1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Remote Processor Framework Elf loader
4 *
5 * Copyright (C) 2011 Texas Instruments, Inc.
6 * Copyright (C) 2011 Google, Inc.
7 *
8 * Ohad Ben-Cohen <ohad@wizery.com>
9 * Brian Swetland <swetland@google.com>
10 * Mark Grosen <mgrosen@ti.com>
11 * Fernando Guzman Lugo <fernando.lugo@ti.com>
12 * Suman Anna <s-anna@ti.com>
13 * Robert Tivy <rtivy@ti.com>
14 * Armando Uribe De Leon <x0095078@ti.com>
15 * Sjur Brændeland <sjur.brandeland@stericsson.com>
16 */
17
18 #define pr_fmt(fmt) "%s: " fmt, __func__
19
20 #include <linux/module.h>
21 #include <linux/firmware.h>
22 #include <linux/remoteproc.h>
23 #include <linux/elf.h>
24
25 #include "remoteproc_internal.h"
26 #include "remoteproc_elf_helpers.h"
27
28 /**
29 * rproc_elf_sanity_check() - Sanity Check for ELF32/ELF64 firmware image
30 * @rproc: the remote processor handle
31 * @fw: the ELF firmware image
32 *
33 * Make sure this fw image is sane (ie a correct ELF32/ELF64 file).
34 */
rproc_elf_sanity_check(struct rproc * rproc,const struct firmware * fw)35 int rproc_elf_sanity_check(struct rproc *rproc, const struct firmware *fw)
36 {
37 const char *name = rproc->firmware;
38 struct device *dev = &rproc->dev;
39 /*
40 * Elf files are beginning with the same structure. Thus, to simplify
41 * header parsing, we can use the elf32_hdr one for both elf64 and
42 * elf32.
43 */
44 struct elf32_hdr *ehdr;
45 u32 elf_shdr_get_size;
46 u64 phoff, shoff;
47 char class;
48 u16 phnum;
49
50 if (!fw) {
51 dev_err(dev, "failed to load %s\n", name);
52 return -EINVAL;
53 }
54
55 if (fw->size < sizeof(struct elf32_hdr)) {
56 dev_err(dev, "Image is too small\n");
57 return -EINVAL;
58 }
59
60 ehdr = (struct elf32_hdr *)fw->data;
61
62 if (memcmp(ehdr->e_ident, ELFMAG, SELFMAG)) {
63 dev_err(dev, "Image is corrupted (bad magic)\n");
64 return -EINVAL;
65 }
66
67 class = ehdr->e_ident[EI_CLASS];
68 if (class != ELFCLASS32 && class != ELFCLASS64) {
69 dev_err(dev, "Unsupported class: %d\n", class);
70 return -EINVAL;
71 }
72
73 if (class == ELFCLASS64 && fw->size < sizeof(struct elf64_hdr)) {
74 dev_err(dev, "elf64 header is too small\n");
75 return -EINVAL;
76 }
77
78 /* We assume the firmware has the same endianness as the host */
79 # ifdef __LITTLE_ENDIAN
80 if (ehdr->e_ident[EI_DATA] != ELFDATA2LSB) {
81 # else /* BIG ENDIAN */
82 if (ehdr->e_ident[EI_DATA] != ELFDATA2MSB) {
83 # endif
84 dev_err(dev, "Unsupported firmware endianness\n");
85 return -EINVAL;
86 }
87
88 phoff = elf_hdr_get_e_phoff(class, fw->data);
89 shoff = elf_hdr_get_e_shoff(class, fw->data);
90 phnum = elf_hdr_get_e_phnum(class, fw->data);
91 elf_shdr_get_size = elf_size_of_shdr(class);
92
93 if (fw->size < shoff + elf_shdr_get_size) {
94 dev_err(dev, "Image is too small\n");
95 return -EINVAL;
96 }
97
98 if (phnum == 0) {
99 dev_err(dev, "No loadable segments\n");
100 return -EINVAL;
101 }
102
103 if (phoff > fw->size) {
104 dev_err(dev, "Firmware size is too small\n");
105 return -EINVAL;
106 }
107
108 dev_dbg(dev, "Firmware is an elf%d file\n",
109 class == ELFCLASS32 ? 32 : 64);
110
111 return 0;
112 }
113 EXPORT_SYMBOL(rproc_elf_sanity_check);
114
115 /**
116 * rproc_elf_get_boot_addr() - Get rproc's boot address.
117 * @rproc: the remote processor handle
118 * @fw: the ELF firmware image
119 *
120 * This function returns the entry point address of the ELF
121 * image.
122 *
123 * Note that the boot address is not a configurable property of all remote
124 * processors. Some will always boot at a specific hard-coded address.
