1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Coredump functionality for Remoteproc framework.
4 *
5 * Copyright (c) 2020, The Linux Foundation. All rights reserved.
6 */
7
8 #include <linux/completion.h>
9 #include <linux/devcoredump.h>
10 #include <linux/device.h>
11 #include <linux/kernel.h>
12 #include <linux/remoteproc.h>
13 #include "remoteproc_internal.h"
14 #include "remoteproc_elf_helpers.h"
15
16 struct rproc_coredump_state {
17 struct rproc *rproc;
18 void *header;
19 struct completion dump_done;
20 };
21
22 /**
23 * rproc_coredump_cleanup() - clean up dump_segments list
24 * @rproc: the remote processor handle
25 */
rproc_coredump_cleanup(struct rproc * rproc)26 void rproc_coredump_cleanup(struct rproc *rproc)
27 {
28 struct rproc_dump_segment *entry, *tmp;
29
30 list_for_each_entry_safe(entry, tmp, &rproc->dump_segments, node) {
31 list_del(&entry->node);
32 kfree(entry);
33 }
34 }
35
36 /**
37 * rproc_coredump_add_segment() - add segment of device memory to coredump
38 * @rproc: handle of a remote processor
39 * @da: device address
40 * @size: size of segment
41 *
42 * Add device memory to the list of segments to be included in a coredump for
43 * the remoteproc.
44 *
45 * Return: 0 on success, negative errno on error.
46 */
rproc_coredump_add_segment(struct rproc * rproc,dma_addr_t da,size_t size)47 int rproc_coredump_add_segment(struct rproc *rproc, dma_addr_t da, size_t size)
48 {
49 struct rproc_dump_segment *segment;
50
51 segment = kzalloc(sizeof(*segment), GFP_KERNEL);
52 if (!segment)
53 return -ENOMEM;
54
55 segment->da = da;
56 segment->size = size;
57
58 list_add_tail(&segment->node, &rproc->dump_segments);
59
60 return 0;
61 }
62 EXPORT_SYMBOL(rproc_coredump_add_segment);
63
64 /**
65 * rproc_coredump_add_custom_segment() - add custom coredump segment
66 * @rproc: handle of a remote processor
67 * @da: device address
68 * @size: size of segment
69 * @dumpfn: custom dump function called for each segment during coredump
70 * @priv: private data
71 *
72 * Add device memory to the list of segments to be included in the coredump
73 * and associate the segment with the given custom dump function and private
74 * data.
75 *
76 * Return: 0 on success, negative errno on error.
77 */
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)78 int rproc_coredump_add_custom_segment(struct rproc *rproc,
79 dma_addr_t da, size_t size,
80 void (*dumpfn)(struct rproc *rproc,
81 struct rproc_dump_segment *segment,
82 void *dest, size_t offset,
83 size_t size),
84 void *priv)
85 {
86 struct rproc_dump_segment *segment;
87
88 segment = kzalloc(sizeof(*segment), GFP_KERNEL);
89 if (!segment)
90 return -ENOMEM;
91
92 segment->da = da;
93 segment->size = size;
94 segment->priv = priv;
95 segment->dump = dumpfn;
96
97 list_add_tail(&segment->node, &rproc->dump_segments);
98
99 return 0;
100 }
101 EXPORT_SYMBOL(rproc_coredump_add_custom_segment);
102
103 /**
104 * rproc_coredump_set_elf_info() - set coredump elf information
105 * @rproc: handle of a remote processor
106 * @class: elf class for coredump elf file
107 * @machine: elf machine for coredump elf file
108 *
109 * Set elf information which will be used for coredump elf file.
110 *
111 * Return: 0 on success, negative errno on error.
