efi/arm: Remove __efistub_global annotation

Instead of using __efistub_global to force variables into the .data
section, leave them in the .bss but pull the EFI stub's .bss section
into .data in the linker script for the compressed kernel.

Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20200416151227.3360778-2-nivedita@alum.mit.edu
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

diff --git a/arch/arm/boot/compressed/vmlinux.lds.S b/arch/arm/boot/compressed/vmlinux.lds.S
index b247f39..b6793c7 100644 (file)
--- a/arch/arm/boot/compressed/vmlinux.lds.S
+++ b/arch/arm/boot/compressed/vmlinux.lds.S
@@ -78,7 +78,7 @@ SECTIONS
      * 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
      */
-    *(.data.efistub)
+    *(.data.efistub .bss.efistub)
     __pecoff_data_end = .;
 
     /*

diff --git a/drivers/firmware/efi/libstub/Makefile b/drivers/firmware/efi/libstub/Makefile
index 9a712a6..aa3ab9a 100644 (file)
--- a/drivers/firmware/efi/libstub/Makefile
+++ b/drivers/firmware/efi/libstub/Makefile
@@ -101,8 +101,9 @@ quiet_cmd_stubcopy = STUBCPY $@
 
 #
 # ARM discards the .data section because it disallows r/w data in the
-# decompressor. So move our .data to .data.efistub, which is preserved
-# explicitly by the decompressor linker script.
+# decompressor. So move our .data to .data.efistub and .bss to .bss.efistub,
+# which are preserved explicitly by the decompressor linker script.
 #
-STUBCOPY_FLAGS-$(CONFIG_ARM)   += --rename-section .data=.data.efistub
+STUBCOPY_FLAGS-$(CONFIG_ARM)   += --rename-section .data=.data.efistub \
+                                  --rename-section .bss=.bss.efistub,load,alloc
 STUBCOPY_RELOC-$(CONFIG_ARM)   := R_ARM_ABS

diff --git a/drivers/firmware/efi/libstub/efistub.h b/drivers/firmware/efi/libstub/efistub.h
index 2a0698d..96e25b1 100644 (file)
--- a/drivers/firmware/efi/libstub/efistub.h
+++ b/drivers/firmware/efi/libstub/efistub.h
@@ -25,7 +25,7 @@
 #define EFI_ALLOC_ALIGN                EFI_PAGE_SIZE
 #endif
 
-#if defined(CONFIG_ARM) || defined(CONFIG_X86)
+#if defined(CONFIG_X86)
 #define __efistub_global       __section(.data)
 #else
 #define __efistub_global