Merge tag 'tiny/for-3.18' of git://git.kernel.org/pub/scm/linux/kerne…

…l/git/josh/linux

Pull "tinification" patches from Josh Triplett.

Work on making smaller kernels.

* tag 'tiny/for-3.18' of git://git.kernel.org/pub/scm/linux/kernel/git/josh/linux:
  bloat-o-meter: Ignore syscall aliases SyS_ and compat_SyS_
  mm: Support compiling out madvise and fadvise
  x86: Support compiling out human-friendly processor feature names
  x86: Drop support for /proc files when !CONFIG_PROC_FS
  x86, boot: Don't compile early_serial_console.c when !CONFIG_EARLY_PRINTK
  x86, boot: Don't compile aslr.c when !CONFIG_RANDOMIZE_BASE
  x86, boot: Use the usual -y -n mechanism for objects in vmlinux
  x86: Add "make tinyconfig" to configure the tiniest possible kernel
  x86, platform, kconfig: move kvmconfig functionality to a helper

arch/x86/Kconfig

@@ -137,6 +137,7 @@ config X86
 	select HAVE_ACPI_APEI if ACPI
 	select HAVE_ACPI_APEI_NMI if ACPI
 	select ACPI_LEGACY_TABLES_LOOKUP if ACPI
+	select X86_FEATURE_NAMES if PROC_FS
 
 config INSTRUCTION_DECODER
 	def_bool y
@@ -314,6 +315,17 @@ config SMP
 
 	  If you don't know what to do here, say N.
 
+config X86_FEATURE_NAMES
+	bool "Processor feature human-readable names" if EMBEDDED
+	default y
+	---help---
+	  This option compiles in a table of x86 feature bits and corresponding
+	  names.  This is required to support /proc/cpuinfo and a few kernel
+	  messages.  You can disable this to save space, at the expense of
+	  making those few kernel messages show numeric feature bits instead.
+
+	  If in doubt, say Y.
+
 config X86_X2APIC
 	bool "Support x2apic"
 	depends on X86_LOCAL_APIC && X86_64 && IRQ_REMAP

arch/x86/Makefile

@@ -253,12 +253,6 @@ archclean:
 	$(Q)$(MAKE) $(clean)=arch/x86/tools
 	$(Q)$(MAKE) $(clean)=arch/x86/purgatory
 
-PHONY += kvmconfig
-kvmconfig:
-	$(if $(wildcard $(objtree)/.config),, $(error You need an existing .config for this target))
-	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/kconfig/merge_config.sh -m -O $(objtree) $(objtree)/.config $(srctree)/arch/x86/configs/kvm_guest.config
-	$(Q)yes "" | $(MAKE) -f $(srctree)/Makefile oldconfig
-
 define archhelp
   echo  '* bzImage      - Compressed kernel image (arch/x86/boot/bzImage)'
   echo  '  install      - Install kernel using'
@@ -272,5 +266,4 @@ define archhelp
   echo  '                  bzdisk/fdimage*/isoimage also accept:'
   echo  '                  FDARGS="..."  arguments for the booted kernel'
   echo  '                  FDINITRD=file initrd for the booted kernel'
-  echo  '  kvmconfig	- Enable additional options for guest kernel support'
 endef

arch/x86/boot/Makefile

@@ -35,19 +35,22 @@ setup-y		+= video-vesa.o
 setup-y		+= video-bios.o
 
 targets		+= $(setup-y)
-hostprogs-y	:= mkcpustr tools/build
+hostprogs-y	:= tools/build
+hostprogs-$(CONFIG_X86_FEATURE_NAMES) += mkcpustr
 
 HOST_EXTRACFLAGS += -I$(srctree)/tools/include \
 		    -include include/generated/autoconf.h \
 	            -D__EXPORTED_HEADERS__
 
+ifdef CONFIG_X86_FEATURE_NAMES
 $(obj)/cpu.o: $(obj)/cpustr.h
 
 quiet_cmd_cpustr = CPUSTR  $@
       cmd_cpustr = $(obj)/mkcpustr > $@
-targets		+= cpustr.h
+targets += cpustr.h
 $(obj)/cpustr.h: $(obj)/mkcpustr FORCE
 	$(call if_changed,cpustr)
+endif
 
 # ---------------------------------------------------------------------------
 

arch/x86/boot/compressed/Makefile

@@ -26,25 +26,26 @@ LDFLAGS_vmlinux := -T
 hostprogs-y	:= mkpiggy
 HOST_EXTRACFLAGS += -I$(srctree)/tools/include
 
