Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]


Groups > linux.kernel > #1303500

Re: [PATCH v3] ARM: fix atags_to_fdt with stack-protector-strong

From Russell King - ARM Linux <linux@arm.linux.org.uk>
Newsgroups linux.kernel
Subject Re: [PATCH v3] ARM: fix atags_to_fdt with stack-protector-strong
Date 2016-01-07 12:40 +0100
Message-ID <qOh57-7sH-11@gated-at.bofh.it> (permalink)
References <qO5Qm-7Zi-23@gated-at.bofh.it>
Organization linux.* mail to news gateway

Show all headers | View raw


On Wed, Jan 06, 2016 at 03:36:56PM -0800, Kees Cook wrote:
> diff --git a/arch/arm/boot/compressed/Makefile b/arch/arm/boot/compressed/Makefile
> index 3f9a9ebc77c3..d7d2c2981f65 100644
> --- a/arch/arm/boot/compressed/Makefile
> +++ b/arch/arm/boot/compressed/Makefile
> @@ -106,6 +106,14 @@ ORIG_CFLAGS := $(KBUILD_CFLAGS)
>  KBUILD_CFLAGS = $(subst -pg, , $(ORIG_CFLAGS))
>  endif
>  
> +# -fstack-protector-strong triggers protection checks in this code,
> +# but it is being used too early to link to meaningful stack_chk logic.
> +CFLAGS_atags_to_fdt.o := $(call cc-option, -fno-stack-protector)
> +CFLAGS_fdt.o := $(call cc-option, -fno-stack-protector)
> +CFLAGS_fdt_ro.o := $(call cc-option, -fno-stack-protector)
> +CFLAGS_fdt_rw.o := $(call cc-option, -fno-stack-protector)
> +CFLAGS_fdt_wip.o := $(call cc-option, -fno-stack-protector)

This will result in "$(call cc-option, -fno-stack-protector)" being
called five times when this Makefile is parsed, which seems very
wasteful.  I'm sure there's better solutions to that - maybe caching
the value in a variable in a higher level makefile (eg,
arch/arm/Makefile) ?

Also, I suspect that all of the decompressor should be built with
-fno-stack-protector as we don't have sufficient environment here.
Maybe it should be placed in the global CFLAGS for the decompressor?

-- 
RMK's Patch system: http://www.arm.linux.org.uk/developer/patches/
FTTC broadband for 0.8mile line: currently at 9.6Mbps down 400kbps up
according to speedtest.net.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Back to linux.kernel | Previous | NextPrevious in thread | Next in thread | Find similar | Unroll thread


Thread

[PATCH v3] ARM: fix atags_to_fdt with stack-protector-strong Kees Cook <keescook@chromium.org> - 2016-01-07 00:40 +0100
  Re: [PATCH v3] ARM: fix atags_to_fdt with stack-protector-strong Arnd Bergmann <arnd@arndb.de> - 2016-01-07 11:50 +0100
  Re: [PATCH v3] ARM: fix atags_to_fdt with stack-protector-strong Russell King - ARM Linux <linux@arm.linux.org.uk> - 2016-01-07 12:40 +0100
    Re: [PATCH v3] ARM: fix atags_to_fdt with stack-protector-strong Kees Cook <keescook@chromium.org> - 2016-01-07 19:50 +0100
      Re: [PATCH v3] ARM: fix atags_to_fdt with stack-protector-strong Geert Uytterhoeven <geert@linux-m68k.org> - 2016-01-07 20:20 +0100
        Re: [PATCH v3] ARM: fix atags_to_fdt with stack-protector-strong Kees Cook <keescook@chromium.org> - 2016-01-07 20:20 +0100

csiph-web