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>

1 files changed, 35 insertions, 0 deletions

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 < $< > $@