Revision 63cae12bce9861cec309798d34701cf3da20bc71 authored by Peter Zijlstra on 09 December 2016, 13:59:00 UTC, committed by Ingo Molnar on 14 January 2017, 09:56:10 UTC
There is problem with installing an event in a task that is 'stuck' on
an offline CPU.

Blocked tasks are not dis-assosciated from offlined CPUs, after all, a
blocked task doesn't run and doesn't require a CPU etc.. Only on
wakeup do we ammend the situation and place the task on a available
CPU.

If we hit such a task with perf_install_in_context() we'll loop until
either that task wakes up or the CPU comes back online, if the task
waking depends on the event being installed, we're stuck.

While looking into this issue, I also spotted another problem, if we
hit a task with perf_install_in_context() that is in the middle of
being migrated, that is we observe the old CPU before sending the IPI,
but run the IPI (on the old CPU) while the task is already running on
the new CPU, things also go sideways.

Rework things to rely on task_curr() -- outside of rq->lock -- which
is rather tricky. Imagine the following scenario where we're trying to
install the first event into our task 't':

CPU0            CPU1            CPU2

                (current == t)

t->perf_event_ctxp[] = ctx;
smp_mb();
cpu = task_cpu(t);

                switch(t, n);
                                migrate(t, 2);
                                switch(p, t);

                                ctx = t->perf_event_ctxp[]; // must not be NULL

smp_function_call(cpu, ..);

                generic_exec_single()
                  func();
                    spin_lock(ctx->lock);
                    if (task_curr(t)) // false

                    add_event_to_ctx();
                    spin_unlock(ctx->lock);

                                perf_event_context_sched_in();
                                  spin_lock(ctx->lock);
                                  // sees event

So its CPU0's store of t->perf_event_ctxp[] that must not go 'missing'.
Because if CPU2's load of that variable were to observe NULL, it would
not try to schedule the ctx and we'd have a task running without its
counter, which would be 'bad'.

As long as we observe !NULL, we'll acquire ctx->lock. If we acquire it
first and not see the event yet, then CPU0 must observe task_curr()
and retry. If the install happens first, then we must see the event on
sched-in and all is well.

I think we can translate the first part (until the 'must not be NULL')
of the scenario to a litmus test like:

  C C-peterz

  {
  }

  P0(int *x, int *y)
  {
          int r1;

          WRITE_ONCE(*x, 1);
          smp_mb();
          r1 = READ_ONCE(*y);
  }

  P1(int *y, int *z)
  {
          WRITE_ONCE(*y, 1);
          smp_store_release(z, 1);
  }

  P2(int *x, int *z)
  {
          int r1;
          int r2;

          r1 = smp_load_acquire(z);
	  smp_mb();
          r2 = READ_ONCE(*x);
  }

  exists
  (0:r1=0 /\ 2:r1=1 /\ 2:r2=0)

Where:
  x is perf_event_ctxp[],
  y is our tasks's CPU, and
  z is our task being placed on the rq of CPU2.

The P0 smp_mb() is the one added by this patch, ordering the store to
perf_event_ctxp[] from find_get_context() and the load of task_cpu()
in task_function_call().

The smp_store_release/smp_load_acquire model the RCpc locking of the
rq->lock and the smp_mb() of P2 is the context switch switching from
whatever CPU2 was running to our task 't'.

This litmus test evaluates into:

  Test C-peterz Allowed
  States 7
  0:r1=0; 2:r1=0; 2:r2=0;
  0:r1=0; 2:r1=0; 2:r2=1;
  0:r1=0; 2:r1=1; 2:r2=1;
  0:r1=1; 2:r1=0; 2:r2=0;
  0:r1=1; 2:r1=0; 2:r2=1;
  0:r1=1; 2:r1=1; 2:r2=0;
  0:r1=1; 2:r1=1; 2:r2=1;
  No
  Witnesses
  Positive: 0 Negative: 7
  Condition exists (0:r1=0 /\ 2:r1=1 /\ 2:r2=0)
  Observation C-peterz Never 0 7
  Hash=e427f41d9146b2a5445101d3e2fcaa34

And the strong and weak model agree.

Reported-by: Mark Rutland <mark.rutland@arm.com>
Tested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: Will Deacon <will.deacon@arm.com>
Cc: jeremy.linton@arm.com
Link: http://lkml.kernel.org/r/20161209135900.GU3174@twins.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
1 parent ad5013d
Raw File
gcm.c
/*
 * GCM: Galois/Counter Mode.
 *
 * Copyright (c) 2007 Nokia Siemens Networks - Mikko Herranen <mh1@iki.fi>
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 as published
 * by the Free Software Foundation.
 */

#include <crypto/gf128mul.h>
#include <crypto/internal/aead.h>
#include <crypto/internal/skcipher.h>
#include <crypto/internal/hash.h>
#include <crypto/null.h>
#include <crypto/scatterwalk.h>
#include <crypto/hash.h>
#include "internal.h"
#include <linux/completion.h>
#include <linux/err.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/slab.h>

struct gcm_instance_ctx {
	struct crypto_skcipher_spawn ctr;
	struct crypto_ahash_spawn ghash;
};

struct crypto_gcm_ctx {
	struct crypto_skcipher *ctr;
	struct crypto_ahash *ghash;
};

struct crypto_rfc4106_ctx {
	struct crypto_aead *child;
	u8 nonce[4];
};

struct crypto_rfc4106_req_ctx {
	struct scatterlist src[3];
	struct scatterlist dst[3];
	struct aead_request subreq;
};

struct crypto_rfc4543_instance_ctx {
	struct crypto_aead_spawn aead;
};

struct crypto_rfc4543_ctx {
	struct crypto_aead *child;
	struct crypto_skcipher *null;
	u8 nonce[4];
};

struct crypto_rfc4543_req_ctx {
	struct aead_request subreq;
};

struct crypto_gcm_ghash_ctx {
	unsigned int cryptlen;
	struct scatterlist *src;
	int (*complete)(struct aead_request *req, u32 flags);
};

