linux/drivers/soc/qcom/mdt_loader.c
Bjorn Andersson 0d25da8e7e soc: qcom: mdt_loader: Fix split image detection
The enhanced detection introduced in commit '210d12c8197a ("soc: qcom:
mdt_loader: Enhance split binary detection")' requires that all segments
lies within the file on disk.

But the Qualcomm firmware files consistently has a BSS-like segment at
the end, with a p_offset aligned to the next 4k boundary. As the p_size
is 0 and there's nothing to load, the image is not padded to cover this
(empty) segment.

Ignore zero-sized segments when determining if the image is split, to
avoid this problem.

Fixes: 210d12c819 ("soc: qcom: mdt_loader: Enhance split binary detection")
Signed-off-by: Bjorn Andersson <quic_bjorande@quicinc.com>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Tested-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org> # qrb5165-rb5
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20230612215804.1883458-1-quic_bjorande@quicinc.com
2023-06-13 10:13:01 -07:00

450 lines
12 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* Qualcomm Peripheral Image Loader
*
* Copyright (C) 2016 Linaro Ltd
* Copyright (C) 2015 Sony Mobile Communications Inc
* Copyright (c) 2012-2013, The Linux Foundation. All rights reserved.
*/
#include <linux/device.h>
#include <linux/elf.h>
#include <linux/firmware.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/firmware/qcom/qcom_scm.h>
#include <linux/sizes.h>
#include <linux/slab.h>
#include <linux/soc/qcom/mdt_loader.h>
static bool mdt_phdr_valid(const struct elf32_phdr *phdr)
{
if (phdr->p_type != PT_LOAD)
return false;
if ((phdr->p_flags & QCOM_MDT_TYPE_MASK) == QCOM_MDT_TYPE_HASH)
return false;
if (!phdr->p_memsz)
return false;
return true;
}
static ssize_t mdt_load_split_segment(void *ptr, const struct elf32_phdr *phdrs,
unsigned int segment, const char *fw_name,
struct device *dev)
{
const struct elf32_phdr *phdr = &phdrs[segment];
const struct firmware *seg_fw;
char *seg_name;
ssize_t ret;
if (strlen(fw_name) < 4)
return -EINVAL;
seg_name = kstrdup(fw_name, GFP_KERNEL);
if (!seg_name)
return -ENOMEM;
sprintf(seg_name + strlen(fw_name) - 3, "b%02d", segment);
ret = request_firmware_into_buf(&seg_fw, seg_name, dev,
ptr, phdr->p_filesz);
if (ret) {
dev_err(dev, "error %zd loading %s\n", ret, seg_name);
kfree(seg_name);
return ret;
}
if (seg_fw->size != phdr->p_filesz) {
dev_err(dev,
"failed to load segment %d from truncated file %s\n",
segment, seg_name);
ret = -EINVAL;
}
release_firmware(seg_fw);
kfree(seg_name);
return ret;
}
/**
* qcom_mdt_get_size() - acquire size of the memory region needed to load mdt
* @fw: firmware object for the mdt file
*
* Returns size of the loaded firmware blob, or -EINVAL on failure.
*/
ssize_t qcom_mdt_get_size(const struct firmware *fw)
{
const struct elf32_phdr *phdrs;
const struct elf32_phdr *phdr;
const struct elf32_hdr *ehdr;
phys_addr_t min_addr = PHYS_ADDR_MAX;
phys_addr_t max_addr = 0;
int i;
ehdr = (struct elf32_hdr *)fw->data;
phdrs = (struct elf32_phdr *)(ehdr + 1);
for (i = 0; i < ehdr->e_phnum; i++) {
phdr = &phdrs[i];
if (!mdt_phdr_valid(phdr))
continue;
if (phdr->p_paddr < min_addr)
min_addr = phdr->p_paddr;
if (phdr->p_paddr + phdr->p_memsz > max_addr)
max_addr = ALIGN(phdr->p_paddr + phdr->p_memsz, SZ_4K);
}
return min_addr < max_addr ? max_addr - min_addr : -EINVAL;
}
EXPORT_SYMBOL_GPL(qcom_mdt_get_size);
/**
* qcom_mdt_read_metadata() - read header and metadata from mdt or mbn
* @fw: firmware of mdt header or mbn
* @data_len: length of the read metadata blob
* @fw_name: name of the firmware, for construction of segment file names
* @dev: device handle to associate resources with
*
* The mechanism that performs the authentication of the loading firmware
* expects an ELF header directly followed by the segment of hashes, with no
* padding inbetween. This function allocates a chunk of memory for this pair
* and copy the two pieces into the buffer.
