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 void *ptr;
156
157 if (segment->dump) {
158 segment->dump(rproc, segment, dest, offset, size);
159 } else {
160 ptr = rproc_da_to_va(rproc, segment->da + offset, size);
161 if (!ptr) {
162 dev_err(&rproc->dev,
163 "invalid copy request for segment %pad with offset %zu and size %zu)\n",
164 &segment->da, offset, size);
165 memset(dest, 0xff, size);
166 } else {
167 memcpy(dest, ptr, size);
168 }
169 }
170 }
171
rproc_coredump_read(char * buffer,loff_t offset,size_t count,void * data,size_t header_sz)172 static ssize_t rproc_coredump_read(char *buffer, loff_t offset, size_t count,
173 void *data, size_t header_sz)
174 {
175 size_t seg_data, bytes_left = count;
176 ssize_t copy_sz;
177 struct rproc_dump_segment *seg;
178 struct rproc_coredump_state *dump_state = data;
179 struct rproc *rproc = dump_state->rproc;
180 void *elfcore = dump_state->header;
181
182 /* Copy the vmalloc'ed header first. */
183 if (offset < header_sz) {
184 copy_sz = memory_read_from_buffer(buffer, count, &offset,
185 elfcore, header_sz);
186
187 return copy_sz;
188 }
189
190 /*
191 * Find out the segment memory chunk to be copied based on offset.
192 * Keep copying data until count bytes are read.
193 */
194 while (bytes_left) {
195 seg = rproc_coredump_find_segment(offset - header_sz,
196 &rproc->dump_segments,
197 &seg_data);
198 /* EOF check */
199 if (!seg) {
200 dev_info(&rproc->dev, "Ramdump done, %lld bytes read",
201 offset);
202 break;
203 }
204
205 copy_sz = min_t(size_t, bytes_left, seg_data);
206
207 rproc_copy_segment(rproc, buffer, seg, seg->size - seg_data,
208 copy_sz);
209
210 offset += copy_sz;
211 buffer += copy_sz;
212 bytes_left -= copy_sz;
213 }
214
215 return count - bytes_left;
216 }
217
218 /**
219 * rproc_coredump() - perform coredump
220 * @rproc: rproc handle
221 *
222 * This function will generate an ELF header for the registered segments
223 * and create a devcoredump device associated with rproc. Based on the
224 * coredump configuration this function will directly copy the segments
225 * from device memory to userspace or copy segments from device memory to
226 * a separate buffer, which can then be read by userspace.
227 * The first approach avoids using extra vmalloc memory. But it will stall
228 * recovery flow until dump is read by userspace.
229 */
rproc_coredump(struct rproc * rproc)230 void rproc_coredump(struct rproc *rproc)
231 {
232 struct rproc_dump_segment *segment;
233 void *phdr;
234 void *ehdr;
235 size_t data_size;
236 size_t offset;
237 void *data;
238 u8 class = rproc->elf_class;
239 int phnum = 0;
240 struct rproc_coredump_state dump_state;
241 enum rproc_dump_mechanism dump_conf = rproc->dump_conf;
242
243 if (list_empty(&rproc->dump_segments) ||
244 dump_conf == RPROC_COREDUMP_DISABLED)
245 return;
246
247 if (class == ELFCLASSNONE) {
248 dev_err(&rproc->dev, "Elf class is not set\n");
249 return;
250 }
251
252 data_size = elf_size_of_hdr(class);
253 list_for_each_entry(segment, &rproc->dump_segments, node) {
254 /*
255 * For default configuration buffer includes headers & segments.
256 * For inline dump buffer just includes headers as segments are
257 * directly read from device memory.
258 */
259 data_size += elf_size_of_phdr(class);
260 if (dump_conf == RPROC_COREDUMP_ENABLED)
261 data_size += segment->size;
262
263 phnum++;
264 }
265
266 data = vmalloc(data_size);
267 if (!data)
268 return;
269
270 ehdr = data;
271
272 memset(ehdr, 0, elf_size_of_hdr(class));
273 /* e_ident field is common for both elf32 and elf64 */
274 elf_hdr_init_ident(ehdr, class);
275
276 elf_hdr_set_e_type(class, ehdr, ET_CORE);
277 elf_hdr_set_e_machine(class, ehdr, rproc->elf_machine);
278 elf_hdr_set_e_version(class, ehdr, EV_CURRENT);
279 elf_hdr_set_e_entry(class, ehdr, rproc->bootaddr);
280 elf_hdr_set_e_phoff(class, ehdr, elf_size_of_hdr(class));
281 elf_hdr_set_e_ehsize(class, ehdr, elf_size_of_hdr(class));
282 elf_hdr_set_e_phentsize(class, ehdr, elf_size_of_phdr(class));
283 elf_hdr_set_e_phnum(class, ehdr, phnum);
284
285 phdr = data + elf_hdr_get_e_phoff(class, ehdr);
286 offset = elf_hdr_get_e_phoff(class, ehdr);
287 offset += elf_size_of_phdr(class) * elf_hdr_get_e_phnum(class, ehdr);
288
289 list_for_each_entry(segment, &rproc->dump_segments, node) {
290 memset(phdr, 0, elf_size_of_phdr(class));
291 elf_phdr_set_p_type(class, phdr, PT_LOAD);
292 elf_phdr_set_p_offset(class, phdr, offset);
293 elf_phdr_set_p_vaddr(class, phdr, segment->da);
294 elf_phdr_set_p_paddr(class, phdr, segment->da);
295 elf_phdr_set_p_filesz(class, phdr, segment->size);
296 elf_phdr_set_p_memsz(class, phdr, segment->size);
297 elf_phdr_set_p_flags(class, phdr, PF_R | PF_W | PF_X);
298 elf_phdr_set_p_align(class, phdr, 0);
299
300 if (dump_conf == RPROC_COREDUMP_ENABLED)
301 rproc_copy_segment(rproc, data + offset, segment, 0,
302 segment->size);
303
304 offset += elf_phdr_get_p_filesz(class, phdr);
305 phdr += elf_size_of_phdr(class);
306 }
307 if (dump_conf == RPROC_COREDUMP_ENABLED) {
308 dev_coredumpv(&rproc->dev, data, data_size, GFP_KERNEL);
309 return;
310 }
311
312 /* Initialize the dump state struct to be used by rproc_coredump_read */
313 dump_state.rproc = rproc;
314 dump_state.header = data;
315 init_completion(&dump_state.dump_done);
316
317 dev_coredumpm(&rproc->dev, NULL, &dump_state, data_size, GFP_KERNEL,
318 rproc_coredump_read, rproc_coredump_free);
319
320 /*
321 * Wait until the dump is read and free is called. Data is freed
322 * by devcoredump framework automatically after 5 minutes.
323 */
324 wait_for_completion(&dump_state.dump_done);
325 }
326