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 *
35 * Return: 0 on success and -EINVAL upon any failure
36 */
rproc_elf_sanity_check(struct rproc * rproc,const struct firmware * fw)37 int rproc_elf_sanity_check(struct rproc *rproc, const struct firmware *fw)
38 {
39 const char *name = rproc->firmware;
40 struct device *dev = &rproc->dev;
41 /*
42 * Elf files are beginning with the same structure. Thus, to simplify
43 * header parsing, we can use the elf32_hdr one for both elf64 and
44 * elf32.
45 */
46 struct elf32_hdr *ehdr;
47 u32 elf_shdr_get_size;
48 u64 phoff, shoff;
49 char class;
50 u16 phnum;
51
52 if (!fw) {
53 dev_err(dev, "failed to load %s\n", name);
54 return -EINVAL;
55 }
56
57 if (fw->size < sizeof(struct elf32_hdr)) {
58 dev_err(dev, "Image is too small\n");
59 return -EINVAL;
60 }
61
62 ehdr = (struct elf32_hdr *)fw->data;
63
64 if (memcmp(ehdr->e_ident, ELFMAG, SELFMAG)) {
65 dev_err(dev, "Image is corrupted (bad magic)\n");
66 return -EINVAL;
67 }
68
69 class = ehdr->e_ident[EI_CLASS];
70 if (class != ELFCLASS32 && class != ELFCLASS64) {
71 dev_err(dev, "Unsupported class: %d\n", class);
72 return -EINVAL;
73 }
74
75 if (class == ELFCLASS64 && fw->size < sizeof(struct elf64_hdr)) {
76 dev_err(dev, "elf64 header is too small\n");
77 return -EINVAL;
78 }
79
80 /* We assume the firmware has the same endianness as the host */
81 # ifdef __LITTLE_ENDIAN
82 if (ehdr->e_ident[EI_DATA] != ELFDATA2LSB) {
83 # else /* BIG ENDIAN */
84 if (ehdr->e_ident[EI_DATA] != ELFDATA2MSB) {
85 # endif
86 dev_err(dev, "Unsupported firmware endianness\n");
87 return -EINVAL;
88 }
89
90 phoff = elf_hdr_get_e_phoff(class, fw->data);
91 shoff = elf_hdr_get_e_shoff(class, fw->data);
92 phnum = elf_hdr_get_e_phnum(class, fw->data);
93 elf_shdr_get_size = elf_size_of_shdr(class);
94
95 if (fw->size < shoff + elf_shdr_get_size) {
96 dev_err(dev, "Image is too small\n");
97 return -EINVAL;
98 }
99
100 if (phnum == 0) {
101 dev_err(dev, "No loadable segments\n");
102 return -EINVAL;
103 }
104
105 if (phoff > fw->size) {
106 dev_err(dev, "Firmware size is too small\n");
107 return -EINVAL;
108 }
109
110 dev_dbg(dev, "Firmware is an elf%d file\n",
111 class == ELFCLASS32 ? 32 : 64);
112
113 return 0;
114 }
115 EXPORT_SYMBOL(rproc_elf_sanity_check);
116
117 /**
118 * rproc_elf_get_boot_addr() - Get rproc's boot address.
119 * @rproc: the remote processor handle
120 * @fw: the ELF firmware image
121 *
122 * Note that the boot address is not a configurable property of all remote
123 * processors. Some will always boot at a specific hard-coded address.
124 *
125 * Return: entry point address of the ELF image
126 *
127 */
128 u64 rproc_elf_get_boot_addr(struct rproc *rproc, const struct firmware *fw)
129 {
130 return elf_hdr_get_e_entry(fw_elf_get_class(fw), fw->data);
131 }
132 EXPORT_SYMBOL(rproc_elf_get_boot_addr);
133
134 /**
135 * rproc_elf_load_segments() - load firmware segments to memory
136 * @rproc: remote processor which will be booted using these fw segments
137 * @fw: the ELF firmware image
138 *
139 * This function loads the firmware segments to memory, where the remote
140 * processor expects them.
141 *
142 * Some remote processors will expect their code and data to be placed
143 * in specific device addresses, and can't have them dynamically assigned.
144 *
145 * We currently support only those kind of remote processors, and expect
146 * the program header's paddr member to contain those addresses. We then go
147 * through the physically contiguous "carveout" memory regions which we
148 * allocated (and mapped) earlier on behalf of the remote processor,
149 * and "translate" device address to kernel addresses, so we can copy the
150 * segments where they are expected.
