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authorStephen Rothwell <sfr@canb.auug.org.au>2018-06-08 07:55:25 +1000
committerStephen Rothwell <sfr@canb.auug.org.au>2018-06-08 07:55:25 +1000
commitdb58653b3f8e180b2e86d063ca9a10aed46ccbbb (patch)
treed9fb83435d659f3149e3ffb03277cd5e42d079ed /Makefile
parent975032b80e8ab0f202855f73ca19ceae83dc1521 (diff)
parente216bbe870c0db84edbbc2ad5748bc5b59e4d0ea (diff)
Merge remote-tracking branch 'kbuild/for-next'
Diffstat (limited to 'Makefile')
-rw-r--r--Makefile95
1 files changed, 7 insertions, 88 deletions
diff --git a/Makefile b/Makefile
index 019a5a020606..edf6ed07169d 100644
--- a/Makefile
+++ b/Makefile
@@ -631,7 +631,7 @@ all: vmlinux
CFLAGS_GCOV := -fprofile-arcs -ftest-coverage \
$(call cc-option,-fno-tree-loop-im) \
$(call cc-disable-warning,maybe-uninitialized,)
-export CFLAGS_GCOV CFLAGS_KCOV
+export CFLAGS_GCOV
# The arch Makefile can set ARCH_{CPP,A,C}FLAGS to override the default
# values of the respective KBUILD_* variables
@@ -680,55 +680,11 @@ ifneq ($(CONFIG_FRAME_WARN),0)
KBUILD_CFLAGS += $(call cc-option,-Wframe-larger-than=${CONFIG_FRAME_WARN})
endif
-# This selects the stack protector compiler flag. Testing it is delayed
-# until after .config has been reprocessed, in the prepare-compiler-check
-# target.
-ifdef CONFIG_CC_STACKPROTECTOR_AUTO
- stackp-flag := $(call cc-option,-fstack-protector-strong,$(call cc-option,-fstack-protector))
- stackp-name := AUTO
-else
-ifdef CONFIG_CC_STACKPROTECTOR_REGULAR
- stackp-flag := -fstack-protector
- stackp-name := REGULAR
-else
-ifdef CONFIG_CC_STACKPROTECTOR_STRONG
- stackp-flag := -fstack-protector-strong
- stackp-name := STRONG
-else
- # If either there is no stack protector for this architecture or
- # CONFIG_CC_STACKPROTECTOR_NONE is selected, we're done, and $(stackp-name)
- # is empty, skipping all remaining stack protector tests.
- #
- # Force off for distro compilers that enable stack protector by default.
- KBUILD_CFLAGS += $(call cc-option, -fno-stack-protector)
-endif
-endif
-endif
-# Find arch-specific stack protector compiler sanity-checking script.
-ifdef stackp-name
-ifneq ($(stackp-flag),)
- stackp-path := $(srctree)/scripts/gcc-$(SRCARCH)_$(BITS)-has-stack-protector.sh
- stackp-check := $(wildcard $(stackp-path))
- # If the wildcard test matches a test script, run it to check functionality.
- ifdef stackp-check
- ifneq ($(shell $(CONFIG_SHELL) $(stackp-check) $(CC) $(KBUILD_CPPFLAGS) $(biarch)),y)
- stackp-broken := y
- endif
- endif
- ifndef stackp-broken
- # If the stack protector is functional, enable code that depends on it.
- KBUILD_CPPFLAGS += -DCONFIG_CC_STACKPROTECTOR
- # Either we've already detected the flag (for AUTO) or we'll fail the
- # build in the prepare-compiler-check rule (for specific flag).
- KBUILD_CFLAGS += $(stackp-flag)
- else
- # We have to make sure stack protector is unconditionally disabled if
- # the compiler is broken (in case we're going to continue the build in
- # AUTO mode).
- KBUILD_CFLAGS += $(call cc-option, -fno-stack-protector)
- endif
-endif
-endif
+stackp-flags-$(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 += $(stackp-flags-y)
ifeq ($(cc-name),clang)
KBUILD_CPPFLAGS += $(call cc-option,-Qunused-arguments,)
@@ -1112,7 +1068,7 @@ endif
# prepare2 creates a makefile if using a separate output directory.
# From this point forward, .config has been reprocessed, so any rules
# that need to depend on updated CONFIG_* values can be checked here.
-prepare2: prepare3 prepare-compiler-check outputmakefile asm-generic
+prepare2: prepare3 outputmakefile asm-generic
prepare1: prepare2 $(version_h) $(autoksyms_h) include/generated/utsrelease.h \
include/config/auto.conf
@@ -1138,43 +1094,6 @@ uapi-asm-generic:
PHONY += prepare-objtool
prepare-objtool: $(objtool_target)
-# Check for CONFIG flags that require compiler support. Abort the build
-# after .config has been processed, but before the kernel build starts.
-#
-# For security-sensitive CONFIG options, we don't want to fallback and/or
-# silently change which compiler flags will be used, since that leads to
-# producing kernels with different security feature characteristics
-# depending on the compiler used. (For example, "But I selected
-# CC_STACKPROTECTOR_STRONG! Why did it build with _REGULAR?!")
-PHONY += prepare-compiler-check
-prepare-compiler-check: FORCE
-# Make sure compiler supports requested stack protector flag.
-ifdef stackp-name
- # Warn about CONFIG_CC_STACKPROTECTOR_AUTO having found no option.
- ifeq ($(stackp-flag),)
- @echo CONFIG_CC_STACKPROTECTOR_$(stackp-name): \
- Compiler does not support any known stack-protector >&2
- else
- # Fail if specifically requested stack protector is missing.
- ifeq ($(call cc-option, $(stackp-flag)),)
- @echo Cannot use CONFIG_CC_STACKPROTECTOR_$(stackp-name): \
- $(stackp-flag) not supported by compiler >&2 && exit 1
- endif
- endif
-endif
-# Make sure compiler does not have buggy stack-protector support. If a
-# specific stack-protector was requested, fail the build, otherwise warn.
-ifdef stackp-broken
- ifeq ($(stackp-name),AUTO)
- @echo CONFIG_CC_STACKPROTECTOR_$(stackp-name): \
- $(stackp-flag) available but compiler is broken: disabling >&2
- else
- @echo Cannot use CONFIG_CC_STACKPROTECTOR_$(stackp-name): \
- $(stackp-flag) available but compiler is broken >&2 && exit 1
- endif
-endif
- @:
-
# Generate some files
# ---------------------------------------------------------------------------