112 */
rproc_coredump_set_elf_info(struct rproc * rproc,u8 class,u16 machine)113 int rproc_coredump_set_elf_info(struct rproc *rproc, u8 class, u16 machine)
114 {
115 if (class != ELFCLASS64 && class != ELFCLASS32)
116 return -EINVAL;
117
118 rproc->elf_class = class;
119 rproc->elf_machine = machine;
120
121 return 0;
122 }
123 EXPORT_SYMBOL(rproc_coredump_set_elf_info);
124
rproc_coredump_free(void * data)125 static void rproc_coredump_free(void *data)
126 {
127 struct rproc_coredump_state *dump_state = data;
128
129 vfree(dump_state->header);
130 complete(&dump_state->dump_done);
131 }
132
rproc_coredump_find_segment(loff_t user_offset,struct list_head * segments,size_t * data_left)133 static void *rproc_coredump_find_segment(loff_t user_offset,
134 struct list_head *segments,
135 size_t *data_left)
136 {
137 struct rproc_dump_segment *segment;
138
139 list_for_each_entry(segment, segments, node) {
140 if (user_offset < segment->size) {
141 *data_left = segment->size - user_offset;
142 return segment;
143 }
144 user_offset -= segment->size;
145 }
146
147 *data_left = 0;
148 return NULL;
149 }
150
rproc_copy_segment(struct rproc * rproc,void * dest,struct rproc_dump_segment * segment,size_t offset,size_t size)151 static void rproc_copy_segment(struct rproc *rproc, void *dest,
152 struct rproc_dump_segment *segment,
153 size_t offset, size_t size)
154 {
155 bool is_iomem = false;
156 void *ptr;
157
158 if (segment->dump) {
159 segment->dump(rproc, segment, dest, offset, size);
160 } else {
161 ptr = rproc_da_to_va(rproc, segment->da + offset, size, &is_iomem);
162 if (!ptr) {
163 dev_err(&rproc->dev,
164 "invalid copy request for segment %pad with offset %zu and size %zu)\n",
165 &segment->da, offset, size);
166 memset(dest, 0xff, size);
167 } else {
168 if (is_iomem)
169 memcpy_fromio(dest, (void const __iomem *)ptr, size);
170 else
171 memcpy(dest, ptr, size);
172 }
173 }
174 }
175
rproc_coredump_read(char * buffer,loff_t offset,size_t count,void * data,size_t header_sz)176 static ssize_t rproc_coredump_read(char *buffer, loff_t offset, size_t count,
177 void *data, size_t header_sz)
178 {
179 size_t seg_data, bytes_left = count;
180 ssize_t copy_sz;
181 struct rproc_dump_segment *seg;
182 struct rproc_coredump_state *dump_state = data;
183 struct rproc *rproc = dump_state->rproc;
184 void *elfcore = dump_state->header;
185
186 /* Copy the vmalloc'ed header first. */
187 if (offset < header_sz) {
188 copy_sz = memory_read_from_buffer(buffer, count, &offset,
189 elfcore, header_sz);
190
191 return copy_sz;
192 }
193
194 /*
195 * Find out the segment memory chunk to be copied based on offset.
196 * Keep copying data until count bytes are read.
197 */
198 while (bytes_left) {
199 seg = rproc_coredump_find_segment(offset - header_sz,
200 &rproc->dump_segments,
201 &seg_data);
202 /* EOF check */
203 if (!seg) {
204 dev_info(&rproc->dev, "Ramdump done, %lld bytes read",
205 offset);
206 break;
207 }
208
209 copy_sz = min_t(size_t, bytes_left, seg_data);
210
211 rproc_copy_segment(rproc, buffer, seg, seg->size - seg_data,
212 copy_sz);
213
214 offset += copy_sz;
215 buffer += copy_sz;
216 bytes_left -= copy_sz;
217 }
218
219 return count - bytes_left;
220 }
221
222 /**
223 * rproc_coredump() - perform coredump
224 * @rproc: rproc handle
225 *
226 * This function will generate an ELF header for the registered segments
227 * and create a devcoredump device associated with rproc. Based on the
228 * coredump configuration this function will directly copy the segments
229 * from device memory to userspace or copy segments from device memory to
230 * a separate buffer, which can then be read by userspace.
231 * The first approach avoids using extra vmalloc memory. But it will stall
232 * recovery flow until dump is read by userspace.
233 */
rproc_coredump(struct rproc * rproc)234 void rproc_coredump(struct rproc *rproc)
235 {
236 struct rproc_dump_segment *segment;
237 void *phdr;
238 void *ehdr;
239 size_t data_size;
240 size_t offset;
241 void *data;
242 u8 class = rproc->elf_class;
243 int phnum = 0;
244 struct rproc_coredump_state dump_state;
245 enum rproc_dump_mechanism dump_conf = rproc->dump_conf;
246
247 if (list_empty(&rproc->dump_segments) ||
248 dump_conf == RPROC_COREDUMP_DISABLED)
249 return;
250
251 if (class == ELFCLASSNONE) {
252 dev_err(&rproc->dev, "Elf class is not set\n");
253 return;
254 }
255
256 data_size = elf_size_of_hdr(class);
257 list_for_each_entry(segment, &rproc->dump_segments, node) {
258 /*
259 * For default configuration buffer includes headers & segments.
260 * For inline dump buffer just includes headers as segments are
261 * directly read from device memory.