*
* In the case of split firmware the hash is found directly following the ELF
* header, rather than at p_offset described by the second program header.
*
* The caller is responsible to free (kfree()) the returned pointer.
*
* Return: pointer to data, or ERR_PTR()
*/
void *qcom_mdt_read_metadata(const struct firmware *fw, size_t *data_len,
const char *fw_name, struct device *dev)
{
const struct elf32_phdr *phdrs;
const struct elf32_hdr *ehdr;
unsigned int hash_segment = 0;
size_t hash_offset;
size_t hash_size;
size_t ehdr_size;
unsigned int i;
ssize_t ret;
void *data;
ehdr = (struct elf32_hdr *)fw->data;
phdrs = (struct elf32_phdr *)(ehdr + 1);
if (ehdr->e_phnum < 2)
return ERR_PTR(-EINVAL);
if (phdrs[0].p_type == PT_LOAD)
return ERR_PTR(-EINVAL);
for (i = 1; i < ehdr->e_phnum; i++) {
if ((phdrs[i].p_flags & QCOM_MDT_TYPE_MASK) == QCOM_MDT_TYPE_HASH) {
hash_segment = i;
break;
}
}
if (!hash_segment) {
dev_err(dev, "no hash segment found in %s\n", fw_name);
return ERR_PTR(-EINVAL);
}
ehdr_size = phdrs[0].p_filesz;
hash_size = phdrs[hash_segment].p_filesz;
data = kmalloc(ehdr_size + hash_size, GFP_KERNEL);
if (!data)
return ERR_PTR(-ENOMEM);
/* Copy ELF header */
memcpy(data, fw->data, ehdr_size);
if (ehdr_size + hash_size == fw->size) {
/* Firmware is split and hash is packed following the ELF header */
hash_offset = phdrs[0].p_filesz;
memcpy(data + ehdr_size, fw->data + hash_offset, hash_size);
} else if (phdrs[hash_segment].p_offset + hash_size <= fw->size) {
/* Hash is in its own segment, but within the loaded file */
hash_offset = phdrs[hash_segment].p_offset;
memcpy(data + ehdr_size, fw->data + hash_offset, hash_size);
} else {
/* Hash is in its own segment, beyond the loaded file */
ret = mdt_load_split_segment(data + ehdr_size, phdrs, hash_segment, fw_name, dev);
if (ret) {
kfree(data);
return ERR_PTR(ret);
}
}
*data_len = ehdr_size + hash_size;
return data;
}
EXPORT_SYMBOL_GPL(qcom_mdt_read_metadata);
/**
* qcom_mdt_pas_init() - initialize PAS region for firmware loading
* @dev: device handle to associate resources with
* @fw: firmware object for the mdt file
* @fw_name: name of the firmware, for construction of segment file names
* @pas_id: PAS identifier
* @mem_phys: physical address of allocated memory region
* @ctx: PAS metadata context, to be released by caller
*
* Returns 0 on success, negative errno otherwise.
