Flush instruction cache before starting aa64 kernel

Signed-off-by: Robbie Harwood <rharwood@redhat.com>

0283-linuxefi-Invalidate-i-cache-before-starting-the-kern.patch

@@ -0,0 +1,39 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: dann frazier <dann.frazier@canonical.com>
+Date: Thu, 25 Aug 2022 17:08:09 -0600
+Subject: [PATCH] linuxefi: Invalidate i-cache before starting the kernel
+
+We need to flush the memory range of the code we are about to execute
+from the instruction cache before we can safely execute it. Not doing
+so appears to be the source of rare synchronous exceptions a user
+is seeing on a Cortex-A72-based platform while executing the Linux EFI
+stub. Notably they seem to correlate with an instruction on a cache
+line boundary.
+
+Signed-off-by: dann frazier <dann.frazier@canonical.com>
+---
+ grub-core/loader/efi/linux.c | 4 ++++
+ 1 file changed, 4 insertions(+)
+
+diff --git a/grub-core/loader/efi/linux.c b/grub-core/loader/efi/linux.c
+index 277f352e0c..e413bdcc23 100644
+--- a/grub-core/loader/efi/linux.c
++++ b/grub-core/loader/efi/linux.c
+@@ -16,6 +16,7 @@
+  *  along with GRUB.  If not, see <http://www.gnu.org/licenses/>.
+  */
+ 
++#include <grub/cache.h>
+ #include <grub/err.h>
+ #include <grub/mm.h>
+ #include <grub/types.h>
+@@ -210,6 +211,9 @@ grub_efi_linux_boot (grub_addr_t kernel_addr, grub_size_t kernel_size,
+   asm volatile ("cli");
+ #endif
+ 
++  /* Invalidate the instruction cache */
++  grub_arch_sync_caches((void *)kernel_addr, kernel_size);
++
+   hf = (handover_func)((char *)kernel_addr + handover_offset + offset);
+   hf (grub_efi_image_handle, grub_efi_system_table, kernel_params);
+ 

grub.patches

@@ -280,3 +280,4 @@ Patch0279: 0279-ieee1275-implement-vec5-for-cas-negotiation.patch
 Patch0280: 0280-blscfg-Don-t-root-device-in-emu-builds.patch
 Patch0281: 0281-loader-arm64-linux-Remove-magic-number-header-field-.patch
 Patch0282: 0282-Correct-BSS-zeroing-on-aarch64.patch
+Patch0283: 0283-linuxefi-Invalidate-i-cache-before-starting-the-kern.patch

grub2.spec

@@ -17,7 +17,7 @@
 Name:		grub2
 Epoch:		1
 Version:	2.06
-Release:	58%{?dist}
+Release:	59%{?dist}
 Summary:	Bootloader with support for Linux, Multiboot and more
 License:	GPLv3+
 URL:		http://www.gnu.org/software/grub/
@@ -530,6 +530,9 @@ mv ${EFI_HOME}/grub.cfg.stb ${EFI_HOME}/grub.cfg
 %endif
 
 %changelog
+* Tue Oct 04 2022 Robbie Harwood <rharwood@redhat.com> - 2.06-59
+- Flush instruction cache before starting aa64 kernel
+
 * Fri Sep 09 2022 Robbie Harwood <rharwood@redhat.com> - 2.06-58
 - Bump spec for grub.macros gettext changes from Jens