On Tue, Jul 26, 2016 at 2:06 PM, Michal Marek <[email protected]> wrote: > On Tue, Jul 12, 2016 at 03:30:43PM -0700, Kees Cook wrote: >> Before, the stack protector flag was sanity checked before .config had >> been reprocessed. This meant the build couldn't be aborted early, and >> only a warning could be emitted followed later by the compiler blowing >> up with an unknown flag. This has caused a lot of confusion over time, >> so this splits the flag selection from sanity checking and performs the >> sanity checking after the make has been restarted from a reprocessed >> .config, so builds can be aborted as early as possible now. >> >> Additionally moves the x86-specific sanity check to the same location, >> since it suffered from the same warn-then-wait-for-compiler-failure >> problem. >> >> Signed-off-by: Kees Cook <[email protected]> > > Hi Kees, > > sorry for the late review. > > >> +# Find arch-specific stack protector compiler sanity-checking script. >> +ifdef CONFIG_CC_STACKPROTECTOR >> + stackp-path := >> $(srctree)/scripts/gcc-$(ARCH)_$(BITS)-has-stack-protector.sh > > You need to use SRCARCH here if you want "x86" on x86. > > >> + ifneq ($(wildcard $(stackp-path)),) >> + stackp-check := $(stackp-path) >> + endif > > stackp-check := $(wildcard $(stackp-path)) > > is more straightforward. But the long version is correct as well.
Ah! Yes, thanks. I was thinking I needed to handle "defined but empty", but that's not true for Makefiles. I'll send a v2 with this and SRCARCH fixed. -Kees -- Kees Cook Chrome OS & Brillo Security
