[U-Boot] [PATCH v2] efi_loader: set image_base and image_size to correct values

[AKASHI Takahiro]

On Thu, Oct 11, 2018 at 04:18:33PM +0200, Heinrich Schuchardt wrote:
> On 10/11/2018 01:11 PM, AKASHI Takahiro wrote:
> > Currently, image's image_base points to an address where the image was
> > temporarily uploaded for further loading. Since efi_loader relocates
> > the image to final destination, image_base and image_size should reflect
> > that.
> > 
> > This bug was detected in UEFI SCT, "Loaded Image Protocol Test - test 2,"
> > which shows that 'Unload' function doesn't fit into a range suggested by
> > image_base and image_size.
> > 	TestCase/UEFI/EFI/Protocol/LoadedImage/BlackBoxTest/
> > 	LoadedImageBBTestMain.c:1002
> > 
> > Changes in this patch also includes:
> > * reverts a patch, "efi_loader: save image relocation address
> >   and size" since newly added fields are no longer needed.
> > * copy PE headers as well since those information will be needed
> >   for module loading, in particular, at gurb.
> >   (This bug was reported by Heinrich.)
> > 
> > Signed-off-by: AKASHI Takahiro <takahiro.akashi at linaro.org>
> > Reported-by: Heinrich Schuchardt <xypron.glpk at gmx.de>
> > ---
> >  lib/efi_loader/efi_image_loader.c | 22 +++++++++++-----------
> >  1 file changed, 11 insertions(+), 11 deletions(-)
> > 
> > diff --git a/lib/efi_loader/efi_image_loader.c b/lib/efi_loader/efi_image_loader.c
> > index a18ce0a5705e..d1b6c0d3cdf2 100644
> > --- a/lib/efi_loader/efi_image_loader.c
> > +++ b/lib/efi_loader/efi_image_loader.c
> > @@ -59,10 +59,10 @@ static efi_status_t efi_print_image_info(struct efi_loaded_image_obj *obj,
> >  {
> >  	printf("UEFI image");
> >  	printf(" [0x%p:0x%p]",
> > -	       obj->reloc_base, obj->reloc_base + obj->reloc_size - 1);
> > -	if (pc && pc >= obj->reloc_base &&
> > -	    pc < obj->reloc_base + obj->reloc_size)
> > -		printf(" pc=0x%zx", pc - obj->reloc_base);
> > +	       image->image_base, image->image_base + image->image_size - 1);
> > +	if (pc && pc >= image->image_base &&
> > +	    pc < image->image_base + image->image_size)
> > +		printf(" pc=0x%zx", pc - image->image_base);
> >  	if (image->file_path)
> >  		printf(" '%pD'", image->file_path);
> >  	printf("\n");
> > @@ -212,7 +212,6 @@ void *efi_load_pe(struct efi_loaded_image_obj *handle, void *efi,
> >  	int rel_idx = IMAGE_DIRECTORY_ENTRY_BASERELOC;
> >  	void *entry;
> >  	uint64_t image_base;
> > -	uint64_t image_size;
> >  	unsigned long virt_size = 0;
> >  	int supported = 0;
> >  
> > @@ -256,7 +255,6 @@ void *efi_load_pe(struct efi_loaded_image_obj *handle, void *efi,
> >  		IMAGE_NT_HEADERS64 *nt64 = (void *)nt;
> >  		IMAGE_OPTIONAL_HEADER64 *opt = &nt64->OptionalHeader;
> >  		image_base = opt->ImageBase;
> > -		image_size = opt->SizeOfImage;
> >  		efi_set_code_and_data_type(loaded_image_info, opt->Subsystem);
> >  		efi_reloc = efi_alloc(virt_size,
> >  				      loaded_image_info->image_code_type);
> > @@ -272,7 +270,6 @@ void *efi_load_pe(struct efi_loaded_image_obj *handle, void *efi,
> >  	} else if (nt->OptionalHeader.Magic == IMAGE_NT_OPTIONAL_HDR32_MAGIC) {
> >  		IMAGE_OPTIONAL_HEADER32 *opt = &nt->OptionalHeader;
> >  		image_base = opt->ImageBase;
> > -		image_size = opt->SizeOfImage;
> >  		efi_set_code_and_data_type(loaded_image_info, opt->Subsystem);
> >  		efi_reloc = efi_alloc(virt_size,
> >  				      loaded_image_info->image_code_type);
> > @@ -291,6 +288,11 @@ void *efi_load_pe(struct efi_loaded_image_obj *handle, void *efi,
> >  		return NULL;
> >  	}
> >  
> > +	/* Copy PE headers */
> > +	memcpy(efi_reloc, efi, sizeof(*dos) + sizeof(*nt)
> > +			+ nt->FileHeader.SizeOfOptionalHeader
> > +			+ num_sections * sizeof(IMAGE_SECTION_HEADER));
> > +
> 
> Why do we have to copy PE headers and the sections below separately? My
> understanding is that the relative positions do not need any adjustment.

I think I have already answered your questions here:
https://lists.denx.de/pipermail/u-boot/2018-October/343876.html

Did you read it?

> Nothing in the spec requires the COFF header to be at offset
> sizeof(dos). You can put the COFF headder anywhere in the file. Please,
> read

But as far as I look at grub code (that you pointed out in your e-mail),
grub expects that PE headers be also "loaded" within an allocated region
(more specifically at the beginning of the region)
along with other sections in order to handle a (grub-specific? I don't know)
"mods" section.

-Takahiro Akashi

> https://media.blackhat.com/bh-us-11/Vuksan/BH_US_11_VuksanPericin_PECOFF_WP.pdf
> 
> We should not assign new memory here. Nor should we copy anything here.
> We should simply use the relocation table to update the indicated memory
> locations.
> 
> Best regards
> 
> Heinrich
> 
> 
> >  	/* Load sections into RAM */
> >  	for (i = num_sections - 1; i >= 0; i--) {
> >  		IMAGE_SECTION_HEADER *sec = &sections[i];
> > @@ -315,10 +317,8 @@ void *efi_load_pe(struct efi_loaded_image_obj *handle, void *efi,
> >  	invalidate_icache_all();
> >  
> >  	/* Populate the loaded image interface bits */
> > -	loaded_image_info->image_base = efi;
> > -	loaded_image_info->image_size = image_size;
> > -	handle->reloc_base = efi_reloc;
> > -	handle->reloc_size = virt_size;
> > +	loaded_image_info->image_base = efi_reloc;
> > +	loaded_image_info->image_size = virt_size;
> >  
> >  	return entry;
> >  }
> > 
>