Commit ff487d41 authored by Jiaxun Yang's avatar Jiaxun Yang Committed by Thomas Bogendoerfer
Browse files

MIPS: Truncate link address into 32bit for 32bit kernel 



LLD failed to link vmlinux with 64bit load address for 32bit ELF
while bfd will strip 64bit address into 32bit silently.
To fix LLD build, we should truncate load address provided by platform
into 32bit for 32bit kernel.

Signed-off-by: default avatarJiaxun Yang <jiaxun.yang@flygoat.com>
Link: https://github.com/ClangBuiltLinux/linux/issues/786
Link: https://sourceware.org/bugzilla/show_bug.cgi?id=25784


Reviewed-by: default avatarFangrui Song <maskray@google.com>
Reviewed-by: default avatarKees Cook <keescook@chromium.org>
Tested-by: default avatarNathan Chancellor <natechancellor@gmail.com>
Cc: Maciej W. Rozycki <macro@linux-mips.org>
Tested-by: default avatarNick Desaulniers <ndesaulniers@google.com>
Signed-off-by: default avatarThomas Bogendoerfer <tsbogend@alpha.franken.de>
parent 53635eb2

arch/mips/Makefile

+12 −1
Original line number Diff line number Diff line
@@ -288,12 +288,23 @@ ifdef CONFIG_64BIT 
  endif

endif



# When linking a 32-bit executable the LLVM linker cannot cope with a

# 32-bit load address that has been sign-extended to 64 bits.  Simply

# remove the upper 32 bits then, as it is safe to do so with other

# linkers.

ifdef CONFIG_64BIT

	load-ld			= $(load-y)

else

	load-ld			= $(subst 0xffffffff,0x,$(load-y))

endif



KBUILD_AFLAGS	+= $(cflags-y)

KBUILD_CFLAGS	+= $(cflags-y)

KBUILD_CPPFLAGS += -DVMLINUX_LOAD_ADDRESS=$(load-y)

KBUILD_CPPFLAGS += -DVMLINUX_LOAD_ADDRESS=$(load-y) -DLINKER_LOAD_ADDRESS=$(load-ld)

KBUILD_CPPFLAGS += -DDATAOFFSET=$(if $(dataoffset-y),$(dataoffset-y),0)



bootvars-y	= VMLINUX_LOAD_ADDRESS=$(load-y) \

		  LINKER_LOAD_ADDRESS=$(load-ld) \

		  VMLINUX_ENTRY_ADDRESS=$(entry-y) \

		  PLATFORM="$(platform-y)" \

		  ITS_INPUTS="$(its-y)"

arch/mips/boot/compressed/Makefile

+1 −1
Original line number Diff line number Diff line
@@ -90,7 +90,7 @@ ifneq ($(zload-y),) 
VMLINUZ_LOAD_ADDRESS := $(zload-y)

else

VMLINUZ_LOAD_ADDRESS = $(shell $(obj)/calc_vmlinuz_load_addr \

		$(obj)/vmlinux.bin $(VMLINUX_LOAD_ADDRESS))

		$(obj)/vmlinux.bin $(LINKER_LOAD_ADDRESS))

endif

UIMAGE_LOADADDR = $(VMLINUZ_LOAD_ADDRESS)

arch/mips/kernel/vmlinux.lds.S

+1 −1
Original line number Diff line number Diff line
@@ -55,7 +55,7 @@ SECTIONS 
	/* . = 0xa800000000300000; */

	. = 0xffffffff80300000;

#endif

	. = VMLINUX_LOAD_ADDRESS;

	. = LINKER_LOAD_ADDRESS;

	/* read-only */

	_text = .;	/* Text and read-only data */

	.text : {

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