xref: /netbsd-src/sys/kern/subr_kmem.c (revision 181254a7b1bdde6873432bffef2d2decc4b5c22f) 
1 /*	$NetBSD: subr_kmem.c,v 1.80 2020/05/14 17:01:34 maxv Exp $	*/
2 
3 /*
4  * Copyright (c) 2009-2020 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by Andrew Doran and Maxime Villard.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29  * POSSIBILITY OF SUCH DAMAGE.
30  */
31 
32 /*
33  * Copyright (c)2006 YAMAMOTO Takashi,
34  * All rights reserved.
35  *
36  * Redistribution and use in source and binary forms, with or without
37  * modification, are permitted provided that the following conditions
38  * are met:
39  * 1. Redistributions of source code must retain the above copyright
40  *    notice, this list of conditions and the following disclaimer.
41  * 2. Redistributions in binary form must reproduce the above copyright
42  *    notice, this list of conditions and the following disclaimer in the
43  *    documentation and/or other materials provided with the distribution.
44  *
45  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
46  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
47  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
48  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
49  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
50  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
51  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
52  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
53  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
54  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
55  * SUCH DAMAGE.
56  */
57 
58 /*
59  * Allocator of kernel wired memory. This allocator has some debug features
60  * enabled with "option DIAGNOSTIC" and "option DEBUG".
61  */
62 
63 /*
64  * KMEM_SIZE: detect alloc/free size mismatch bugs.
65  *	Append to each allocation a fixed-sized footer and record the exact
66  *	user-requested allocation size in it.  When freeing, compare it with
67  *	kmem_free's "size" argument.
68  *
69  * This option is enabled on DIAGNOSTIC.
70  *
71  *  |CHUNK|CHUNK|CHUNK|CHUNK|CHUNK|CHUNK|CHUNK|CHUNK|CHUNK| |
72  *  +-----+-----+-----+-----+-----+-----+-----+-----+-----+-+
73  *  |     |     |     |     |     |     |     |     |/////|U|
74  *  |     |     |     |     |     |     |     |     |/HSZ/|U|
75  *  |     |     |     |     |     |     |     |     |/////|U|
76  *  +-----+-----+-----+-----+-----+-----+-----+-----+-----+-+
77  *  | Buffer usable by the caller (requested size)  |Size |Unused
78  */
79 
80 #include <sys/cdefs.h>
81 __KERNEL_RCSID(0, "$NetBSD: subr_kmem.c,v 1.80 2020/05/14 17:01:34 maxv Exp $");
82 
83 #ifdef _KERNEL_OPT
84 #include "opt_kmem.h"
85 #endif
86 
87 #include <sys/param.h>
88 #include <sys/callback.h>
89 #include <sys/kmem.h>
90 #include <sys/pool.h>
91 #include <sys/debug.h>
92 #include <sys/lockdebug.h>
93 #include <sys/cpu.h>
94 #include <sys/asan.h>
95 #include <sys/msan.h>
96 
97 #include <uvm/uvm_extern.h>
98 #include <uvm/uvm_map.h>
99 
100 #include <lib/libkern/libkern.h>
101 
102 struct kmem_cache_info {
103 	size_t		kc_size;
104 	const char *	kc_name;
105 };
106 
107 static const struct kmem_cache_info kmem_cache_sizes[] = {
108 	{  8, "kmem-00008" },
109 	{ 16, "kmem-00016" },
110 	{ 24, "kmem-00024" },
111 	{ 32, "kmem-00032" },
112 	{ 40, "kmem-00040" },
113 	{ 48, "kmem-00048" },
114 	{ 56, "kmem-00056" },
115 	{ 64, "kmem-00064" },
116 	{ 80, "kmem-00080" },
117 	{ 96, "kmem-00096" },
118 	{ 112, "kmem-00112" },
119 	{ 128, "kmem-00128" },
120 	{ 160, "kmem-00160" },
121 	{ 192, "kmem-00192" },
122 	{ 224, "kmem-00224" },
123 	{ 256, "kmem-00256" },
124 	{ 320, "kmem-00320" },
125 	{ 384, "kmem-00384" },
126 	{ 448, "kmem-00448" },
127 	{ 512, "kmem-00512" },
128 	{ 768, "kmem-00768" },
129 	{ 1024, "kmem-01024" },
130 	{ 0, NULL }
131 };
132 
133 static const struct kmem_cache_info kmem_cache_big_sizes[] = {
134 	{ 2048, "kmem-02048" },
135 	{ 4096, "kmem-04096" },
136 	{ 8192, "kmem-08192" },
137 	{ 16384, "kmem-16384" },
138 	{ 0, NULL }
139 };
140 
141 /*
142  * KMEM_ALIGN is the smallest guaranteed alignment and also the
143  * smallest allocateable quantum.
