[PATCH v2 2/2] remoteproc: Add elf64 support in elf loader

Clement Leger
2020-02-04T14:36:11Z

From: Clément Leger <cleger@kalray.eu>

elf32 and elf64 mainly differ by their types. In order to avoid
copy/pasting the whole loader code, generate static inline functions
which will access values according to the elf class. It allows to keep a
common loader basis.
In order to accommodate both elf types sizes, the maximum size for a
elf header member is chosen using the maximum value of both elf class.

Signed-off-by: Clement Leger <cleger@kalray.eu>
Tested-by: Arnaud POULIQUEN <arnaud.pouliquen@st.com>
---
V2:
- Add check for elf64 header size
- Add comments for name table parsing
- Fix typo in "accommodate"

Documentation/remoteproc.txt | 2 +-
drivers/remoteproc/remoteproc_elf_loader.c | 147 ++++++++++++++++++-----------
drivers/remoteproc/remoteproc_elf_loader.h | 69 ++++++++++++++
drivers/remoteproc/remoteproc_internal.h | 2 +-
drivers/remoteproc/st_remoteproc.c | 2 +-
include/linux/remoteproc.h | 4 +-
6 files changed, 167 insertions(+), 59 deletions(-)
create mode 100644 drivers/remoteproc/remoteproc_elf_loader.h

diff --git a/Documentation/remoteproc.txt b/Documentation/remoteproc.txt
index 03c3d2e568b0..2be1147256e0 100644
--- a/Documentation/remoteproc.txt
+++ b/Documentation/remoteproc.txt
@@ -230,7 +230,7 @@ in the used rings.
Binary Firmware Structure
=========================

-At this point remoteproc only supports ELF32 firmware binaries. However,
+At this point remoteproc supports ELF32 and ELF64 firmware binaries. However,
it is quite expected that other platforms/devices which we'd want to
support with this framework will be based on different binary formats.

diff --git a/drivers/remoteproc/remoteproc_elf_loader.c b/drivers/remoteproc/remoteproc_elf_loader.c
index 606aae166eba..21fd2b2fe5ae 100644
--- a/drivers/remoteproc/remoteproc_elf_loader.c
+++ b/drivers/remoteproc/remoteproc_elf_loader.c
@@ -23,6 +23,7 @@
#include <linux/elf.h>

#include "remoteproc_internal.h"
+#include "remoteproc_elf_loader.h"

/**
* rproc_elf_sanity_check() - Sanity Check ELF firmware image
@@ -35,8 +36,16 @@ 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_size;
+ u64 phoff, shoff;
char class;
+ u16 phnum;

if (!fw) {
dev_err(dev, "failed to load %s\n", name);
@@ -50,13 +59,22 @@ int rproc_elf_sanity_check(struct rproc *rproc, const struct firmware *fw)

ehdr = (struct elf32_hdr *)fw->data;

- /* We only support ELF32 at this point */
+ 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) {
+ 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) {
@@ -67,26 +85,29 @@ int rproc_elf_sanity_check(struct rproc *rproc, const struct firmware *fw)
return -EINVAL;
}

- if (fw->size < ehdr->e_shoff + sizeof(struct elf32_shdr)) {
- dev_err(dev, "Image is too small\n");
- return -EINVAL;
- }
+ phoff = elf_hdr_e_phoff(class, fw->data);
+ shoff = elf_hdr_e_shoff(class, fw->data);
+ phnum = elf_hdr_e_phnum(class, fw->data);
+ elf_shdr_size = elf_size_of_shdr(class);

- if (memcmp(ehdr->e_ident, ELFMAG, SELFMAG)) {
- dev_err(dev, "Image is corrupted (bad magic)\n");
+ if (fw->size < shoff + elf_shdr_size) {
+ dev_err(dev, "Image is too small\n");
return -EINVAL;
}

- if (ehdr->e_phnum == 0) {
+ if (phnum == 0) {
dev_err(dev, "No loadable segments\n");
return -EINVAL;
}

- if (ehdr->e_phoff > fw->size) {
+ 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);
@@ -102,11 +123,9 @@ EXPORT_SYMBOL(rproc_elf_sanity_check);
* Note that the boot address is not a configurable property of all remote
* processors. Some will always boot at a specific hard-coded address.
*/
-u32 rproc_elf_get_boot_addr(struct rproc *rproc, const struct firmware *fw)
+u64 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;
+ return elf_hdr_e_entry(fw_elf_get_class(fw), fw->data);
}
EXPORT_SYMBOL(rproc_elf_get_boot_addr);

@@ -137,37 +156,41 @@ EXPORT_SYMBOL(rproc_elf_get_boot_addr);
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;
+ 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_size = elf_size_of_phdr(class);

- ehdr = (struct elf32_hdr *)elf_data;
- phdr = (struct elf32_phdr *)(elf_data + ehdr->e_phoff);
+ ehdr = elf_data;
+ phnum = elf_hdr_e_phnum(class, ehdr);
+ phdr = elf_data + elf_hdr_e_phoff(class, ehdr);

