linux/drivers/remoteproc/remoteproc_elf_loader.c
Alexey Dobriyan 70e79866ab ELF: fix all "Elf" typos
ELF is acronym and therefore should be spelled in all caps.

I left one exception at Documentation/arm/nwfpe/nwfpe.rst which looks like
being written in the first person.

Link: https://lkml.kernel.org/r/Y/3wGWQviIOkyLJW@p183
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-08 13:45:37 -07:00

396 lines
11 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* 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>
*/
#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"
#include "remoteproc_elf_helpers.h"
/**
* rproc_elf_sanity_check() - Sanity Check for ELF32/ELF64 firmware image
* @rproc: the remote processor handle
* @fw: the ELF firmware image
*
* Make sure this fw image is sane (ie a correct ELF32/ELF64 file).
*
* Return: 0 on success and -EINVAL upon any failure
*/
int rproc_elf_sanity_check(struct rproc *rproc, const struct firmware *fw)
{
const char *name = rproc->firmware;
struct device *dev = &rproc->dev;
/*
* ELF files are beginning with the same structure. Thus, to simplify
* header parsing, we can use the elf32_hdr one for both elf64 and
* elf32.
*/
struct elf32_hdr *ehdr;
u32 elf_shdr_get_size;
u64 phoff, shoff;
char class;
u16 phnum;
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;
if (memcmp(ehdr->e_ident, ELFMAG, SELFMAG)) {
dev_err(dev, "Image is corrupted (bad magic)\n");
return -EINVAL;
}
class = ehdr->e_ident[EI_CLASS];
if (class != ELFCLASS32 && class != ELFCLASS64) {
dev_err(dev, "Unsupported class: %d\n", class);
return -EINVAL;
}
if (class == ELFCLASS64 && fw->size < sizeof(struct elf64_hdr)) {
dev_err(dev, "elf64 header is too small\n");
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;
}
phoff = elf_hdr_get_e_phoff(class, fw->data);
shoff = elf_hdr_get_e_shoff(class, fw->data);
phnum = elf_hdr_get_e_phnum(class, fw->data);
elf_shdr_get_size = elf_size_of_shdr(class);
if (fw->size < shoff + elf_shdr_get_size) {
dev_err(dev, "Image is too small\n");
return -EINVAL;
}
if (phnum == 0) {
dev_err(dev, "No loadable segments\n");
return -EINVAL;
}
if (phoff > fw->size) {
dev_err(dev, "Firmware size is too small\n");
return -EINVAL;
}
dev_dbg(dev, "Firmware is an elf%d file\n",
class == ELFCLASS32 ? 32 : 64);
return 0;
}
EXPORT_SYMBOL(rproc_elf_sanity_check);
/**
* rproc_elf_get_boot_addr() - Get rproc's boot address.
* @rproc: the remote processor handle
* @fw: the ELF firmware 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.
*
* Return: entry point address of the ELF image
*
*/
u64 rproc_elf_get_boot_addr(struct rproc *rproc, const struct firmware *fw)
{
return elf_hdr_get_e_entry(fw_elf_get_class(fw), fw->data);
}
EXPORT_SYMBOL(rproc_elf_get_boot_addr);
/**
* 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.
*
* Return: 0 on success and an appropriate error code otherwise
*/
int rproc_elf_load_segments(struct rproc *rproc, const struct firmware *fw)
{
struct device *dev = &rproc->dev;
const void *ehdr, *phdr;
int i, ret = 0;
u16 phnum;
const u8 *elf_data = fw->data;
u8 class = fw_elf_get_class(fw);
u32 elf_phdr_get_size = elf_size_of_phdr(class);
ehdr = elf_data;
phnum = elf_hdr_get_e_phnum(class, ehdr);
phdr = elf_data + elf_hdr_get_e_phoff(class, ehdr);
/* go through the available ELF segments */
for (i = 0; i < phnum; i++, phdr += elf_phdr_get_size) {
u64 da = elf_phdr_get_p_paddr(class, phdr);
u64 memsz = elf_phdr_get_p_memsz(class, phdr);
u64 filesz = elf_phdr_get_p_filesz(class, phdr);
u64 offset = elf_phdr_get_p_offset(class, phdr);
u32 type = elf_phdr_get_p_type(class, phdr);
bool is_iomem = false;
void *ptr;
if (type != PT_LOAD || !memsz)
continue;
dev_dbg(dev, "phdr: type %d da 0x%llx memsz 0x%llx filesz 0x%llx\n",
type, da, memsz, filesz);
if (filesz > memsz) {
dev_err(dev, "bad phdr filesz 0x%llx memsz 0x%llx\n",
filesz, memsz);
ret = -EINVAL;
break;
}
if (offset + filesz > fw->size) {
dev_err(dev, "truncated fw: need 0x%llx avail 0x%zx\n",
offset + filesz, fw->size);
ret = -EINVAL;
break;
}
if (!rproc_u64_fit_in_size_t(memsz)) {