144  * Every cache size >= CACHE_LINE_SIZE gets CACHE_LINE_SIZE alignment.
145  */
146 #define	KMEM_ALIGN		8
147 #define	KMEM_SHIFT		3
148 #define	KMEM_MAXSIZE		1024
149 #define	KMEM_CACHE_COUNT	(KMEM_MAXSIZE >> KMEM_SHIFT)
150 
151 static pool_cache_t kmem_cache[KMEM_CACHE_COUNT] __cacheline_aligned;
152 static size_t kmem_cache_maxidx __read_mostly;
153 
154 #define	KMEM_BIG_ALIGN		2048
155 #define	KMEM_BIG_SHIFT		11
156 #define	KMEM_BIG_MAXSIZE	16384
157 #define	KMEM_CACHE_BIG_COUNT	(KMEM_BIG_MAXSIZE >> KMEM_BIG_SHIFT)
158 
159 static pool_cache_t kmem_cache_big[KMEM_CACHE_BIG_COUNT] __cacheline_aligned;
160 static size_t kmem_cache_big_maxidx __read_mostly;
161 
162 #if defined(DIAGNOSTIC) && defined(_HARDKERNEL)
163 #define	KMEM_SIZE
164 #endif
165 
166 #if defined(DEBUG) && defined(_HARDKERNEL)
167 static void *kmem_freecheck;
168 #endif
169 
170 #if defined(KMEM_SIZE)
171 #define	SIZE_SIZE	sizeof(size_t)
172 static void kmem_size_set(void *, size_t);
173 static void kmem_size_check(void *, size_t);
174 #else
175 #define	SIZE_SIZE	0
176 #define	kmem_size_set(p, sz)	/* nothing */
177 #define	kmem_size_check(p, sz)	/* nothing */
178 #endif
179 
180 CTASSERT(KM_SLEEP == PR_WAITOK);
181 CTASSERT(KM_NOSLEEP == PR_NOWAIT);
182 
183 /*
184  * kmem_intr_alloc: allocate wired memory.
185  */
186 void *
187 kmem_intr_alloc(size_t requested_size, km_flag_t kmflags)
188 {
189 #ifdef KASAN
190 	const size_t origsize = requested_size;
191 #endif
192 	size_t allocsz, index;
193 	size_t size;
194 	pool_cache_t pc;
195 	uint8_t *p;
196 
197 	KASSERT(requested_size > 0);
198 
199 	KASSERT((kmflags & KM_SLEEP) || (kmflags & KM_NOSLEEP));
200 	KASSERT(!(kmflags & KM_SLEEP) || !(kmflags & KM_NOSLEEP));
201 
202 	kasan_add_redzone(&requested_size);
203 	size = kmem_roundup_size(requested_size);
204 	allocsz = size + SIZE_SIZE;
205 
206 	if ((index = ((allocsz -1) >> KMEM_SHIFT))
207 	    < kmem_cache_maxidx) {
208 		pc = kmem_cache[index];
209 	} else if ((index = ((allocsz - 1) >> KMEM_BIG_SHIFT))
210 	    < kmem_cache_big_maxidx) {
211 		pc = kmem_cache_big[index];
212 	} else {
213 		int ret = uvm_km_kmem_alloc(kmem_va_arena,
214 		    (vsize_t)round_page(size),
215 		    ((kmflags & KM_SLEEP) ? VM_SLEEP : VM_NOSLEEP)
216 		     | VM_INSTANTFIT, (vmem_addr_t *)&p);
217 		if (ret) {
218 			return NULL;
219 		}
220 		FREECHECK_OUT(&kmem_freecheck, p);
221 		return p;
222 	}
223 
224 	p = pool_cache_get(pc, kmflags);
225 
226 	if (__predict_true(p != NULL)) {
227 		FREECHECK_OUT(&kmem_freecheck, p);
228 		kmem_size_set(p, requested_size);
229 		kasan_mark(p, origsize, size, KASAN_KMEM_REDZONE);
230 		return p;
231 	}
232 	return p;
233 }
234 
235 /*
236  * kmem_intr_zalloc: allocate zeroed wired memory.
