Merge remote-tracking branch 'kbuild/for-next'

11 files changed, 106 insertions, 22 deletions

diff --git a/Makefile b/Makefile
index ddbf627cad8f..89417877f62b 100644
--- a/Makefile
+++ b/Makefile
@@ -487,18 +487,18 @@ endif
 
 ifneq ($(shell $(CC) --version 2>&1 | head -n 1 | grep clang),)
 ifneq ($(CROSS_COMPILE),)
-CLANG_TARGET	:= --target=$(notdir $(CROSS_COMPILE:%-=%))
+CLANG_FLAGS	:= --target=$(notdir $(CROSS_COMPILE:%-=%))
 GCC_TOOLCHAIN_DIR := $(dir $(shell which $(LD)))
-CLANG_PREFIX	:= --prefix=$(GCC_TOOLCHAIN_DIR)
+CLANG_FLAGS	+= --prefix=$(GCC_TOOLCHAIN_DIR)
 GCC_TOOLCHAIN	:= $(realpath $(GCC_TOOLCHAIN_DIR)/..)
 endif
 ifneq ($(GCC_TOOLCHAIN),)
-CLANG_GCC_TC	:= --gcc-toolchain=$(GCC_TOOLCHAIN)
+CLANG_FLAGS	+= --gcc-toolchain=$(GCC_TOOLCHAIN)
 endif
-KBUILD_CFLAGS += $(CLANG_TARGET) $(CLANG_GCC_TC) $(CLANG_PREFIX)
-KBUILD_AFLAGS += $(CLANG_TARGET) $(CLANG_GCC_TC) $(CLANG_PREFIX)
-KBUILD_CFLAGS += $(call cc-option, -no-integrated-as)
-KBUILD_AFLAGS += $(call cc-option, -no-integrated-as)
+CLANG_FLAGS	+= -no-integrated-as
+KBUILD_CFLAGS	+= $(CLANG_FLAGS)
+KBUILD_AFLAGS	+= $(CLANG_FLAGS)
+export CLANG_FLAGS
 endif
 
 RETPOLINE_CFLAGS_GCC := -mindirect-branch=thunk-extern -mindirect-branch-register
@@ -662,6 +662,10 @@ KBUILD_CFLAGS	+= $(call cc-disable-warning, format-truncation)
 KBUILD_CFLAGS	+= $(call cc-disable-warning, format-overflow)
 KBUILD_CFLAGS	+= $(call cc-disable-warning, int-in-bool-context)
 
+ifdef CONFIG_CC_OPTIMIZE_FOR_DEBUGGING
+KBUILD_CFLAGS	+= -Og
+KBUILD_CFLAGS	+= $(call cc-disable-warning,maybe-uninitialized,)
+else
 ifdef CONFIG_CC_OPTIMIZE_FOR_SIZE
 KBUILD_CFLAGS	+= $(call cc-option,-Oz,-Os)
 KBUILD_CFLAGS	+= $(call cc-disable-warning,maybe-uninitialized,)
@@ -672,6 +676,7 @@ else
 KBUILD_CFLAGS   += -O2
 endif
 endif
+endif
 
 KBUILD_CFLAGS += $(call cc-ifversion, -lt, 0409, \
 			$(call cc-disable-warning,maybe-uninitialized,))
@@ -754,6 +759,12 @@ KBUILD_CFLAGS 	+= $(call cc-option, -femit-struct-debug-baseonly) \
 		   $(call cc-option,-fno-var-tracking)
 endif
 
+ifdef CONFIG_NO_AUTO_INLINE
+KBUILD_CFLAGS   += $(call cc-option, -fno-inline-functions) \
+		   $(call cc-option, -fno-inline-small-functions) \
+		   $(call cc-option, -fno-inline-functions-called-once)
+endif
+
 ifdef CONFIG_FUNCTION_TRACER
 ifdef CONFIG_FTRACE_MCOUNT_RECORD
   # gcc 5 supports generating the mcount tables directly
@@ -1602,8 +1613,6 @@ help:
 