151 *
152 * Currently we only support remote processors that required carveout
153 * allocations and got them mapped onto their iommus. Some processors
154 * might be different: they might not have iommus, and would prefer to
155 * directly allocate memory for every segment/resource. This is not yet
156 * supported, though.
157 *
158 * Return: 0 on success and an appropriate error code otherwise
159 */
160 int rproc_elf_load_segments(struct rproc *rproc, const struct firmware *fw)
161 {
162 struct device *dev = &rproc->dev;
163 const void *ehdr, *phdr;
164 int i, ret = 0;
165 u16 phnum;
166 const u8 *elf_data = fw->data;
167 u8 class = fw_elf_get_class(fw);
168 u32 elf_phdr_get_size = elf_size_of_phdr(class);
169
170 ehdr = elf_data;
171 phnum = elf_hdr_get_e_phnum(class, ehdr);
172 phdr = elf_data + elf_hdr_get_e_phoff(class, ehdr);
173
174 /* go through the available ELF segments */
175 for (i = 0; i < phnum; i++, phdr += elf_phdr_get_size) {
176 u64 da = elf_phdr_get_p_paddr(class, phdr);
177 u64 memsz = elf_phdr_get_p_memsz(class, phdr);
178 u64 filesz = elf_phdr_get_p_filesz(class, phdr);
179 u64 offset = elf_phdr_get_p_offset(class, phdr);
180 u32 type = elf_phdr_get_p_type(class, phdr);
181 bool is_iomem = false;
182 void *ptr;
183
184 if (type != PT_LOAD || !memsz)
185 continue;
186
187 dev_dbg(dev, "phdr: type %d da 0x%llx memsz 0x%llx filesz 0x%llx\n",
188 type, da, memsz, filesz);
189
190 if (filesz > memsz) {
191 dev_err(dev, "bad phdr filesz 0x%llx memsz 0x%llx\n",
192 filesz, memsz);
193 ret = -EINVAL;
194 break;
195 }
196
197 if (offset + filesz > fw->size) {
198 dev_err(dev, "truncated fw: need 0x%llx avail 0x%zx\n",
199 offset + filesz, fw->size);
200 ret = -EINVAL;
201 break;
202 }
203
204 if (!rproc_u64_fit_in_size_t(memsz)) {
205 dev_err(dev, "size (%llx) does not fit in size_t type\n",
206 memsz);
207 ret = -EOVERFLOW;
208 break;
209 }
210
211 /* grab the kernel address for this device address */
212 ptr = rproc_da_to_va(rproc, da, memsz, &is_iomem);
213 if (!ptr) {
214 dev_err(dev, "bad phdr da 0x%llx mem 0x%llx\n", da,
215 memsz);
216 ret = -EINVAL;
217 break;
218 }
219
220 /* put the segment where the remote processor expects it */
221 if (filesz) {
222 if (is_iomem)
223 memcpy_toio((void __iomem *)ptr, elf_data + offset, filesz);
224 else
225 memcpy(ptr, elf_data + offset, filesz);
226 }
227
228 /*
229 * Zero out remaining memory for this segment.
230 *
231 * This isn't strictly required since dma_alloc_coherent already
232 * did this for us. albeit harmless, we may consider removing
233 * this.
234 */
235 if (memsz > filesz) {
236 if (is_iomem)
237 memset_io((void __iomem *)(ptr + filesz), 0, memsz - filesz);
238 else
239 memset(ptr + filesz, 0, memsz - filesz);
240 }
241 }
242
243 return ret;
244 }
245 EXPORT_SYMBOL(rproc_elf_load_segments);
246
247 static const void *
248 find_table(struct device *dev, const struct firmware *fw)
249 {
250 const void *shdr, *name_table_shdr;
251 int i;
252 const char *name_table;
253 struct resource_table *table = NULL;
254 const u8 *elf_data = (void *)fw->data;
255 u8 class = fw_elf_get_class(fw);
256 size_t fw_size = fw->size;
257 const void *ehdr = elf_data;
258 u16 shnum = elf_hdr_get_e_shnum(class, ehdr);
259 u32 elf_shdr_get_size = elf_size_of_shdr(class);
260 u16 shstrndx = elf_hdr_get_e_shstrndx(class, ehdr);
261
262 /* look for the resource table and handle it */
263 /* First, get the section header according to the elf class */
264 shdr = elf_data + elf_hdr_get_e_shoff(class, ehdr);
265 /* Compute name table section header entry in shdr array */
266 name_table_shdr = shdr + (shstrndx * elf_shdr_get_size);
267 /* Finally, compute the name table section address in elf */
268 name_table = elf_data + elf_shdr_get_sh_offset(class, name_table_shdr);
269
270 for (i = 0; i < shnum; i++, shdr += elf_shdr_get_size) {
271 u64 size = elf_shdr_get_sh_size(class, shdr);
272 u64 offset = elf_shdr_get_sh_offset(class, shdr);
273 u32 name = elf_shdr_get_sh_name(class, shdr);
274
275 if (strcmp(name_table + name, ".resource_table"))
276 continue;
277
278 table = (struct resource_table *)(elf_data + offset);
279
280 /* make sure we have the entire table */
281 if (offset + size > fw_size || offset + size < size) {
282 dev_err(dev, "resource table truncated\n");
283 return NULL;
284 }
285
286 /* make sure table has at least the header */
287 if (sizeof(struct resource_table) > size) {
288 dev_err(dev, "header-less resource table\n");
289 return NULL;
290 }
291
292 /* we don't support any version beyond the first */
293 if (table->ver != 1) {
294 dev_err(dev, "unsupported fw ver: %d\n", table->ver);
295 return NULL;
296 }
297
298 /* make sure reserved bytes are zeroes */
299 if (table->reserved[0] || table->reserved[1]) {
300 dev_err(dev, "non zero reserved bytes\n");
301 return NULL;
302 }
303
304 /* make sure the offsets array isn't truncated */
305 if (struct_size(table, offset, table->num) > size) {
306 dev_err(dev, "resource table incomplete\n");
307 return NULL;
308 }
309
310 return shdr;
311 }
312
313 return NULL;
314 }
315
316 /**
317 * rproc_elf_load_rsc_table() - load the resource table
318 * @rproc: the rproc handle
319 * @fw: the ELF firmware image
320 *
321 * This function finds the resource table inside the remote processor's
322 * firmware, load it into the @cached_table and update @table_ptr.
323 *
324 * Return: 0 on success, negative errno on failure.
325 */
326 int rproc_elf_load_rsc_table(struct rproc *rproc, const struct firmware *fw)
327 {
328 const void *shdr;
329 struct device *dev = &rproc->dev;
330 struct resource_table *table = NULL;
331 const u8 *elf_data = fw->data;
332 size_t tablesz;
333 u8 class = fw_elf_get_class(fw);
334 u64 sh_offset;
335
336 shdr = find_table(dev, fw);
337 if (!shdr)
338 return -EINVAL;
339
340 sh_offset = elf_shdr_get_sh_offset(class, shdr);
341 table = (struct resource_table *)(elf_data + sh_offset);
342 tablesz = elf_shdr_get_sh_size(class, shdr);
343
344 /*
345 * Create a copy of the resource table. When a virtio device starts
346 * and calls vring_new_virtqueue() the address of the allocated vring
347 * will be stored in the cached_table. Before the device is started,
348 * cached_table will be copied into device memory.
349 */
350 rproc->cached_table = kmemdup(table, tablesz, GFP_KERNEL);
351 if (!rproc->cached_table)
352 return -ENOMEM;
353
354 rproc->table_ptr = rproc->cached_table;
355 rproc->table_sz = tablesz;
356
357 return 0;
358 }
359 EXPORT_SYMBOL(rproc_elf_load_rsc_table);
360
361 /**
362 * rproc_elf_find_loaded_rsc_table() - find the loaded resource table
363 * @rproc: the rproc handle
364 * @fw: the ELF firmware image
365 *
366 * This function finds the location of the loaded resource table. Don't
367 * call this function if the table wasn't loaded yet - it's a bug if you do.
368 *
369 * Return: pointer to the resource table if it is found or NULL otherwise.
370 * If the table wasn't loaded yet the result is unspecified.
371 */
372 struct resource_table *rproc_elf_find_loaded_rsc_table(struct rproc *rproc,
373 const struct firmware *fw)
374 {
375 const void *shdr;
376 u64 sh_addr, sh_size;
377 u8 class = fw_elf_get_class(fw);
378 struct device *dev = &rproc->dev;
379
380 shdr = find_table(&rproc->dev, fw);
381 if (!shdr)
382 return NULL;
383
384 sh_addr = elf_shdr_get_sh_addr(class, shdr);
385 sh_size = elf_shdr_get_sh_size(class, shdr);
386
387 if (!rproc_u64_fit_in_size_t(sh_size)) {
388 dev_err(dev, "size (%llx) does not fit in size_t type\n",
389 sh_size);
390 return NULL;
391 }
392
393 return rproc_da_to_va(rproc, sh_addr, sh_size, NULL);
394 }
395 EXPORT_SYMBOL(rproc_elf_find_loaded_rsc_table);
396