Messages in this thread |  | | From | Masahiro Yamada <> | Date | Sun, 15 Apr 2018 18:40:20 +0900 | Subject | Re: [PATCH 21/30] stack-protector: test compiler capability in Kconfig and drop AUTO mode |
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2018-04-14 1:41 GMT+09:00 Kees Cook <keescook@chromium.org>: > On Thu, Apr 12, 2018 at 10:06 PM, Masahiro Yamada > <yamada.masahiro@socionext.com> wrote: >> +stackp-flags-$(CONFIG_CC_HAS_STACKPROTECTOR_NONE) := -fno-stack-protector >> +stackp-flags-$(CONFIG_CC_STACKPROTECTOR) := -fstack-protector >> +stackp-flags-$(CONFIG_CC_STACKPROTECTOR_STRONG) := -fstack-protector-strong >> + >> +KBUILD_CFLAGS += $(stackp-flags-y) > > So, technically, this works just fine. I wonder if it has an overly > confusing result, in that the compiler under normal situations will > see: > > gcc ... -fno-stack-protector -fstack-protector -fstack-protector-strong ...
Kees, you are wrong.
Look at my code closely.
I used := operator instead of +=.
$(stackp-flags-y) contains only one flag at most.
> How about something like this instead: > > ifdef CONFIG_CC_STACKPROTECTOR_STRONG > KBUILD_CFLAGS += -fstack-protector-strong > else > ifdef CONFIG_CC_STACKPROTECTOR > KBUILD_CFLAGS += -fstack-protector > else > KBUILD_CFLAGS += -fno-stack-protector > endif > endif >
My code is much cleaner, and working fine.
-- Best Regards Masahiro Yamada
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