Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit e818fac5 authored by Matt Redfearn's avatar Matt Redfearn Committed by Ralf Baechle
Browse files

MIPS: Generate relocation table when CONFIG_RELOCATABLE 



When CONFIG_RELOCATABLE is enabled (added in later patch) add
--emit-relocs to vmlinux LDFLAGS so that fully linked vmlinux contains
relocation information.

Run the previously added relocs tool to fill in the .data.relocs section
of vmlinux with a table of relocations. The relocs tool will also remove
(mark as 0 length) the relocation sections added to vmlinux.

When vmlinux is passed to the boot makefile for conversion into a boot
image the now empty relocation sections will be removed and the
populated relocation table will be included in the binary image.

Signed-off-by: default avatarMatt Redfearn <matt.redfearn@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: kernel-hardening@lists.openwall.com
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/12983/


Signed-off-by: default avatarRalf Baechle <ralf@linux-mips.org>
parent 069fd766

arch/mips/Makefile

+16 −0
Original line number Diff line number Diff line
@@ -96,6 +96,10 @@ LDFLAGS_vmlinux += -G 0 -static -n -nostdlib 
KBUILD_AFLAGS_MODULE		+= -mlong-calls

KBUILD_CFLAGS_MODULE		+= -mlong-calls



ifeq ($(CONFIG_RELOCATABLE),y)

LDFLAGS_vmlinux			+= --emit-relocs

endif



#

# pass -msoft-float to GAS if it supports it.  However on newer binutils

# (specifically newer than 2.24.51.20140728) we then also need to explicitly
@@ -313,6 +317,10 @@ rom.bin rom.sw: vmlinux 
		$(bootvars-y) $@

endif



CMD_RELOCS = arch/mips/boot/tools/relocs

quiet_cmd_relocs = RELOCS  $<

      cmd_relocs = $(CMD_RELOCS) $<



#

# Some machines like the Indy need 32-bit ELF binaries for booting purposes.

# Other need ECOFF, so we build a 32-bit ELF binary for them which we then
@@ -321,6 +329,11 @@ endif 
quiet_cmd_32 = OBJCOPY $@

	cmd_32 = $(OBJCOPY) -O $(32bit-bfd) $(OBJCOPYFLAGS) $< $@

vmlinux.32: vmlinux

ifeq ($(CONFIG_RELOCATABLE)$(CONFIG_64BIT),yy)

# Currently, objcopy fails to handle the relocations in the elf64

# So the relocs tool must be run here to remove them first

	$(call cmd,relocs)

endif

	$(call cmd,32)



#
@@ -336,6 +349,9 @@ all: $(all-y) 


# boot

$(boot-y): $(vmlinux-32) FORCE

ifeq ($(CONFIG_RELOCATABLE)$(CONFIG_32BIT),yy)

	$(call cmd,relocs)

endif

	$(Q)$(MAKE) $(build)=arch/mips/boot VMLINUX=$(vmlinux-32) \

		$(bootvars-y) arch/mips/boot/$@