grub2/0184-arm-Move-trampolines-into-code-section.patch

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Alexander Graf <agraf@csgraf.de>
Date: Tue, 30 Apr 2019 22:43:56 +0200
Subject: [PATCH] arm: Move trampolines into code section

When creating T32->A32 transition jumps, the relocation code in grub
will generate trampolines. These trampolines live in the .data section
of our PE binary which means they are not marked as executable.

This misbehavior was unmasked by commit a51f953f4ee87 ("mkimage: Align
efi sections on 4k boundary") which made the X/NX boundary more obvious
because everything became page aligned.

To put things into proper order, let's move the arm trampolines into the
.text section instead. That way everyone knows they are executable.

Fixes: a51f953f4ee87 ("mkimage: Align efi sections on 4k boundary")
Reported-by: Julien ROBIN <julien.robin28@free.fr>
Reported-by: Leif Lindholm <leif.lindholm@linaro.org>
Signed-off-by: Alexander Graf <agraf@csgraf.de>
Tested-by: Julien ROBIN <julien.robin28@free.fr>
Reviewed-by: Leif Lindholm <leif.lindholm@linaro.org>
Tested-by: Leif Lindholm <leif.lindholm@linaro.org>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
---
 util/grub-mkimagexx.c | 32 +++++++++++++++-----------------
 1 file changed, 15 insertions(+), 17 deletions(-)

diff --git a/util/grub-mkimagexx.c b/util/grub-mkimagexx.c
index a483c674c49..86e6254a27e 100644
--- a/util/grub-mkimagexx.c
+++ b/util/grub-mkimagexx.c
@@ -1900,6 +1900,21 @@ SUFFIX (locate_sections) (Elf_Ehdr *e, const char *kernel_path,
 	  }
       }
 
+#ifdef MKIMAGE_ELF32
+  if (image_target->elf_target == EM_ARM)
+    {
+      grub_size_t tramp;
+
+      layout->kernel_size = ALIGN_UP (layout->kernel_size, 16);
+
+      tramp = arm_get_trampoline_size (e, smd->sections, smd->section_entsize,
+				       smd->num_sections, image_target);
+
+      layout->tramp_off = layout->kernel_size;
+      layout->kernel_size += ALIGN_UP (tramp, 16);
+    }
+#endif
+
   layout->kernel_size = ALIGN_UP (layout->kernel_size + image_target->vaddr_offset,
 			      image_target->section_align)
     - image_target->vaddr_offset;
@@ -1913,23 +1928,6 @@ SUFFIX (locate_sections) (Elf_Ehdr *e, const char *kernel_path,
       layout->kernel_size = SUFFIX (put_section) (s, i, layout->kernel_size, smd,
 						  image_target);
 
-#ifdef MKIMAGE_ELF32
-  if (image_target->elf_target == EM_ARM)
-    {
-      grub_size_t tramp;
-      layout->kernel_size = ALIGN_UP (layout->kernel_size + image_target->vaddr_offset,
-				      image_target->section_align) - image_target->vaddr_offset;
-
-      layout->kernel_size = ALIGN_UP (layout->kernel_size, 16);
-
-      tramp = arm_get_trampoline_size (e, smd->sections, smd->section_entsize,
-				       smd->num_sections, image_target);
-
-      layout->tramp_off = layout->kernel_size;
-      layout->kernel_size += ALIGN_UP (tramp, 16);
-    }
-#endif
-
   layout->bss_start = layout->kernel_size;
   layout->end = layout->kernel_size;