linux/drivers/remoteproc/remoteproc_elf_loader.c
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   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 */
  37int 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}
 115EXPORT_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 */
 128u64 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}
 132EXPORT_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 */
 160int 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                void *ptr;
 182                bool is_iomem;
 183
 184                if (type != PT_LOAD)
 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_fromio(ptr, (void __iomem *)(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}
 245EXPORT_SYMBOL(rproc_elf_load_segments);
 246
 247static const void *
 248find_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 */
 326int 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}
 359EXPORT_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 */
 372struct 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}
 395EXPORT_SYMBOL(rproc_elf_find_loaded_rsc_table);
 396