summaryrefslogtreecommitdiff
path: root/drivers/remoteproc/remoteproc_coredump.c
blob: 6ede8c0c93ad5a6e1c572aeb49c97174df2815c4 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
// SPDX-License-Identifier: GPL-2.0-only
/*
 * Coredump functionality for Remoteproc framework.
 *
 * Copyright (c) 2020, The Linux Foundation. All rights reserved.
 */

#include <linux/completion.h>
#include <linux/devcoredump.h>
#include <linux/device.h>
#include <linux/kernel.h>
#include <linux/remoteproc.h>
#include "remoteproc_internal.h"
#include "remoteproc_elf_helpers.h"

struct rproc_coredump_state {
	struct rproc *rproc;
	void *header;
	struct completion dump_done;
};

/**
 * rproc_coredump_cleanup() - clean up dump_segments list
 * @rproc: the remote processor handle
 */
void rproc_coredump_cleanup(struct rproc *rproc)
{
	struct rproc_dump_segment *entry, *tmp;

	list_for_each_entry_safe(entry, tmp, &rproc->dump_segments, node) {
		list_del(&entry->node);
		kfree(entry);
	}
}
EXPORT_SYMBOL_GPL(rproc_coredump_cleanup);

/**
 * rproc_coredump_add_segment() - add segment of device memory to coredump
 * @rproc:	handle of a remote processor
 * @da:		device address
 * @size:	size of segment
 *
 * Add device memory to the list of segments to be included in a coredump for
 * the remoteproc.
 *
 * Return: 0 on success, negative errno on error.
 */
int rproc_coredump_add_segment(struct rproc *rproc, dma_addr_t da, size_t size)
{
	struct rproc_dump_segment *segment;

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

	segment->da = da;
	segment->size = size;

	list_add_tail(&segment->node, &rproc->dump_segments);

	return 0;
}
EXPORT_SYMBOL(rproc_coredump_add_segment);

/**
 * rproc_coredump_add_custom_segment() - add custom coredump segment
 * @rproc:	handle of a remote processor
 * @da:		device address
 * @size:	size of segment
 * @dumpfn:	custom dump function called for each segment during coredump
 * @priv:	private data
 *
 * Add device memory to the list of segments to be included in the coredump
 * and associate the segment with the given custom dump function and private
 * data.
 *
 * Return: 0 on success, negative errno on error.
 */
int rproc_coredump_add_custom_segment(struct rproc *rproc,
				      dma_addr_t da, size_t size,
				      void (*dumpfn)(struct rproc *rproc,
						     struct rproc_dump_segment *segment,
						     void *dest, size_t offset,
						     size_t size),
				      void *priv)
{
	struct rproc_dump_segment *segment;

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

	segment->da = da;
	segment->size = size;
	segment->priv = priv;
	segment->dump = dumpfn;

	list_add_tail(&segment->node, &rproc->dump_segments);

	return 0;
}
EXPORT_SYMBOL(rproc_coredump_add_custom_segment);

/**
 * rproc_coredump_set_elf_info() - set coredump elf information
 * @rproc:	handle of a remote processor
 * @class:	elf class for coredump elf file
 * @machine:	elf machine for coredump elf file
 *
 * Set elf information which will be used for coredump elf file.
 *
 * Return: 0 on success, negative errno on error.
 */
int rproc_coredump_set_elf_info(struct rproc *rproc, u8 class, u16 machine)
{
	if (class != ELFCLASS64 && class != ELFCLASS32)
		return -EINVAL;

	rproc->elf_class = class;
	rproc->elf_machine = machine;

	return 0;
}
EXPORT_SYMBOL(rproc_coredump_set_elf_info);

static void rproc_coredump_free(void *data)
{
	struct rproc_coredump_state *dump_state = data;

	vfree(dump_state->header);
	complete(&dump_state->dump_done);
}

static void *rproc_coredump_find_segment(loff_t user_offset,
					 struct list_head *segments,
					 size_t *data_left)
{
	struct rproc_dump_segment *segment;

	list_for_each_entry(segment, segments, node) {
		if (user_offset < segment->size) {
			*data_left = segment->size - user_offset;
			return segment;
		}
		user_offset -= segment->size;
	}