262 */
263 data_size += elf_size_of_phdr(class);
264 if (dump_conf == RPROC_COREDUMP_ENABLED)
265 data_size += segment->size;
266
267 phnum++;
268 }
269
270 data = vmalloc(data_size);
271 if (!data)
272 return;
273
274 ehdr = data;
275
276 memset(ehdr, 0, elf_size_of_hdr(class));
277 /* e_ident field is common for both elf32 and elf64 */
278 elf_hdr_init_ident(ehdr, class);
279
280 elf_hdr_set_e_type(class, ehdr, ET_CORE);
281 elf_hdr_set_e_machine(class, ehdr, rproc->elf_machine);
282 elf_hdr_set_e_version(class, ehdr, EV_CURRENT);
283 elf_hdr_set_e_entry(class, ehdr, rproc->bootaddr);
284 elf_hdr_set_e_phoff(class, ehdr, elf_size_of_hdr(class));
285 elf_hdr_set_e_ehsize(class, ehdr, elf_size_of_hdr(class));
286 elf_hdr_set_e_phentsize(class, ehdr, elf_size_of_phdr(class));
287 elf_hdr_set_e_phnum(class, ehdr, phnum);
288
289 phdr = data + elf_hdr_get_e_phoff(class, ehdr);
290 offset = elf_hdr_get_e_phoff(class, ehdr);
291 offset += elf_size_of_phdr(class) * elf_hdr_get_e_phnum(class, ehdr);
292
293 list_for_each_entry(segment, &rproc->dump_segments, node) {
294 memset(phdr, 0, elf_size_of_phdr(class));
295 elf_phdr_set_p_type(class, phdr, PT_LOAD);
296 elf_phdr_set_p_offset(class, phdr, offset);
297 elf_phdr_set_p_vaddr(class, phdr, segment->da);
298 elf_phdr_set_p_paddr(class, phdr, segment->da);
299 elf_phdr_set_p_filesz(class, phdr, segment->size);
300 elf_phdr_set_p_memsz(class, phdr, segment->size);
301 elf_phdr_set_p_flags(class, phdr, PF_R | PF_W | PF_X);
302 elf_phdr_set_p_align(class, phdr, 0);
303
304 if (dump_conf == RPROC_COREDUMP_ENABLED)
305 rproc_copy_segment(rproc, data + offset, segment, 0,
306 segment->size);
307
308 offset += elf_phdr_get_p_filesz(class, phdr);
309 phdr += elf_size_of_phdr(class);
310 }
311 if (dump_conf == RPROC_COREDUMP_ENABLED) {
312 dev_coredumpv(&rproc->dev, data, data_size, GFP_KERNEL);
313 return;
314 }
315
316 /* Initialize the dump state struct to be used by rproc_coredump_read */
317 dump_state.rproc = rproc;
318 dump_state.header = data;
319 init_completion(&dump_state.dump_done);
320
321 dev_coredumpm(&rproc->dev, NULL, &dump_state, data_size, GFP_KERNEL,
322 rproc_coredump_read, rproc_coredump_free);
323
324 /*
325 * Wait until the dump is read and free is called. Data is freed
326 * by devcoredump framework automatically after 5 minutes.
327 */
328 wait_for_completion(&dump_state.dump_done);
329 }
330
331 /**
332 * rproc_coredump_using_sections() - perform coredump using section headers
333 * @rproc: rproc handle
334 *
335 * This function will generate an ELF header for the registered sections of
336 * segments and create a devcoredump device associated with rproc. Based on
337 * the coredump configuration this function will directly copy the segments
338 * from device memory to userspace or copy segments from device memory to
339 * a separate buffer, which can then be read by userspace.
340 * The first approach avoids using extra vmalloc memory. But it will stall
341 * recovery flow until dump is read by userspace.
342 */
rproc_coredump_using_sections(struct rproc * rproc)343 void rproc_coredump_using_sections(struct rproc *rproc)
344 {
345 struct rproc_dump_segment *segment;
346 void *shdr;
347 void *ehdr;
348 size_t data_size;
349 size_t strtbl_size = 0;
350 size_t strtbl_index = 1;
351 size_t offset;
352 void *data;
353 u8 class = rproc->elf_class;
354 int shnum;
355 struct rproc_coredump_state dump_state;
356 unsigned int dump_conf = rproc->dump_conf;
357 char *str_tbl = "STR_TBL";
358
359 if (list_empty(&rproc->dump_segments) ||
360 dump_conf == RPROC_COREDUMP_DISABLED)
361 return;
362
363 if (class == ELFCLASSNONE) {
364 dev_err(&rproc->dev, "Elf class is not set\n");
365 return;
366 }
367
368 /*
369 * We allocate two extra section headers. The first one is null.
370 * Second section header is for the string table. Also space is
371 * allocated for string table.
