diff options
Diffstat (limited to 'Makefile')
| -rw-r--r-- | Makefile | 19 |
1 files changed, 19 insertions, 0 deletions
@@ -621,6 +621,9 @@ else KBUILD_CFLAGS += -O2 endif +# Tell gcc to never replace conditional load with a non-conditional one +KBUILD_CFLAGS += $(call cc-option,--param=allow-store-data-races=0) + ifdef CONFIG_READABLE_ASM # Disable optimizations that make assembler listings hard to read. # reorder blocks reorders the control in the function @@ -636,6 +639,22 @@ KBUILD_CFLAGS += $(call cc-option,-Wframe-larger-than=${CONFIG_FRAME_WARN}) endif # Handle stack protector mode. +# +# Since kbuild can potentially perform two passes (first with the old +# .config values and then with updated .config values), we cannot error out +# if a desired compiler option is unsupported. If we were to error, kbuild +# could never get to the second pass and actually notice that we changed +# the option to something that was supported. +# +# Additionally, we don't want to fallback and/or silently change which compiler +# flags will be used, since that leads to producing kernels with different +# security feature characteristics depending on the compiler used. ("But I +# selected CC_STACKPROTECTOR_STRONG! Why did it build with _REGULAR?!") +# +# The middle ground is to warn here so that the failed option is obvious, but +# to let the build fail with bad compiler flags so that we can't produce a +# kernel when there is a CONFIG and compiler mismatch. +# ifdef CONFIG_CC_STACKPROTECTOR_REGULAR stackp-flag := -fstack-protector ifeq ($(call cc-option, $(stackp-flag)),) |