Patchwork powerpc/le: Avoid creatng R_PPC64_TOCSAVE relocations for modules.

login
register
mail settings
Submitter Tony Breeds
Date March 12, 2014, 4:12 a.m.
Message ID <20140312041201.GA13555@thor.bakeyournoodle.com>
Download mbox | patch
Permalink /patch/329296/
State Accepted
Headers show

Comments

Tony Breeds - March 12, 2014, 4:12 a.m.
When building modules with a native le toolchain the linker will
generate R_PPC64_TOCSAVE relocations when it's safe to omit saving r2 on
a plt call.  This isn't helpful in the conext of a kernel module and the
kernel will fail to load those modules with an error like:
	nf_conntrack: Unknown ADD relocation: 109

This patch tells the linker to avoid createing R_PPC64_TOCSAVE
relocations allowing modules to load.

Signed-off-by: Tony Breeds <tony@bakeyournoodle.com>
---
 arch/powerpc/Makefile | 3 +++
 1 file changed, 3 insertions(+)
Anton Blanchard - April 6, 2014, 11:55 p.m.
Hi Tony,

> When building modules with a native le toolchain the linker will
> generate R_PPC64_TOCSAVE relocations when it's safe to omit saving r2
> on a plt call.  This isn't helpful in the conext of a kernel module
> and the kernel will fail to load those modules with an error like:
> 	nf_conntrack: Unknown ADD relocation: 109
> 
> This patch tells the linker to avoid createing R_PPC64_TOCSAVE
> relocations allowing modules to load.

Looks good.

Signed-off-by: Anton Blanchard <anton@samba.org>

> +ifeq ($(call cc-option-yn,-mno-save-toc-indirect),y)
> +       KBUILD_CFLAGS_MODULE += -mno-save-toc-indirect
> +endif

Low priority bikeshedding, but could we save ourselves a few lines with:

KBUILD_CFLAGS_MODULE += $(call cc-option,-mno-save-toc-indirect)

Anton

Patch

diff --git a/arch/powerpc/Makefile b/arch/powerpc/Makefile
index 0f4344e..fff3945 100644
--- a/arch/powerpc/Makefile
+++ b/arch/powerpc/Makefile
@@ -74,6 +74,9 @@  override CROSS32AS += -mlittle-endian
 LDEMULATION	:= lppc
 GNUTARGET	:= powerpcle
 MULTIPLEWORD	:= -mno-multiple
+ifeq ($(call cc-option-yn,-mno-save-toc-indirect),y)
+       KBUILD_CFLAGS_MODULE += -mno-save-toc-indirect
+endif
 else
 ifeq ($(call cc-option-yn,-mbig-endian),y)
 override CC	+= -mbig-endian