struct crypto_gcm_req_priv_ctx {
	u8 iv[16];
	u8 auth_tag[16];
	u8 iauth_tag[16];
	struct scatterlist src[3];
	struct scatterlist dst[3];
	struct scatterlist sg;
	struct crypto_gcm_ghash_ctx ghash_ctx;
	union {
		struct ahash_request ahreq;
		struct skcipher_request skreq;
	} u;
};

struct crypto_gcm_setkey_result {
	int err;
	struct completion completion;
};

static struct {
	u8 buf[16];
	struct scatterlist sg;
} *gcm_zeroes;

static int crypto_rfc4543_copy_src_to_dst(struct aead_request *req, bool enc);

static inline struct crypto_gcm_req_priv_ctx *crypto_gcm_reqctx(
	struct aead_request *req)
{
	unsigned long align = crypto_aead_alignmask(crypto_aead_reqtfm(req));

	return (void *)PTR_ALIGN((u8 *)aead_request_ctx(req), align + 1);
}

static void crypto_gcm_setkey_done(struct crypto_async_request *req, int err)
{
	struct crypto_gcm_setkey_result *result = req->data;

	if (err == -EINPROGRESS)
		return;

	result->err = err;
	complete(&result->completion);
}

static int crypto_gcm_setkey(struct crypto_aead *aead, const u8 *key,
			     unsigned int keylen)
{
	struct crypto_gcm_ctx *ctx = crypto_aead_ctx(aead);
	struct crypto_ahash *ghash = ctx->ghash;
	struct crypto_skcipher *ctr = ctx->ctr;
	struct {
		be128 hash;
		u8 iv[16];

		struct crypto_gcm_setkey_result result;

		struct scatterlist sg[1];
		struct skcipher_request req;
	} *data;
	int err;

	crypto_skcipher_clear_flags(ctr, CRYPTO_TFM_REQ_MASK);
	crypto_skcipher_set_flags(ctr, crypto_aead_get_flags(aead) &
				       CRYPTO_TFM_REQ_MASK);
	err = crypto_skcipher_setkey(ctr, key, keylen);
	crypto_aead_set_flags(aead, crypto_skcipher_get_flags(ctr) &
				    CRYPTO_TFM_RES_MASK);
	if (err)
		return err;

	data = kzalloc(sizeof(*data) + crypto_skcipher_reqsize(ctr),
		       GFP_KERNEL);
	if (!data)
		return -ENOMEM;

	init_completion(&data->result.completion);
	sg_init_one(data->sg, &data->hash, sizeof(data->hash));
	skcipher_request_set_tfm(&data->req, ctr);
	skcipher_request_set_callback(&data->req, CRYPTO_TFM_REQ_MAY_SLEEP |
						  CRYPTO_TFM_REQ_MAY_BACKLOG,
				      crypto_gcm_setkey_done,
				      &data->result);
	skcipher_request_set_crypt(&data->req, data->sg, data->sg,
				   sizeof(data->hash), data->iv);

	err = crypto_skcipher_encrypt(&data->req);
	if (err == -EINPROGRESS || err == -EBUSY) {
		err = wait_for_completion_interruptible(
			&data->result.completion);
		if (!err)
			err = data->result.err;
	}

	if (err)
		goto out;

	crypto_ahash_clear_flags(ghash, CRYPTO_TFM_REQ_MASK);
	crypto_ahash_set_flags(ghash, crypto_aead_get_flags(aead) &
			       CRYPTO_TFM_REQ_MASK);
	err = crypto_ahash_setkey(ghash, (u8 *)&data->hash, sizeof(be128));
	crypto_aead_set_flags(aead, crypto_ahash_get_flags(ghash) &
			      CRYPTO_TFM_RES_MASK);

out:
	kzfree(data);
	return err;
}

static int crypto_gcm_setauthsize(struct crypto_aead *tfm,
				  unsigned int authsize)
{
	switch (authsize) {
	case 4:
	case 8:
	case 12:
	case 13:
	case 14:
	case 15:
	case 16:
		break;
	default:
		return -EINVAL;
	}

	return 0;
}

static void crypto_gcm_init_common(struct aead_request *req)
{
	struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
	__be32 counter = cpu_to_be32(1);
	struct scatterlist *sg;

	memset(pctx->auth_tag, 0, sizeof(pctx->auth_tag));
	memcpy(pctx->iv, req->iv, 12);
	memcpy(pctx->iv + 12, &counter, 4);

	sg_init_table(pctx->src, 3);
	sg_set_buf(pctx->src, pctx->auth_tag, sizeof(pctx->auth_tag));
	sg = scatterwalk_ffwd(pctx->src + 1, req->src, req->assoclen);
	if (sg != pctx->src + 1)
		sg_chain(pctx->src, 2, sg);

	if (req->src != req->dst) {
		sg_init_table(pctx->dst, 3);
		sg_set_buf(pctx->dst, pctx->auth_tag, sizeof(pctx->auth_tag));
		sg = scatterwalk_ffwd(pctx->dst + 1, req->dst, req->assoclen);
		if (sg != pctx->dst + 1)
			sg_chain(pctx->dst, 2, sg);
	}
}

static void crypto_gcm_init_crypt(struct aead_request *req,
				  unsigned int cryptlen)
{
	struct crypto_aead *aead = crypto_aead_reqtfm(req);
	struct crypto_gcm_ctx *ctx = crypto_aead_ctx(aead);
	struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
	struct skcipher_request *skreq = &pctx->u.skreq;
	struct scatterlist *dst;

	dst = req->src == req->dst ? pctx->src : pctx->dst;

	skcipher_request_set_tfm(skreq, ctx->ctr);
	skcipher_request_set_crypt(skreq, pctx->src, dst,
				     cryptlen + sizeof(pctx->auth_tag),
				     pctx->iv);
}

static inline unsigned int gcm_remain(unsigned int len)
{
	len &= 0xfU;
	return len ? 16 - len : 0;
}

static void gcm_hash_len_done(struct crypto_async_request *areq, int err);

static int gcm_hash_update(struct aead_request *req,
			   crypto_completion_t compl,
			   struct scatterlist *src,
			   unsigned int len, u32 flags)
{
	struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
	struct ahash_request *ahreq = &pctx->u.ahreq;

