From e818fac595ab94900f0046baba1f1a0e2d5c2435 Mon Sep 17 00:00:00 2001 From: Matt Redfearn Date: Thu, 31 Mar 2016 10:05:35 +0100 Subject: [PATCH] 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: Matt Redfearn 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: Ralf Baechle --- arch/mips/Makefile | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) diff --git a/arch/mips/Makefile b/arch/mips/Makefile index a61031e7c06f..c0b002a09bef 100644 --- a/arch/mips/Makefile +++ b/arch/mips/Makefile @@ -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) \ $(bootvars-y) arch/mips/boot/$@ -- 2.20.1