 # Dummies...
 PHONY += prepare scripts
-prepare: ;
-scripts: ;
 endif # KBUILD_EXTMOD
 
 clean: $(clean-dirs)
diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c
index f5cc1ccfea3d..fcded2c0547c 100644
--- a/arch/arm/mm/mmu.c
+++ b/arch/arm/mm/mmu.c
@@ -1599,7 +1599,7 @@ static void __init early_fixmap_shutdown(void)
 		pte_t *pte;
 		struct map_desc map;
 
-		map.virtual = fix_to_virt(i);
+		map.virtual = __fix_to_virt(i);
 		pte = pte_offset_early_fixmap(pmd_off_k(map.virtual), map.virtual);
 
 		/* Only i/o device mappings are supported ATM */
diff --git a/arch/openrisc/mm/cache.c b/arch/openrisc/mm/cache.c
index b747bf1fc1b6..4a4b2b6e006b 100644
--- a/arch/openrisc/mm/cache.c
+++ b/arch/openrisc/mm/cache.c
@@ -20,7 +20,7 @@
 #include <asm/cacheflush.h>
 #include <asm/tlbflush.h>
 
-static void cache_loop(struct page *page, const unsigned int reg)
+static inline void cache_loop(struct page *page, const unsigned int reg)
 {
 	unsigned long paddr = page_to_pfn(page) << PAGE_SHIFT;
 	unsigned long line = paddr & ~(L1_CACHE_BYTES - 1);
diff --git a/arch/powerpc/boot/Makefile b/arch/powerpc/boot/Makefile
index 39354365f54a..111f97b1ccec 100644
--- a/arch/powerpc/boot/Makefile
+++ b/arch/powerpc/boot/Makefile
@@ -55,6 +55,11 @@ BOOTAFLAGS	:= -D__ASSEMBLY__ $(BOOTCFLAGS) -traditional -nostdinc
 
 BOOTARFLAGS	:= -cr$(KBUILD_ARFLAGS)
 
+ifdef CONFIG_CC_IS_CLANG
+BOOTCFLAGS += $(CLANG_FLAGS)
+BOOTAFLAGS += $(CLANG_FLAGS)
+endif
+
 ifdef CONFIG_DEBUG_INFO
 BOOTCFLAGS	+= -g
 endif
diff --git a/arch/x86/kernel/head64.c b/arch/x86/kernel/head64.c
index 7663a8eb602b..163c56ae4be6 100644
--- a/arch/x86/kernel/head64.c
+++ b/arch/x86/kernel/head64.c
@@ -98,7 +98,7 @@ static bool __head check_la57_support(unsigned long physaddr)
 	return true;
 }
 #else
-static bool __head check_la57_support(unsigned long physaddr)
+static inline bool __head check_la57_support(unsigned long physaddr)
 {
 	return false;
 }
diff --git a/include/linux/compiler-gcc.h b/include/linux/compiler-gcc.h
index 2010493e1040..a437a2b79ebc 100644
--- a/include/linux/compiler-gcc.h
+++ b/include/linux/compiler-gcc.h
@@ -76,8 +76,10 @@
 
 #define __compiletime_object_size(obj) __builtin_object_size(obj, 0)
 
+#ifndef CONFIG_CC_OPTIMIZE_FOR_DEBUGGING
 #define __compiletime_warning(message) __attribute__((__warning__(message)))
 #define __compiletime_error(message) __attribute__((__error__(message)))
+#endif
 
 #if defined(LATENT_ENTROPY_PLUGIN) && !defined(__CHECKER__)
 #define __latent_entropy __attribute__((latent_entropy))
diff --git a/init/Kconfig b/init/Kconfig
index a4112e95724a..d5fb0ee1400a 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -1105,6 +1105,27 @@ config CC_OPTIMIZE_FOR_SIZE
 
 	  If unsure, say N.
 