237  */
238 void *
239 kmem_intr_zalloc(size_t size, km_flag_t kmflags)
240 {
241 	void *p;
242 
243 	p = kmem_intr_alloc(size, kmflags);
244 	if (p != NULL) {
245 		memset(p, 0, size);
246 	}
247 	return p;
248 }
249 
250 /*
251  * kmem_intr_free: free wired memory allocated by kmem_alloc.
252  */
253 void
254 kmem_intr_free(void *p, size_t requested_size)
255 {
256 	size_t allocsz, index;
257 	size_t size;
258 	pool_cache_t pc;
259 
260 	KASSERT(p != NULL);
261 	if (__predict_false(requested_size == 0)) {
262 		panic("%s: zero size with pointer %p", __func__, p);
263 	}
264 
265 	kasan_add_redzone(&requested_size);
266 	size = kmem_roundup_size(requested_size);
267 	allocsz = size + SIZE_SIZE;
268 
269 	if ((index = ((allocsz -1) >> KMEM_SHIFT))
270 	    < kmem_cache_maxidx) {
271 		pc = kmem_cache[index];
272 	} else if ((index = ((allocsz - 1) >> KMEM_BIG_SHIFT))
273 	    < kmem_cache_big_maxidx) {
274 		pc = kmem_cache_big[index];
275 	} else {
276 		FREECHECK_IN(&kmem_freecheck, p);
277 		uvm_km_kmem_free(kmem_va_arena, (vaddr_t)p,
278 		    round_page(size));
279 		return;
280 	}
281 
282 	kasan_mark(p, size, size, 0);
283 
284 	kmem_size_check(p, requested_size);
285 	FREECHECK_IN(&kmem_freecheck, p);
286 	LOCKDEBUG_MEM_CHECK(p, size);
287 
288 	pool_cache_put(pc, p);
289 }
290 
291 /* -------------------------------- Kmem API -------------------------------- */
292 
293 /*
294  * kmem_alloc: allocate wired memory.
295  * => must not be called from interrupt context.
296  */
297 void *
298 kmem_alloc(size_t size, km_flag_t kmflags)
299 {
300 	void *v;
301 
302 	KASSERTMSG((!cpu_intr_p() && !cpu_softintr_p()),
303 	    "kmem(9) should not be used from the interrupt context");
304 	v = kmem_intr_alloc(size, kmflags);
305 	if (__predict_true(v != NULL)) {
306 		kmsan_mark(v, size, KMSAN_STATE_UNINIT);
307 		kmsan_orig(v, size, KMSAN_TYPE_KMEM, __RET_ADDR);
308 	}
309 	KASSERT(v || (kmflags & KM_NOSLEEP) != 0);
310 	return v;
311 }
312 
313 /*
314  * kmem_zalloc: allocate zeroed wired memory.
315  * => must not be called from interrupt context.
316  */
317 void *
318 kmem_zalloc(size_t size, km_flag_t kmflags)
319 {
320 	void *v;
321 
322 	KASSERTMSG((!cpu_intr_p() && !cpu_softintr_p()),
323 	    "kmem(9) should not be used from the interrupt context");
324 	v = kmem_intr_zalloc(size, kmflags);
325 	KASSERT(v || (kmflags & KM_NOSLEEP) != 0);
326 	return v;
327 }
328 
329 /*
330  * kmem_free: free wired memory allocated by kmem_alloc.
331  * => must not be called from interrupt context.
332  */
333 void
334 kmem_free(void *p, size_t size)
335 {
336 	KASSERT(!cpu_intr_p());
337 	KASSERT(!cpu_softintr_p());
338 	kmem_intr_free(p, size);
339 	kmsan_mark(p, size, KMSAN_STATE_INITED);
340 }
341 
342 static size_t
343 kmem_create_caches(const struct kmem_cache_info *array,
344     pool_cache_t alloc_table[], size_t maxsize, int shift, int ipl)
345 {
346 	size_t maxidx = 0;
347 	size_t table_unit = (1 << shift);
348 	size_t size = table_unit;
349 	int i;
350 
351 	for (i = 0; array[i].kc_size != 0 ; i++) {
352 		const char *name = array[i].kc_name;
353 		size_t cache_size = array[i].kc_size;
354 		struct pool_allocator *pa;
355 		int flags = 0;
356 		pool_cache_t pc;
357 		size_t align;
358 
359 		/* check if we reached the requested size */
360 		if (cache_size > maxsize || cache_size > PAGE_SIZE) {
361 			break;
362 		}
363 
364 		/*
365 		 * Exclude caches with size not a factor or multiple of the
366 		 * coherency unit.
