[PATCH] uml: cross-build support : kernel_offsets

The next group of helpers is a bit trickier - they want the constants similar
to those in user-offsets.h, but we need target sc.h for it.  So we can't put
that into user-offsets (sc.h depends on it) and need the second generated
header for that stuff (kernel-offsets.h.  BFD...
Signed-off-by: Al Viro <viro@parcelfarce.linux.theplanet.co.uk>
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

arch/um/Makefile

@@ -174,6 +174,19 @@ $(ARCH_DIR)/user-offsets.h: $(ARCH_DIR)/user-offsets.s
 
 CLEAN_FILES += $(ARCH_DIR)/user-offsets.s  $(ARCH_DIR)/user-offsets.h
 
+$(ARCH_DIR)/kernel-offsets.s: $(ARCH_DIR)/sys-$(SUBARCH)/kernel-offsets.c \
+				   $(ARCH_SYMLINKS) \
+				   $(SYS_DIR)/sc.h \
+				   include/asm include/linux/version.h \
+				   include/config/MARKER \
+				   $(ARCH_DIR)/include/user_constants.h
+	$(CC) $(CFLAGS) $(NOSTDINC_FLAGS) $(CPPFLAGS) -S -o $@ $<
+
+$(ARCH_DIR)/kernel-offsets.h: $(ARCH_DIR)/kernel-offsets.s
+	$(call filechk,gen-asm-offsets)
+
+CLEAN_FILES += $(ARCH_DIR)/kernel-offsets.s  $(ARCH_DIR)/kernel-offsets.h
+
 $(ARCH_DIR)/include/task.h: $(ARCH_DIR)/util/mk_task
 	$(call filechk,gen_header)
 

arch/um/include/common-offsets.h

+/* for use by sys-$SUBARCH/kernel-offsets.c */
+
+OFFSET(TASK_REGS, task_struct, thread.regs);
+OFFSET(TASK_PID, task_struct, pid);
+DEFINE(UM_KERN_PAGE_SIZE, PAGE_SIZE);
+DEFINE(UM_NSEC_PER_SEC, NSEC_PER_SEC);
+DEFINE_STR(UM_KERN_EMERG, KERN_EMERG);
+DEFINE_STR(UM_KERN_ALERT, KERN_ALERT);
+DEFINE_STR(UM_KERN_CRIT, KERN_CRIT);
+DEFINE_STR(UM_KERN_ERR, KERN_ERR);
+DEFINE_STR(UM_KERN_WARNING, KERN_WARNING);
+DEFINE_STR(UM_KERN_NOTICE, KERN_NOTICE);
+DEFINE_STR(UM_KERN_INFO, KERN_INFO);
+DEFINE_STR(UM_KERN_DEBUG, KERN_DEBUG);

arch/um/sys-i386/kernel-offsets.c

+#include <linux/config.h>
+#include <linux/stddef.h>
+#include <linux/sched.h>
+#include <linux/time.h>
+#include <asm/page.h>
+
+#define DEFINE(sym, val) \
+        asm volatile("\n->" #sym " %0 " #val : : "i" (val))
+
+#define STR(x) #x
+#define DEFINE_STR(sym, val) asm volatile("\n->" #sym " " STR(val) " " #val: : )
+
+#define BLANK() asm volatile("\n->" : : )
+
+#define OFFSET(sym, str, mem) \
+	DEFINE(sym, offsetof(struct str, mem));
+
+void foo(void)
+{
+	OFFSET(TASK_DEBUGREGS, task_struct, thread.arch.debugregs);
+#ifdef CONFIG_MODE_TT
+	OFFSET(TASK_EXTERN_PID, task_struct, thread.mode.tt.extern_pid);
+#endif
+#include <common-offsets.h>
+}

arch/um/sys-x86_64/kernel-offsets.c

+#include <linux/config.h>
+#include <linux/stddef.h>
+#include <linux/sched.h>
+#include <linux/time.h>
+#include <asm/page.h>
+
+#define DEFINE(sym, val) \
+        asm volatile("\n->" #sym " %0 " #val : : "i" (val))
+
+#define DEFINE_STR1(x) #x
+#define DEFINE_STR(sym, val) asm volatile("\n->" #sym " " DEFINE_STR1(val) " " #val: : )
+
+#define BLANK() asm volatile("\n->" : : )
+
+#define OFFSET(sym, str, mem) \
+	DEFINE(sym, offsetof(struct str, mem));
+
+void foo(void)
+{
+#ifdef CONFIG_MODE_TT
+	OFFSET(TASK_EXTERN_PID, task_struct, thread.mode.tt.extern_pid);
+#endif
+#include <common-offsets.h>
+}