+config CC_OPTIMIZE_FOR_DEBUGGING
+	bool "Optimize for better debugging experience (-Og)"
+	depends on CC_IS_GCC
+	depends on $(cc-option,-Og)
+	select NO_AUTO_INLINE
+	help
+	  This will apply GCC '-Og' optimization level which is supported
+	  since GCC 4.8. This optimization level offers a reasonable level
+	  of optimization while maintaining fast compilation and a good
+	  debugging experience. It is similar to '-O1' while preferring to
+	  keep debug ability over runtime speed. The overall performance
+	  will drop a bit (~6%).
+
+	  Use only if you want to debug the kernel, especially if you want
+	  to have better kernel debugging experience with gdb facilities
+	  like kgdb or qemu. If enabling this option breaks your kernel,
+	  you should either disable this or find a fix (mostly in the arch
+	  code).
+
+	  If unsure, select N.
+
 endchoice
 
 config HAVE_LD_DEAD_CODE_DATA_ELIMINATION
diff --git a/kernel/configs/tiny.config b/kernel/configs/tiny.config
index 7fa0c4ae6394..599ea86b0800 100644
--- a/kernel/configs/tiny.config
+++ b/kernel/configs/tiny.config
@@ -1,5 +1,6 @@
 # CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE is not set
 CONFIG_CC_OPTIMIZE_FOR_SIZE=y
+# CONFIG_CC_OPTIMIZE_FOR_DEBUGGING is not set
 # CONFIG_KERNEL_GZIP is not set
 # CONFIG_KERNEL_BZIP2 is not set
 # CONFIG_KERNEL_LZMA is not set
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 1af29b8224fd..60750a72cbe2 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -211,6 +211,23 @@ config GDB_SCRIPTS
 	  instance. See Documentation/dev-tools/gdb-kernel-debugging.rst
 	  for further details.
 
+config NO_AUTO_INLINE
+	bool "Disable compiler auto-inline optimizations"
+	help
+	  This will prevent the compiler from optimizing the kernel by
+	  auto-inlining functions not marked with the inline keyword.
+	  With this option, only functions explicitly marked with
+	  "inline" will be inlined. This will allow the function tracer
+	  to trace more functions because it only traces functions that
+	  the compiler has not inlined.
+
+	  Enabling this function can help debugging a kernel if using
+	  the function tracer. But it can also change how the kernel
+	  works, because inlining functions may change the timing,
+	  which could make it difficult while debugging race conditions.
+
+	  If unsure, select N.
+
 config ENABLE_MUST_CHECK
 	bool "Enable __must_check logic"
 	default y
diff --git a/scripts/kconfig/merge_config.sh b/scripts/kconfig/merge_config.sh
index 0ef906499646..9b89791b202c 100755
--- a/scripts/kconfig/merge_config.sh
+++ b/scripts/kconfig/merge_config.sh
@@ -22,6 +22,7 @@
 
 clean_up() {
 	rm -f $TMP_FILE
+	rm -f $MERGE_FILE
 	exit
 }
 trap clean_up HUP INT TERM
@@ -32,6 +33,7 @@ usage() {
 	echo "  -m    only merge the fragments, do not execute the make command"
 	echo "  -n    use allnoconfig instead of alldefconfig"
 	echo "  -r    list redundant entries when merging fragments"
+	echo "  -y    make builtin have precedence over modules"
 	echo "  -O    dir to put generated output files.  Consider setting \$KCONFIG_CONFIG instead."
 	echo
 	echo "Used prefix: '$CONFIG_PREFIX'. You can redefine it with \$CONFIG_ environment variable."
@@ -40,6 +42,7 @@ usage() {
 RUNMAKE=true
 ALLTARGET=alldefconfig
 WARNREDUN=false
+BUILTIN=false
 OUTPUT=.
 CONFIG_PREFIX=${CONFIG_-CONFIG_}
 
@@ -64,6 +67,11 @@ while true; do
 		shift
 		continue
 		;;
+	"-y")
+		BUILTIN=true
+		shift
+		continue
+		;;
 	"-O")
 		if [ -d $2 ];then
 			OUTPUT=$(echo $2 | sed 's/\/*$//')
@@ -106,32 +114,45 @@ SED_CONFIG_EXP1="s/^\(${CONFIG_PREFIX}[a-zA-Z0-9_]*\)=.*/\1/p"
 SED_CONFIG_EXP2="s/^# \(${CONFIG_PREFIX}[a-zA-Z0-9_]*\) is not set$/\1/p"
 
 TMP_FILE=$(mktemp ./.tmp.config.XXXXXXXXXX)
+MERGE_FILE=$(mktemp ./.merge_tmp.config.XXXXXXXXXX)
 
 echo "Using $INITFILE as base"
 cat $INITFILE > $TMP_FILE
 
 # Merge files, printing warnings on overridden values
-for MERGE_FILE in $MERGE_LIST ; do
-	echo "Merging $MERGE_FILE"
-	if [ ! -r "$MERGE_FILE" ]; then
-		echo "The merge file '$MERGE_FILE' does not exist.  Exit." >&2
+for ORIG_MERGE_FILE in $MERGE_LIST ; do
+	echo "Merging $ORIG_MERGE_FILE"
+	if [ ! -r "$ORIG_MERGE_FILE" ]; then
+		echo "The merge file '$ORIG_MERGE_FILE' does not exist.  Exit." >&2
 		exit 1
 	fi
+	cat $ORIG_MERGE_FILE > $MERGE_FILE
 	CFG_LIST=$(sed -n -e "$SED_CONFIG_EXP1" -e "$SED_CONFIG_EXP2" $MERGE_FILE)
 
 	for CFG in $CFG_LIST ; do
 		grep -q -w $CFG $TMP_FILE || continue
 		PREV_VAL=$(grep -w $CFG $TMP_FILE)
 		NEW_VAL=$(grep -w $CFG $MERGE_FILE)
-		if [ "x$PREV_VAL" != "x$NEW_VAL" ] ; then
-			echo Value of $CFG is redefined by fragment $MERGE_FILE:
+		BUILTIN_FLAG=false
+		if [ "$BUILTIN" = "true" ] && [ "${NEW_VAL#CONFIG_*=}" = "m" ] && [ "${PREV_VAL#CONFIG_*=}" = "y" ]; then
+			echo Previous  value: $PREV_VAL
+			echo New value:       $NEW_VAL
+			echo -y passed, will not demote y to m
+			echo
+			BUILTIN_FLAG=true
+		elif [ "x$PREV_VAL" != "x$NEW_VAL" ] ; then
+			echo Value of $CFG is redefined by fragment $ORIG_MERGE_FILE:
 			echo Previous  value: $PREV_VAL
 			echo New value:       $NEW_VAL
 			echo
 		elif [ "$WARNREDUN" = "true" ]; then
-			echo Value of $CFG is redundant by fragment $MERGE_FILE:
+			echo Value of $CFG is redundant by fragment $ORIG_MERGE_FILE:
+		fi
+		if [ "$BUILTIN_FLAG" = "false" ]; then
+			sed -i "/$CFG[ =]/d" $TMP_FILE
+		else
+			sed -i "/$CFG[ =]/d" $MERGE_FILE
 		fi
-		sed -i "/$CFG[ =]/d" $TMP_FILE
 	done
 	cat $MERGE_FILE >> $TMP_FILE
 done
diff --git a/scripts/setlocalversion b/scripts/setlocalversion
index 71f39410691b..365b3c2b8f43 100755
--- a/scripts/setlocalversion
+++ b/scripts/setlocalversion
@@ -73,8 +73,16 @@ scm_version()
 			printf -- '-svn%s' "`git svn find-rev $head`"
 		fi
 
-		# Check for uncommitted changes
-		if git diff-index --name-only HEAD | grep -qv "^scripts/package"; then
+		# Check for uncommitted changes.
+		# First, with git-status, but --no-optional-locks is only
+		# supported in git >= 2.14, so fall back to git-diff-index if
+		# it fails. Note that git-diff-index does not refresh the
+		# index, so it may give misleading results. See
+		# git-update-index(1), git-diff-index(1), and git-status(1).
+		if {
+			git --no-optional-locks status -uno --porcelain 2>/dev/null ||
+			git diff-index --name-only HEAD
+		} | grep -qvE '^(.. )?scripts/package'; then
 			printf '%s' -dirty
 		fi