Re: GRUB error: unknown filesystem on ia64

[Javier Martinez Canillas <fmartine@redhat.com>]

Hello Adrian,

Sorry for the delay, I didn't have time to look at this issue before.

On 4/12/21 8:57 AM, John Paul Adrian Glaubitz wrote:
> Hi Javier!
> 
> On 4/12/21 8:21 AM, Javier Martinez Canillas wrote:
>> Interesting, thanks for the input.
>>
>> Could you please share a both GRUB binary that works and one that
>> fails to compare ?
> 
> Here are both the EFI as well as the GRUB directory for the broken
> and working cases:
> 
>> https://people.debian.org/~glaubitz/grub-ia64/
> 
> If you compare the two core.efi images, you will see the issue immediately:
> 

Thanks for the binaries, as you said the ".data" and "mods" sections had
wrong size and content. Could you please try the following patch [0] ?

It's an RFC since I'm not really an expert on binary formats, but there
were a few problems with the patch you mentioned as far as I can tell.

I Cc'ed Daniel and Peter so they can correct me if I got anything wrong.

Best regards,
Javier

[0]
From 31c9864ff6543b624d404d8fabc9c517756a470a Mon Sep 17 00:00:00 2001
From: Javier Martinez Canillas <javierm@redhat.com>
Date: Fri, 16 Apr 2021 17:01:44 +0200
Subject: [RFC PATCH] util/mkimage: Some fixes to PE binaries section size
 calculation

Commit f60ba9e5945 (util/mkimage: Refactor section setup to use a helper)
added a helper function to setup PE sections, but it caused regressions
in some arches where the natural alignment lead to wrong section sizes.

This patch fixes a few things that were caused the section sizes to be
calculated wrongly. These fixes are:

 * Only align the virtual memory addresses but not the raw data offsets.
 * Use aligned sizes for virtual memory sizes but not for raw data sizes.
 * Always align the sizes to set the virtual memory sizes.

These seems to not cause problems for x64 and aa64 EFI platforms but was
a problem for ia64. Because the size of the ".data" and "mods" sections
were wrong and didn't have the correct content. Which lead to GRUB not
being able to load any built-in module.

Reported-by: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
---
 util/mkimage.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/util/mkimage.c b/util/mkimage.c
index 8b475a69109..0d33f0e9766 100644
--- a/util/mkimage.c
+++ b/util/mkimage.c
@@ -841,7 +841,7 @@ init_pe_section(const struct grub_install_image_target_desc *image_target,
 
   section->raw_data_offset = grub_host_to_target32 (*rda);
   section->raw_data_size = grub_host_to_target32 (rsz);
-  (*rda) = ALIGN_UP (*rda + rsz, GRUB_PE32_FILE_ALIGNMENT);
+  (*rda) = *rda + rsz;
 
   section->characteristics = grub_host_to_target32 (characteristics);
 
@@ -1389,26 +1389,26 @@ grub_install_generate_image (const char *dir, const char *prefix,
 
 	section = init_pe_section (image_target, section, ".data",
 				   &vma, scn_size, image_target->section_align,
-				   &raw_data, scn_size,
+				   &raw_data, layout.kernel_size - layout.exec_size,
 				   GRUB_PE32_SCN_CNT_INITIALIZED_DATA |
 				   GRUB_PE32_SCN_MEM_READ |
 				   GRUB_PE32_SCN_MEM_WRITE);
 
-	scn_size = pe_size - layout.reloc_size - raw_data;
+	scn_size = ALIGN_UP (pe_size - layout.reloc_size - raw_data, GRUB_PE32_FILE_ALIGNMENT);
 	section = init_pe_section (image_target, section, "mods",
 				   &vma, scn_size, image_target->section_align,
-				   &raw_data, scn_size,
+				   &raw_data, pe_size - layout.reloc_size - raw_data,
 				   GRUB_PE32_SCN_CNT_INITIALIZED_DATA |
 				   GRUB_PE32_SCN_MEM_READ |
 				   GRUB_PE32_SCN_MEM_WRITE);
 
-	scn_size = layout.reloc_size;
+	scn_size = ALIGN_UP (layout.reloc_size, GRUB_PE32_FILE_ALIGNMENT);
 	PE_OHDR (o32, o64, base_relocation_table.rva) = grub_host_to_target32 (vma);
 	PE_OHDR (o32, o64, base_relocation_table.size) = grub_host_to_target32 (scn_size);
 	memcpy (pe_img + raw_data, layout.reloc_section, scn_size);
 	init_pe_section (image_target, section, ".reloc",
 			 &vma, scn_size, image_target->section_align,
-			 &raw_data, scn_size,
+			 &raw_data, layout.reloc_size,
 			 GRUB_PE32_SCN_CNT_INITIALIZED_DATA |
 			 GRUB_PE32_SCN_MEM_DISCARDABLE |
 			 GRUB_PE32_SCN_MEM_READ);
-- 
2.30.2