-VMLINUX_OBJS = $(obj)/vmlinux.lds $(obj)/head_$(BITS).o $(obj)/misc.o \
-	$(obj)/string.o $(obj)/cmdline.o $(obj)/early_serial_console.o \
-	$(obj)/piggy.o $(obj)/cpuflags.o $(obj)/aslr.o
+vmlinux-objs-y := $(obj)/vmlinux.lds $(obj)/head_$(BITS).o $(obj)/misc.o \
+	$(obj)/string.o $(obj)/cmdline.o \
+	$(obj)/piggy.o $(obj)/cpuflags.o
+
+vmlinux-objs-$(CONFIG_EARLY_PRINTK) += $(obj)/early_serial_console.o
+vmlinux-objs-$(CONFIG_RANDOMIZE_BASE) += $(obj)/aslr.o
 
 $(obj)/eboot.o: KBUILD_CFLAGS += -fshort-wchar -mno-red-zone
 
-ifeq ($(CONFIG_EFI_STUB), y)
-	VMLINUX_OBJS += $(obj)/eboot.o $(obj)/efi_stub_$(BITS).o
-endif
+vmlinux-objs-$(CONFIG_EFI_STUB) += $(obj)/eboot.o $(obj)/efi_stub_$(BITS).o
 
-$(obj)/vmlinux: $(VMLINUX_OBJS) FORCE
+$(obj)/vmlinux: $(vmlinux-objs-y) FORCE
 	$(call if_changed,ld)
 	@:
 
 OBJCOPYFLAGS_vmlinux.bin :=  -R .comment -S
 $(obj)/vmlinux.bin: vmlinux FORCE
 	$(call if_changed,objcopy)
 
-targets += $(patsubst $(obj)/%,%,$(VMLINUX_OBJS)) vmlinux.bin.all vmlinux.relocs
+targets += $(patsubst $(obj)/%,%,$(vmlinux-objs-y)) vmlinux.bin.all vmlinux.relocs
 
 CMD_RELOCS = arch/x86/tools/relocs
 quiet_cmd_relocs = RELOCS  $@

arch/x86/boot/compressed/aslr.c

@@ -1,6 +1,5 @@
 #include "misc.h"
 
-#ifdef CONFIG_RANDOMIZE_BASE
 #include <asm/msr.h>
 #include <asm/archrandom.h>
 #include <asm/e820.h>
@@ -335,5 +334,3 @@ unsigned char *choose_kernel_location(unsigned char *input,
 out:
 	return (unsigned char *)choice;
 }
-
-#endif /* CONFIG_RANDOMIZE_BASE */

arch/x86/boot/compressed/early_serial_console.c

@@ -1,9 +1,5 @@
 #include "misc.h"
 
-#ifdef CONFIG_EARLY_PRINTK
-
 int early_serial_base;
 
 #include "../early_serial_console.c"
-
-#endif

arch/x86/boot/cpu.c

@@ -16,7 +16,9 @@
  */
 
 #include "boot.h"
+#ifdef CONFIG_X86_FEATURE_NAMES
 #include "cpustr.h"
+#endif
 
 static char *cpu_name(int level)
 {
@@ -32,11 +34,48 @@ static char *cpu_name(int level)
 	}
 }
 
+static void show_cap_strs(u32 *err_flags)
+{
+	int i, j;
+#ifdef CONFIG_X86_FEATURE_NAMES
+	const unsigned char *msg_strs = (const unsigned char *)x86_cap_strs;
+	for (i = 0; i < NCAPINTS; i++) {
+		u32 e = err_flags[i];
+		for (j = 0; j < 32; j++) {
+			if (msg_strs[0] < i ||
+			    (msg_strs[0] == i && msg_strs[1] < j)) {
+				/* Skip to the next string */
+				msg_strs += 2;
+				while (*msg_strs++)
+					;
+			}
+			if (e & 1) {
+				if (msg_strs[0] == i &&
+				    msg_strs[1] == j &&
+				    msg_strs[2])
+					printf("%s ", msg_strs+2);
+				else
+					printf("%d:%d ", i, j);
+			}
+			e >>= 1;
+		}
+	}
+#else
+	for (i = 0; i < NCAPINTS; i++) {
+		u32 e = err_flags[i];
+		for (j = 0; j < 32; j++) {
+			if (e & 1)
+				printf("%d:%d ", i, j);
+			e >>= 1;
+		}
+	}
+#endif
+}
+
 int validate_cpu(void)
 {
 	u32 *err_flags;
 	int cpu_level, req_level;
-	const unsigned char *msg_strs;
 
 	check_cpu(&cpu_level, &req_level, &err_flags);
 