	*data_left = 0;
	return NULL;
}

static void rproc_copy_segment(struct rproc *rproc, void *dest,
			       struct rproc_dump_segment *segment,
			       size_t offset, size_t size)
{
	bool is_iomem = false;
	void *ptr;

	if (segment->dump) {
		segment->dump(rproc, segment, dest, offset, size);
	} else {
		ptr = rproc_da_to_va(rproc, segment->da + offset, size, &is_iomem);
		if (!ptr) {
			dev_err(&rproc->dev,
				"invalid copy request for segment %pad with offset %zu and size %zu)\n",
				&segment->da, offset, size);
			memset(dest, 0xff, size);
		} else {
			if (is_iomem)
				memcpy_fromio(dest, (void const __iomem *)ptr, size);
			else
				memcpy(dest, ptr, size);
		}
	}
}

static ssize_t rproc_coredump_read(char *buffer, loff_t offset, size_t count,
				   void *data, size_t header_sz)
{
	size_t seg_data, bytes_left = count;
	ssize_t copy_sz;
	struct rproc_dump_segment *seg;
	struct rproc_coredump_state *dump_state = data;
	struct rproc *rproc = dump_state->rproc;
	void *elfcore = dump_state->header;

	/* Copy the vmalloc'ed header first. */
	if (offset < header_sz) {
		copy_sz = memory_read_from_buffer(buffer, count, &offset,
						  elfcore, header_sz);

		return copy_sz;
	}

	/*
	 * Find out the segment memory chunk to be copied based on offset.
	 * Keep copying data until count bytes are read.
	 */
	while (bytes_left) {
		seg = rproc_coredump_find_segment(offset - header_sz,
						  &rproc->dump_segments,
						  &seg_data);
		/* EOF check */
		if (!seg) {
			dev_info(&rproc->dev, "Ramdump done, %lld bytes read",
				 offset);
			break;
		}

		copy_sz = min_t(size_t, bytes_left, seg_data);

		rproc_copy_segment(rproc, buffer, seg, seg->size - seg_data,
				   copy_sz);

		offset += copy_sz;
		buffer += copy_sz;
		bytes_left -= copy_sz;
	}

	return count - bytes_left;
}

/**
 * rproc_coredump() - perform coredump
 * @rproc:	rproc handle
 *
 * This function will generate an ELF header for the registered segments
 * and create a devcoredump device associated with rproc. Based on the
 * coredump configuration this function will directly copy the segments
 * from device memory to userspace or copy segments from device memory to
 * a separate buffer, which can then be read by userspace.
 * The first approach avoids using extra vmalloc memory. But it will stall
 * recovery flow until dump is read by userspace.
 */
void rproc_coredump(struct rproc *rproc)
{
	struct rproc_dump_segment *segment;
	void *phdr;
	void *ehdr;
	size_t data_size;
	size_t offset;
	void *data;
	u8 class = rproc->elf_class;
	int phnum = 0;
	struct rproc_coredump_state dump_state;
	enum rproc_dump_mechanism dump_conf = rproc->dump_conf;

	if (list_empty(&rproc->dump_segments) ||
	    dump_conf == RPROC_COREDUMP_DISABLED)
		return;

	if (class == ELFCLASSNONE) {
		dev_err(&rproc->dev, "ELF class is not set\n");
		return;
	}

	data_size = elf_size_of_hdr(class);
	list_for_each_entry(segment, &rproc->dump_segments, node) {
		/*
		 * For default configuration buffer includes headers & segments.
		 * For inline dump buffer just includes headers as segments are
		 * directly read from device memory.
		 */
		data_size += elf_size_of_phdr(class);
		if (dump_conf == RPROC_COREDUMP_ENABLED)
			data_size += segment->size;

		phnum++;
	}

	data = vmalloc(data_size);
	if (!data)
		return;

	ehdr = data;

	memset(ehdr, 0, elf_size_of_hdr(class));
	/* e_ident field is common for both elf32 and elf64 */
	elf_hdr_init_ident(ehdr, class);