*/
int qcom_mdt_pas_init(struct device *dev, const struct firmware *fw,
const char *fw_name, int pas_id, phys_addr_t mem_phys,
struct qcom_scm_pas_metadata *ctx)
{
const struct elf32_phdr *phdrs;
const struct elf32_phdr *phdr;
const struct elf32_hdr *ehdr;
phys_addr_t min_addr = PHYS_ADDR_MAX;
phys_addr_t max_addr = 0;
bool relocate = false;
size_t metadata_len;
void *metadata;
int ret;
int i;
ehdr = (struct elf32_hdr *)fw->data;
phdrs = (struct elf32_phdr *)(ehdr + 1);
for (i = 0; i < ehdr->e_phnum; i++) {
phdr = &phdrs[i];
if (!mdt_phdr_valid(phdr))
continue;
if (phdr->p_flags & QCOM_MDT_RELOCATABLE)
relocate = true;
if (phdr->p_paddr < min_addr)
min_addr = phdr->p_paddr;
if (phdr->p_paddr + phdr->p_memsz > max_addr)
max_addr = ALIGN(phdr->p_paddr + phdr->p_memsz, SZ_4K);
}
metadata = qcom_mdt_read_metadata(fw, &metadata_len, fw_name, dev);
if (IS_ERR(metadata)) {
ret = PTR_ERR(metadata);
dev_err(dev, "error %d reading firmware %s metadata\n", ret, fw_name);
goto out;
}
ret = qcom_scm_pas_init_image(pas_id, metadata, metadata_len, ctx);
kfree(metadata);
if (ret) {
/* Invalid firmware metadata */
dev_err(dev, "error %d initializing firmware %s\n", ret, fw_name);
goto out;
}
if (relocate) {
ret = qcom_scm_pas_mem_setup(pas_id, mem_phys, max_addr - min_addr);
if (ret) {
/* Unable to set up relocation */
dev_err(dev, "error %d setting up firmware %s\n", ret, fw_name);
goto out;
}
}
out:
return ret;
}
EXPORT_SYMBOL_GPL(qcom_mdt_pas_init);
static bool qcom_mdt_bins_are_split(const struct firmware *fw, const char *fw_name)
{
const struct elf32_phdr *phdrs;
const struct elf32_hdr *ehdr;
uint64_t seg_start, seg_end;
int i;
ehdr = (struct elf32_hdr *)fw->data;
phdrs = (struct elf32_phdr *)(ehdr + 1);
for (i = 0; i < ehdr->e_phnum; i++) {
/*
* The size of the MDT file is not padded to include any
* zero-sized segments at the end. Ignore these, as they should
* not affect the decision about image being split or not.
*/
if (!phdrs[i].p_filesz)
continue;
seg_start = phdrs[i].p_offset;
seg_end = phdrs[i].p_offset + phdrs[i].p_filesz;
if (seg_start > fw->size || seg_end > fw->size)
return true;
}
return false;
}
static int __qcom_mdt_load(struct device *dev, const struct firmware *fw,
const char *fw_name, int pas_id, void *mem_region,
phys_addr_t mem_phys, size_t mem_size,
phys_addr_t *reloc_base, bool pas_init)
{
const struct elf32_phdr *phdrs;
const struct elf32_phdr *phdr;
const struct elf32_hdr *ehdr;
phys_addr_t mem_reloc;
phys_addr_t min_addr = PHYS_ADDR_MAX;
ssize_t offset;
bool relocate = false;
bool is_split;
void *ptr;
int ret = 0;
int i;
if (!fw || !mem_region || !mem_phys || !mem_size)
return -EINVAL;
is_split = qcom_mdt_bins_are_split(fw, fw_name);
ehdr = (struct elf32_hdr *)fw->data;
phdrs = (struct elf32_phdr *)(ehdr + 1);
for (i = 0; i < ehdr->e_phnum; i++) {
phdr = &phdrs[i];
if (!mdt_phdr_valid(phdr))
continue;
if (phdr->p_flags & QCOM_MDT_RELOCATABLE)
relocate = true;
if (phdr->p_paddr < min_addr)
min_addr = phdr->p_paddr;
}
if (relocate) {
/*
* The image is relocatable, so offset each segment based on
* the lowest segment address.
