mdt_loader.c

  1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 * Qualcomm Peripheral Image Loader
  4 *
  5 * Copyright (C) 2016 Linaro Ltd
  6 * Copyright (C) 2015 Sony Mobile Communications Inc
  7 * Copyright (c) 2012-2013, The Linux Foundation. All rights reserved.
  8 */
  9
 10#include <linux/cleanup.h>
 11#include <linux/device.h>
 12#include <linux/elf.h>
 13#include <linux/firmware.h>
 14#include <linux/kernel.h>
 15#include <linux/module.h>
 16#include <linux/firmware/qcom/qcom_scm.h>
 17#include <linux/sizes.h>
 18#include <linux/slab.h>
 19#include <linux/soc/qcom/mdt_loader.h>
 20
 21static bool mdt_header_valid(const struct firmware *fw)
 22{
 23	const struct elf32_hdr *ehdr;
 24	size_t phend;
 25	size_t shend;
 26
 27	if (fw->size < sizeof(*ehdr))
 28		return false;
 29
 30	ehdr = (struct elf32_hdr *)fw->data;
 31
 32	if (memcmp(ehdr->e_ident, ELFMAG, SELFMAG))
 33		return false;
 34
 35	if (ehdr->e_phentsize != sizeof(struct elf32_phdr))
 36		return false;
 37
 38	phend = size_add(size_mul(sizeof(struct elf32_phdr), ehdr->e_phnum), ehdr->e_phoff);
 39	if (phend > fw->size)
 40		return false;
 41
 42	if (ehdr->e_shentsize || ehdr->e_shnum) {
 43		if (ehdr->e_shentsize != sizeof(struct elf32_shdr))
 44			return false;
 45
 46		shend = size_add(size_mul(sizeof(struct elf32_shdr), ehdr->e_shnum), ehdr->e_shoff);
 47		if (shend > fw->size)
 48			return false;
 49	}
 50
 51	return true;
 52}
 53
 54static bool mdt_phdr_loadable(const struct elf32_phdr *phdr)
 55{
 56	if (phdr->p_type != PT_LOAD)
 57		return false;
 58
 59	if ((phdr->p_flags & QCOM_MDT_TYPE_MASK) == QCOM_MDT_TYPE_HASH)
 60		return false;
 61
 62	if (!phdr->p_memsz)
 63		return false;
 64
 65	return true;
 66}
 67
 68static ssize_t mdt_load_split_segment(void *ptr, const struct elf32_phdr *phdrs,
 69				      unsigned int segment, const char *fw_name,
 70				      struct device *dev)
 71{
 72	const struct elf32_phdr *phdr = &phdrs[segment];
 73	const struct firmware *seg_fw;
 74	ssize_t ret;
 75
 76	if (strlen(fw_name) < 4)
 77		return -EINVAL;
 78
 79	char *seg_name __free(kfree) = kstrdup(fw_name, GFP_KERNEL);
 80	if (!seg_name)
 81		return -ENOMEM;
 82
 83	sprintf(seg_name + strlen(fw_name) - 3, "b%02d", segment);
 84	ret = request_firmware_into_buf(&seg_fw, seg_name, dev,
 85					ptr, phdr->p_filesz);
 86	if (ret) {
 87		dev_err(dev, "error %zd loading %s\n", ret, seg_name);
 88		return ret;
 89	}
 90
 91	if (seg_fw->size != phdr->p_filesz) {
 92		dev_err(dev,
 93			"failed to load segment %d from truncated file %s\n",
 94			segment, seg_name);
 95		ret = -EINVAL;
 96	}
 97
 98	release_firmware(seg_fw);
 99
100	return ret;
101}
102
103/**
104 * qcom_mdt_get_size() - acquire size of the memory region needed to load mdt
105 * @fw:		firmware object for the mdt file
106 *
107 * Returns size of the loaded firmware blob, or -EINVAL on failure.
108 */
109ssize_t qcom_mdt_get_size(const struct firmware *fw)
110{
111	const struct elf32_phdr *phdrs;
112	const struct elf32_phdr *phdr;
113	const struct elf32_hdr *ehdr;
114	phys_addr_t min_addr = PHYS_ADDR_MAX;
115	phys_addr_t max_addr = 0;
116	int i;
117
118	if (!mdt_header_valid(fw))
119		return -EINVAL;
120
121	ehdr = (struct elf32_hdr *)fw->data;
122	phdrs = (struct elf32_phdr *)(fw->data + ehdr->e_phoff);
123
124	for (i = 0; i < ehdr->e_phnum; i++) {
125		phdr = &phdrs[i];
126
127		if (!mdt_phdr_loadable(phdr))
128			continue;
129
130		if (phdr->p_paddr < min_addr)
131			min_addr = phdr->p_paddr;
132
133		if (phdr->p_paddr + phdr->p_memsz > max_addr)
134			max_addr = ALIGN(phdr->p_paddr + phdr->p_memsz, SZ_4K);
135	}
136
137	return min_addr < max_addr ? max_addr - min_addr : -EINVAL;
138}
139EXPORT_SYMBOL_GPL(qcom_mdt_get_size);
140
141/**
142 * qcom_mdt_read_metadata() - read header and metadata from mdt or mbn
143 * @fw:		firmware of mdt header or mbn
144 * @data_len:	length of the read metadata blob
145 * @fw_name:	name of the firmware, for construction of segment file names
146 * @dev:	device handle to associate resources with
147 *
148 * The mechanism that performs the authentication of the loading firmware
149 * expects an ELF header directly followed by the segment of hashes, with no
150 * padding inbetween. This function allocates a chunk of memory for this pair
151 * and copy the two pieces into the buffer.
152 *
153 * In the case of split firmware the hash is found directly following the ELF
154 * header, rather than at p_offset described by the second program header.
155 *
156 * The caller is responsible to free (kfree()) the returned pointer.
157 *
158 * Return: pointer to data, or ERR_PTR()
159 */
160void *qcom_mdt_read_metadata(const struct firmware *fw, size_t *data_len,
161			     const char *fw_name, struct device *dev)
162{
163	const struct elf32_phdr *phdrs;
164	const struct elf32_hdr *ehdr;
165	unsigned int hash_segment = 0;
166	size_t hash_offset;
167	size_t hash_size;
168	size_t ehdr_size;
169	unsigned int i;
170	ssize_t ret;
171	void *data;
172
173	if (!mdt_header_valid(fw))
174		return ERR_PTR(-EINVAL);
175
176	ehdr = (struct elf32_hdr *)fw->data;
177	phdrs = (struct elf32_phdr *)(fw->data + ehdr->e_phoff);
178
179	if (ehdr->e_phnum < 2)
180		return ERR_PTR(-EINVAL);
181
182	if (phdrs[0].p_type == PT_LOAD)
183		return ERR_PTR(-EINVAL);
184
185	for (i = 1; i < ehdr->e_phnum; i++) {
186		if ((phdrs[i].p_flags & QCOM_MDT_TYPE_MASK) == QCOM_MDT_TYPE_HASH) {
187			hash_segment = i;
188			break;
189		}
190	}
191
192	if (!hash_segment) {
193		dev_err(dev, "no hash segment found in %s\n", fw_name);
194		return ERR_PTR(-EINVAL);
195	}
196
197	ehdr_size = phdrs[0].p_filesz;
198	hash_size = phdrs[hash_segment].p_filesz;
199
200	data = kmalloc(ehdr_size + hash_size, GFP_KERNEL);
201	if (!data)
202		return ERR_PTR(-ENOMEM);
203
204	/* Copy ELF header */
205	memcpy(data, fw->data, ehdr_size);
206
207	if (ehdr_size + hash_size == fw->size) {
208		/* Firmware is split and hash is packed following the ELF header */
209		hash_offset = phdrs[0].p_filesz;
210		memcpy(data + ehdr_size, fw->data + hash_offset, hash_size);
211	} else if (phdrs[hash_segment].p_offset + hash_size <= fw->size) {
212		/* Hash is in its own segment, but within the loaded file */
213		hash_offset = phdrs[hash_segment].p_offset;
214		memcpy(data + ehdr_size, fw->data + hash_offset, hash_size);
215	} else {
216		/* Hash is in its own segment, beyond the loaded file */
217		ret = mdt_load_split_segment(data + ehdr_size, phdrs, hash_segment, fw_name, dev);
218		if (ret) {
219			kfree(data);
220			return ERR_PTR(ret);
221		}
222	}
223
224	*data_len = ehdr_size + hash_size;
225
226	return data;
227}
228EXPORT_SYMBOL_GPL(qcom_mdt_read_metadata);
229
230/**
231 * qcom_mdt_pas_init() - initialize PAS region for firmware loading
232 * @dev:	device handle to associate resources with
233 * @fw:		firmware object for the mdt file
234 * @fw_name:	name of the firmware, for construction of segment file names
235 * @pas_id:	PAS identifier
236 * @mem_phys:	physical address of allocated memory region
237 * @ctx:	PAS metadata context, to be released by caller
238 *
239 * Returns 0 on success, negative errno otherwise.