@@ -49,34 +88,9 @@ int validate_cpu(void)
 	}
 
 	if (err_flags) {
-		int i, j;
 		puts("This kernel requires the following features "
 		     "not present on the CPU:\n");
-
-		msg_strs = (const unsigned char *)x86_cap_strs;
-
-		for (i = 0; i < NCAPINTS; i++) {
-			u32 e = err_flags[i];
-
-			for (j = 0; j < 32; j++) {
-				if (msg_strs[0] < i ||
-				    (msg_strs[0] == i && msg_strs[1] < j)) {
-					/* Skip to the next string */
-					msg_strs += 2;
-					while (*msg_strs++)
-						;
-				}
-				if (e & 1) {
-					if (msg_strs[0] == i &&
-					    msg_strs[1] == j &&
-					    msg_strs[2])
-						printf("%s ", msg_strs+2);
-					else
-						printf("%d:%d ", i, j);
-				}
-				e >>= 1;
-			}
-		}
+		show_cap_strs(err_flags);
 		putchar('\n');
 		return -1;
 	} else {

arch/x86/configs/tiny.config

@@ -0,0 +1 @@
+CONFIG_NOHIGHMEM=y

arch/x86/include/asm/cpufeature.h

@@ -250,8 +250,15 @@
 #include <asm/asm.h>
 #include <linux/bitops.h>
 
+#ifdef CONFIG_X86_FEATURE_NAMES
 extern const char * const x86_cap_flags[NCAPINTS*32];
 extern const char * const x86_power_flags[32];
+#define X86_CAP_FMT "%s"
+#define x86_cap_flag(flag) x86_cap_flags[flag]
+#else
+#define X86_CAP_FMT "%d:%d"
+#define x86_cap_flag(flag) ((flag) >> 5), ((flag) & 31)
+#endif
 
 /*
  * In order to save room, we index into this array by doing

arch/x86/kernel/cpu/Makefile

@@ -13,10 +13,13 @@ nostackp := $(call cc-option, -fno-stack-protector)
 CFLAGS_common.o		:= $(nostackp)
 
 obj-y			:= intel_cacheinfo.o scattered.o topology.o
-obj-y			+= proc.o capflags.o powerflags.o common.o
+obj-y			+= common.o
 obj-y			+= rdrand.o
 obj-y			+= match.o
 
+obj-$(CONFIG_PROC_FS)	+= proc.o
+obj-$(CONFIG_X86_FEATURE_NAMES) += capflags.o powerflags.o
+
 obj-$(CONFIG_X86_32)	+= bugs.o
 obj-$(CONFIG_X86_64)	+= bugs_64.o
 
@@ -48,6 +51,7 @@ obj-$(CONFIG_X86_LOCAL_APIC)		+= perfctr-watchdog.o perf_event_amd_ibs.o
 
 obj-$(CONFIG_HYPERVISOR_GUEST)		+= vmware.o hypervisor.o mshyperv.o
 
+ifdef CONFIG_X86_FEATURE_NAMES
 quiet_cmd_mkcapflags = MKCAP   $@
       cmd_mkcapflags = $(CONFIG_SHELL) $(srctree)/$(src)/mkcapflags.sh $< $@
 
@@ -56,3 +60,4 @@ cpufeature = $(src)/../../include/asm/cpufeature.h
 targets += capflags.c
 $(obj)/capflags.c: $(cpufeature) $(src)/mkcapflags.sh FORCE
 	$(call if_changed,mkcapflags)
+endif

arch/x86/kernel/cpu/common.c

@@ -346,8 +346,8 @@ static void filter_cpuid_features(struct cpuinfo_x86 *c, bool warn)
 			continue;
 
 		printk(KERN_WARNING
-		       "CPU: CPU feature %s disabled, no CPUID level 0x%x\n",
-				x86_cap_flags[df->feature], df->level);
+		       "CPU: CPU feature " X86_CAP_FMT " disabled, no CPUID level 0x%x\n",
+				x86_cap_flag(df->feature), df->level);
 	}
 }
 

init/Kconfig

@@ -1540,6 +1540,16 @@ config AIO
 	  by some high performance threaded applications. Disabling
 	  this option saves about 7k.
 
