Re: Linker error with latest tree on EM64T

[Marcel Holtmann <marcel@holtmann.org>]

Hi Arjan,

> > when trying to build the latest tree on an EM64T Dual-Core, I am getting
> > this error:
> > 
> >   LD      .tmp_vmlinux1
> > init/built-in.o: In function `try_name':
> > do_mounts.c:(.text+0x51d): undefined reference to `__stack_chk_fail'
> > init/built-in.o: In function `name_to_dev_t':
> > (.text+0x797): undefined reference to `__stack_chk_fail'
> > init/built-in.o: In function `mount_block_root':
> > (.init.text+0x823): undefined reference to `__stack_chk_fail'
> > init/built-in.o: In function `md_run_setup':
> > (.init.text+0x1131): undefined reference to `__stack_chk_fail'
> > init/built-in.o: In function `do_header':
> > initramfs.c:(.init.text+0x24a4): undefined reference to `__stack_chk_fail'
> > arch/x86_64/kernel/built-in.o:(.text+0x2f52): more undefined references to `__st
> > ack_chk_fail' follow
> > make: *** [.tmp_vmlinux1] Error 1
> 
> you are using ubuntu which has a compiler that adds -fstack-protector
> implicitly to the compiler options, yet you don't have a kernel that
> provides this infrastructure ;)
> (I have code for that but it's not merged yet, it's pending one gcc
> patch to get merged upstream)
> in the mean time.. I'm pretty sure Sam sent a patch to Linus that adds
> -fno-stack-protector...

I couldn't find such a patch in Sam's repository, but the following
worked for me:

diff --git a/Makefile b/Makefile
index 7c010f3..b4a2a80 100644
--- a/Makefile
+++ b/Makefile
@@ -308,7 +308,7 @@ LINUXINCLUDE    := -Iinclude \
 CPPFLAGS        := -D__KERNEL__ $(LINUXINCLUDE)
 
 CFLAGS          := -Wall -Wundef -Wstrict-prototypes -Wno-trigraphs \
-                   -fno-strict-aliasing -fno-common
+                   -fno-strict-aliasing -fno-common -fno-stack-protector
 # Force gcc to behave correct even for buggy distributions
 CFLAGS          += $(call cc-option, -fno-stack-protector-all \
                                      -fno-stack-protector)

Thanks for the quick answer.

Regards

Marcel