	elf_hdr_set_e_type(class, ehdr, ET_CORE);
	elf_hdr_set_e_machine(class, ehdr, rproc->elf_machine);
	elf_hdr_set_e_version(class, ehdr, EV_CURRENT);
	elf_hdr_set_e_entry(class, ehdr, rproc->bootaddr);
	elf_hdr_set_e_phoff(class, ehdr, elf_size_of_hdr(class));
	elf_hdr_set_e_ehsize(class, ehdr, elf_size_of_hdr(class));
	elf_hdr_set_e_phentsize(class, ehdr, elf_size_of_phdr(class));
	elf_hdr_set_e_phnum(class, ehdr, phnum);

	phdr = data + elf_hdr_get_e_phoff(class, ehdr);
	offset = elf_hdr_get_e_phoff(class, ehdr);
	offset += elf_size_of_phdr(class) * elf_hdr_get_e_phnum(class, ehdr);

	list_for_each_entry(segment, &rproc->dump_segments, node) {
		memset(phdr, 0, elf_size_of_phdr(class));
		elf_phdr_set_p_type(class, phdr, PT_LOAD);
		elf_phdr_set_p_offset(class, phdr, offset);
		elf_phdr_set_p_vaddr(class, phdr, segment->da);
		elf_phdr_set_p_paddr(class, phdr, segment->da);
		elf_phdr_set_p_filesz(class, phdr, segment->size);
		elf_phdr_set_p_memsz(class, phdr, segment->size);
		elf_phdr_set_p_flags(class, phdr, PF_R | PF_W | PF_X);
		elf_phdr_set_p_align(class, phdr, 0);

		if (dump_conf == RPROC_COREDUMP_ENABLED)
			rproc_copy_segment(rproc, data + offset, segment, 0,
					   segment->size);

		offset += elf_phdr_get_p_filesz(class, phdr);
		phdr += elf_size_of_phdr(class);
	}
	if (dump_conf == RPROC_COREDUMP_ENABLED) {
		dev_coredumpv(&rproc->dev, data, data_size, GFP_KERNEL);
		return;
	}

	/* Initialize the dump state struct to be used by rproc_coredump_read */
	dump_state.rproc = rproc;
	dump_state.header = data;
	init_completion(&dump_state.dump_done);

	dev_coredumpm(&rproc->dev, NULL, &dump_state, data_size, GFP_KERNEL,
		      rproc_coredump_read, rproc_coredump_free);

	/*
	 * Wait until the dump is read and free is called. Data is freed
	 * by devcoredump framework automatically after 5 minutes.
	 */
	wait_for_completion(&dump_state.dump_done);
}
EXPORT_SYMBOL_GPL(rproc_coredump);

/**
 * rproc_coredump_using_sections() - perform coredump using section headers
 * @rproc:	rproc handle
 *
 * This function will generate an ELF header for the registered sections of
 * segments and create a devcoredump device associated with rproc. Based on
 * the coredump configuration this function will directly copy the segments
 * from device memory to userspace or copy segments from device memory to
 * a separate buffer, which can then be read by userspace.
 * The first approach avoids using extra vmalloc memory. But it will stall
 * recovery flow until dump is read by userspace.
 */
void rproc_coredump_using_sections(struct rproc *rproc)
{
	struct rproc_dump_segment *segment;
	void *shdr;
	void *ehdr;
	size_t data_size;
	size_t strtbl_size = 0;
	size_t strtbl_index = 1;
	size_t offset;
	void *data;
	u8 class = rproc->elf_class;
	int shnum;
	struct rproc_coredump_state dump_state;
	unsigned int dump_conf = rproc->dump_conf;
	char *str_tbl = "STR_TBL";

	if (list_empty(&rproc->dump_segments) ||
	    dump_conf == RPROC_COREDUMP_DISABLED)
		return;

	if (class == ELFCLASSNONE) {
		dev_err(&rproc->dev, "ELF class is not set\n");
		return;
	}

	/*
	 * We allocate two extra section headers. The first one is null.
	 * Second section header is for the string table. Also space is
	 * allocated for string table.
	 */
	data_size = elf_size_of_hdr(class) + 2 * elf_size_of_shdr(class);
	shnum = 2;

