2002-09-18 02:12:20

by Rusty Russell

[permalink] [raw]
Subject: [PATCH] In-kernel module loader 2/7

Name: KBUILD_MODNAME define for build system
Author: Kai Germaschewski
Status: Tested on 2.5.35

D: This patch adds a -DKBUILD_MODNAME to the kernel compile, which
D: contains the base of the module name which is being built.
D:
D: - Some sreorganization of the c_flags since they're needed for
D: generating modversions (.ver) and compiling
D: - Use the right KBUILD_MODNAME also when the user just wants a .i/.s/.lst
D: file for debugging and also when generating modversions
D: - It looks like with your current approach you can't have a ',' or '-' in
D: KBUILD_MODNAME - however, that means that KBUILD_MODNAME is not quite
D: right for passing module parameters for built-in modules on the command
D: line, it would be confusing to pass parameters for ide-cd as
D: ide_cd.foo=whatever. So that part could use a little more thought.
D: - If you think your module_names trick makes a noticable difference, feel
D: free to re-add it.
D: - It's possible that objects are linked into more than one module - I
D: suppose this shouldn't be a problem, since these objects hopefully
D: don't have a module_init() nor do they export symbols. Not sure if your
D: patch did handle this.
D:
D: --Kai

===== Rules.make 1.68 vs edited =====
--- 1.68/Rules.make Mon Jul 29 14:55:41 2002
+++ edited/Rules.make Tue Jul 30 21:27:46 2002
@@ -95,11 +95,15 @@
multi-used-y := $(filter-out $(list-multi),$(__multi-used-y))
multi-used-m := $(filter-out $(list-multi),$(__multi-used-m))

+multi-used := $(multi-used-y) $(multi-used-m)
+
# Build list of the parts of our composite objects, our composite
# objects depend on those (obviously)
multi-objs-y := $(foreach m, $(multi-used-y), $($(m:.o=-objs)))
multi-objs-m := $(foreach m, $(multi-used-m), $($(m:.o=-objs)))

+multi-objs := $(multi-objs-y) $(multi-objs-m)
+
# $(subdir-obj-y) is the list of objects in $(obj-y) which do not live
# in the local directory
subdir-obj-y := $(foreach o,$(obj-y),$(if $(filter-out $(o),$(notdir $(o))),$(o)))
@@ -115,6 +119,23 @@
# contain a comma
depfile = $(subst $(comma),_,$(@D)/.$(@F).d)

+# These flags are needed for modversions and compiling, so we define them here
+# already
+# $(modname_flags) #defines KBUILD_MODNAME as the name of the module it will
+# end up in (or would, if it gets compiled in)
+# Note: It's possible that one object gets potentially linked into more
+# than one module. In that case KBUILD_MODNAME will be set to foo_bar,
+# where foo and bar are the name of the modules.
+basename_flags = -DKBUILD_BASENAME=$(subst $(comma),_,$(subst -,_,$(*F)))
+modname_flags = -DKBUILD_MODNAME=$(subst $(comma),_,$(subst -,_,$(modname)))
+c_flags = -Wp,-MD,$(depfile) $(CFLAGS) $(NOSTDINC_FLAGS) \
+ $(modkern_cflags) $(EXTRA_CFLAGS) $(CFLAGS_$(*F).o) \
+ $(basename_flags) $(modname_flags) $(export_flags)
+
+# Finds the multi-part object the current object will be linked into
+modname-multi = $(subst $(space),_,$(strip $(foreach m,$(multi-used),\
+ $(if $(filter $(*F).o,$($(m:.o=-objs))),$(m:.o=)))))
+
# We're called for one of three purposes:
# o fastdep: build module version files (.ver) for $(export-objs) in
# the current directory
@@ -164,11 +185,10 @@
$(addprefix $(MODVERDIR)/,$(real-objs-y:.o=.ver)): modkern_cflags := $(CFLAGS_KERNEL)
$(addprefix $(MODVERDIR)/,$(real-objs-m:.o=.ver)): modkern_cflags := $(CFLAGS_MODULE)
$(addprefix $(MODVERDIR)/,$(export-objs:.o=.ver)): export_flags := -D__GENKSYMS__
+# Default for not multi-part modules
+modname = $(*F)

-c_flags = -Wp,-MD,$(depfile) $(CFLAGS) $(NOSTDINC_FLAGS) \
- $(modkern_cflags) $(EXTRA_CFLAGS) $(CFLAGS_$(*F).o) \
- -DKBUILD_BASENAME=$(subst $(comma),_,$(subst -,_,$(*F))) \
- $(export_flags)
+$(addprefix $(MODVERDIR)/,$(multi-objs:.o=.ver)) : modname = $(modname-multi)

# Our objects only depend on modversions.h, not on the individual .ver
# files (fix-dep filters them), so touch modversions.h if any of the .ver
@@ -259,6 +279,7 @@

$(real-objs-m) : modkern_cflags := $(CFLAGS_MODULE)
$(real-objs-m:.o=.i) : modkern_cflags := $(CFLAGS_MODULE)
+$(real-objs-m:.o=.s) : modkern_cflags := $(CFLAGS_MODULE)
$(real-objs-m:.o=.lst): modkern_cflags := $(CFLAGS_MODULE)

$(export-objs) : export_flags := $(EXPORT_FLAGS)
@@ -266,10 +287,13 @@
$(export-objs:.o=.s) : export_flags := $(EXPORT_FLAGS)
$(export-objs:.o=.lst): export_flags := $(EXPORT_FLAGS)

-c_flags = -Wp,-MD,$(depfile) $(CFLAGS) $(NOSTDINC_FLAGS) \
- $(modkern_cflags) $(EXTRA_CFLAGS) $(CFLAGS_$(*F).o) \
- -DKBUILD_BASENAME=$(subst $(comma),_,$(subst -,_,$(*F))) \
- $(export_flags)
+# Default for not multi-part modules
+modname = $(*F)
+
+$(multi-objs) : modname = $(modname-multi)
+$(multi-objs:.o=.i) : modname = $(modname-multi)
+$(multi-objs:.o=.s) : modname = $(modname-multi)
+$(multi-objs:.o=.lst) : modname = $(modname-multi)

quiet_cmd_cc_s_c = CC $(echo_target)
cmd_cc_s_c = $(CC) $(c_flags) -S -o $@ $<
diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .1187-linux-2.5.34/net/unix/af_unix.c .1187-linux-2.5.34.updated/net/unix/af_unix.c
--- .1187-linux-2.5.34/net/unix/af_unix.c 2002-08-28 09:29:55.000000000 +1000
+++ .1187-linux-2.5.34.updated/net/unix/af_unix.c 2002-09-10 16:39:53.000000000 +1000
@@ -79,6 +79,8 @@
* with BSD names.
*/

+#undef unix /* KBUILD_MODNAME */
+
#include <linux/module.h>
#include <linux/config.h>
#include <linux/kernel.h>

--
Anyone who quotes me in their sig is an idiot. -- Rusty Russell.