/* 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;
+ for (i = 0; i < phnum; i++, phdr += elf_phdr_size) {
+ u64 da = elf_phdr_p_paddr(class, phdr);
+ u64 memsz = elf_phdr_p_memsz(class, phdr);
+ u64 filesz = elf_phdr_p_filesz(class, phdr);
+ u64 offset = elf_phdr_p_offset(class, phdr);
+ u32 type = elf_phdr_p_type(class, phdr);
void *ptr;

- if (phdr->p_type != PT_LOAD)
+ if (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);
+ 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%x memsz 0x%x\n",
+ 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%x avail 0x%zx\n",
+ dev_err(dev, "truncated fw: need 0x%llx avail 0x%zx\n",
offset + filesz, fw->size);
ret = -EINVAL;
break;
@@ -176,14 +199,15 @@ int rproc_elf_load_segments(struct rproc *rproc, const struct firmware *fw)
/* 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);
+ 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 (phdr->p_filesz)
- memcpy(ptr, elf_data + phdr->p_offset, filesz);
+ if (filesz)
+ memcpy(ptr, elf_data + offset, filesz);

/*
* Zero out remaining memory for this segment.
@@ -200,24 +224,35 @@ int rproc_elf_load_segments(struct rproc *rproc, const struct firmware *fw)
}
EXPORT_SYMBOL(rproc_elf_load_segments);

-static struct elf32_shdr *
-find_table(struct device *dev, struct elf32_hdr *ehdr, size_t fw_size)
+static const void *
+find_table(struct device *dev, const struct firmware *fw)
{
- struct elf32_shdr *shdr;
+ const void *shdr, *name_table_shdr;
int i;
const char *name_table;
struct resource_table *table = NULL;
- const u8 *elf_data = (void *)ehdr;
+ 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_e_shnum(class, ehdr);
+ u32 elf_shdr_size = elf_size_of_shdr(class);
+ u16 shstrndx = elf_hdr_e_shstrndx(class, 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"))
+ /* First, get the section header according to the elf class */
+ shdr = elf_data + elf_hdr_e_shoff(class, ehdr);
+ /* Compute name table section header entry in shdr array */
+ name_table_shdr = shdr + (shstrndx * elf_shdr_size);
+ /* Finally, compute the name table section address in elf */
+ name_table = elf_data + elf_shdr_sh_offset(class, name_table_shdr);
+
+ for (i = 0; i < shnum; i++, shdr += elf_shdr_size) {
+ u64 size = elf_shdr_sh_size(class, shdr);
+ u64 offset = elf_shdr_sh_offset(class, shdr);
+ u32 name = elf_shdr_sh_name(class, shdr);
+
+ if (strcmp(name_table + name, ".resource_table"))
continue;

table = (struct resource_table *)(elf_data + offset);
@@ -270,21 +305,21 @@ find_table(struct device *dev, struct elf32_hdr *ehdr, size_t fw_size)
*/
int rproc_elf_load_rsc_table(struct rproc *rproc, const struct firmware *fw)
{
- struct elf32_hdr *ehdr;
- struct elf32_shdr *shdr;
+ 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;

- ehdr = (struct elf32_hdr *)elf_data;
-
- shdr = find_table(dev, ehdr, fw->size);
+ shdr = find_table(dev, fw);
if (!shdr)
return -EINVAL;

- table = (struct resource_table *)(elf_data + shdr->sh_offset);
- tablesz = shdr->sh_size;
+ sh_offset = elf_shdr_sh_offset(class, shdr);
+ table = (struct resource_table *)(elf_data + sh_offset);
+ tablesz = elf_shdr_sh_size(class, shdr);

/*
* Create a copy of the resource table. When a virtio device starts
@@ -317,13 +352,17 @@ EXPORT_SYMBOL(rproc_elf_load_rsc_table);
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;
+ const void *shdr;
+ u64 sh_addr, sh_size;
+ u8 class = fw_elf_get_class(fw);

- shdr = find_table(&rproc->dev, ehdr, fw->size);
+ shdr = find_table(&rproc->dev, fw);
if (!shdr)
return NULL;

