xref: /linux/crypto/scompress.c (revision a32f1923c6d6e9e727d00558a15ec0af6639de19)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Synchronous Compression operations
4  *
5  * Copyright 2015 LG Electronics Inc.
6  * Copyright (c) 2016, Intel Corporation
7  * Author: Giovanni Cabiddu <giovanni.cabiddu@intel.com>
8  */
9 
10 #include <crypto/internal/acompress.h>
11 #include <crypto/internal/scompress.h>
12 #include <crypto/scatterwalk.h>
13 #include <linux/cryptouser.h>
14 #include <linux/err.h>
15 #include <linux/highmem.h>
16 #include <linux/kernel.h>
17 #include <linux/module.h>
18 #include <linux/overflow.h>
19 #include <linux/scatterlist.h>
20 #include <linux/seq_file.h>
21 #include <linux/slab.h>
22 #include <linux/string.h>
23 #include <linux/vmalloc.h>
24 #include <net/netlink.h>
25 
26 #include "compress.h"
27 
28 #define SCOMP_SCRATCH_SIZE 65400
29 
30 struct scomp_scratch {
31 	spinlock_t	lock;
32 	union {
33 		void	*src;
34 		unsigned long saddr;
35 	};
36 	void		*dst;
37 };
38 
39 static DEFINE_PER_CPU(struct scomp_scratch, scomp_scratch) = {
40 	.lock = __SPIN_LOCK_UNLOCKED(scomp_scratch.lock),
41 };
42 
43 static const struct crypto_type crypto_scomp_type;
44 static int scomp_scratch_users;
45 static DEFINE_MUTEX(scomp_lock);
46 
47 static int __maybe_unused crypto_scomp_report(
48 	struct sk_buff *skb, struct crypto_alg *alg)
49 {
50 	struct crypto_report_comp rscomp;
51 
52 	memset(&rscomp, 0, sizeof(rscomp));
53 
54 	strscpy(rscomp.type, "scomp", sizeof(rscomp.type));
55 
56 	return nla_put(skb, CRYPTOCFGA_REPORT_COMPRESS,
57 		       sizeof(rscomp), &rscomp);
58 }
59 
60 static void crypto_scomp_show(struct seq_file *m, struct crypto_alg *alg)
61 	__maybe_unused;
62 
63 static void crypto_scomp_show(struct seq_file *m, struct crypto_alg *alg)
64 {
65 	seq_puts(m, "type         : scomp\n");
66 }
67 
68 static void crypto_scomp_free_scratches(void)
69 {
70 	struct scomp_scratch *scratch;
71 	int i;
72 
73 	for_each_possible_cpu(i) {
74 		scratch = per_cpu_ptr(&scomp_scratch, i);
75 
76 		free_page(scratch->saddr);
77 		vfree(scratch->dst);
78 		scratch->src = NULL;
79 		scratch->dst = NULL;
80 	}
81 }
82 
83 static int crypto_scomp_alloc_scratches(void)
84 {
85 	struct scomp_scratch *scratch;
86 	int i;
87 
88 	for_each_possible_cpu(i) {
89 		struct page *page;
90 		void *mem;
91 
92 		scratch = per_cpu_ptr(&scomp_scratch, i);
93 
94 		page = alloc_pages_node(cpu_to_node(i), GFP_KERNEL, 0);
95 		if (!page)
96 			goto error;
97 		scratch->src = page_address(page);
98 		mem = vmalloc_node(SCOMP_SCRATCH_SIZE, cpu_to_node(i));
99 		if (!mem)
100 			goto error;
101 		scratch->dst = mem;
102 	}
103 	return 0;
104 error:
105 	crypto_scomp_free_scratches();
106 	return -ENOMEM;
107 }
108 
109 static void scomp_free_streams(struct scomp_alg *alg)