*/
mem_reloc = min_addr;
} else {
/*
* Image is not relocatable, so offset each segment based on
* the allocated physical chunk of memory.
*/
mem_reloc = mem_phys;
}
for (i = 0; i < ehdr->e_phnum; i++) {
phdr = &phdrs[i];
if (!mdt_phdr_valid(phdr))
continue;
offset = phdr->p_paddr - mem_reloc;
if (offset < 0 || offset + phdr->p_memsz > mem_size) {
dev_err(dev, "segment outside memory range\n");
ret = -EINVAL;
break;
}
if (phdr->p_filesz > phdr->p_memsz) {
dev_err(dev,
"refusing to load segment %d with p_filesz > p_memsz\n",
i);
ret = -EINVAL;
break;
}
ptr = mem_region + offset;
if (phdr->p_filesz && !is_split) {
/* Firmware is large enough to be non-split */
if (phdr->p_offset + phdr->p_filesz > fw->size) {
dev_err(dev, "file %s segment %d would be truncated\n",
fw_name, i);
ret = -EINVAL;
break;
}
memcpy(ptr, fw->data + phdr->p_offset, phdr->p_filesz);
} else if (phdr->p_filesz) {
/* Firmware not large enough, load split-out segments */
ret = mdt_load_split_segment(ptr, phdrs, i, fw_name, dev);
if (ret)
break;
}
if (phdr->p_memsz > phdr->p_filesz)
memset(ptr + phdr->p_filesz, 0, phdr->p_memsz - phdr->p_filesz);
}
if (reloc_base)
*reloc_base = mem_reloc;
return ret;
}
/**
* qcom_mdt_load() - load the firmware which header is loaded as fw
* @dev: device handle to associate resources with
* @fw: firmware object for the mdt file
* @firmware: name of the firmware, for construction of segment file names
* @pas_id: PAS identifier
* @mem_region: allocated memory region to load firmware into
* @mem_phys: physical address of allocated memory region
* @mem_size: size of the allocated memory region
* @reloc_base: adjusted physical address after relocation
*
* Returns 0 on success, negative errno otherwise.
*/
int qcom_mdt_load(struct device *dev, const struct firmware *fw,
const char *firmware, int pas_id, void *mem_region,
phys_addr_t mem_phys, size_t mem_size,
phys_addr_t *reloc_base)
{
int ret;
ret = qcom_mdt_pas_init(dev, fw, firmware, pas_id, mem_phys, NULL);
if (ret)
return ret;
return __qcom_mdt_load(dev, fw, firmware, pas_id, mem_region, mem_phys,
mem_size, reloc_base, true);
}
EXPORT_SYMBOL_GPL(qcom_mdt_load);
/**
* qcom_mdt_load_no_init() - load the firmware which header is loaded as fw
* @dev: device handle to associate resources with
* @fw: firmware object for the mdt file
* @firmware: name of the firmware, for construction of segment file names
* @pas_id: PAS identifier
* @mem_region: allocated memory region to load firmware into
* @mem_phys: physical address of allocated memory region
* @mem_size: size of the allocated memory region
* @reloc_base: adjusted physical address after relocation
*
* Returns 0 on success, negative errno otherwise.
*/
int qcom_mdt_load_no_init(struct device *dev, const struct firmware *fw,
const char *firmware, int pas_id,
void *mem_region, phys_addr_t mem_phys,
size_t mem_size, phys_addr_t *reloc_base)
{
return __qcom_mdt_load(dev, fw, firmware, pas_id, mem_region, mem_phys,
mem_size, reloc_base, false);
}
EXPORT_SYMBOL_GPL(qcom_mdt_load_no_init);
MODULE_DESCRIPTION("Firmware parser for Qualcomm MDT format");
MODULE_LICENSE("GPL v2");