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 bool is_iomem = false;
178 void *ptr;
179
180 if (type != PT_LOAD)
181 continue;
182
183 dev_dbg(dev, "phdr: type %d da 0x%llx memsz 0x%llx filesz 0x%llx\n",
184 type, da, memsz, filesz);
185
186 if (filesz > memsz) {
187 dev_err(dev, "bad phdr filesz 0x%llx memsz 0x%llx\n",
188 filesz, memsz);
189 ret = -EINVAL;
190 break;
191 }
192
193 if (offset + filesz > fw->size) {
194 dev_err(dev, "truncated fw: need 0x%llx avail 0x%zx\n",
195 offset + filesz, fw->size);
196 ret = -EINVAL;
197 break;
198 }
199
200 if (!rproc_u64_fit_in_size_t(memsz)) {
201 dev_err(dev, "size (%llx) does not fit in size_t type\n",
202 memsz);
203 ret = -EOVERFLOW;
204 break;
205 }
206
207 /* grab the kernel address for this device address */
208 ptr = rproc_da_to_va(rproc, da, memsz, &is_iomem);
209 if (!ptr) {
210 dev_err(dev, "bad phdr da 0x%llx mem 0x%llx\n", da,
211 memsz);
212 ret = -EINVAL;
213 break;
214 }
215
216 /* put the segment where the remote processor expects it */
217 if (filesz) {
218 if (is_iomem)
219 memcpy_toio((void __iomem *)ptr, elf_data + offset, filesz);
220 else
221 memcpy(ptr, elf_data + offset, filesz);
222 }
223
224 /*
225 * Zero out remaining memory for this segment.
226 *
227 * This isn't strictly required since dma_alloc_coherent already
228 * did this for us. albeit harmless, we may consider removing
229 * this.
230 */
231 if (memsz > filesz) {
232 if (is_iomem)
233 memset_io((void __iomem *)(ptr + filesz), 0, memsz - filesz);
234 else
235 memset(ptr + filesz, 0, memsz - filesz);
236 }
237 }
238
239 return ret;
240 }
241 EXPORT_SYMBOL(rproc_elf_load_segments);
242
243 static const void *
244 find_table(struct device *dev, const struct firmware *fw)
245 {
246 const void *shdr, *name_table_shdr;
247 int i;
248 const char *name_table;
249 struct resource_table *table = NULL;
250 const u8 *elf_data = (void *)fw->data;
251 u8 class = fw_elf_get_class(fw);
252 size_t fw_size = fw->size;
253 const void *ehdr = elf_data;
254 u16 shnum = elf_hdr_get_e_shnum(class, ehdr);
255 u32 elf_shdr_get_size = elf_size_of_shdr(class);
256 u16 shstrndx = elf_hdr_get_e_shstrndx(class, ehdr);
257
258 /* look for the resource table and handle it */
259 /* First, get the section header according to the elf class */
260 shdr = elf_data + elf_hdr_get_e_shoff(class, ehdr);
261 /* Compute name table section header entry in shdr array */
262 name_table_shdr = shdr + (shstrndx * elf_shdr_get_size);
263 /* Finally, compute the name table section address in elf */
264 name_table = elf_data + elf_shdr_get_sh_offset(class, name_table_shdr);
265
266 for (i = 0; i < shnum; i++, shdr += elf_shdr_get_size) {
267 u64 size = elf_shdr_get_sh_size(class, shdr);
268 u64 offset = elf_shdr_get_sh_offset(class, shdr);
269 u32 name = elf_shdr_get_sh_name(class, shdr);
270
271 if (strcmp(name_table + name, ".resource_table"))
272 continue;
273
274 table = (struct resource_table *)(elf_data + offset);
275
276 /* make sure we have the entire table */
277 if (offset + size > fw_size || offset + size < size) {
278 dev_err(dev, "resource table truncated\n");
279 return NULL;
280 }
281
282 /* make sure table has at least the header */
283 if (sizeof(struct resource_table) > size) {
284 dev_err(dev, "header-less resource table\n");
285 return NULL;
286 }
287
288 /* we don't support any version beyond the first */
289 if (table->ver != 1) {
290 dev_err(dev, "unsupported fw ver: %d\n", table->ver);
291 return NULL;
292 }
293
294 /* make sure reserved bytes are zeroes */
295 if (table->reserved[0] || table->reserved[1]) {
296 dev_err(dev, "non zero reserved bytes\n");
297 return NULL;
298 }
299
300 /* make sure the offsets array isn't truncated */
301 if (struct_size(table, offset, table->num) > size) {
302 dev_err(dev, "resource table incomplete\n");
303 return NULL;
304 }
305
306 return shdr;
307 }
308
309 return NULL;
310 }
311
312 /**
313 * rproc_elf_load_rsc_table() - load the resource table
314 * @rproc: the rproc handle
315 * @fw: the ELF firmware image
316 *
317 * This function finds the resource table inside the remote processor's
318 * firmware, load it into the @cached_table and update @table_ptr.
