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