367 		 */
368 		if (cache_size < COHERENCY_UNIT) {
369 			if (COHERENCY_UNIT % cache_size > 0) {
370 			    	continue;
371 			}
372 			flags |= PR_NOTOUCH;
373 			align = KMEM_ALIGN;
374 		} else if ((cache_size & (PAGE_SIZE - 1)) == 0) {
375 			align = PAGE_SIZE;
376 		} else {
377 			if ((cache_size % COHERENCY_UNIT) > 0) {
378 				continue;
379 			}
380 			align = COHERENCY_UNIT;
381 		}
382 
383 		if ((cache_size >> shift) > maxidx) {
384 			maxidx = cache_size >> shift;
385 		}
386 
387 		pa = &pool_allocator_kmem;
388 		pc = pool_cache_init(cache_size, align, 0, flags,
389 		    name, pa, ipl, NULL, NULL, NULL);
390 
391 		while (size <= cache_size) {
392 			alloc_table[(size - 1) >> shift] = pc;
393 			size += table_unit;
394 		}
395 	}
396 	return maxidx;
397 }
398 
399 void
400 kmem_init(void)
401 {
402 	kmem_cache_maxidx = kmem_create_caches(kmem_cache_sizes,
403 	    kmem_cache, KMEM_MAXSIZE, KMEM_SHIFT, IPL_VM);
404 	kmem_cache_big_maxidx = kmem_create_caches(kmem_cache_big_sizes,
405 	    kmem_cache_big, PAGE_SIZE, KMEM_BIG_SHIFT, IPL_VM);
406 }
407 
408 size_t
409 kmem_roundup_size(size_t size)
410 {
411 	return (size + (KMEM_ALIGN - 1)) & ~(KMEM_ALIGN - 1);
412 }
413 
414 /*
415  * Used to dynamically allocate string with kmem accordingly to format.
416  */
417 char *
418 kmem_asprintf(const char *fmt, ...)
419 {
420 	int size __diagused, len;
421 	va_list va;
422 	char *str;
423 
424 	va_start(va, fmt);
425 	len = vsnprintf(NULL, 0, fmt, va);
426 	va_end(va);
427 
428 	str = kmem_alloc(len + 1, KM_SLEEP);
429 
430 	va_start(va, fmt);
431 	size = vsnprintf(str, len + 1, fmt, va);
432 	va_end(va);
433 
434 	KASSERT(size == len);
435 
436 	return str;
437 }
438 
439 char *
440 kmem_strdupsize(const char *str, size_t *lenp, km_flag_t flags)
441 {
442 	size_t len = strlen(str) + 1;
443 	char *ptr = kmem_alloc(len, flags);
444 	if (ptr == NULL)
445 		return NULL;
446 
447 	if (lenp)
448 		*lenp = len;
449 	memcpy(ptr, str, len);
450 	return ptr;
451 }
452 
453 char *
454 kmem_strndup(const char *str, size_t maxlen, km_flag_t flags)
455 {
456 	KASSERT(str != NULL);
457 	KASSERT(maxlen != 0);
458 
459 	size_t len = strnlen(str, maxlen);
460 	char *ptr = kmem_alloc(len + 1, flags);
461 	if (ptr == NULL)
462 		return NULL;
463 
464 	memcpy(ptr, str, len);
465 	ptr[len] = '\0';
466 
467 	return ptr;
468 }
469 
470 void
471 kmem_strfree(char *str)
472 {
473 	if (str == NULL)
474 		return;
475 
476 	kmem_free(str, strlen(str) + 1);
477 }
478 
479 /* --------------------------- DEBUG / DIAGNOSTIC --------------------------- */
480 
481 #if defined(KMEM_SIZE)
482 static void
483 kmem_size_set(void *p, size_t sz)
484 {
485 	memcpy((size_t *)((uintptr_t)p + sz), &sz, sizeof(size_t));
486 }
487 
488 static void
489 kmem_size_check(void *p, size_t sz)
490 {
491 	size_t hsz;
492 
493 	memcpy(&hsz, (size_t *)((uintptr_t)p + sz), sizeof(size_t));
494 
495 	if (hsz != sz) {
496 		panic("kmem_free(%p, %zu) != allocated size %zu; overwrote?",
497 		    p, sz, hsz);
498 	}
499 
500 	memset((size_t *)((uintptr_t)p + sz), 0xff, sizeof(size_t));
501 }
502 #endif /* defined(KMEM_SIZE) */
503