[PATCH 04/13] common: elf: add elf_load_binary

[Clément Léger]

Le Fri, 14 Jan 2022 17:52:03 +0100,
Jules Maselbas <jmaselbas at kalray.eu> a écrit :

> From: Clement Leger <cleger at kalray.eu>
> 
> In order to load elf from a binary buffer, add elf_load_binary. This
> will be used by FIT support to allow loading an elf from FIT.
> 
> Signed-off-by: Clement Leger <cleger at kalray.eu>

Hi Jules,

This is not my mail address anymore, could you update it with
clement.leger at bootlin.com ?

Thanks.

> Signed-off-by: Jules Maselbas <jmaselbas at kalray.eu>
> ---
>  common/elf.c  | 83 +++++++++++++++++++++++++++++++++++++--------------
>  include/elf.h |  1 +
>  2 files changed, 62 insertions(+), 22 deletions(-)
> 
> diff --git a/common/elf.c b/common/elf.c
> index af22be37e6..f10fb77953 100644
> --- a/common/elf.c
> +++ b/common/elf.c
> @@ -101,15 +101,17 @@ static int elf_section_cmp(void *priv, struct list_head *a, struct list_head *b)
>  static int load_elf_to_memory(struct elf_image *elf)
>  {
>  	void *dst;
> -	int ret, fd;
> +	int ret, fd = -1;
>  	u64 p_filesz, p_memsz, p_offset;
>  	struct elf_section *r;
>  	struct list_head *list = &elf->list;
>  
> -	fd = open(elf->filename, O_RDONLY);
> -	if (fd < 0) {
> -		pr_err("could not open: %s\n", errno_str());
> -		return -errno;
> +	if (elf->filename) {
> +		fd = open(elf->filename, O_RDONLY);
> +		if (fd < 0) {
> +			pr_err("could not open: %s\n", errno_str());
> +			return -errno;
> +		}
>  	}
>  
>  	list_for_each_entry(r, list, list) {
> @@ -118,21 +120,26 @@ static int load_elf_to_memory(struct elf_image *elf)
>  		p_memsz = elf_phdr_p_memsz(elf, r->phdr);
>  		dst = (void *) (phys_addr_t) elf_phdr_p_paddr(elf, r->phdr);
>  
> -		ret = lseek(fd, p_offset, SEEK_SET);
> -		if (ret == -1) {
> -			pr_err("lseek at offset 0x%llx failed\n", p_offset);
> -			close(fd);
> -			return ret;
> -		}
> -
>  		pr_debug("Loading phdr offset 0x%llx to 0x%p (%llu bytes)\n",
>  			 p_offset, dst, p_filesz);
>  
> -		if (read_full(fd, dst, p_filesz) < 0) {
> -			pr_err("could not read elf segment: %s\n",
> -			       errno_str());
> -			close(fd);
> -			return -errno;
> +		if (fd >= 0) {
> +			ret = lseek(fd, p_offset, SEEK_SET);
> +			if (ret == -1) {
> +				pr_err("lseek at offset 0x%llx failed\n",
> +				       p_offset);
> +				close(fd);
> +				return ret;
> +			}
> +
> +			if (read_full(fd, dst, p_filesz) < 0) {
> +				pr_err("could not read elf segment: %s\n",
> +				       errno_str());
> +				close(fd);
> +				return -errno;
> +			}
> +		} else {
> +			memcpy(dst, elf->hdr_buf + p_offset, p_filesz);
>  		}
>  
>  		if (p_filesz < p_memsz)
> @@ -202,6 +209,37 @@ static int elf_check_image(struct elf_image *elf, void *buf)
>  	return 0;
>  }
>  
> +static void elf_init_struct(struct elf_image *elf)
> +{
> +	INIT_LIST_HEAD(&elf->list);
> +	elf->low_addr = (void *) (unsigned long) -1;
> +	elf->high_addr = 0;
> +	elf->filename = NULL;
> +}
> +
> +struct elf_image *elf_open_binary(void *buf)
> +{
> +	int ret;
> +	struct elf_image *elf;
> +
> +	elf = calloc(1, sizeof(*elf));
> +	if (!elf)
> +		return ERR_PTR(-ENOMEM);
> +
> +	elf_init_struct(elf);
> +
> +	elf->hdr_buf = buf;
> +	ret = elf_check_image(elf, buf);
> +	if (ret) {
> +		free(elf);
> +		return ERR_PTR(-EINVAL);
> +	}
> +
> +	elf->entry = elf_hdr_e_entry(elf, elf->hdr_buf);
> +
> +	return elf;
> +}
> +
>  static struct elf_image *elf_check_init(const char *filename)
>  {
>  	int ret, fd;
> @@ -213,9 +251,7 @@ static struct elf_image *elf_check_init(const char *filename)
>  	if (!elf)
>  		return ERR_PTR(-ENOMEM);
>  
> -	INIT_LIST_HEAD(&elf->list);
> -	elf->low_addr = (void *) (unsigned long) -1;
> -	elf->high_addr = 0;
> +	elf_init_struct(elf);
>  
>  	/* First pass is to read elf header only */
>  	fd = open(filename, O_RDONLY);
> @@ -299,7 +335,10 @@ void elf_close(struct elf_image *elf)
>  {
>  	elf_release_regions(elf);
>  
> -	free(elf->hdr_buf);
> -	free(elf->filename);
> +	if (elf->filename) {
> +		free(elf->hdr_buf);
> +		free(elf->filename);
> +	}
> +
>  	free(elf);
>  }
> diff --git a/include/elf.h b/include/elf.h
> index 7970fd2c95..12673e93ed 100644
> --- a/include/elf.h
> +++ b/include/elf.h
> @@ -414,6 +414,7 @@ static inline size_t elf_get_mem_size(struct elf_image *elf)
>  	return elf->high_addr - elf->low_addr;
>  }
>  
> +struct elf_image *elf_open_binary(void *buf);
>  struct elf_image *elf_open(const char *filename);
>  void elf_close(struct elf_image *elf);
>  int elf_load(struct elf_image *elf);



-- 
Clément Léger,
Embedded Linux and Kernel engineer at Bootlin
https://bootlin.com