x86/efi: Include a .bss section within the PE/COFF headers
The PE/COFF headers currently describe only the initialised-data
portions of the image, and result in no space being allocated for the
uninitialised-data portions. Consequently, the EFI boot stub will end
up overwriting unexpected areas of memory, with unpredictable results.
Fix by including a .bss section in the PE/COFF headers (functionally
equivalent to the init_size field in the bzImage header).
Signed-off-by: Michael Brown <mbrown@fensystems.co.uk>
Cc: Thomas Bächler <thomas@archlinux.org>
Cc: Josh Boyer <jwboyer@fedoraproject.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
diff --git a/arch/x86/boot/header.S b/arch/x86/boot/header.S
index 84c2234..7a6d43a 100644
--- a/arch/x86/boot/header.S
+++ b/arch/x86/boot/header.S
@@ -91,10 +91,9 @@
.section ".bsdata", "a"
bugger_off_msg:
- .ascii "Direct floppy boot is not supported. "
- .ascii "Use a boot loader program instead.\r\n"
+ .ascii "Use a boot loader.\r\n"
.ascii "\n"
- .ascii "Remove disk and press any key to reboot ...\r\n"
+ .ascii "Remove disk and press any key to reboot...\r\n"
.byte 0
#ifdef CONFIG_EFI_STUB
@@ -108,7 +107,7 @@
#else
.word 0x8664 # x86-64
#endif
- .word 3 # nr_sections
+ .word 4 # nr_sections
.long 0 # TimeDateStamp
.long 0 # PointerToSymbolTable
.long 1 # NumberOfSymbols
@@ -250,6 +249,25 @@
.word 0 # NumberOfLineNumbers
.long 0x60500020 # Characteristics (section flags)
+ #
+ # The offset & size fields are filled in by build.c.
+ #
+ .ascii ".bss"
+ .byte 0
+ .byte 0
+ .byte 0
+ .byte 0
+ .long 0
+ .long 0x0
+ .long 0 # Size of initialized data
+ # on disk
+ .long 0x0
+ .long 0 # PointerToRelocations
+ .long 0 # PointerToLineNumbers
+ .word 0 # NumberOfRelocations
+ .word 0 # NumberOfLineNumbers
+ .long 0xc8000080 # Characteristics (section flags)
+
#endif /* CONFIG_EFI_STUB */
# Kernel attributes; used by setup. This is part 1 of the