240 */
241int qcom_mdt_pas_init(struct device *dev, const struct firmware *fw,
242		      const char *fw_name, int pas_id, phys_addr_t mem_phys,
243		      struct qcom_scm_pas_metadata *ctx)
244{
245	const struct elf32_phdr *phdrs;
246	const struct elf32_phdr *phdr;
247	const struct elf32_hdr *ehdr;
248	phys_addr_t min_addr = PHYS_ADDR_MAX;
249	phys_addr_t max_addr = 0;
250	bool relocate = false;
251	size_t metadata_len;
252	void *metadata;
253	int ret;
254	int i;
255
256	if (!mdt_header_valid(fw))
257		return -EINVAL;
258
259	ehdr = (struct elf32_hdr *)fw->data;
260	phdrs = (struct elf32_phdr *)(fw->data + ehdr->e_phoff);
261
262	for (i = 0; i < ehdr->e_phnum; i++) {
263		phdr = &phdrs[i];
264
265		if (!mdt_phdr_loadable(phdr))
266			continue;
267
268		if (phdr->p_flags & QCOM_MDT_RELOCATABLE)
269			relocate = true;
270
271		if (phdr->p_paddr < min_addr)
272			min_addr = phdr->p_paddr;
273
274		if (phdr->p_paddr + phdr->p_memsz > max_addr)
275			max_addr = ALIGN(phdr->p_paddr + phdr->p_memsz, SZ_4K);
276	}
277
278	metadata = qcom_mdt_read_metadata(fw, &metadata_len, fw_name, dev);
279	if (IS_ERR(metadata)) {
280		ret = PTR_ERR(metadata);
281		dev_err(dev, "error %d reading firmware %s metadata\n", ret, fw_name);
282		goto out;
283	}
284
285	ret = qcom_scm_pas_init_image(pas_id, metadata, metadata_len, ctx);
286	kfree(metadata);
287	if (ret) {
288		/* Invalid firmware metadata */
289		dev_err(dev, "error %d initializing firmware %s\n", ret, fw_name);
290		goto out;
291	}
292
293	if (relocate) {
294		ret = qcom_scm_pas_mem_setup(pas_id, mem_phys, max_addr - min_addr);
295		if (ret) {
296			/* Unable to set up relocation */
297			dev_err(dev, "error %d setting up firmware %s\n", ret, fw_name);
298			goto out;
299		}
300	}
301
302out:
303	return ret;
304}
305EXPORT_SYMBOL_GPL(qcom_mdt_pas_init);
306
307static bool qcom_mdt_bins_are_split(const struct firmware *fw)
308{
309	const struct elf32_phdr *phdrs;
310	const struct elf32_hdr *ehdr;
311	uint64_t seg_start, seg_end;
312	int i;
313
314	ehdr = (struct elf32_hdr *)fw->data;
315	phdrs = (struct elf32_phdr *)(fw->data + ehdr->e_phoff);
316
317	for (i = 0; i < ehdr->e_phnum; i++) {
318		/*
319		 * The size of the MDT file is not padded to include any
320		 * zero-sized segments at the end. Ignore these, as they should
321		 * not affect the decision about image being split or not.
322		 */
323		if (!phdrs[i].p_filesz)
324			continue;
325
326		seg_start = phdrs[i].p_offset;
327		seg_end = phdrs[i].p_offset + phdrs[i].p_filesz;
328		if (seg_start > fw->size || seg_end > fw->size)
329			return true;
330	}
331
332	return false;
333}
334
335/**
336 * qcom_mdt_load_no_init() - load the firmware which header is loaded as fw
337 * @dev:	device handle to associate resources with
338 * @fw:		firmware object for the mdt file
339 * @fw_name:	name of the firmware, for construction of segment file names
340 * @mem_region:	allocated memory region to load firmware into
341 * @mem_phys:	physical address of allocated memory region
342 * @mem_size:	size of the allocated memory region
343 * @reloc_base:	adjusted physical address after relocation
344 *
345 * Returns 0 on success, negative errno otherwise.