110 {
111 	struct crypto_acomp_stream __percpu *stream = alg->stream;
112 	int i;
113 
114 	alg->stream = NULL;
115 	if (!stream)
116 		return;
117 
118 	for_each_possible_cpu(i) {
119 		struct crypto_acomp_stream *ps = per_cpu_ptr(stream, i);
120 
121 		if (IS_ERR_OR_NULL(ps->ctx))
122 			break;
123 
124 		alg->free_ctx(ps->ctx);
125 	}
126 
127 	free_percpu(stream);
128 }
129 
130 static int scomp_alloc_streams(struct scomp_alg *alg)
131 {
132 	struct crypto_acomp_stream __percpu *stream;
133 	int i;
134 
135 	stream = alloc_percpu(struct crypto_acomp_stream);
136 	if (!stream)
137 		return -ENOMEM;
138 
139 	alg->stream = stream;
140 
141 	for_each_possible_cpu(i) {
142 		struct crypto_acomp_stream *ps = per_cpu_ptr(stream, i);
143 
144 		ps->ctx = alg->alloc_ctx();
145 		if (IS_ERR(ps->ctx)) {
146 			scomp_free_streams(alg);
147 			return PTR_ERR(ps->ctx);
148 		}
149 
150 		spin_lock_init(&ps->lock);
151 	}
152 	return 0;
153 }
154 
155 static int crypto_scomp_init_tfm(struct crypto_tfm *tfm)
156 {
157 	struct scomp_alg *alg = crypto_scomp_alg(__crypto_scomp_tfm(tfm));
158 	int ret = 0;
159 
160 	mutex_lock(&scomp_lock);
161 	if (!alg->stream) {
162 		ret = scomp_alloc_streams(alg);
163 		if (ret)
164 			goto unlock;
165 	}
166 	if (!scomp_scratch_users++) {
167 		ret = crypto_scomp_alloc_scratches();
168 		if (ret)
169 			scomp_scratch_users--;
170 	}
171 unlock:
172 	mutex_unlock(&scomp_lock);
173 
174 	return ret;
175 }
176 
177 static int scomp_acomp_comp_decomp(struct acomp_req *req, int dir)
178 {
179 	struct scomp_scratch *scratch = raw_cpu_ptr(&scomp_scratch);
180 	struct crypto_acomp *tfm = crypto_acomp_reqtfm(req);
181 	struct crypto_scomp **tfm_ctx = acomp_tfm_ctx(tfm);
182 	struct crypto_scomp *scomp = *tfm_ctx;
183 	struct crypto_acomp_stream *stream;
184 	unsigned int slen = req->slen;
185 	unsigned int dlen = req->dlen;
186 	struct page *spage, *dpage;
187 	unsigned int n;
188 	const u8 *src;
189 	size_t soff;
190 	size_t doff;
191 	u8 *dst;
192 	int ret;
193 
194 	if (!req->src || !slen)
195 		return -EINVAL;
196 
197 	if (!req->dst || !dlen)
198 		return -EINVAL;
199 
200 	if (acomp_request_src_isvirt(req))
201 		src = req->svirt;
202 	else {
203 		src = scratch->src;
204 		do {
205 			if (acomp_request_src_isfolio(req)) {
206 				spage = folio_page(req->sfolio, 0);
207 				soff = req->soff;
208 			} else if (slen <= req->src->length) {
209 				spage = sg_page(req->src);
210 				soff = req->src->offset;
211 			} else
212 				break;
213 
214 			spage = nth_page(spage, soff / PAGE_SIZE);
215 			soff = offset_in_page(soff);
216 
217 			n = (slen - 1) / PAGE_SIZE;
218 			n += (offset_in_page(slen - 1) + soff) / PAGE_SIZE;
219 			if (PageHighMem(nth_page(spage, n)) &&
220 			    size_add(soff, slen) > PAGE_SIZE)
221 				break;
222 			src = kmap_local_page(spage) + soff;
223 		} while (0);
224 	}
225 
226 	if (acomp_request_dst_isvirt(req))
227 		dst = req->dvirt;
228 	else {
229 		unsigned int max = SCOMP_SCRATCH_SIZE;
230 
231 		dst = scratch->dst;
232 		do {
233 			if (acomp_request_dst_isfolio(req)) {
234 				dpage = folio_page(req->dfolio, 0);
235 				doff = req->doff;
236 			} else if (dlen <= req->dst->length) {
237 				dpage = sg_page(req->dst);
238 				doff = req->dst->offset;
239 			} else
240 				break;
241 
242 			dpage = nth_page(dpage, doff / PAGE_SIZE);
243 			doff = offset_in_page(doff);
244 
245 			n = (dlen - 1) / PAGE_SIZE;
246 			n += (offset_in_page(dlen - 1) + doff) / PAGE_SIZE;
247 			if (PageHighMem(nth_page(dpage, n)) &&
248 			    size_add(doff, dlen) > PAGE_SIZE)
249 				break;
250 			dst = kmap_local_page(dpage) + doff;
251 			max = dlen;
252 		} while (0);
253 		dlen = min(dlen, max);
254 	}
255 
256 	spin_lock_bh(&scratch->lock);
257 
258 	if (src == scratch->src)
259 		memcpy_from_sglist(scratch->src, req->src, 0, slen);
260 
261 	stream = raw_cpu_ptr(crypto_scomp_alg(scomp)->stream);
262 	spin_lock(&stream->lock);
263 	if (dir)
264 		ret = crypto_scomp_compress(scomp, src, slen,
265 					    dst, &dlen, stream->ctx);
266 	else
267 		ret = crypto_scomp_decompress(scomp, src, slen,
268 					      dst, &dlen, stream->ctx);
269 
270 	if (dst == scratch->dst)
271 		memcpy_to_sglist(req->dst, 0, dst, dlen);
272 
273 	spin_unlock(&stream->lock);
274 	spin_unlock_bh(&scratch->lock);
275 
276 	req->dlen = dlen;
277 
278 	if (!acomp_request_dst_isvirt(req) && dst != scratch->dst) {
279 		kunmap_local(dst);
280 		dlen += doff;
281 		for (;;) {
282 			flush_dcache_page(dpage);
283 			if (dlen <= PAGE_SIZE)
284 				break;
285 			dlen -= PAGE_SIZE;
286 			dpage = nth_page(dpage, 1);
287 		}
288 	}
289 	if (!acomp_request_src_isvirt(req) && src != scratch->src)
290 		kunmap_local(src);
291 
292 	return ret;
293 }
294 
295 static int scomp_acomp_chain(struct acomp_req *req, int dir)
296 {
297 	struct acomp_req *r2;
298 	int err;
299 
300 	err = scomp_acomp_comp_decomp(req, dir);
301 	req->base.err = err;
302 
303 	list_for_each_entry(r2, &req->base.list, base.list)
304 		r2->base.err = scomp_acomp_comp_decomp(r2, dir);
305 
306 	return err;
307 }
308 
309 static int scomp_acomp_compress(struct acomp_req *req)
310 {
311 	return scomp_acomp_chain(req, 1);
312 }
313 
314 static int scomp_acomp_decompress(struct acomp_req *req)
315 {
316 	return scomp_acomp_chain(req, 0);
317 }
318 
319 static void crypto_exit_scomp_ops_async(struct crypto_tfm *tfm)
320 {
321 	struct crypto_scomp **ctx = crypto_tfm_ctx(tfm);
322 
323 	crypto_free_scomp(*ctx);
324 
325 	mutex_lock(&scomp_lock);
326 	if (!--scomp_scratch_users)
327 		crypto_scomp_free_scratches();