	/* the extra byte is for the null character at index 0 */
	strtbl_size += strlen(str_tbl) + 2;

	list_for_each_entry(segment, &rproc->dump_segments, node) {
		data_size += elf_size_of_shdr(class);
		strtbl_size += strlen(segment->priv) + 1;
		if (dump_conf == RPROC_COREDUMP_ENABLED)
			data_size += segment->size;
		shnum++;
	}

	data_size += strtbl_size;

	data = vmalloc(data_size);
	if (!data)
		return;

	ehdr = data;
	memset(ehdr, 0, elf_size_of_hdr(class));
	/* e_ident field is common for both elf32 and elf64 */
	elf_hdr_init_ident(ehdr, class);

	elf_hdr_set_e_type(class, ehdr, ET_CORE);
	elf_hdr_set_e_machine(class, ehdr, rproc->elf_machine);
	elf_hdr_set_e_version(class, ehdr, EV_CURRENT);
	elf_hdr_set_e_entry(class, ehdr, rproc->bootaddr);
	elf_hdr_set_e_shoff(class, ehdr, elf_size_of_hdr(class));
	elf_hdr_set_e_ehsize(class, ehdr, elf_size_of_hdr(class));
	elf_hdr_set_e_shentsize(class, ehdr, elf_size_of_shdr(class));
	elf_hdr_set_e_shnum(class, ehdr, shnum);
	elf_hdr_set_e_shstrndx(class, ehdr, 1);

	/*
	 * The zeroth index of the section header is reserved and is rarely used.
	 * Set the section header as null (SHN_UNDEF) and move to the next one.
	 */
	shdr = data + elf_hdr_get_e_shoff(class, ehdr);
	memset(shdr, 0, elf_size_of_shdr(class));
	shdr += elf_size_of_shdr(class);

	/* Initialize the string table. */
	offset = elf_hdr_get_e_shoff(class, ehdr) +
		 elf_size_of_shdr(class) * elf_hdr_get_e_shnum(class, ehdr);
	memset(data + offset, 0, strtbl_size);

	/* Fill in the string table section header. */
	memset(shdr, 0, elf_size_of_shdr(class));
	elf_shdr_set_sh_type(class, shdr, SHT_STRTAB);
	elf_shdr_set_sh_offset(class, shdr, offset);
	elf_shdr_set_sh_size(class, shdr, strtbl_size);
	elf_shdr_set_sh_entsize(class, shdr, 0);
	elf_shdr_set_sh_flags(class, shdr, 0);
	elf_shdr_set_sh_name(class, shdr, elf_strtbl_add(str_tbl, ehdr, class, &strtbl_index));
	offset += elf_shdr_get_sh_size(class, shdr);
	shdr += elf_size_of_shdr(class);

	list_for_each_entry(segment, &rproc->dump_segments, node) {
		memset(shdr, 0, elf_size_of_shdr(class));
		elf_shdr_set_sh_type(class, shdr, SHT_PROGBITS);
		elf_shdr_set_sh_offset(class, shdr, offset);
		elf_shdr_set_sh_addr(class, shdr, segment->da);
		elf_shdr_set_sh_size(class, shdr, segment->size);
		elf_shdr_set_sh_entsize(class, shdr, 0);
		elf_shdr_set_sh_flags(class, shdr, SHF_WRITE);
		elf_shdr_set_sh_name(class, shdr,
				     elf_strtbl_add(segment->priv, ehdr, class, &strtbl_index));

		/* No need to copy segments for inline dumps */
		if (dump_conf == RPROC_COREDUMP_ENABLED)
			rproc_copy_segment(rproc, data + offset, segment, 0,
					   segment->size);
		offset += elf_shdr_get_sh_size(class, shdr);
		shdr += elf_size_of_shdr(class);
	}

	if (dump_conf == RPROC_COREDUMP_ENABLED) {
		dev_coredumpv(&rproc->dev, data, data_size, GFP_KERNEL);
		return;
	}

	/* Initialize the dump state struct to be used by rproc_coredump_read */
	dump_state.rproc = rproc;
	dump_state.header = data;
	init_completion(&dump_state.dump_done);

	dev_coredumpm(&rproc->dev, NULL, &dump_state, data_size, GFP_KERNEL,
		      rproc_coredump_read, rproc_coredump_free);

	/* Wait until the dump is read and free is called. Data is freed
	 * by devcoredump framework automatically after 5 minutes.
	 */
	wait_for_completion(&dump_state.dump_done);
}
EXPORT_SYMBOL(rproc_coredump_using_sections);