	ahash_request_set_callback(ahreq, flags, compl, req);
	ahash_request_set_crypt(ahreq, src, NULL, len);

	return crypto_ahash_update(ahreq);
}

static int gcm_hash_remain(struct aead_request *req,
			   unsigned int remain,
			   crypto_completion_t compl, u32 flags)
{
	return gcm_hash_update(req, compl, &gcm_zeroes->sg, remain, flags);
}

static int gcm_hash_len(struct aead_request *req, u32 flags)
{
	struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
	struct ahash_request *ahreq = &pctx->u.ahreq;
	struct crypto_gcm_ghash_ctx *gctx = &pctx->ghash_ctx;
	u128 lengths;

	lengths.a = cpu_to_be64(req->assoclen * 8);
	lengths.b = cpu_to_be64(gctx->cryptlen * 8);
	memcpy(pctx->iauth_tag, &lengths, 16);
	sg_init_one(&pctx->sg, pctx->iauth_tag, 16);
	ahash_request_set_callback(ahreq, flags, gcm_hash_len_done, req);
	ahash_request_set_crypt(ahreq, &pctx->sg,
				pctx->iauth_tag, sizeof(lengths));

	return crypto_ahash_finup(ahreq);
}

static int gcm_hash_len_continue(struct aead_request *req, u32 flags)
{
	struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
	struct crypto_gcm_ghash_ctx *gctx = &pctx->ghash_ctx;

	return gctx->complete(req, flags);
}

static void gcm_hash_len_done(struct crypto_async_request *areq, int err)
{
	struct aead_request *req = areq->data;

	if (err)
		goto out;

	err = gcm_hash_len_continue(req, 0);
	if (err == -EINPROGRESS)
		return;

out:
	aead_request_complete(req, err);
}

static int gcm_hash_crypt_remain_continue(struct aead_request *req, u32 flags)
{
	return gcm_hash_len(req, flags) ?:
	       gcm_hash_len_continue(req, flags);
}

static void gcm_hash_crypt_remain_done(struct crypto_async_request *areq,
				       int err)
{
	struct aead_request *req = areq->data;

	if (err)
		goto out;

	err = gcm_hash_crypt_remain_continue(req, 0);
	if (err == -EINPROGRESS)
		return;

out:
	aead_request_complete(req, err);
}

static int gcm_hash_crypt_continue(struct aead_request *req, u32 flags)
{
	struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
	struct crypto_gcm_ghash_ctx *gctx = &pctx->ghash_ctx;
	unsigned int remain;

	remain = gcm_remain(gctx->cryptlen);
	if (remain)
		return gcm_hash_remain(req, remain,
				       gcm_hash_crypt_remain_done, flags) ?:
		       gcm_hash_crypt_remain_continue(req, flags);

	return gcm_hash_crypt_remain_continue(req, flags);
}

static void gcm_hash_crypt_done(struct crypto_async_request *areq, int err)
{
	struct aead_request *req = areq->data;

	if (err)
		goto out;

	err = gcm_hash_crypt_continue(req, 0);
	if (err == -EINPROGRESS)
		return;

out:
	aead_request_complete(req, err);
}

static int gcm_hash_assoc_remain_continue(struct aead_request *req, u32 flags)
{
	struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
	struct crypto_gcm_ghash_ctx *gctx = &pctx->ghash_ctx;

	if (gctx->cryptlen)
		return gcm_hash_update(req, gcm_hash_crypt_done,
				       gctx->src, gctx->cryptlen, flags) ?:
		       gcm_hash_crypt_continue(req, flags);

	return gcm_hash_crypt_remain_continue(req, flags);
}

static void gcm_hash_assoc_remain_done(struct crypto_async_request *areq,
				       int err)
{
	struct aead_request *req = areq->data;

	if (err)
		goto out;

	err = gcm_hash_assoc_remain_continue(req, 0);
	if (err == -EINPROGRESS)
		return;

out:
	aead_request_complete(req, err);
}

static int gcm_hash_assoc_continue(struct aead_request *req, u32 flags)
{
	unsigned int remain;

	remain = gcm_remain(req->assoclen);
	if (remain)
		return gcm_hash_remain(req, remain,
				       gcm_hash_assoc_remain_done, flags) ?:
		       gcm_hash_assoc_remain_continue(req, flags);

	return gcm_hash_assoc_remain_continue(req, flags);
}

static void gcm_hash_assoc_done(struct crypto_async_request *areq, int err)
{
	struct aead_request *req = areq->data;

	if (err)
		goto out;

	err = gcm_hash_assoc_continue(req, 0);
	if (err == -EINPROGRESS)
		return;

out:
	aead_request_complete(req, err);
}

static int gcm_hash_init_continue(struct aead_request *req, u32 flags)
{
	if (req->assoclen)
		return gcm_hash_update(req, gcm_hash_assoc_done,
				       req->src, req->assoclen, flags) ?:
		       gcm_hash_assoc_continue(req, flags);

	return gcm_hash_assoc_remain_continue(req, flags);
}

static void gcm_hash_init_done(struct crypto_async_request *areq, int err)
{
	struct aead_request *req = areq->data;

	if (err)
		goto out;

	err = gcm_hash_init_continue(req, 0);
	if (err == -EINPROGRESS)
		return;

out:
	aead_request_complete(req, err);
}

static int gcm_hash(struct aead_request *req, u32 flags)
{
	struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
	struct ahash_request *ahreq = &pctx->u.ahreq;
	struct crypto_gcm_ctx *ctx = crypto_aead_ctx(crypto_aead_reqtfm(req));

	ahash_request_set_tfm(ahreq, ctx->ghash);

	ahash_request_set_callback(ahreq, flags, gcm_hash_init_done, req);
	return crypto_ahash_init(ahreq) ?:
	       gcm_hash_init_continue(req, flags);
}

static int gcm_enc_copy_hash(struct aead_request *req, u32 flags)
{
	struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
	struct crypto_aead *aead = crypto_aead_reqtfm(req);
	u8 *auth_tag = pctx->auth_tag;

