um: Remove stub-data.h include from common-offsets.h

Further commits will require values from common-offsets.h inside
stub-data.h. Resolve the possible circular dependency and simply use
offsetof() inside stub_32.h and stub_64.h.
Signed-off-by: Benjamin Berg <benjamin@sipsolutions.net>
Link: https://patch.msgid.link/20240703134536.1161108-2-benjamin@sipsolutions.netSigned-off-by: Johannes Berg <johannes.berg@intel.com>

arch/um/include/shared/common-offsets.h

 /* SPDX-License-Identifier: GPL-2.0 */
 /* for use by sys-$SUBARCH/kernel-offsets.c */
-#include <stub-data.h>
 
 DEFINE(KERNEL_MADV_REMOVE, MADV_REMOVE);
 
@@ -30,7 +29,3 @@ DEFINE(UML_CONFIG_64BIT, CONFIG_64BIT);
 DEFINE(UML_CONFIG_UML_TIME_TRAVEL_SUPPORT, CONFIG_UML_TIME_TRAVEL_SUPPORT);
 #endif
 
-/* for stub */
-DEFINE(UML_STUB_FIELD_OFFSET, offsetof(struct stub_data, offset));
-DEFINE(UML_STUB_FIELD_CHILD_ERR, offsetof(struct stub_data, child_err));
-DEFINE(UML_STUB_FIELD_FD, offsetof(struct stub_data, fd));

arch/x86/um/shared/sysdep/stub_32.h

@@ -6,6 +6,7 @@
 #ifndef __SYSDEP_STUB_H
 #define __SYSDEP_STUB_H
 
+#include <stddef.h>
 #include <asm/ptrace.h>
 #include <generated/asm-offsets.h>
 
@@ -98,9 +99,9 @@ static __always_inline void remap_stack_and_trap(void)
 		: :
 		"g" (~(STUB_DATA_PAGES * UM_KERN_PAGE_SIZE - 1)),
 		"g" (STUB_MMAP_NR),
-		"g" (UML_STUB_FIELD_FD),
-		"g" (UML_STUB_FIELD_OFFSET),
-		"g" (UML_STUB_FIELD_CHILD_ERR),
+		"g" (offsetof(struct stub_data, fd)),
+		"g" (offsetof(struct stub_data, offset)),
+		"g" (offsetof(struct stub_data, child_err)),
 		"c" (STUB_DATA_PAGES * UM_KERN_PAGE_SIZE),
 		"d" (PROT_READ | PROT_WRITE),
 		"S" (MAP_FIXED | MAP_SHARED)

arch/x86/um/shared/sysdep/stub_64.h

@@ -6,6 +6,7 @@
 #ifndef __SYSDEP_STUB_H
 #define __SYSDEP_STUB_H
 
+#include <stddef.h>
 #include <sysdep/ptrace_user.h>
 #include <generated/asm-offsets.h>
 #include <linux/stddef.h>
@@ -101,9 +102,9 @@ static __always_inline void remap_stack_and_trap(void)
 		"g" (STUB_MMAP_NR),
 		"g" (~(STUB_DATA_PAGES * UM_KERN_PAGE_SIZE - 1)),
 		"g" (MAP_FIXED | MAP_SHARED),
-		"g" (UML_STUB_FIELD_FD),
-		"g" (UML_STUB_FIELD_OFFSET),
-		"g" (UML_STUB_FIELD_CHILD_ERR),
+		"g" (offsetof(struct stub_data, fd)),
+		"g" (offsetof(struct stub_data, offset)),
+		"g" (offsetof(struct stub_data, child_err)),
 		"S" (STUB_DATA_PAGES * UM_KERN_PAGE_SIZE),
 		"d" (PROT_READ | PROT_WRITE)
 		: