lkdtm: fix false positive warning from -Wmaybe-uninitialized

[cascardo/linux.git] / Makefile

diff --git a/Makefile b/Makefile
index 81b2262..776b6a3 100644 (file)
--- a/Makefile
+++ b/Makefile
@@ -1,7 +1,7 @@
 VERSION = 4
 PATCHLEVEL = 7
 SUBLEVEL = 0
-EXTRAVERSION = -rc7
+EXTRAVERSION =
 NAME = Psychotic Stoned Sheep
 
 # *DOCUMENTATION*
@@ -647,41 +647,28 @@ ifneq ($(CONFIG_FRAME_WARN),0)
 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.
-#
+# 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_REGULAR
   stackp-flag := -fstack-protector
-  ifeq ($(call cc-option, $(stackp-flag)),)
-    $(warning Cannot use CONFIG_CC_STACKPROTECTOR_REGULAR: \
-             -fstack-protector not supported by compiler)
-  endif
+  stackp-name := REGULAR
 else
 ifdef CONFIG_CC_STACKPROTECTOR_STRONG
   stackp-flag := -fstack-protector-strong
-  ifeq ($(call cc-option, $(stackp-flag)),)
-    $(warning Cannot use CONFIG_CC_STACKPROTECTOR_STRONG: \
-             -fstack-protector-strong not supported by compiler)
-  endif
+  stackp-name := STRONG
 else
   # Force off for distro compilers that enable stack protector by default.
   stackp-flag := $(call cc-option, -fno-stack-protector)
 endif
 endif
+# Find arch-specific stack protector compiler sanity-checking script.
+ifdef CONFIG_CC_STACKPROTECTOR
+  stackp-path := $(srctree)/scripts/gcc-$(ARCH)_$(BITS)-has-stack-protector.sh
+  ifneq ($(wildcard $(stackp-path)),)
+    stackp-check := $(stackp-path)
+  endif
+endif
 KBUILD_CFLAGS += $(stackp-flag)
 
 ifdef CONFIG_KCOV
@@ -1017,8 +1004,10 @@ ifneq ($(KBUILD_SRC),)
        fi;
 endif
 
-# prepare2 creates a makefile if using a separate output directory
-prepare2: prepare3 outputmakefile asm-generic
+# 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
 
 prepare1: prepare2 $(version_h) include/generated/utsrelease.h \
                    include/config/auto.conf
@@ -1040,7 +1029,7 @@ ifdef CONFIG_STACK_VALIDATION
   ifeq ($(has_libelf),1)
     objtool_target := tools/objtool FORCE
   else
-    $(warning "Cannot use CONFIG_STACK_VALIDATION, please install libelf-dev or elfutils-libelf-devel")
+    $(warning "Cannot use CONFIG_STACK_VALIDATION, please install libelf-dev, libelf-devel or elfutils-libelf-devel")
     SKIP_STACK_VALIDATION := 1
     export SKIP_STACK_VALIDATION
   endif
@@ -1049,6 +1038,32 @@ endif
 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
+  ifeq ($(call cc-option, $(stackp-flag)),)
+       @echo Cannot use CONFIG_CC_STACKPROTECTOR_$(stackp-name): \
+                 $(stackp-flag) not supported by compiler >&2 && exit 1
+  endif
+endif
+# Make sure compiler does not have buggy stack-protector support.
+ifdef stackp-check
+  ifneq ($(shell $(CONFIG_SHELL) $(stackp-check) $(CC) $(KBUILD_CPPFLAGS) $(biarch)),y)
+       @echo Cannot use CONFIG_CC_STACKPROTECTOR_$(stackp-name): \
+                  $(stackp-flag) available but compiler is broken >&2 && exit 1
+  endif
+endif
+       @:
+
 # Generate some files
 # ---------------------------------------------------------------------------
 
@@ -1366,6 +1381,8 @@ help:
        @$(MAKE) $(build)=$(package-dir) help
        @echo  ''
        @echo  'Documentation targets:'
+       @$(MAKE) -f $(srctree)/Documentation/Makefile.sphinx dochelp
+       @echo  ''
        @$(MAKE) -f $(srctree)/Documentation/DocBook/Makefile dochelp
        @echo  ''
        @echo  'Architecture specific targets ($(SRCARCH)):'
@@ -1414,8 +1431,11 @@ $(help-board-dirs): help-%:
 
 # Documentation targets
 # ---------------------------------------------------------------------------
-%docs: scripts_basic FORCE
+DOC_TARGETS := xmldocs sgmldocs psdocs pdfdocs htmldocs mandocs installmandocs epubdocs cleandocs cleanmediadocs
+PHONY += $(DOC_TARGETS)
+$(DOC_TARGETS): scripts_basic FORCE
        $(Q)$(MAKE) $(build)=scripts build_docproc build_check-lc_ctype
+       $(Q)$(MAKE) $(build)=Documentation -f $(srctree)/Documentation/Makefile.sphinx $@
        $(Q)$(MAKE) $(build)=Documentation/DocBook $@
 
 else # KBUILD_EXTMOD