	crypto_xor(auth_tag, pctx->iauth_tag, 16);
	scatterwalk_map_and_copy(auth_tag, req->dst,
				 req->assoclen + req->cryptlen,
				 crypto_aead_authsize(aead), 1);
	return 0;
}

static int gcm_encrypt_continue(struct aead_request *req, u32 flags)
{
	struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
	struct crypto_gcm_ghash_ctx *gctx = &pctx->ghash_ctx;

	gctx->src = sg_next(req->src == req->dst ? pctx->src : pctx->dst);
	gctx->cryptlen = req->cryptlen;
	gctx->complete = gcm_enc_copy_hash;

	return gcm_hash(req, flags);
}

static void gcm_encrypt_done(struct crypto_async_request *areq, int err)
{
	struct aead_request *req = areq->data;

	if (err)
		goto out;

	err = gcm_encrypt_continue(req, 0);
	if (err == -EINPROGRESS)
		return;

out:
	aead_request_complete(req, err);
}

static int crypto_gcm_encrypt(struct aead_request *req)
{
	struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
	struct skcipher_request *skreq = &pctx->u.skreq;
	u32 flags = aead_request_flags(req);

	crypto_gcm_init_common(req);
	crypto_gcm_init_crypt(req, req->cryptlen);
	skcipher_request_set_callback(skreq, flags, gcm_encrypt_done, req);

	return crypto_skcipher_encrypt(skreq) ?:
	       gcm_encrypt_continue(req, flags);
}

static int crypto_gcm_verify(struct aead_request *req)
{
	struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
	struct crypto_aead *aead = crypto_aead_reqtfm(req);
	u8 *auth_tag = pctx->auth_tag;
	u8 *iauth_tag = pctx->iauth_tag;
	unsigned int authsize = crypto_aead_authsize(aead);
	unsigned int cryptlen = req->cryptlen - authsize;

	crypto_xor(auth_tag, iauth_tag, 16);
	scatterwalk_map_and_copy(iauth_tag, req->src,
				 req->assoclen + cryptlen, authsize, 0);
	return crypto_memneq(iauth_tag, auth_tag, authsize) ? -EBADMSG : 0;
}

static void gcm_decrypt_done(struct crypto_async_request *areq, int err)
{
	struct aead_request *req = areq->data;

	if (!err)
		err = crypto_gcm_verify(req);

	aead_request_complete(req, err);
}

static int gcm_dec_hash_continue(struct aead_request *req, u32 flags)
{
	struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
	struct skcipher_request *skreq = &pctx->u.skreq;
	struct crypto_gcm_ghash_ctx *gctx = &pctx->ghash_ctx;

	crypto_gcm_init_crypt(req, gctx->cryptlen);
	skcipher_request_set_callback(skreq, flags, gcm_decrypt_done, req);
	return crypto_skcipher_decrypt(skreq) ?: crypto_gcm_verify(req);
}

static int crypto_gcm_decrypt(struct aead_request *req)
{
	struct crypto_aead *aead = crypto_aead_reqtfm(req);
	struct crypto_gcm_req_priv_ctx *pctx = crypto_gcm_reqctx(req);
	struct crypto_gcm_ghash_ctx *gctx = &pctx->ghash_ctx;
	unsigned int authsize = crypto_aead_authsize(aead);
	unsigned int cryptlen = req->cryptlen;
	u32 flags = aead_request_flags(req);

	cryptlen -= authsize;

	crypto_gcm_init_common(req);

	gctx->src = sg_next(pctx->src);
	gctx->cryptlen = cryptlen;
	gctx->complete = gcm_dec_hash_continue;

	return gcm_hash(req, flags);
}

static int crypto_gcm_init_tfm(struct crypto_aead *tfm)
{
	struct aead_instance *inst = aead_alg_instance(tfm);
	struct gcm_instance_ctx *ictx = aead_instance_ctx(inst);
	struct crypto_gcm_ctx *ctx = crypto_aead_ctx(tfm);
	struct crypto_skcipher *ctr;
	struct crypto_ahash *ghash;
	unsigned long align;
	int err;

	ghash = crypto_spawn_ahash(&ictx->ghash);
	if (IS_ERR(ghash))
		return PTR_ERR(ghash);

	ctr = crypto_spawn_skcipher(&ictx->ctr);
	err = PTR_ERR(ctr);
	if (IS_ERR(ctr))
		goto err_free_hash;

	ctx->ctr = ctr;
	ctx->ghash = ghash;

	align = crypto_aead_alignmask(tfm);
	align &= ~(crypto_tfm_ctx_alignment() - 1);
	crypto_aead_set_reqsize(tfm,
		align + offsetof(struct crypto_gcm_req_priv_ctx, u) +
		max(sizeof(struct skcipher_request) +
		    crypto_skcipher_reqsize(ctr),
		    sizeof(struct ahash_request) +
		    crypto_ahash_reqsize(ghash)));

	return 0;

err_free_hash:
	crypto_free_ahash(ghash);
	return err;
}

static void crypto_gcm_exit_tfm(struct crypto_aead *tfm)
{
	struct crypto_gcm_ctx *ctx = crypto_aead_ctx(tfm);

	crypto_free_ahash(ctx->ghash);
	crypto_free_skcipher(ctx->ctr);
}

static void crypto_gcm_free(struct aead_instance *inst)
{
	struct gcm_instance_ctx *ctx = aead_instance_ctx(inst);

	crypto_drop_skcipher(&ctx->ctr);
	crypto_drop_ahash(&ctx->ghash);
	kfree(inst);
}

static int crypto_gcm_create_common(struct crypto_template *tmpl,
				    struct rtattr **tb,
				    const char *full_name,
				    const char *ctr_name,
				    const char *ghash_name)
{
	struct crypto_attr_type *algt;
	struct aead_instance *inst;
	struct skcipher_alg *ctr;
	struct crypto_alg *ghash_alg;
	struct hash_alg_common *ghash;
	struct gcm_instance_ctx *ctx;
	int err;

	algt = crypto_get_attr_type(tb);
	if (IS_ERR(algt))
		return PTR_ERR(algt);