dev_err(dev, "size (%llx) does not fit in size_t type\n",
memsz);
ret = -EOVERFLOW;
break;
}
/* grab the kernel address for this device address */
ptr = rproc_da_to_va(rproc, da, memsz, &is_iomem);
if (!ptr) {
dev_err(dev, "bad phdr da 0x%llx mem 0x%llx\n", da,
memsz);
ret = -EINVAL;
break;
}
/* put the segment where the remote processor expects it */
if (filesz) {
if (is_iomem)
memcpy_toio((void __iomem *)ptr, elf_data + offset, filesz);
else
memcpy(ptr, elf_data + 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) {
if (is_iomem)
memset_io((void __iomem *)(ptr + filesz), 0, memsz - filesz);
else
memset(ptr + filesz, 0, memsz - filesz);
}
}
return ret;
}
EXPORT_SYMBOL(rproc_elf_load_segments);
static const void *
find_table(struct device *dev, const struct firmware *fw)
{
const void *shdr, *name_table_shdr;
int i;
const char *name_table;
struct resource_table *table = NULL;
const u8 *elf_data = (void *)fw->data;
u8 class = fw_elf_get_class(fw);
size_t fw_size = fw->size;
const void *ehdr = elf_data;
u16 shnum = elf_hdr_get_e_shnum(class, ehdr);
u32 elf_shdr_get_size = elf_size_of_shdr(class);
u16 shstrndx = elf_hdr_get_e_shstrndx(class, ehdr);
/* look for the resource table and handle it */
/* First, get the section header according to the elf class */
shdr = elf_data + elf_hdr_get_e_shoff(class, ehdr);
/* Compute name table section header entry in shdr array */
name_table_shdr = shdr + (shstrndx * elf_shdr_get_size);
/* Finally, compute the name table section address in elf */
name_table = elf_data + elf_shdr_get_sh_offset(class, name_table_shdr);
for (i = 0; i < shnum; i++, shdr += elf_shdr_get_size) {
u64 size = elf_shdr_get_sh_size(class, shdr);
u64 offset = elf_shdr_get_sh_offset(class, shdr);
u32 name = elf_shdr_get_sh_name(class, shdr);
if (strcmp(name_table + 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 (struct_size(table, offset, table->num) > size) {
dev_err(dev, "resource table incomplete\n");
return NULL;
}
return shdr;
}
return NULL;
}
/**
* rproc_elf_load_rsc_table() - load the resource table
* @rproc: the rproc handle
* @fw: the ELF firmware image
*
* This function finds the resource table inside the remote processor's
* firmware, load it into the @cached_table and update @table_ptr.
*
* Return: 0 on success, negative errno on failure.
*/
int rproc_elf_load_rsc_table(struct rproc *rproc, const struct firmware *fw)
{
const void *shdr;
struct device *dev = &rproc->dev;
struct resource_table *table = NULL;
const u8 *elf_data = fw->data;
size_t tablesz;
u8 class = fw_elf_get_class(fw);
u64 sh_offset;
shdr = find_table(dev, fw);
if (!shdr)
return -EINVAL;
sh_offset = elf_shdr_get_sh_offset(class, shdr);
table = (struct resource_table *)(elf_data + sh_offset);
tablesz = elf_shdr_get_sh_size(class, shdr);
/*
* Create a copy of the resource table. When a virtio device starts
* and calls vring_new_virtqueue() the address of the allocated vring
* will be stored in the cached_table. Before the device is started,
* cached_table will be copied into device memory.
*/
rproc->cached_table = kmemdup(table, tablesz, GFP_KERNEL);
if (!rproc->cached_table)
return -ENOMEM;
rproc->table_ptr = rproc->cached_table;
rproc->table_sz = tablesz;
return 0;
}
EXPORT_SYMBOL(rproc_elf_load_rsc_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.
*
* Return: pointer to the resource table if it is found or NULL otherwise.
* If the table wasn't loaded yet the result is unspecified.
*/
struct resource_table *rproc_elf_find_loaded_rsc_table(struct rproc *rproc,
const struct firmware *fw)
{
const void *shdr;
u64 sh_addr, sh_size;
u8 class = fw_elf_get_class(fw);
struct device *dev = &rproc->dev;
shdr = find_table(&rproc->dev, fw);
if (!shdr)
return NULL;
sh_addr = elf_shdr_get_sh_addr(class, shdr);
sh_size = elf_shdr_get_sh_size(class, shdr);
if (!rproc_u64_fit_in_size_t(sh_size)) {
dev_err(dev, "size (%llx) does not fit in size_t type\n",
sh_size);
return NULL;
}
return rproc_da_to_va(rproc, sh_addr, sh_size, NULL);
}
EXPORT_SYMBOL(rproc_elf_find_loaded_rsc_table);