cregit-Linux how code gets into the kernel

Release 4.14 drivers/remoteproc/remoteproc_elf_loader.c

/*
 * Remote Processor Framework Elf loader
 *
 * Copyright (C) 2011 Texas Instruments, Inc.
 * Copyright (C) 2011 Google, Inc.
 *
 * Ohad Ben-Cohen <ohad@wizery.com>
 * Brian Swetland <swetland@google.com>
 * Mark Grosen <mgrosen@ti.com>
 * Fernando Guzman Lugo <fernando.lugo@ti.com>
 * Suman Anna <s-anna@ti.com>
 * Robert Tivy <rtivy@ti.com>
 * Armando Uribe De Leon <x0095078@ti.com>
 * Sjur Brændeland <sjur.brandeland@stericsson.com>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * version 2 as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 */


#define pr_fmt(fmt)    "%s: " fmt, __func__

#include <linux/module.h>
#include <linux/firmware.h>
#include <linux/remoteproc.h>
#include <linux/elf.h>

#include "remoteproc_internal.h"

/**
 * rproc_elf_sanity_check() - Sanity Check ELF firmware image
 * @rproc: the remote processor handle
 * @fw: the ELF firmware image
 *
 * Make sure this fw image is sane.
 */

static int rproc_elf_sanity_check(struct rproc *rproc, const struct firmware *fw) { const char *name = rproc->firmware; struct device *dev = &rproc->dev; struct elf32_hdr *ehdr; char class; if (!fw) { dev_err(dev, "failed to load %s\n", name); return -EINVAL; } if (fw->size < sizeof(struct elf32_hdr)) { dev_err(dev, "Image is too small\n"); return -EINVAL; } ehdr = (struct elf32_hdr *)fw->data; /* We only support ELF32 at this point */ class = ehdr->e_ident[EI_CLASS]; if (class != ELFCLASS32) { dev_err(dev, "Unsupported class: %d\n", class); return -EINVAL; } /* We assume the firmware has the same endianness as the host */ # ifdef __LITTLE_ENDIAN if (ehdr->e_ident[EI_DATA] != ELFDATA2LSB) { # else /* BIG ENDIAN */ if (ehdr->e_ident[EI_DATA] != ELFDATA2MSB) { # endif dev_err(dev, "Unsupported firmware endianness\n"); return -EINVAL; } if (fw->size < ehdr->e_shoff + sizeof(struct elf32_shdr)) { dev_err(dev, "Image is too small\n"); return -EINVAL; } if (memcmp(ehdr->e_ident, ELFMAG, SELFMAG)) { dev_err(dev, "Image is corrupted (bad magic)\n"); return -EINVAL; } if (ehdr->e_phnum == 0) { dev_err(dev, "No loadable segments\n"); return -EINVAL; } if (ehdr->e_phoff > fw->size) { dev_err(dev, "Firmware size is too small\n"); return -EINVAL; } return 0; } /** * rproc_elf_get_boot_addr() - Get rproc's boot address. * @rproc: the remote processor handle * @fw: the ELF firmware image * * This function returns the entry point address of the ELF * image. * * Note that the boot address is not a configurable property of all remote * processors. Some will always boot at a specific hard-coded address. */ static u32 rproc_elf_get_boot_addr(struct rproc *rproc, const struct firmware *fw) { struct elf32_hdr *ehdr = (struct elf32_hdr *)fw->data; return ehdr->e_entry; } /** * rproc_elf_load_segments() - load firmware segments to memory * @rproc: remote processor which will be booted using these fw segments * @fw: the ELF firmware image * * This function loads the firmware segments to memory, where the remote * processor expects them. * * Some remote processors will expect their code and data to be placed * in specific device addresses, and can't have them dynamically assigned. * * We currently support only those kind of remote processors, and expect * the program header's paddr member to contain those addresses. We then go * through the physically contiguous "carveout" memory regions which we * allocated (and mapped) earlier on behalf of the remote processor, * and "translate" device address to kernel addresses, so we can copy the * segments where they are expected. * * Currently we only support remote processors that required carveout * allocations and got them mapped onto their iommus. Some processors * might be different: they might not have iommus, and would prefer to * directly allocate memory for every segment/resource. This is not yet * supported, though. */ static int rproc_elf_load_segments(struct rproc *rproc, const struct firmware *fw) { struct device *dev = &rproc->dev; struct elf32_hdr *ehdr; struct elf32_phdr *phdr; int i, ret = 0; const u8 *elf_data = fw->data; ehdr = (struct elf32_hdr *)elf_data; phdr = (struct elf32_phdr *)(elf_data + ehdr->e_phoff); /* go through the available ELF segments */ for (i = 0; i < ehdr->e_phnum; i++, phdr++) { u32 da = phdr->p_paddr; u32 memsz = phdr->p_memsz; u32 filesz = phdr->p_filesz; u32 offset = phdr->p_offset; void *ptr; if (phdr->p_type != PT_LOAD) continue; dev_dbg(dev, "phdr: type %d da 0x%x memsz 0x%x filesz 0x%x\n", phdr->p_type, da, memsz, filesz); if (filesz > memsz) { dev_err(dev, "bad phdr filesz 0x%x memsz 