	if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & algt->mask)
		return -EINVAL;

	ghash_alg = crypto_find_alg(ghash_name, &crypto_ahash_type,
				    CRYPTO_ALG_TYPE_HASH,
				    CRYPTO_ALG_TYPE_AHASH_MASK |
				    crypto_requires_sync(algt->type,
							 algt->mask));
	if (IS_ERR(ghash_alg))
		return PTR_ERR(ghash_alg);

	ghash = __crypto_hash_alg_common(ghash_alg);

	err = -ENOMEM;
	inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL);
	if (!inst)
		goto out_put_ghash;

	ctx = aead_instance_ctx(inst);
	err = crypto_init_ahash_spawn(&ctx->ghash, ghash,
				      aead_crypto_instance(inst));
	if (err)
		goto err_free_inst;

	err = -EINVAL;
	if (ghash->digestsize != 16)
		goto err_drop_ghash;

	crypto_set_skcipher_spawn(&ctx->ctr, aead_crypto_instance(inst));
	err = crypto_grab_skcipher(&ctx->ctr, ctr_name, 0,
				   crypto_requires_sync(algt->type,
							algt->mask));
	if (err)
		goto err_drop_ghash;

	ctr = crypto_spawn_skcipher_alg(&ctx->ctr);

	/* We only support 16-byte blocks. */
	err = -EINVAL;
	if (crypto_skcipher_alg_ivsize(ctr) != 16)
		goto out_put_ctr;

	/* Not a stream cipher? */
	if (ctr->base.cra_blocksize != 1)
		goto out_put_ctr;

	err = -ENAMETOOLONG;
	if (snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME,
		     "gcm_base(%s,%s)", ctr->base.cra_driver_name,
		     ghash_alg->cra_driver_name) >=
	    CRYPTO_MAX_ALG_NAME)
		goto out_put_ctr;

	memcpy(inst->alg.base.cra_name, full_name, CRYPTO_MAX_ALG_NAME);

	inst->alg.base.cra_flags = (ghash->base.cra_flags |
				    ctr->base.cra_flags) & CRYPTO_ALG_ASYNC;
	inst->alg.base.cra_priority = (ghash->base.cra_priority +
				       ctr->base.cra_priority) / 2;
	inst->alg.base.cra_blocksize = 1;
	inst->alg.base.cra_alignmask = ghash->base.cra_alignmask |
				       ctr->base.cra_alignmask;
	inst->alg.base.cra_ctxsize = sizeof(struct crypto_gcm_ctx);
	inst->alg.ivsize = 12;
	inst->alg.chunksize = crypto_skcipher_alg_chunksize(ctr);
	inst->alg.maxauthsize = 16;
	inst->alg.init = crypto_gcm_init_tfm;
	inst->alg.exit = crypto_gcm_exit_tfm;
	inst->alg.setkey = crypto_gcm_setkey;
	inst->alg.setauthsize = crypto_gcm_setauthsize;
	inst->alg.encrypt = crypto_gcm_encrypt;
	inst->alg.decrypt = crypto_gcm_decrypt;

	inst->free = crypto_gcm_free;

	err = aead_register_instance(tmpl, inst);
	if (err)
		goto out_put_ctr;

out_put_ghash:
	crypto_mod_put(ghash_alg);
	return err;

out_put_ctr:
	crypto_drop_skcipher(&ctx->ctr);
err_drop_ghash:
	crypto_drop_ahash(&ctx->ghash);
err_free_inst:
	kfree(inst);
	goto out_put_ghash;
}

static int crypto_gcm_create(struct crypto_template *tmpl, struct rtattr **tb)
{
	const char *cipher_name;
	char ctr_name[CRYPTO_MAX_ALG_NAME];
	char full_name[CRYPTO_MAX_ALG_NAME];

	cipher_name = crypto_attr_alg_name(tb[1]);
	if (IS_ERR(cipher_name))
		return PTR_ERR(cipher_name);

	if (snprintf(ctr_name, CRYPTO_MAX_ALG_NAME, "ctr(%s)", cipher_name) >=
	    CRYPTO_MAX_ALG_NAME)
		return -ENAMETOOLONG;

	if (snprintf(full_name, CRYPTO_MAX_ALG_NAME, "gcm(%s)", cipher_name) >=
	    CRYPTO_MAX_ALG_NAME)
		return -ENAMETOOLONG;

	return crypto_gcm_create_common(tmpl, tb, full_name,
					ctr_name, "ghash");
}

static struct crypto_template crypto_gcm_tmpl = {
	.name = "gcm",
	.create = crypto_gcm_create,
	.module = THIS_MODULE,
};

static int crypto_gcm_base_create(struct crypto_template *tmpl,
				  struct rtattr **tb)
{
	const char *ctr_name;
	const char *ghash_name;
	char full_name[CRYPTO_MAX_ALG_NAME];

	ctr_name = crypto_attr_alg_name(tb[1]);
	if (IS_ERR(ctr_name))
		return PTR_ERR(ctr_name);

	ghash_name = crypto_attr_alg_name(tb[2]);
	if (IS_ERR(ghash_name))
		return PTR_ERR(ghash_name);

	if (snprintf(full_name, CRYPTO_MAX_ALG_NAME, "gcm_base(%s,%s)",
		     ctr_name, ghash_name) >= CRYPTO_MAX_ALG_NAME)
		return -ENAMETOOLONG;

	return crypto_gcm_create_common(tmpl, tb, full_name,
					ctr_name, ghash_name);
}

static struct crypto_template crypto_gcm_base_tmpl = {
	.name = "gcm_base",
	.create = crypto_gcm_base_create,
	.module = THIS_MODULE,
};

static int crypto_rfc4106_setkey(struct crypto_aead *parent, const u8 *key,
				 unsigned int keylen)
{
	struct crypto_rfc4106_ctx *ctx = crypto_aead_ctx(parent);
	struct crypto_aead *child = ctx->child;
	int err;

	if (keylen < 4)
		return -EINVAL;

	keylen -= 4;
	memcpy(ctx->nonce, key + keylen, 4);