+config ADVISE_SYSCALLS
+	bool "Enable madvise/fadvise syscalls" if EXPERT
+	default y
+	help
+	  This option enables the madvise and fadvise syscalls, used by
+	  applications to advise the kernel about their future memory or file
+	  usage, improving performance. If building an embedded system where no
+	  applications use these syscalls, you can disable this option to save
+	  space.
+
 config PCI_QUIRKS
 	default y
 	bool "Enable PCI quirk workarounds" if EXPERT

kernel/configs/tiny.config

@@ -0,0 +1,4 @@
+CONFIG_CC_OPTIMIZE_FOR_SIZE=y
+CONFIG_KERNEL_XZ=y
+CONFIG_OPTIMIZE_INLINING=y
+CONFIG_SLOB=y

kernel/sys_ni.c

@@ -156,6 +156,9 @@ cond_syscall(sys_process_vm_writev);
 cond_syscall(compat_sys_process_vm_readv);
 cond_syscall(compat_sys_process_vm_writev);
 cond_syscall(sys_uselib);
+cond_syscall(sys_fadvise64);
+cond_syscall(sys_fadvise64_64);
+cond_syscall(sys_madvise);
 
 /* arch-specific weak syscall entries */
 cond_syscall(sys_pciconfig_read);

mm/Makefile

@@ -3,15 +3,15 @@
 #
 
 mmu-y			:= nommu.o
-mmu-$(CONFIG_MMU)	:= fremap.o gup.o highmem.o madvise.o memory.o mincore.o \
+mmu-$(CONFIG_MMU)	:= fremap.o gup.o highmem.o memory.o mincore.o \
 			   mlock.o mmap.o mprotect.o mremap.o msync.o rmap.o \
 			   vmalloc.o pagewalk.o pgtable-generic.o
 
 ifdef CONFIG_CROSS_MEMORY_ATTACH
 mmu-$(CONFIG_MMU)	+= process_vm_access.o
 endif
 
-obj-y			:= filemap.o mempool.o oom_kill.o fadvise.o \
+obj-y			:= filemap.o mempool.o oom_kill.o \
 			   maccess.o page_alloc.o page-writeback.o \
 			   readahead.o swap.o truncate.o vmscan.o shmem.o \
 			   util.o mmzone.o vmstat.o backing-dev.o \
@@ -28,6 +28,9 @@ else
 	obj-y		+= bootmem.o
 endif
 
+ifdef CONFIG_MMU
+	obj-$(CONFIG_ADVISE_SYSCALLS)	+= fadvise.o madvise.o
+endif
 obj-$(CONFIG_HAVE_MEMBLOCK) += memblock.o
 
 obj-$(CONFIG_SWAP)	+= page_io.o swap_state.o swapfile.o

scripts/bloat-o-meter

@@ -20,6 +20,8 @@ def getsizes(file):
         if type in "tTdDbBrR":
             # strip generated symbols
             if name.startswith("__mod_"): continue
+            if name.startswith("SyS_"): continue
+            if name.startswith("compat_SyS_"): continue
             if name == "linux_banner": continue
             # statics and some other optimizations adds random .NUMBER
             name = re.sub(r'\.[0-9]+', '', name)

scripts/kconfig/Makefile

@@ -104,6 +104,23 @@ endif
 %_defconfig: $(obj)/conf
 	$(Q)$< --defconfig=arch/$(SRCARCH)/configs/$@ $(Kconfig)
 
+configfiles=$(wildcard $(srctree)/kernel/configs/$(1).config $(srctree)/arch/$(SRCARCH)/configs/$(1).config)
+
+define mergeconfig
+$(if $(wildcard $(objtree)/.config),, $(error You need an existing .config for this target))
+$(if $(call configfiles,$(1)),, $(error No configuration exists for this target on this architecture))
+$(Q)$(CONFIG_SHELL) $(srctree)/scripts/kconfig/merge_config.sh -m -O $(objtree) $(objtree)/.config $(call configfiles,$(1))
+$(Q)yes "" | $(MAKE) -f $(srctree)/Makefile oldconfig
+endef
+
+PHONY += kvmconfig
+kvmconfig:
+	$(call mergeconfig,kvm_guest)
+
+PHONY += tinyconfig
+tinyconfig: allnoconfig
+	$(call mergeconfig,tiny)
+
 # Help text used by make help
 help:
 	@echo  '  config	  - Update current config utilising a line-oriented program'
@@ -124,6 +141,8 @@ help:
 	@echo  '  randconfig	  - New config with random answer to all options'
 	@echo  '  listnewconfig   - List new options'
 	@echo  '  olddefconfig	  - Same as silentoldconfig but sets new symbols to their default value'
+	@echo  '  kvmconfig	  - Enable additional options for guest kernel support'
+	@echo  '  tinyconfig	  - Configure the tiniest possible kernel'
 
 # lxdialog stuff
 check-lxdialog  := $(srctree)/$(src)/lxdialog/check-lxdialog.sh