[PATCH v3] util/mkimage: Fix wrong PE32+ section sizes for some arches

* [PATCH v3] util/mkimage: Fix wrong PE32+ section sizes for some arches
@ 2021-04-27 10:25 Javier Martinez Canillas
  2021-04-27 10:48 ` John Paul Adrian Glaubitz
  0 siblings, 1 reply; 6+ messages in thread
From: Javier Martinez Canillas @ 2021-04-27 10:25 UTC (permalink / raw)
  To: grub-devel
  Cc: John Paul Adrian Glaubitz, Daniel Kiper, Javier Martinez Canillas

Commit f60ba9e5945 (util/mkimage: Refactor section setup to use a helper)
added a helper function to setup PE sections. But it also changed how the
raw data offsets were calculated since all the section sizes are aligned.

However, for some platforms, i.e ia64-efi and arm64-efi, the kernel image
size is not aligned using the section alignment.

This leads to the situation in which the mods section offset in its PE
section header does not match its real placement in the PE file.
So, finally the GRUB is not able to locate and load built-in modules.

The problem surfaces on ia64-efi and arm64-efi because both platforms
require additional relocation data which is added behind .bss section.
So, we have to add some padding behind this extra data to make the
beginning of mods section properly aligned in the PE file.

Fix it by aligning the kernel_size to the section alignment. That makes
the sizes and offsets in the PE section headers to match relevant sections
in the PE32+ binary file.

Reported-by: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
---

Changes in v3:
- Drop the RFC prefix since I'm confident now about the solution.
- Improve commit message (suggested by Daniel Kiper).
- Don't use virtual memory addresses to calculate the kernel size,
  but instead use the raw data sizes (suggested by Daniel Kiper).

Changes in v2:
- Align up for any arch in the is_relocatable (image_target) patch and
  not only for MKIMAGE_ELF64 or EM_AARCH64 (suggested by Daniel Kiper).

 util/grub-mkimagexx.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/util/grub-mkimagexx.c b/util/grub-mkimagexx.c
index 00f49ccaaaf..d78fa3e5330 100644
--- a/util/grub-mkimagexx.c
+++ b/util/grub-mkimagexx.c
@@ -2388,6 +2388,10 @@ SUFFIX (grub_mkimage_load_image) (const char *kernel_path,
 	  layout->kernel_size += ALIGN_UP (layout->got_size, 16);
 	}
 #endif
+
+      if (image_target->id == IMAGE_EFI)
+        layout->kernel_size = ALIGN_UP (layout->kernel_size,
+                                        GRUB_PE32_FILE_ALIGNMENT);
     }
   else
     {
-- 
2.31.1



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