	crypto_aead_clear_flags(child, CRYPTO_TFM_REQ_MASK);
	crypto_aead_set_flags(child, crypto_aead_get_flags(parent) &
				     CRYPTO_TFM_REQ_MASK);
	err = crypto_aead_setkey(child, key, keylen);
	crypto_aead_set_flags(parent, crypto_aead_get_flags(child) &
				      CRYPTO_TFM_RES_MASK);

	return err;
}

static int crypto_rfc4106_setauthsize(struct crypto_aead *parent,
				      unsigned int authsize)
{
	struct crypto_rfc4106_ctx *ctx = crypto_aead_ctx(parent);

	switch (authsize) {
	case 8:
	case 12:
	case 16:
		break;
	default:
		return -EINVAL;
	}

	return crypto_aead_setauthsize(ctx->child, authsize);
}

static struct aead_request *crypto_rfc4106_crypt(struct aead_request *req)
{
	struct crypto_rfc4106_req_ctx *rctx = aead_request_ctx(req);
	struct crypto_aead *aead = crypto_aead_reqtfm(req);
	struct crypto_rfc4106_ctx *ctx = crypto_aead_ctx(aead);
	struct aead_request *subreq = &rctx->subreq;
	struct crypto_aead *child = ctx->child;
	struct scatterlist *sg;
	u8 *iv = PTR_ALIGN((u8 *)(subreq + 1) + crypto_aead_reqsize(child),
			   crypto_aead_alignmask(child) + 1);

	scatterwalk_map_and_copy(iv + 12, req->src, 0, req->assoclen - 8, 0);

	memcpy(iv, ctx->nonce, 4);
	memcpy(iv + 4, req->iv, 8);

	sg_init_table(rctx->src, 3);
	sg_set_buf(rctx->src, iv + 12, req->assoclen - 8);
	sg = scatterwalk_ffwd(rctx->src + 1, req->src, req->assoclen);
	if (sg != rctx->src + 1)
		sg_chain(rctx->src, 2, sg);

	if (req->src != req->dst) {
		sg_init_table(rctx->dst, 3);
		sg_set_buf(rctx->dst, iv + 12, req->assoclen - 8);
		sg = scatterwalk_ffwd(rctx->dst + 1, req->dst, req->assoclen);
		if (sg != rctx->dst + 1)
			sg_chain(rctx->dst, 2, sg);
	}

	aead_request_set_tfm(subreq, child);
	aead_request_set_callback(subreq, req->base.flags, req->base.complete,
				  req->base.data);
	aead_request_set_crypt(subreq, rctx->src,
			       req->src == req->dst ? rctx->src : rctx->dst,
			       req->cryptlen, iv);
	aead_request_set_ad(subreq, req->assoclen - 8);

	return subreq;
}

static int crypto_rfc4106_encrypt(struct aead_request *req)
{
	if (req->assoclen != 16 && req->assoclen != 20)
		return -EINVAL;

	req = crypto_rfc4106_crypt(req);

	return crypto_aead_encrypt(req);
}

static int crypto_rfc4106_decrypt(struct aead_request *req)
{
	if (req->assoclen != 16 && req->assoclen != 20)
		return -EINVAL;

	req = crypto_rfc4106_crypt(req);

	return crypto_aead_decrypt(req);
}

static int crypto_rfc4106_init_tfm(struct crypto_aead *tfm)
{
	struct aead_instance *inst = aead_alg_instance(tfm);
	struct crypto_aead_spawn *spawn = aead_instance_ctx(inst);
	struct crypto_rfc4106_ctx *ctx = crypto_aead_ctx(tfm);
	struct crypto_aead *aead;
	unsigned long align;

	aead = crypto_spawn_aead(spawn);
	if (IS_ERR(aead))
		return PTR_ERR(aead);

	ctx->child = aead;

	align = crypto_aead_alignmask(aead);
	align &= ~(crypto_tfm_ctx_alignment() - 1);
	crypto_aead_set_reqsize(
		tfm,
		sizeof(struct crypto_rfc4106_req_ctx) +
		ALIGN(crypto_aead_reqsize(aead), crypto_tfm_ctx_alignment()) +
		align + 24);

	return 0;
}

static void crypto_rfc4106_exit_tfm(struct crypto_aead *tfm)
{
	struct crypto_rfc4106_ctx *ctx = crypto_aead_ctx(tfm);

	crypto_free_aead(ctx->child);
}

static void crypto_rfc4106_free(struct aead_instance *inst)
{
	crypto_drop_aead(aead_instance_ctx(inst));
	kfree(inst);
}

static int crypto_rfc4106_create(struct crypto_template *tmpl,
				 struct rtattr **tb)
{
	struct crypto_attr_type *algt;
	struct aead_instance *inst;
	struct crypto_aead_spawn *spawn;
	struct aead_alg *alg;
	const char *ccm_name;
	int err;

	algt = crypto_get_attr_type(tb);
	if (IS_ERR(algt))
		return PTR_ERR(algt);

	if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & algt->mask)
		return -EINVAL;

	ccm_name = crypto_attr_alg_name(tb[1]);
	if (IS_ERR(ccm_name))
		return PTR_ERR(ccm_name);

	inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
	if (!inst)
		return -ENOMEM;

	spawn = aead_instance_ctx(inst);
	crypto_set_aead_spawn(spawn, aead_crypto_instance(inst));
	err = crypto_grab_aead(spawn, ccm_name, 0,
			       crypto_requires_sync(algt->type, algt->mask));
	if (err)
		goto out_free_inst;

	alg = crypto_spawn_aead_alg(spawn);

	err = -EINVAL;

	/* Underlying IV size must be 12. */
	if (crypto_aead_alg_ivsize(alg) != 12)
		goto out_drop_alg;

