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

[Jules Maselbas]

On Fri, Jan 14, 2022 at 06:21:09PM +0100, Clément Léger wrote:
> 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 ?
Sure can, I wasn't sure which email I should have used. I'll send a v2.

> 
> 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
> 
> 
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>