346 */
347int qcom_mdt_load_no_init(struct device *dev, const struct firmware *fw,
348			  const char *fw_name, void *mem_region,
349			  phys_addr_t mem_phys, size_t mem_size,
350			  phys_addr_t *reloc_base)
351{
352	const struct elf32_phdr *phdrs;
353	const struct elf32_phdr *phdr;
354	const struct elf32_hdr *ehdr;
355	phys_addr_t mem_reloc;
356	phys_addr_t min_addr = PHYS_ADDR_MAX;
357	ssize_t offset;
358	bool relocate = false;
359	bool is_split;
360	void *ptr;
361	int ret = 0;
362	int i;
363
364	if (!fw || !mem_region || !mem_phys || !mem_size)
365		return -EINVAL;
366
367	if (!mdt_header_valid(fw))
368		return -EINVAL;
369
370	is_split = qcom_mdt_bins_are_split(fw);
371	ehdr = (struct elf32_hdr *)fw->data;
372	phdrs = (struct elf32_phdr *)(fw->data + ehdr->e_phoff);
373
374	for (i = 0; i < ehdr->e_phnum; i++) {
375		phdr = &phdrs[i];
376
377		if (!mdt_phdr_loadable(phdr))
378			continue;
379
380		if (phdr->p_flags & QCOM_MDT_RELOCATABLE)
381			relocate = true;
382
383		if (phdr->p_paddr < min_addr)
384			min_addr = phdr->p_paddr;
385	}
386
387	if (relocate) {
388		/*
389		 * The image is relocatable, so offset each segment based on
390		 * the lowest segment address.
391		 */
392		mem_reloc = min_addr;
393	} else {
394		/*
395		 * Image is not relocatable, so offset each segment based on
396		 * the allocated physical chunk of memory.
397		 */
398		mem_reloc = mem_phys;
399	}
400
401	for (i = 0; i < ehdr->e_phnum; i++) {
402		phdr = &phdrs[i];
403
404		if (!mdt_phdr_loadable(phdr))
405			continue;
406
407		offset = phdr->p_paddr - mem_reloc;
408		if (offset < 0 || offset + phdr->p_memsz > mem_size) {
409			dev_err(dev, "segment outside memory range\n");
410			ret = -EINVAL;
411			break;
412		}
413
414		if (phdr->p_filesz > phdr->p_memsz) {
415			dev_err(dev,
416				"refusing to load segment %d with p_filesz > p_memsz\n",
417				i);
418			ret = -EINVAL;
419			break;
420		}
421
422		ptr = mem_region + offset;
423
424		if (phdr->p_filesz && !is_split) {
425			/* Firmware is large enough to be non-split */
426			if (phdr->p_offset + phdr->p_filesz > fw->size) {
427				dev_err(dev, "file %s segment %d would be truncated\n",
428					fw_name, i);
429				ret = -EINVAL;
430				break;
431			}
432
433			memcpy(ptr, fw->data + phdr->p_offset, phdr->p_filesz);
434		} else if (phdr->p_filesz) {
435			/* Firmware not large enough, load split-out segments */
436			ret = mdt_load_split_segment(ptr, phdrs, i, fw_name, dev);
437			if (ret)
438				break;
439		}
440
441		if (phdr->p_memsz > phdr->p_filesz)
442			memset(ptr + phdr->p_filesz, 0, phdr->p_memsz - phdr->p_filesz);
443	}
444
445	if (reloc_base)
446		*reloc_base = mem_reloc;
447
448	return ret;
449}
450EXPORT_SYMBOL_GPL(qcom_mdt_load_no_init);
451
452/**
453 * qcom_mdt_load() - load the firmware which header is loaded as fw
454 * @dev:	device handle to associate resources with
455 * @fw:		firmware object for the mdt file
456 * @fw_name:	name of the firmware, for construction of segment file names
457 * @pas_id:	PAS identifier
458 * @mem_region:	allocated memory region to load firmware into
459 * @mem_phys:	physical address of allocated memory region
460 * @mem_size:	size of the allocated memory region
461 * @reloc_base:	adjusted physical address after relocation
462 *
463 * Returns 0 on success, negative errno otherwise.
464 */
465int qcom_mdt_load(struct device *dev, const struct firmware *fw,
466		  const char *fw_name, int pas_id, void *mem_region,
467		  phys_addr_t mem_phys, size_t mem_size,
468		  phys_addr_t *reloc_base)
469{
470	int ret;
471
472	ret = qcom_mdt_pas_init(dev, fw, fw_name, pas_id, mem_phys, NULL);
473	if (ret)
474		return ret;
475
476	return qcom_mdt_load_no_init(dev, fw, fw_name, mem_region, mem_phys,
477				     mem_size, reloc_base);
478}
479EXPORT_SYMBOL_GPL(qcom_mdt_load);
480
481MODULE_DESCRIPTION("Firmware parser for Qualcomm MDT format");
482MODULE_LICENSE("GPL v2");