125 */
126 u64 rproc_elf_get_boot_addr(struct rproc *rproc, const struct firmware *fw)
127 {
128 return elf_hdr_get_e_entry(fw_elf_get_class(fw), fw->data);
129 }
130 EXPORT_SYMBOL(rproc_elf_get_boot_addr);
131
132 /**
133 * rproc_elf_load_segments() - load firmware segments to memory
134 * @rproc: remote processor which will be booted using these fw segments
135 * @fw: the ELF firmware image
136 *
137 * This function loads the firmware segments to memory, where the remote
138 * processor expects them.
139 *
140 * Some remote processors will expect their code and data to be placed
141 * in specific device addresses, and can't have them dynamically assigned.
142 *
143 * We currently support only those kind of remote processors, and expect
144 * the program header's paddr member to contain those addresses. We then go
145 * through the physically contiguous "carveout" memory regions which we
146 * allocated (and mapped) earlier on behalf of the remote processor,
147 * and "translate" device address to kernel addresses, so we can copy the
148 * segments where they are expected.
149 *
150 * Currently we only support remote processors that required carveout
151 * allocations and got them mapped onto their iommus. Some processors
152 * might be different: they might not have iommus, and would prefer to
153 * directly allocate memory for every segment/resource. This is not yet
154 * supported, though.
155 */
156 int rproc_elf_load_segments(struct rproc *rproc, const struct firmware *fw)
157 {
158 struct device *dev = &rproc->dev;
159 const void *ehdr, *phdr;
160 int i, ret = 0;
161 u16 phnum;
162 const u8 *elf_data = fw->data;
163 u8 class = fw_elf_get_class(fw);
164 u32 elf_phdr_get_size = elf_size_of_phdr(class);
165
166 ehdr = elf_data;
167 phnum = elf_hdr_get_e_phnum(class, ehdr);
168 phdr = elf_data + elf_hdr_get_e_phoff(class, ehdr);
169
170 /* go through the available ELF segments */
171 for (i = 0; i < phnum; i++, phdr += elf_phdr_get_size) {
172 u64 da = elf_phdr_get_p_paddr(class, phdr);
173 u64 memsz = elf_phdr_get_p_memsz(class, phdr);
174 u64 filesz = elf_phdr_get_p_filesz(class, phdr);
175 u64 offset = elf_phdr_get_p_offset(class, phdr);
176 u32 type = elf_phdr_get_p_type(class, phdr);
177 void *ptr;
178
179 if (type != PT_LOAD)
180 continue;
181
182 dev_dbg(dev, "phdr: type %d da 0x%llx memsz 0x%llx filesz 0x%llx\n",
183 type, da, memsz, filesz);
184
185 if (filesz > memsz) {
186 dev_err(dev, "bad phdr filesz 0x%llx memsz 0x%llx\n",
187 filesz, memsz);
188 ret = -EINVAL;
189 break;
190 }
191
192 if (offset + filesz > fw->size) {
193 dev_err(dev, "truncated fw: need 0x%llx avail 0x%zx\n",
194 offset + filesz, fw->size);
195 ret = -EINVAL;
196 break;
197 }
198
199 if (!rproc_u64_fit_in_size_t(memsz)) {
200 dev_err(dev, "size (%llx) does not fit in size_t type\n",
201 memsz);
202 ret = -EOVERFLOW;
203 break;
204 }
205
206 /* grab the kernel address for this device address */
207 ptr = rproc_da_to_va(rproc, da, memsz);
208 if (!ptr) {
209 dev_err(dev, "bad phdr da 0x%llx mem 0x%llx\n", da,
210 memsz);
211 ret = -EINVAL;
212 break;
213 }
214
215 /* put the segment where the remote processor expects it */
216 if (filesz)
217 memcpy(ptr, elf_data + offset, filesz);
218
219 /*
220 * Zero out remaining memory for this segment.
221 *
222 * This isn't strictly required since dma_alloc_coherent already
223 * did this for us. albeit harmless, we may consider removing
224 * this.