	/* Not a stream cipher? */
	if (alg->base.cra_blocksize != 1)
		goto out_drop_alg;

	err = -ENAMETOOLONG;
	if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME,
		     "rfc4106(%s)", alg->base.cra_name) >=
	    CRYPTO_MAX_ALG_NAME ||
	    snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME,
		     "rfc4106(%s)", alg->base.cra_driver_name) >=
	    CRYPTO_MAX_ALG_NAME)
		goto out_drop_alg;

	inst->alg.base.cra_flags = alg->base.cra_flags & CRYPTO_ALG_ASYNC;
	inst->alg.base.cra_priority = alg->base.cra_priority;
	inst->alg.base.cra_blocksize = 1;
	inst->alg.base.cra_alignmask = alg->base.cra_alignmask;

	inst->alg.base.cra_ctxsize = sizeof(struct crypto_rfc4106_ctx);

	inst->alg.ivsize = 8;
	inst->alg.chunksize = crypto_aead_alg_chunksize(alg);
	inst->alg.maxauthsize = crypto_aead_alg_maxauthsize(alg);

	inst->alg.init = crypto_rfc4106_init_tfm;
	inst->alg.exit = crypto_rfc4106_exit_tfm;

	inst->alg.setkey = crypto_rfc4106_setkey;
	inst->alg.setauthsize = crypto_rfc4106_setauthsize;
	inst->alg.encrypt = crypto_rfc4106_encrypt;
	inst->alg.decrypt = crypto_rfc4106_decrypt;

	inst->free = crypto_rfc4106_free;

	err = aead_register_instance(tmpl, inst);
	if (err)
		goto out_drop_alg;

out:
	return err;

out_drop_alg:
	crypto_drop_aead(spawn);
out_free_inst:
	kfree(inst);
	goto out;
}

static struct crypto_template crypto_rfc4106_tmpl = {
	.name = "rfc4106",
	.create = crypto_rfc4106_create,
	.module = THIS_MODULE,
};

static int crypto_rfc4543_setkey(struct crypto_aead *parent, const u8 *key,
				 unsigned int keylen)
{
	struct crypto_rfc4543_ctx *ctx = crypto_aead_ctx(parent);
	struct crypto_aead *child = ctx->child;
	int err;

	if (keylen < 4)
		return -EINVAL;

	keylen -= 4;
	memcpy(ctx->nonce, key + keylen, 4);

	crypto_aead_clear_flags(child, CRYPTO_TFM_REQ_MASK);
	crypto_aead_set_flags(child, crypto_aead_get_flags(parent) &
				     CRYPTO_TFM_REQ_MASK);
	err = crypto_aead_setkey(child, key, keylen);
	crypto_aead_set_flags(parent, crypto_aead_get_flags(child) &
				      CRYPTO_TFM_RES_MASK);

	return err;
}

static int crypto_rfc4543_setauthsize(struct crypto_aead *parent,
				      unsigned int authsize)
{
	struct crypto_rfc4543_ctx *ctx = crypto_aead_ctx(parent);

	if (authsize != 16)
		return -EINVAL;

	return crypto_aead_setauthsize(ctx->child, authsize);
}

static int crypto_rfc4543_crypt(struct aead_request *req, bool enc)
{
	struct crypto_aead *aead = crypto_aead_reqtfm(req);
	struct crypto_rfc4543_ctx *ctx = crypto_aead_ctx(aead);
	struct crypto_rfc4543_req_ctx *rctx = aead_request_ctx(req);
	struct aead_request *subreq = &rctx->subreq;
	unsigned int authsize = crypto_aead_authsize(aead);
	u8 *iv = PTR_ALIGN((u8 *)(rctx + 1) + crypto_aead_reqsize(ctx->child),
			   crypto_aead_alignmask(ctx->child) + 1);
	int err;

	if (req->src != req->dst) {
		err = crypto_rfc4543_copy_src_to_dst(req, enc);
		if (err)
			return err;
	}

	memcpy(iv, ctx->nonce, 4);
	memcpy(iv + 4, req->iv, 8);

	aead_request_set_tfm(subreq, ctx->child);
	aead_request_set_callback(subreq, req->base.flags,
				  req->base.complete, req->base.data);
	aead_request_set_crypt(subreq, req->src, req->dst,
			       enc ? 0 : authsize, iv);
	aead_request_set_ad(subreq, req->assoclen + req->cryptlen -
				    subreq->cryptlen);

	return enc ? crypto_aead_encrypt(subreq) : crypto_aead_decrypt(subreq);
}

static int crypto_rfc4543_copy_src_to_dst(struct aead_request *req, bool enc)
{
	struct crypto_aead *aead = crypto_aead_reqtfm(req);
	struct crypto_rfc4543_ctx *ctx = crypto_aead_ctx(aead);
	unsigned int authsize = crypto_aead_authsize(aead);
	unsigned int nbytes = req->assoclen + req->cryptlen -
			      (enc ? 0 : authsize);
	SKCIPHER_REQUEST_ON_STACK(nreq, ctx->null);

	skcipher_request_set_tfm(nreq, ctx->null);
	skcipher_request_set_callback(nreq, req->base.flags, NULL, NULL);
	skcipher_request_set_crypt(nreq, req->src, req->dst, nbytes, NULL);

	return crypto_skcipher_encrypt(nreq);
}

static int crypto_rfc4543_encrypt(struct aead_request *req)
{
	return crypto_rfc4543_crypt(req, true);
}

static int crypto_rfc4543_decrypt(struct aead_request *req)
{
	return crypto_rfc4543_crypt(req, false);
}

static int crypto_rfc4543_init_tfm(struct crypto_aead *tfm)
{
	struct aead_instance *inst = aead_alg_instance(tfm);
	struct crypto_rfc4543_instance_ctx *ictx = aead_instance_ctx(inst);
	struct crypto_aead_spawn *spawn = &ictx->aead;
	struct crypto_rfc4543_ctx *ctx = crypto_aead_ctx(tfm);
	struct crypto_aead *aead;
	struct crypto_skcipher *null;
	unsigned long align;
	int err = 0;

	aead = crypto_spawn_aead(spawn);
	if (IS_ERR(aead))
		return PTR_ERR(aead);

	null = crypto_get_default_null_skcipher2();
	err = PTR_ERR(null);
	if (IS_ERR(null))
		goto err_free_aead;

	ctx->child = aead;
	ctx->null = null;

