID_FIELD(serio_device_id, extra);
+
+        DEVID(acpi_device_id);
+        DEVID_FIELD(acpi_device_id, id);
+
+        DEVID(pnp_device_id);
+        DEVID_FIELD(pnp_device_id, id);
+
+        DEVID(pnp_card_device_id);
+        DEVID_FIELD(pnp_card_device_id, devs);
+
+        DEVID(pcmcia_device_id);
+        DEVID_FIELD(pcmcia_device_id, match_flags);
+        DEVID_FIELD(pcmcia_device_id, manf_id);
+        DEVID_FIELD(pcmcia_device_id, card_id);
+        DEVID_FIELD(pcmcia_device_id, func_id);
+        DEVID_FIELD(pcmcia_device_id, function);
+        DEVID_FIELD(pcmcia_device_id, device_no);
+        DEVID_FIELD(pcmcia_device_id, prod_id_hash);
+
+        DEVID(of_device_id);
+        DEVID_FIELD(of_device_id, name);
+        DEVID_FIELD(of_device_id, type);
+        DEVID_FIELD(of_device_id, compatible);
+
+        DEVID(vio_device_id);
+        DEVID_FIELD(vio_device_id, type);
+        DEVID_FIELD(vio_device_id, compat);
+
+        DEVID(input_device_id);
+        DEVID_FIELD(input_device_id, flags);
+        DEVID_FIELD(input_device_id, bustype);
+        DEVID_FIELD(input_device_id, vendor);