Fix kabi breakage in struct bpf_map

hulk inclusion
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/IAD6H2



--------------------------------

After backport LTS commit 4b359df7b2ad ("[Backport] bpf: Optimize the
free of inner map"), two fields `free_after_rcu_gp` and `sleepable_refcnt`
were introduced into struct bpf_map, which result in a kabi breakage.

Use KABI_FILL_HOLE and KABI_USE to fix kabi breakage in struct bpf_map.

Before:
------
struct bpf_map {
	<SNIP>
	/* --- cacheline 3 boundary (192 bytes) --- */
	struct mutex               freeze_mutex;         /*   192    32 */
	atomic64_t                 writecnt;             /*   224     8 */
	struct {
		spinlock_t         lock;                 /*   232     4 */
		enum bpf_prog_type type;                 /*   236     4 */
		bool               jited;                /*   240     1 */
		bool               xdp_has_frags;        /*   241     1 */
	} owner;                                         /*   232    12 */

	/* XXX last struct has 2 bytes of padding */

	bool                       bypass_spec_v1;       /*   244     1 */
	bool                       frozen;               /*   245     1 */
	bool                       free_after_mult_rcu_gp; /*   246     1 */

	/* XXX 1 byte hole, try to pack */

	s64 *                      elem_count;           /*   248     8 */
	/* --- cacheline 4 boundary (256 bytes) --- */
	u64                        kabi_reserved1;       /*   256     8 */
	u64                        kabi_reserved2;       /*   264     8 */
	u64                        kabi_reserved3;       /*   272     8 */
	u64                        kabi_reserved4;       /*   280     8 */

	/* size: 320, cachelines: 5, members: 32 */
	/* sum members: 271, holes: 2, sum holes: 17 */
	/* padding: 32 */
	/* paddings: 1, sum paddings: 2 */
	/* forced alignments: 3, forced holes: 1, sum forced holes: 16 */
} __attribute__((__aligned__(64)));

After:
------
struct bpf_map {
	<SNIP>
	/* --- cacheline 3 boundary (192 bytes) --- */
	struct mutex               freeze_mutex;         /*   192    32 */
	atomic64_t                 writecnt;             /*   224     8 */
	struct {
		spinlock_t         lock;                 /*   232     4 */
		enum bpf_prog_type type;                 /*   236     4 */
		bool               jited;                /*   240     1 */
		bool               xdp_has_frags;        /*   241     1 */
	} owner;                                         /*   232    12 */

	/* XXX last struct has 2 bytes of padding */

	bool                       bypass_spec_v1;       /*   244     1 */
	bool                       frozen;               /*   245     1 */
	bool                       free_after_mult_rcu_gp; /*   246     1 */
	bool                       free_after_rcu_gp;    /*   247     1 */
	s64 *                      elem_count;           /*   248     8 */
	/* --- cacheline 4 boundary (256 bytes) --- */
	union {
		atomic64_t         sleepable_refcnt;     /*   256     8 */
		struct {
			u64        kabi_reserved1;       /*   256     8 */
		} kabi_hidden_308;                       /*   256     8 */
		union {
		};                                       /*   256     0 */
	};                                               /*   256     8 */
	u64                        kabi_reserved2;       /*   264     8 */
	u64                        kabi_reserved3;       /*   272     8 */
	u64                        kabi_reserved4;       /*   280     8 */

	/* size: 320, cachelines: 5, members: 33 */
	/* sum members: 272, holes: 1, sum holes: 16 */
	/* padding: 32 */
	/* paddings: 1, sum paddings: 2 */
	/* forced alignments: 3, forced holes: 1, sum forced holes: 16 */
} __attribute__((__aligned__(64)));

Fixes: 1e23ac5c8eda ("bpf: Optimize the free of inner map")
Signed-off-by: Tengda Wu <wutengda2@huawei.com>
Signed-off-by: Pu Lehui <pulehui@huawei.com>