225 */
226 if (memsz > filesz)
227 memset(ptr + filesz, 0, memsz - filesz);
228 }
229
230 return ret;
231 }
232 EXPORT_SYMBOL(rproc_elf_load_segments);
233
234 static const void *
235 find_table(struct device *dev, const struct firmware *fw)
236 {
237 const void *shdr, *name_table_shdr;
238 int i;
239 const char *name_table;
240 struct resource_table *table = NULL;
241 const u8 *elf_data = (void *)fw->data;
242 u8 class = fw_elf_get_class(fw);
243 size_t fw_size = fw->size;
244 const void *ehdr = elf_data;
245 u16 shnum = elf_hdr_get_e_shnum(class, ehdr);
246 u32 elf_shdr_get_size = elf_size_of_shdr(class);
247 u16 shstrndx = elf_hdr_get_e_shstrndx(class, ehdr);
248
249 /* look for the resource table and handle it */
250 /* First, get the section header according to the elf class */
251 shdr = elf_data + elf_hdr_get_e_shoff(class, ehdr);
252 /* Compute name table section header entry in shdr array */
253 name_table_shdr = shdr + (shstrndx * elf_shdr_get_size);
254 /* Finally, compute the name table section address in elf */
255 name_table = elf_data + elf_shdr_get_sh_offset(class, name_table_shdr);
256
257 for (i = 0; i < shnum; i++, shdr += elf_shdr_get_size) {
258 u64 size = elf_shdr_get_sh_size(class, shdr);
259 u64 offset = elf_shdr_get_sh_offset(class, shdr);
260 u32 name = elf_shdr_get_sh_name(class, shdr);
261
262 if (strcmp(name_table + name, ".resource_table"))
263 continue;
264
265 table = (struct resource_table *)(elf_data + offset);
266
267 /* make sure we have the entire table */
268 if (offset + size > fw_size || offset + size < size) {
269 dev_err(dev, "resource table truncated\n");
270 return NULL;
271 }
272
273 /* make sure table has at least the header */
274 if (sizeof(struct resource_table) > size) {
275 dev_err(dev, "header-less resource table\n");
276 return NULL;
277 }
278
279 /* we don't support any version beyond the first */
280 if (table->ver != 1) {
281 dev_err(dev, "unsupported fw ver: %d\n", table->ver);
282 return NULL;
283 }
284
285 /* make sure reserved bytes are zeroes */
286 if (table->reserved[0] || table->reserved[1]) {
287 dev_err(dev, "non zero reserved bytes\n");
288 return NULL;
289 }
290
291 /* make sure the offsets array isn't truncated */
292 if (struct_size(table, offset, table->num) > size) {
293 dev_err(dev, "resource table incomplete\n");
294 return NULL;
295 }
296
297 return shdr;
298 }
299
300 return NULL;
301 }
302
303 /**
304 * rproc_elf_load_rsc_table() - load the resource table
305 * @rproc: the rproc handle
306 * @fw: the ELF firmware image
307 *
308 * This function finds the resource table inside the remote processor's
309 * firmware, load it into the @cached_table and update @table_ptr.
310 *
311 * Return: 0 on success, negative errno on failure.
312 */
313 int rproc_elf_load_rsc_table(struct rproc *rproc, const struct firmware *fw)
314 {
315 const void *shdr;
316 struct device *dev = &rproc->dev;
317 struct resource_table *table = NULL;
318 const u8 *elf_data = fw->data;
319 size_t tablesz;
320 u8 class = fw_elf_get_class(fw);
321 u64 sh_offset;
322
323 shdr = find_table(dev, fw);
324 if (!shdr)
325 return -EINVAL;
326
327 sh_offset = elf_shdr_get_sh_offset(class, shdr);
328 table = (struct resource_table *)(elf_data + sh_offset);
329 tablesz = elf_shdr_get_sh_size(class, shdr);
330
331 /*
332 * Create a copy of the resource table. When a virtio device starts
333 * and calls vring_new_virtqueue() the address of the allocated vring
334 * will be stored in the cached_table. Before the device is started,
335 * cached_table will be copied into device memory.
336 */
337 rproc->cached_table = kmemdup(table, tablesz, GFP_KERNEL);
338 if (!rproc->cached_table)
339 return -ENOMEM;
340
341 rproc->table_ptr = rproc->cached_table;
342 rproc->table_sz = tablesz;
343
344 return 0;
345 }
346 EXPORT_SYMBOL(rproc_elf_load_rsc_table);
347
348 /**
349 * rproc_elf_find_loaded_rsc_table() - find the loaded resource table
350 * @rproc: the rproc handle
351 * @fw: the ELF firmware image
352 *
353 * This function finds the location of the loaded resource table. Don't
354 * call this function if the table wasn't loaded yet - it's a bug if you do.
355 *
356 * Returns the pointer to the resource table if it is found or NULL otherwise.
357 * If the table wasn't loaded yet the result is unspecified.
358 */
359 struct resource_table *rproc_elf_find_loaded_rsc_table(struct rproc *rproc,
360 const struct firmware *fw)
361 {
362 const void *shdr;
363 u64 sh_addr, sh_size;
364 u8 class = fw_elf_get_class(fw);
365 struct device *dev = &rproc->dev;
366
367 shdr = find_table(&rproc->dev, fw);
368 if (!shdr)
369 return NULL;
370
371 sh_addr = elf_shdr_get_sh_addr(class, shdr);
372 sh_size = elf_shdr_get_sh_size(class, shdr);
373
374 if (!rproc_u64_fit_in_size_t(sh_size)) {
375 dev_err(dev, "size (%llx) does not fit in size_t type\n",
376 sh_size);
377 return NULL;
378 }
379
380 return rproc_da_to_va(rproc, sh_addr, sh_size);
381 }
382 EXPORT_SYMBOL(rproc_elf_find_loaded_rsc_table);
383