319 *
320 * Return: 0 on success, negative errno on failure.
321 */
322 int rproc_elf_load_rsc_table(struct rproc *rproc, const struct firmware *fw)
323 {
324 const void *shdr;
325 struct device *dev = &rproc->dev;
326 struct resource_table *table = NULL;
327 const u8 *elf_data = fw->data;
328 size_t tablesz;
329 u8 class = fw_elf_get_class(fw);
330 u64 sh_offset;
331
332 shdr = find_table(dev, fw);
333 if (!shdr)
334 return -EINVAL;
335
336 sh_offset = elf_shdr_get_sh_offset(class, shdr);
337 table = (struct resource_table *)(elf_data + sh_offset);
338 tablesz = elf_shdr_get_sh_size(class, shdr);
339
340 /*
341 * Create a copy of the resource table. When a virtio device starts
342 * and calls vring_new_virtqueue() the address of the allocated vring
343 * will be stored in the cached_table. Before the device is started,
344 * cached_table will be copied into device memory.
345 */
346 rproc->cached_table = kmemdup(table, tablesz, GFP_KERNEL);
347 if (!rproc->cached_table)
348 return -ENOMEM;
349
350 rproc->table_ptr = rproc->cached_table;
351 rproc->table_sz = tablesz;
352
353 return 0;
354 }
355 EXPORT_SYMBOL(rproc_elf_load_rsc_table);
356
357 /**
358 * rproc_elf_find_loaded_rsc_table() - find the loaded resource table
359 * @rproc: the rproc handle
360 * @fw: the ELF firmware image
361 *
362 * This function finds the location of the loaded resource table. Don't
363 * call this function if the table wasn't loaded yet - it's a bug if you do.
364 *
365 * Returns the pointer to the resource table if it is found or NULL otherwise.
366 * If the table wasn't loaded yet the result is unspecified.
367 */
368 struct resource_table *rproc_elf_find_loaded_rsc_table(struct rproc *rproc,
369 const struct firmware *fw)
370 {
371 const void *shdr;
372 u64 sh_addr, sh_size;
373 u8 class = fw_elf_get_class(fw);
374 struct device *dev = &rproc->dev;
375
376 shdr = find_table(&rproc->dev, fw);
377 if (!shdr)
378 return NULL;
379
380 sh_addr = elf_shdr_get_sh_addr(class, shdr);
381 sh_size = elf_shdr_get_sh_size(class, shdr);
382
383 if (!rproc_u64_fit_in_size_t(sh_size)) {
384 dev_err(dev, "size (%llx) does not fit in size_t type\n",
385 sh_size);
386 return NULL;
387 }
388
389 return rproc_da_to_va(rproc, sh_addr, sh_size, NULL);
390 }
391 EXPORT_SYMBOL(rproc_elf_find_loaded_rsc_table);
392