On Mon, Nov 14, 2016 at 09:45:29PM +0100, Borislav Petkov wrote: > From: Borislav Petkov <bp@xxxxxxx> > Date: Mon, 14 Nov 2016 19:41:31 +0100 > Subject: [PATCH] kbuild: Steal gcc's pie from the very beginning > > So Sebastian turned off the PIE for kernel builds but that was too late > - Kbuild.include already uses KBUILD_CFLAGS and trying to disable gcc > options with, say cc-disable-warning, fails: > > gcc -D__KERNEL__ -Wall -Wundef -Wstrict-prototypes -Wno-trigraphs > ... > -Wno-sign-compare -fno-asynchronous-unwind-tables -Wframe-address -c -x c /dev/null -o .31392.tmp > /dev/null:1:0: error: code model kernel does not support PIC mode > > because that returns an error and we can't disable the warning. For > example in this case: > > KBUILD_CFLAGS += $(call cc-disable-warning,frame-address,) > > which leads to gcc issuing all those warnings again. > > So let's turn off PIE/PIC at the earliest possible moment, when we > declare KBUILD_CFLAGS so that cc-disable-warning picks it up too. > > Also, we need the $(call cc-option ...) because -fno-PIE is supported > since gcc v3.4 and our lowest supported gcc version is 3.2 right now. > > Signed-off-by: Borislav Petkov <bp@xxxxxxx> > Cc: stable@xxxxxxxxxxxxxxx > Cc: Ben Hutchings <ben@xxxxxxxxxxxxxxx> > Cc: Michal Marek <mmarek@xxxxxxxx> > Cc: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx> Thanks, applied to kbuild.git#rc-fixes. Michal -- To unsubscribe from this list: send the line "unsubscribe linux-kbuild" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
