On Mon, Feb 16, 2009 at 05:20:01PM +0300, Anton Vorontsov wrote:
> On Sat, Feb 14, 2009 at 08:57:02PM +0100, Sam Ravnborg wrote:
> [...]
> > > > --- a/Makefile
> > > > +++ b/Makefile
> > > > @@ -525,8 +525,6 @@ else
> > > > KBUILD_CFLAGS += -O2
> > > > endif
> > > >
> > > > -include $(srctree)/arch/$(SRCARCH)/Makefile
> > > > -
> > > > ifneq (CONFIG_FRAME_WARN,0)
> > > > KBUILD_CFLAGS += $(call cc-option,-Wframe-larger-than=${CONFIG_FRAME_WARN})
> > > > endif
> > > > @@ -555,6 +553,8 @@ ifdef CONFIG_DEBUG_SECTION_MISMATCH
> > > > KBUILD_CFLAGS += $(call cc-option, -fno-inline-functions-called-once)
> > > > endif
> > > >
> > > > +include $(srctree)/arch/$(SRCARCH)/Makefile
> > > > +
> > > > # arch Makefile may override CC so keep this after arch Makefile is included
> > > > NOSTDINC_FLAGS += -nostdinc -isystem $(shell $(CC) -print-file-name=include)
> > > > CHECKFLAGS += $(NOSTDINC_FLAGS)
> > > > --
> > >
> > > this patch is really for Sam to judge - Cc:-ed him.
> >
> > If we move the include further down then the following:
> >
> > # Force gcc to behave correct even for buggy distributions
> > # Arch Makefiles may override this setting
> > KBUILD_CFLAGS += $(call cc-option, -fno-stack-protector)
> >
> > will most likely fail.
>
> Hm... I don't get it, the comment says that the arch "may override
> this setting", but currently it may not, since arch makefile is
> included before this line. So my patch also fixes this "bug", no?
>
> Or arches supposed to overwrite "cc-option" behaviour? Hm..
>
> There is an interesting commit:
>
> commit e06b8b98da071f7dd78fb7822991694288047df0
> Author: Sam Ravnborg <sam@xxxxxxxxxxxx>
> Date: Wed Feb 13 22:43:28 2008 +0100
>
> kbuild: allow -fstack-protector to take effect
> [...]
> --- a/Makefile
> +++ b/Makefile
> @@ -507,6 +507,10 @@ else
> KBUILD_CFLAGS += -O2
> endif
>
> +# Force gcc to behave correct even for buggy distributions
> +# Arch Makefiles may override this setting
> +KBUILD_CFLAGS += $(call cc-option, -fno-stack-protector)
> +
> include $(srctree)/arch/$(SRCARCH)/Makefile
>
> ifdef CONFIG_FRAME_POINTER
> @@ -525,9 +529,6 @@ ifdef CONFIG_DEBUG_SECTION_MISMATCH
> KBUILD_CFLAGS += $(call cc-option, -fno-inline-functions-called-once)
> endif
>
> -# Force gcc to behave correct even for buggy distributions
> -KBUILD_CFLAGS += $(call cc-option, -fno-stack-protector)
> -
> # arch Makefile may override CC so keep this after arch Makefile is included
> NOSTDINC_FLAGS += -nostdinc -isystem $(shell $(CC) -print-file-name=include)
> CHECKFLAGS += $(NOSTDINC_FLAGS)
>
>
> ^^ Which does the same (wrt fno-stack-protector) as the patch I
> sent, i.e. includes arch Makefile later.
>
> But then, this commit reverted things back (w/o your Ack):
>
> commit bef5b54bd7bf8117c75cb943d64549134c6d9a1f
> Author: Ralf Baechle <ralf@xxxxxxxxxxxxxx>
> Date: Wed Jul 16 13:02:24 2008 +0100
>
> Fix MIPS cross-compile problem
> [...]
> Signed-off-by: Ralf Baechle <ralf@xxxxxxxxxxxxxx>
> Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Ok, I think I got it. It seems that Ralf was using this feature
of arch/mips/Makefile:
ifneq ($(SUBARCH),$(ARCH))
ifeq ($(CROSS_COMPILE),)
CROSS_COMPILE := $(call cc-cross-prefix, $(tool-archpref)-linux- $(tool-archpref)-linux-gnu- $(tool-archpref)-unknown-linux-gnu-)
endif
endif
There are few arches that have "auto detection" of CROSS_COMPILE
variable: mips, m68k, parisc, xtensa, h8300 and blackfin.
So `normal' arches don't have any chance to overwrite the flags
because of the few offenders above. ;-)
> [...]
> --- a/Makefile
> +++ b/Makefile
> @@ -508,6 +508,8 @@ else
> KBUILD_CFLAGS += -O2
> endif
>
> +include $(srctree)/arch/$(SRCARCH)/Makefile
> +
> ifneq (CONFIG_FRAME_WARN,0)
> KBUILD_CFLAGS += $(call cc-option,-Wframe-larger-than=${CONFIG_FRAME_WARN})
> endif
> @@ -516,8 +518,6 @@ endif
> # Arch Makefiles may override this setting
> KBUILD_CFLAGS += $(call cc-option, -fno-stack-protector)
>
> -include $(srctree)/arch/$(SRCARCH)/Makefile
> -
> ifdef CONFIG_FRAME_POINTER
> KBUILD_CFLAGS += -fno-omit-frame-pointer -fno-optimize-sibling-calls
> else
--
Anton Vorontsov
email: cbouatmailru@xxxxxxxxx
irc://irc.freenode.net/bd2
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