0x%x\n", filesz, memsz); ret = -EINVAL; break; } if (offset + filesz > fw->size) { dev_err(dev, "truncated fw: need 0x%x avail 0x%zx\n", offset + filesz, fw->size); ret = -EINVAL; break; } /* grab the kernel address for this device address */ ptr = rproc_da_to_va(rproc, da, memsz); if (!ptr) { dev_err(dev, "bad phdr da 0x%x mem 0x%x\n", da, memsz); ret = -EINVAL; break; } /* put the segment where the remote processor expects it */ if (phdr->p_filesz) memcpy(ptr, elf_data + phdr->p_offset, filesz); /* * Zero out remaining memory for this segment. * * This isn't strictly required since dma_alloc_coherent already * did this for us. albeit harmless, we may consider removing * this. */ if (memsz > filesz) memset(ptr + filesz, 0, memsz - filesz); } return ret; } static struct elf32_shdr * find_table(struct device *dev, struct elf32_hdr *ehdr, size_t fw_size) { struct elf32_shdr *shdr; int i; const char *name_table; struct resource_table *table = NULL; const u8 *elf_data = (void *)ehdr; /* look for the resource table and handle it */ shdr = (struct elf32_shdr *)(elf_data + ehdr->e_shoff); name_table = elf_data + shdr[ehdr->e_shstrndx].sh_offset; for (i = 0; i < ehdr->e_shnum; i++, shdr++) { u32 size = shdr->sh_size; u32 offset = shdr->sh_offset; if (strcmp(name_table + shdr->sh_name, ".resource_table")) continue; table = (struct resource_table *)(elf_data + offset); /* make sure we have the entire table */ if (offset + size > fw_size || offset + size < size) { dev_err(dev, "resource table truncated\n"); return NULL; } /* make sure table has at least the header */ if (sizeof(struct resource_table) > size) { dev_err(dev, "header-less resource table\n"); return NULL; } /* we don't support any version beyond the first */ if (table->ver != 1) { dev_err(dev, "unsupported fw ver: %d\n", table->ver); return NULL; } /* make sure reserved bytes are zeroes */ if (table->reserved[0] || table->reserved[1]) { dev_err(dev, "non zero reserved bytes\n"); return NULL; } /* make sure the offsets array isn't truncated */ if (table->num * sizeof(table->offset[0]) + sizeof(struct resource_table) > size) { dev_err(dev, "resource table incomplete\n"); return NULL; } return shdr; } return NULL; } /** * rproc_elf_find_rsc_table() - find the resource table * @rproc: the rproc handle * @fw: the ELF firmware image * @tablesz: place holder for providing back the table size * * This function finds the resource table inside the remote processor's * firmware. It is used both upon the registration of @rproc (in order * to look for and register the supported virito devices), and when the * @rproc is booted. * * Returns the pointer to the resource table if it is found, and write its * size into @tablesz. If a valid table isn't found, NULL is returned * (and @tablesz isn't set). */ static struct resource_table * rproc_elf_find_rsc_table(struct rproc *rproc, const struct firmware *fw, int *tablesz) { struct elf32_hdr *ehdr; struct elf32_shdr *shdr; struct device *dev = &rproc->dev; struct resource_table *table = NULL; const u8 *elf_data = fw->data; ehdr = (struct elf32_hdr *)elf_data; shdr = find_table(dev, ehdr, fw->size); if (!shdr) return NULL; table = (struct resource_table *)(elf_data + shdr->sh_offset); *tablesz = shdr->sh_size; return table; } /** * rproc_elf_find_loaded_rsc_table() - find the loaded resource table * @rproc: the rproc handle * @fw: the ELF firmware image * * This function finds the location of the loaded resource table. Don't * call this function if the table wasn't loaded yet - it's a bug if you do. * * Returns the pointer to the resource table if it is found or NULL otherwise. * If the table wasn't loaded yet the result is unspecified. */ static struct resource_table * rproc_elf_find_loaded_rsc_table(struct rproc *rproc, const struct firmware *fw) { struct elf32_hdr *ehdr = (struct elf32_hdr *)fw->data; struct elf32_shdr *shdr; shdr = find_table(&rproc->dev, ehdr, fw->size); if (!shdr) return NULL; return rproc_da_to_va(rproc, shdr->sh_addr, shdr->sh_size); } const struct rproc_fw_ops rproc_elf_fw_ops = { .load = rproc_elf_load_segments, .find_rsc_table = rproc_elf_find_rsc_table, .find_loaded_rsc_table = rproc_elf_find_loaded_rsc_table, .sanity_check = rproc_elf_sanity_check, .get_boot_addr = rproc_elf_get_boot_addr };

Contributors

PersonTokensPropCommitsCommitProp
Sjur Brændeland111999.73%466.67%
Masanari Iida20.18%116.67%
Linus Torvalds10.09%116.67%
Total1122100.00%6100.00%


Overall Contributors

PersonTokensPropCommitsCommitProp
Sjur Brændeland114399.74%466.67%
Masanari Iida20.17%116.67%
Linus Torvalds10.09%116.67%
Total1146100.00%6100.00%
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