328 	mutex_unlock(&scomp_lock);
329 }
330 
331 int crypto_init_scomp_ops_async(struct crypto_tfm *tfm)
332 {
333 	struct crypto_alg *calg = tfm->__crt_alg;
334 	struct crypto_acomp *crt = __crypto_acomp_tfm(tfm);
335 	struct crypto_scomp **ctx = crypto_tfm_ctx(tfm);
336 	struct crypto_scomp *scomp;
337 
338 	if (!crypto_mod_get(calg))
339 		return -EAGAIN;
340 
341 	scomp = crypto_create_tfm(calg, &crypto_scomp_type);
342 	if (IS_ERR(scomp)) {
343 		crypto_mod_put(calg);
344 		return PTR_ERR(scomp);
345 	}
346 
347 	*ctx = scomp;
348 	tfm->exit = crypto_exit_scomp_ops_async;
349 
350 	crt->compress = scomp_acomp_compress;
351 	crt->decompress = scomp_acomp_decompress;
352 
353 	return 0;
354 }
355 
356 static void crypto_scomp_destroy(struct crypto_alg *alg)
357 {
358 	scomp_free_streams(__crypto_scomp_alg(alg));
359 }
360 
361 static const struct crypto_type crypto_scomp_type = {
362 	.extsize = crypto_alg_extsize,
363 	.init_tfm = crypto_scomp_init_tfm,
364 	.destroy = crypto_scomp_destroy,
365 #ifdef CONFIG_PROC_FS
366 	.show = crypto_scomp_show,
367 #endif
368 #if IS_ENABLED(CONFIG_CRYPTO_USER)
369 	.report = crypto_scomp_report,
370 #endif
371 	.maskclear = ~CRYPTO_ALG_TYPE_MASK,
372 	.maskset = CRYPTO_ALG_TYPE_MASK,
373 	.type = CRYPTO_ALG_TYPE_SCOMPRESS,
374 	.tfmsize = offsetof(struct crypto_scomp, base),
375 };
376 
377 static void scomp_prepare_alg(struct scomp_alg *alg)
378 {
379 	struct crypto_alg *base = &alg->calg.base;
380 
381 	comp_prepare_alg(&alg->calg);
382 
383 	base->cra_flags |= CRYPTO_ALG_REQ_CHAIN;
384 }
385 
386 int crypto_register_scomp(struct scomp_alg *alg)
387 {
388 	struct crypto_alg *base = &alg->calg.base;
389 
390 	scomp_prepare_alg(alg);
391 
392 	base->cra_type = &crypto_scomp_type;
393 	base->cra_flags |= CRYPTO_ALG_TYPE_SCOMPRESS;
394 
395 	return crypto_register_alg(base);
396 }
397 EXPORT_SYMBOL_GPL(crypto_register_scomp);
398 
399 void crypto_unregister_scomp(struct scomp_alg *alg)
400 {
401 	crypto_unregister_alg(&alg->base);
402 }
403 EXPORT_SYMBOL_GPL(crypto_unregister_scomp);
404 
405 int crypto_register_scomps(struct scomp_alg *algs, int count)
406 {
407 	int i, ret;
408 
409 	for (i = 0; i < count; i++) {
410 		ret = crypto_register_scomp(&algs[i]);
411 		if (ret)
412 			goto err;
413 	}
414 
415 	return 0;
416 
417 err:
418 	for (--i; i >= 0; --i)
419 		crypto_unregister_scomp(&algs[i]);
420 
421 	return ret;
422 }
423 EXPORT_SYMBOL_GPL(crypto_register_scomps);
424 
425 void crypto_unregister_scomps(struct scomp_alg *algs, int count)
426 {
427 	int i;
428 
429 	for (i = count - 1; i >= 0; --i)
430 		crypto_unregister_scomp(&algs[i]);
431 }
432 EXPORT_SYMBOL_GPL(crypto_unregister_scomps);
433 
434 MODULE_LICENSE("GPL");
435 MODULE_DESCRIPTION("Synchronous compression type");
436