Commit f83b5e32 authored by Ustyugov Roman's avatar Ustyugov Roman Committed by Sam Ravnborg
Browse files

kbuild: set correct KBUILD_MODNAME when using well known kernel symbols as module names 



This patch fixes a problem when we use well known kernel symbols as module
names.

For example, if module source name is current.c, idle_stack.c or etc.,
we have a bad KBUILD_MODNAME value.
For example, KBUILD_MODNAME will be "get_current()" instead of "current", or
"(init_thread_union.stack)" instead of "idle_task".

The trick is to define a stringify macro on the commandline - named
KBUILD_STR for namespace reasons - and then to stringify the module
name.

There are a few uses of KBUILD_MODNAME throughout the tree but the usage
is for debug and will not be harmed by this change so left untouched for now.

While at it KBUILD_BASENAME was changed too. Any spinlock usage in the
unix module would have created wrong section names without it.
Usage in spinlock.h fixed so it no longer stringify KBUILD_BASENAME.

Original patch from Ustyogov Roman - all bugs introduced by me.

Signed-off-by: default avatarSam Ravnborg <sam@ravnborg.org>
parent 4d99f93b

include/linux/spinlock.h

+1 −2
Original line number Diff line number Diff line
@@ -59,8 +59,7 @@ 
/*

 * Must define these before including other files, inline functions need them

 */

#define LOCK_SECTION_NAME                       \

        ".text.lock." __stringify(KBUILD_BASENAME)

#define LOCK_SECTION_NAME ".text.lock."KBUILD_BASENAME



#define LOCK_SECTION_START(extra)               \

        ".subsection 1\n\t"                     \

scripts/Makefile.lib

+5 −3
Original line number Diff line number Diff line
@@ -81,8 +81,10 @@ obj-dirs := $(addprefix $(obj)/,$(obj-dirs)) 
# 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  = $(if $(filter 1,$(words $(modname))),-DKBUILD_MODNAME=$(subst $(comma),_,$(subst -,_,$(modname))))

name-fix = $(subst $(comma),_,$(subst -,_,$1))

basename_flags = -D"KBUILD_BASENAME=KBUILD_STR($(call name-fix,$(*F)))"

modname_flags  = $(if $(filter 1,$(words $(modname))),\

                 -D"KBUILD_MODNAME=KBUILD_STR($(call name-fix,$(modname)))")



_c_flags       = $(CFLAGS) $(EXTRA_CFLAGS) $(CFLAGS_$(*F).o)

_a_flags       = $(AFLAGS) $(EXTRA_AFLAGS) $(AFLAGS_$(*F).o)
@@ -113,7 +115,7 @@ endif 


c_flags        = -Wp,-MD,$(depfile) $(NOSTDINC_FLAGS) $(CPPFLAGS) \

		 $(__c_flags) $(modkern_cflags) \

		 $(basename_flags) $(modname_flags)

		 -D"KBUILD_STR(s)=\#s" $(basename_flags) $(modname_flags)



a_flags        = -Wp,-MD,$(depfile) $(NOSTDINC_FLAGS) $(CPPFLAGS) \

		 $(__a_flags) $(modkern_aflags)

scripts/mod/modpost.c

+1 −2
Original line number Diff line number Diff line
@@ -539,10 +539,9 @@ add_header(struct buffer *b, struct module *mod) 
	buf_printf(b, "\n");

	buf_printf(b, "MODULE_INFO(vermagic, VERMAGIC_STRING);\n");

	buf_printf(b, "\n");

	buf_printf(b, "#undef unix\n"); /* We have a module called "unix" */

	buf_printf(b, "struct module __this_module\n");

	buf_printf(b, "__attribute__((section(\".gnu.linkonce.this_module\"))) = {\n");

	buf_printf(b, " .name = __stringify(KBUILD_MODNAME),\n");

	buf_printf(b, " .name = KBUILD_MODNAME,\n");

	if (mod->has_init)

		buf_printf(b, " .init = init_module,\n");

	if (mod->has_cleanup)

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