- return rproc_da_to_va(rproc, shdr->sh_addr, shdr->sh_size);
+ sh_addr = elf_shdr_sh_addr(class, shdr);
+ sh_size = elf_shdr_sh_size(class, shdr);
+
+ return rproc_da_to_va(rproc, sh_addr, sh_size);
}
EXPORT_SYMBOL(rproc_elf_find_loaded_rsc_table);
diff --git a/drivers/remoteproc/remoteproc_elf_loader.h b/drivers/remoteproc/remoteproc_elf_loader.h
new file mode 100644
index 000000000000..fac3565734f9
--- /dev/null
+++ b/drivers/remoteproc/remoteproc_elf_loader.h
@@ -0,0 +1,69 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Remote processor elf loader defines
+ *
+ * Copyright (C) 2019 Kalray, Inc.
+ */
+
+#ifndef REMOTEPROC_ELF_LOADER_H
+#define REMOTEPROC_ELF_LOADER_H
+
+#include <linux/elf.h>
+#include <linux/types.h>
+
+/**
+ * fw_elf_get_class - Get elf class
+ * @fw: the ELF firmware image
+ *
+ * Note that we use and elf32_hdr to access the class since the start of the
+ * struct is the same for both elf class
+ *
+ * Return: elf class of the firmware
+ */
+static inline u8 fw_elf_get_class(const struct firmware *fw)
+{
+ struct elf32_hdr *ehdr = (struct elf32_hdr *)fw->data;
+
+ return ehdr->e_ident[EI_CLASS];
+}
+
+#define ELF_GET_FIELD(__s, __field, __type) \
+static inline __type elf_##__s##_##__field(u8 class, const void *arg) \
+{ \
+ if (class == ELFCLASS32) \
+ return (__type) ((const struct elf32_##__s *) arg)->__field; \
+ else \
+ return (__type) ((const struct elf64_##__s *) arg)->__field; \
+}
+
+ELF_GET_FIELD(hdr, e_entry, u64)
+ELF_GET_FIELD(hdr, e_phnum, u16)
+ELF_GET_FIELD(hdr, e_shnum, u16)
+ELF_GET_FIELD(hdr, e_phoff, u64)
+ELF_GET_FIELD(hdr, e_shoff, u64)
+ELF_GET_FIELD(hdr, e_shstrndx, u16)
+
+ELF_GET_FIELD(phdr, p_paddr, u64)
+ELF_GET_FIELD(phdr, p_filesz, u64)
+ELF_GET_FIELD(phdr, p_memsz, u64)
+ELF_GET_FIELD(phdr, p_type, u32)
+ELF_GET_FIELD(phdr, p_offset, u64)
+
+ELF_GET_FIELD(shdr, sh_size, u64)
+ELF_GET_FIELD(shdr, sh_offset, u64)
+ELF_GET_FIELD(shdr, sh_name, u32)
+ELF_GET_FIELD(shdr, sh_addr, u64)
+
+#define ELF_STRUCT_SIZE(__s) \
+static inline unsigned long elf_size_of_##__s(u8 class) \
+{ \
+ if (class == ELFCLASS32)\
+ return sizeof(struct elf32_##__s); \
+ else \
+ return sizeof(struct elf64_##__s); \
+}
+
+ELF_STRUCT_SIZE(shdr)
+ELF_STRUCT_SIZE(phdr)
+
+#endif /* REMOTEPROC_ELF_LOADER_H */
diff --git a/drivers/remoteproc/remoteproc_internal.h b/drivers/remoteproc/remoteproc_internal.h
index 004867061721..eeb26434220e 100644
--- a/drivers/remoteproc/remoteproc_internal.h
+++ b/drivers/remoteproc/remoteproc_internal.h
@@ -55,7 +55,7 @@ phys_addr_t rproc_va_to_pa(void *cpu_addr);
int rproc_trigger_recovery(struct rproc *rproc);

int rproc_elf_sanity_check(struct rproc *rproc, const struct firmware *fw);
-u32 rproc_elf_get_boot_addr(struct rproc *rproc, const struct firmware *fw);
+u64 rproc_elf_get_boot_addr(struct rproc *rproc, const struct firmware *fw);
int rproc_elf_load_segments(struct rproc *rproc, const struct firmware *fw);
int rproc_elf_load_rsc_table(struct rproc *rproc, const struct firmware *fw);
struct resource_table *rproc_elf_find_loaded_rsc_table(struct rproc *rproc,
diff --git a/drivers/remoteproc/st_remoteproc.c b/drivers/remoteproc/st_remoteproc.c
index ee13d23b43a9..a3268d95a50e 100644
--- a/drivers/remoteproc/st_remoteproc.c
+++ b/drivers/remoteproc/st_remoteproc.c
@@ -190,7 +190,7 @@ static int st_rproc_start(struct rproc *rproc)
}
}

- dev_info(&rproc->dev, "Started from 0x%x\n", rproc->bootaddr);
+ dev_info(&rproc->dev, "Started from 0x%llx\n", rproc->bootaddr);

return 0;

diff --git a/include/linux/remoteproc.h b/include/linux/remoteproc.h
index f84bd5fe0211..82cebca9344c 100644
--- a/include/linux/remoteproc.h
+++ b/include/linux/remoteproc.h
@@ -382,7 +382,7 @@ struct rproc_ops {
struct rproc *rproc, const struct firmware *fw);
int (*load)(struct rproc *rproc, const struct firmware *fw);
int (*sanity_check)(struct rproc *rproc, const struct firmware *fw);
- u32 (*get_boot_addr)(struct rproc *rproc, const struct firmware *fw);
+ u64 (*get_boot_addr)(struct rproc *rproc, const struct firmware *fw);
};

/**
@@ -498,7 +498,7 @@ struct rproc {
int num_traces;
struct list_head carveouts;
struct list_head mappings;
- u32 bootaddr;
+ u64 bootaddr;
struct list_head rvdevs;
struct list_head subdevs;
struct idr notifyids;
--
2.15.0.276.g89ea799