	align = crypto_aead_alignmask(aead);
	align &= ~(crypto_tfm_ctx_alignment() - 1);
	crypto_aead_set_reqsize(
		tfm,
		sizeof(struct crypto_rfc4543_req_ctx) +
		ALIGN(crypto_aead_reqsize(aead), crypto_tfm_ctx_alignment()) +
		align + 12);

	return 0;

err_free_aead:
	crypto_free_aead(aead);
	return err;
}

static void crypto_rfc4543_exit_tfm(struct crypto_aead *tfm)
{
	struct crypto_rfc4543_ctx *ctx = crypto_aead_ctx(tfm);

	crypto_free_aead(ctx->child);
	crypto_put_default_null_skcipher2();
}

static void crypto_rfc4543_free(struct aead_instance *inst)
{
	struct crypto_rfc4543_instance_ctx *ctx = aead_instance_ctx(inst);

	crypto_drop_aead(&ctx->aead);

	kfree(inst);
}

static int crypto_rfc4543_create(struct crypto_template *tmpl,
				struct rtattr **tb)
{
	struct crypto_attr_type *algt;
	struct aead_instance *inst;
	struct crypto_aead_spawn *spawn;
	struct aead_alg *alg;
	struct crypto_rfc4543_instance_ctx *ctx;
	const char *ccm_name;
	int err;

	algt = crypto_get_attr_type(tb);
	if (IS_ERR(algt))
		return PTR_ERR(algt);

	if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & algt->mask)
		return -EINVAL;

	ccm_name = crypto_attr_alg_name(tb[1]);
	if (IS_ERR(ccm_name))
		return PTR_ERR(ccm_name);

	inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL);
	if (!inst)
		return -ENOMEM;

	ctx = aead_instance_ctx(inst);
	spawn = &ctx->aead;
	crypto_set_aead_spawn(spawn, aead_crypto_instance(inst));
	err = crypto_grab_aead(spawn, ccm_name, 0,
			       crypto_requires_sync(algt->type, algt->mask));
	if (err)
		goto out_free_inst;

	alg = crypto_spawn_aead_alg(spawn);

	err = -EINVAL;

	/* Underlying IV size must be 12. */
	if (crypto_aead_alg_ivsize(alg) != 12)
		goto out_drop_alg;

	/* Not a stream cipher? */
	if (alg->base.cra_blocksize != 1)
		goto out_drop_alg;

	err = -ENAMETOOLONG;
	if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME,
		     "rfc4543(%s)", alg->base.cra_name) >=
	    CRYPTO_MAX_ALG_NAME ||
	    snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME,
		     "rfc4543(%s)", alg->base.cra_driver_name) >=
	    CRYPTO_MAX_ALG_NAME)
		goto out_drop_alg;

	inst->alg.base.cra_flags = alg->base.cra_flags & CRYPTO_ALG_ASYNC;
	inst->alg.base.cra_priority = alg->base.cra_priority;
	inst->alg.base.cra_blocksize = 1;
	inst->alg.base.cra_alignmask = alg->base.cra_alignmask;

	inst->alg.base.cra_ctxsize = sizeof(struct crypto_rfc4543_ctx);

	inst->alg.ivsize = 8;
	inst->alg.chunksize = crypto_aead_alg_chunksize(alg);
	inst->alg.maxauthsize = crypto_aead_alg_maxauthsize(alg);

	inst->alg.init = crypto_rfc4543_init_tfm;
	inst->alg.exit = crypto_rfc4543_exit_tfm;

	inst->alg.setkey = crypto_rfc4543_setkey;
	inst->alg.setauthsize = crypto_rfc4543_setauthsize;
	inst->alg.encrypt = crypto_rfc4543_encrypt;
	inst->alg.decrypt = crypto_rfc4543_decrypt;

	inst->free = crypto_rfc4543_free,

	err = aead_register_instance(tmpl, inst);
	if (err)
		goto out_drop_alg;

out:
	return err;

out_drop_alg:
	crypto_drop_aead(spawn);
out_free_inst:
	kfree(inst);
	goto out;
}

static struct crypto_template crypto_rfc4543_tmpl = {
	.name = "rfc4543",
	.create = crypto_rfc4543_create,
	.module = THIS_MODULE,
};

static int __init crypto_gcm_module_init(void)
{
	int err;

	gcm_zeroes = kzalloc(sizeof(*gcm_zeroes), GFP_KERNEL);
	if (!gcm_zeroes)
		return -ENOMEM;

	sg_init_one(&gcm_zeroes->sg, gcm_zeroes->buf, sizeof(gcm_zeroes->buf));

	err = crypto_register_template(&crypto_gcm_base_tmpl);
	if (err)
		goto out;

	err = crypto_register_template(&crypto_gcm_tmpl);
	if (err)
		goto out_undo_base;

	err = crypto_register_template(&crypto_rfc4106_tmpl);
	if (err)
		goto out_undo_gcm;

	err = crypto_register_template(&crypto_rfc4543_tmpl);
	if (err)
		goto out_undo_rfc4106;

	return 0;

out_undo_rfc4106:
	crypto_unregister_template(&crypto_rfc4106_tmpl);
out_undo_gcm:
	crypto_unregister_template(&crypto_gcm_tmpl);
out_undo_base:
	crypto_unregister_template(&crypto_gcm_base_tmpl);
out:
	kfree(gcm_zeroes);
	return err;
}

static void __exit crypto_gcm_module_exit(void)
{
	kfree(gcm_zeroes);
	crypto_unregister_template(&crypto_rfc4543_tmpl);
	crypto_unregister_template(&crypto_rfc4106_tmpl);
	crypto_unregister_template(&crypto_gcm_tmpl);
	crypto_unregister_template(&crypto_gcm_base_tmpl);
}

module_init(crypto_gcm_module_init);
module_exit(crypto_gcm_module_exit);

MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Galois/Counter Mode");
MODULE_AUTHOR("Mikko Herranen <mh1@iki.fi>");
MODULE_ALIAS_CRYPTO("gcm_base");
MODULE_ALIAS_CRYPTO("rfc4106");
MODULE_ALIAS_CRYPTO("rfc4543");
MODULE_ALIAS_CRYPTO("gcm");
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