From 33b3ab6631ded858f811d6f5f6d7af4ac15dbc65 Mon Sep 17 00:00:00 2001
From: Michal Marek <mmarek@suse.cz>
Date: Fri, 16 Sep 2011 11:56:20 +0200
Subject: [PATCH 3/3] kabi: Add placeholders to a couple of important
 structures
Patch-mainline: Never, kabi
References: fate#312013

Add a void* suse_kabi_padding placeholder to the following structures:
struct smp_ops
struct vm_area_struct
struct mm_struct
struct zone
  - adding an explicit padding here is not strictly required, but can
    serve as documentation that there is some space
struct pglist_data
struct vfsmount
struct module
struct signal_struct
struct sched_entity
struct sock
struct task_struct

The idea is that when a fix appears that requires a new member in any of
these structures, we use this padding:

  #ifdef __GENKSYMS__
          void *suse_kabi_padding;
  #else
          long foo;
  #endif

And we don't have to worry about changing size of the structure, as long
as the new member is a pointer or a long.

Signed-off-by: Michal Marek <mmarek@suse.cz>

---
 arch/x86/include/asm/smp.h   |    1 +
 include/linux/mm_types.h     |    1 +
 include/linux/mmzone.h       |    1 +
 include/linux/module.h       |    1 +
 include/linux/mount.h        |    1 +
 include/linux/sched.h        |    2 ++
 include/linux/sched/signal.h |    1 +
 include/net/sock.h           |    1 +
 8 files changed, 9 insertions(+)

--- a/arch/x86/include/asm/smp.h
+++ b/arch/x86/include/asm/smp.h
@@ -57,6 +57,7 @@ struct smp_ops {
 
 	void (*send_call_func_ipi)(const struct cpumask *mask);
 	void (*send_call_func_single_ipi)(int cpu);
+	void *suse_kabi_padding;
 };
 
 /* Globals due to paravirt */
--- a/include/linux/mm_types.h
+++ b/include/linux/mm_types.h
@@ -343,6 +343,7 @@ struct vm_area_struct {
 	struct mempolicy *vm_policy;	/* NUMA policy for the VMA */
 #endif
 	struct vm_userfaultfd_ctx vm_userfaultfd_ctx;
+	void *suse_kabi_padding;
 };
 
 struct core_thread {
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -504,6 +504,7 @@ struct zone {
 	/* Zone statistics */
 	atomic_long_t		vm_stat[NR_VM_ZONE_STAT_ITEMS];
 	atomic_long_t		vm_numa_stat[NR_VM_NUMA_STAT_ITEMS];
+	void *suse_kabi_padding;
 } ____cacheline_internodealigned_in_smp;
 
 enum pgdat_flags {
--- a/include/linux/module.h
+++ b/include/linux/module.h
@@ -475,6 +475,7 @@ struct module {
 	ctor_fn_t *ctors;
 	unsigned int num_ctors;
 #endif
+	void *suse_kabi_padding;
 } ____cacheline_aligned;
 #ifndef MODULE_ARCH_INIT
 #define MODULE_ARCH_INIT {}
--- a/include/linux/mount.h
+++ b/include/linux/mount.h
@@ -67,6 +67,7 @@ struct vfsmount {
 	struct dentry *mnt_root;	/* root of the mounted tree */
 	struct super_block *mnt_sb;	/* pointer to superblock */
 	int mnt_flags;
+	void *suse_kabi_padding;
 };
 
 struct file; /* forward dec */
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -429,6 +429,7 @@ struct sched_rt_entity {
 	/* rq "owned" by this entity/group: */
 	struct rt_rq			*my_q;
 #endif
+	void *suse_kabi_padding;
 };
 
 struct sched_dl_entity {
@@ -1069,6 +1070,7 @@ struct task_struct {
 #ifdef CONFIG_SECURITY
 	/* Used by LSM modules for access restriction: */
 	void				*security;
+	void				*suse_kabi_padding;
 #endif
 	/* CPU-specific state of this task: */
 	struct thread_struct		thread;
--- a/include/linux/sched/signal.h
+++ b/include/linux/sched/signal.h
@@ -222,6 +222,7 @@ struct signal_struct {
 	struct mutex cred_guard_mutex;	/* guard against foreign influences on
 					 * credential calculations
 					 * (notably. ptrace) */
+	void *suse_kabi_padding;
 };
 
 /*
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -477,6 +477,7 @@ struct sock {
 							struct sk_buff *skb);
 #endif
 	void                    (*sk_destruct)(struct sock *sk);
+	void *suse_kabi_padding;
 	struct sock_reuseport __rcu	*sk_reuseport_cb;
 	struct rcu_head		sk_rcu;
 };