Re: [PATCH v4 34/75] x86/head/64: Build k/head64.c with -fno-stack-protector

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On Tue, Jul 14, 2020 at 02:08:36PM +0200, Joerg Roedel wrote:
> From: Joerg Roedel <jroedel@xxxxxxx>
> 
> The code inserted by the stack protector does not work in the early
> boot environment because it uses the GS segment, at least with memory
> encryption enabled. Make sure the early code is compiled without this
> feature enabled.
> 
> Signed-off-by: Joerg Roedel <jroedel@xxxxxxx>
> ---
>  arch/x86/kernel/Makefile | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile
> index e77261db2391..1b166b866059 100644
> --- a/arch/x86/kernel/Makefile
> +++ b/arch/x86/kernel/Makefile
> @@ -39,6 +39,10 @@ ifdef CONFIG_FRAME_POINTER
>  OBJECT_FILES_NON_STANDARD_ftrace_$(BITS).o		:= y
>  endif
>  
> +# make sure head64.c is built without stack protector
> +nostackp := $(call cc-option, -fno-stack-protector)
> +CFLAGS_head64.o		:= $(nostackp)

Recent refactoring[1] for stack protector suggests this should just
unconditionally be:

CFLAGS_head64.o			+= -fno-stack-protector

But otherwise, yeah, this should be fine here -- it's all early init
stuff.

Reviewed-by: Kees Cook <keescook@xxxxxxxxxxxx>

[1] https://lore.kernel.org/lkml/20200626185913.92890-1-masahiroy@xxxxxxxxxx/

> +
>  # If instrumentation of this dir is enabled, boot hangs during first second.
>  # Probably could be more selective here, but note that files related to irqs,
>  # boot, dumpstack/stacktrace, etc are either non-interesting or can lead to
> -- 
> 2.27.0
> 

-- 
Kees Cook
_______________________________________________
Virtualization mailing list
Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx
https://lists.linuxfoundation.org/mailman/listinfo/virtualization



[Index of Archives]     [KVM Development]     [Libvirt Development]     [Libvirt Users]     [CentOS Virtualization]     [Netdev]     [Ethernet Bridging]     [Linux Wireless]     [Kernel Newbies]     [Security]     [Linux for Hams]     [Netfilter]     [Bugtraq]     [Yosemite Forum]     [MIPS Linux]     [ARM Linux]     [Linux RAID]     [Linux Admin]     [Samba]

  Powered by Linux