Subject: [PATCH v4 4/5] ARM: decompressor: move GOT into .data for EFI enabled builds

From: Ard Biesheuvel <[email-masked]>
Date: Tue, 19 May 2020 18:26:44 +0200

We will be running the decompressor in place after a future patch,
instead of copying it around first. This means we no longer have to
disable and re-enable the MMU and caches either. However, this means
we will be loaded with the restricted permissions set by the UEFI
firmware, which means that we have to move the GOT table into the
data section in order for the contents to be writable by the code
itself.

Signed-off-by: Ard Biesheuvel <[email-masked]>
Reviewed-by: Nicolas Pitre <[email-masked]>
---
 arch/arm/boot/compressed/vmlinux.lds.S | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/arch/arm/boot/compressed/vmlinux.lds.S b/arch/arm/boot/compressed/vmlinux.lds.S
index b247f399de71..d0619ec05705 100644
--- a/arch/arm/boot/compressed/vmlinux.lds.S
+++ b/arch/arm/boot/compressed/vmlinux.lds.S
@@ -63,9 +63,11 @@ SECTIONS
   _etext = .;
 
   .got.plt		: { *(.got.plt) }
+#ifndef CONFIG_EFI_STUB
   _got_start = .;
   .got			: { *(.got) }
   _got_end = .;
+#endif
 
   /* ensure the zImage file size is always a multiple of 64 bits */
   /* (without a dummy byte, ld just ignores the empty section) */
@@ -74,6 +76,9 @@ SECTIONS
 #ifdef CONFIG_EFI_STUB
   .data : ALIGN(4096) {
     __pecoff_data_start = .;
+    _got_start = .;
+    *(.got)
+    _got_end = .;
     /*
      * The EFI stub always executes from RAM, and runs strictly before the
      * decompressor, so we can make an exception for its r/w data, and keep it
-- 
2.17.1

_______________________________________________
linux-arm-kernel mailing list
[email-masked]
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel