ANDROID: GKI: Fix up abi issue in struct scm_fp_list

In commit e7026f590200 ("UPSTREAM: af_unix: Try to run GC async."), a
new field, count_unix, was added to the structure.  This structure is
ONLY dynamically allocated by the core kernel, and only accessable by a
pointer from anyone else.  To work around abi issues, move the new field
to the end of the structure, ensuring that anyone who was attempting to
access the fields of the structure, would continue to do so in a safe
way.

Add some __GENKSYMS__ magic to keep the crc generation sane, but the
field still needs to be documented as an abi break, so add it to the
abi_gki_aarch64.stg.allowed_breaks file.

Change-Id: I849000eac4f9001b04e4d110dfa74c63067cb786
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Fixes: e7026f590200 ("UPSTREAM: af_unix: Try to run GC async.")

android/abi_gki_aarch64.stg

@@ -71069,6 +71069,12 @@ member {
   name: "count_objects"
   type_id: 0x0484940b
 }
+member {
+  id: 0x11d6bf1f
+  name: "count_unix"
+  type_id: 0xb0312d5a
+  offset: 16320
+}
 member {
   id: 0x20014498
   name: "counter"
@@ -266808,11 +266814,12 @@ struct_union {
   kind: STRUCT
   name: "scm_fp_list"
   definition {
-    bytesize: 2040
+    bytesize: 2048
     member_id: 0x65956ee9
     member_id: 0x97463852
     member_id: 0x042a2402
     member_id: 0x5449f846
+    member_id: 0x11d6bf1f
   }
 }
 struct_union {

android/abi_gki_aarch64.stg.allowed_breaks

@@ -141,3 +141,6 @@ type 'struct kvm_hyp_req' changed
     type changed from 'union { struct { u8 dest; int nr_pages; int sz_alloc; } mem; struct { unsigned long guest_ipa; size_t size; } map; }' to 'union { struct { u8 dest; int nr_pages; int sz_alloc; } mem; struct { unsigned long guest_ipa; size_t size; } map; struct { unsigned long guest_ipa; size_t size; } split; }'
       member 'struct { unsigned long guest_ipa; size_t size; } split' was added
 
+type 'struct scm_fp_list' changed
+  byte size changed from 2040 to 2048
+  member 'short count_unix' was added

include/net/scm.h

@@ -24,10 +24,12 @@ struct scm_creds {
 
 struct scm_fp_list {
 	short			count;
-	short			count_unix;
 	short			max;
 	struct user_struct	*user;
 	struct file		*fp[SCM_MAX_FD];
+#ifndef __GENKSYMS__
+	short			count_unix;
+#endif
 };
 
 struct scm_cookie {