372 */
373 data_size = elf_size_of_hdr(class) + 2 * elf_size_of_shdr(class);
374 shnum = 2;
375
376 /* the extra byte is for the null character at index 0 */
377 strtbl_size += strlen(str_tbl) + 2;
378
379 list_for_each_entry(segment, &rproc->dump_segments, node) {
380 data_size += elf_size_of_shdr(class);
381 strtbl_size += strlen(segment->priv) + 1;
382 if (dump_conf == RPROC_COREDUMP_ENABLED)
383 data_size += segment->size;
384 shnum++;
385 }
386
387 data_size += strtbl_size;
388
389 data = vmalloc(data_size);
390 if (!data)
391 return;
392
393 ehdr = data;
394 memset(ehdr, 0, elf_size_of_hdr(class));
395 /* e_ident field is common for both elf32 and elf64 */
396 elf_hdr_init_ident(ehdr, class);
397
398 elf_hdr_set_e_type(class, ehdr, ET_CORE);
399 elf_hdr_set_e_machine(class, ehdr, rproc->elf_machine);
400 elf_hdr_set_e_version(class, ehdr, EV_CURRENT);
401 elf_hdr_set_e_entry(class, ehdr, rproc->bootaddr);
402 elf_hdr_set_e_shoff(class, ehdr, elf_size_of_hdr(class));
403 elf_hdr_set_e_ehsize(class, ehdr, elf_size_of_hdr(class));
404 elf_hdr_set_e_shentsize(class, ehdr, elf_size_of_shdr(class));
405 elf_hdr_set_e_shnum(class, ehdr, shnum);
406 elf_hdr_set_e_shstrndx(class, ehdr, 1);
407
408 /*
409 * The zeroth index of the section header is reserved and is rarely used.
410 * Set the section header as null (SHN_UNDEF) and move to the next one.
411 */
412 shdr = data + elf_hdr_get_e_shoff(class, ehdr);
413 memset(shdr, 0, elf_size_of_shdr(class));
414 shdr += elf_size_of_shdr(class);
415
416 /* Initialize the string table. */
417 offset = elf_hdr_get_e_shoff(class, ehdr) +
418 elf_size_of_shdr(class) * elf_hdr_get_e_shnum(class, ehdr);
419 memset(data + offset, 0, strtbl_size);
420
421 /* Fill in the string table section header. */
422 memset(shdr, 0, elf_size_of_shdr(class));
423 elf_shdr_set_sh_type(class, shdr, SHT_STRTAB);
424 elf_shdr_set_sh_offset(class, shdr, offset);
425 elf_shdr_set_sh_size(class, shdr, strtbl_size);
426 elf_shdr_set_sh_entsize(class, shdr, 0);
427 elf_shdr_set_sh_flags(class, shdr, 0);
428 elf_shdr_set_sh_name(class, shdr, elf_strtbl_add(str_tbl, ehdr, class, &strtbl_index));
429 offset += elf_shdr_get_sh_size(class, shdr);
430 shdr += elf_size_of_shdr(class);
431
432 list_for_each_entry(segment, &rproc->dump_segments, node) {
433 memset(shdr, 0, elf_size_of_shdr(class));
434 elf_shdr_set_sh_type(class, shdr, SHT_PROGBITS);
435 elf_shdr_set_sh_offset(class, shdr, offset);
436 elf_shdr_set_sh_addr(class, shdr, segment->da);
437 elf_shdr_set_sh_size(class, shdr, segment->size);
438 elf_shdr_set_sh_entsize(class, shdr, 0);
439 elf_shdr_set_sh_flags(class, shdr, SHF_WRITE);
440 elf_shdr_set_sh_name(class, shdr,
441 elf_strtbl_add(segment->priv, ehdr, class, &strtbl_index));
442
443 /* No need to copy segments for inline dumps */
444 if (dump_conf == RPROC_COREDUMP_ENABLED)
445 rproc_copy_segment(rproc, data + offset, segment, 0,
446 segment->size);
447 offset += elf_shdr_get_sh_size(class, shdr);
448 shdr += elf_size_of_shdr(class);
449 }
450
451 if (dump_conf == RPROC_COREDUMP_ENABLED) {
452 dev_coredumpv(&rproc->dev, data, data_size, GFP_KERNEL);
453 return;
454 }
455
456 /* Initialize the dump state struct to be used by rproc_coredump_read */
457 dump_state.rproc = rproc;
458 dump_state.header = data;
459 init_completion(&dump_state.dump_done);
460
461 dev_coredumpm(&rproc->dev, NULL, &dump_state, data_size, GFP_KERNEL,
462 rproc_coredump_read, rproc_coredump_free);
463
464 /* Wait until the dump is read and free is called. Data is freed
465 * by devcoredump framework automatically after 5 minutes.
466 */
467 wait_for_completion(&dump_state.dump_done);
468 }
469 EXPORT_SYMBOL(rproc_coredump_using_sections);
470