linux-stable/arch/x86/boot/Makefile
Yinghai Lu d607251ba9 x86/boot: Calculate decompression size during boot not build
Currently z_extract_offset is calculated in boot/compressed/mkpiggy.c.
This doesn't work well because mkpiggy.c doesn't know the details of the
decompressor in use. As a result, it can only make an estimation, which
has risks:

 - output + output_len (VO) could be much bigger than input + input_len
   (ZO). In this case, the decompressed kernel plus relocs could overwrite
   the decompression code while it is running.

 - The head code of ZO could be bigger than z_extract_offset. In this case
   an overwrite could happen when the head code is running to move ZO to
   the end of buffer. Though currently the size of the head code is very
   small it's still a potential risk. Since there is no rule to limit the
   size of the head code of ZO, it runs the risk of suddenly becoming a
   (hard to find) bug.

Instead, this moves the z_extract_offset calculation into header.S, and
makes adjustments to be sure that the above two cases can never happen,
and further corrects the comments describing the calculations.

Since we have (in the previous patch) made ZO always be located against
the end of decompression buffer, z_extract_offset is only used here to
calculate an appropriate buffer size (INIT_SIZE), and is not longer used
elsewhere. As such, it can be removed from voffset.h.

Additionally clean up #if/#else #define to improve readability.

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Baoquan He <bhe@redhat.com>
[ Rewrote the changelog and comments. ]
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: lasse.collin@tukaani.org
Link: http://lkml.kernel.org/r/1461888548-32439-4-git-send-email-keescook@chromium.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-04-29 11:03:29 +02:00

198 lines
6.7 KiB
Makefile

#
# arch/x86/boot/Makefile
#
# This file is subject to the terms and conditions of the GNU General Public
# License. See the file "COPYING" in the main directory of this archive
# for more details.
#
# Copyright (C) 1994 by Linus Torvalds
# Changed by many, many contributors over the years.
#
KASAN_SANITIZE := n
OBJECT_FILES_NON_STANDARD := y
# Kernel does not boot with kcov instrumentation here.
# One of the problems observed was insertion of __sanitizer_cov_trace_pc()
# callback into middle of per-cpu data enabling code. Thus the callback observed
# inconsistent state and crashed. We are interested mostly in syscall coverage,
# so boot code is not interesting anyway.
KCOV_INSTRUMENT := n
# If you want to preset the SVGA mode, uncomment the next line and
# set SVGA_MODE to whatever number you want.
# Set it to -DSVGA_MODE=NORMAL_VGA if you just want the EGA/VGA mode.
# The number is the same as you would ordinarily press at bootup.
SVGA_MODE := -DSVGA_MODE=NORMAL_VGA
targets := vmlinux.bin setup.bin setup.elf bzImage
targets += fdimage fdimage144 fdimage288 image.iso mtools.conf
subdir- := compressed
setup-y += a20.o bioscall.o cmdline.o copy.o cpu.o cpuflags.o cpucheck.o
setup-y += early_serial_console.o edd.o header.o main.o memory.o
setup-y += pm.o pmjump.o printf.o regs.o string.o tty.o video.o
setup-y += video-mode.o version.o
setup-$(CONFIG_X86_APM_BOOT) += apm.o
# The link order of the video-*.o modules can matter. In particular,
# video-vga.o *must* be listed first, followed by video-vesa.o.
# Hardware-specific drivers should follow in the order they should be
# probed, and video-bios.o should typically be last.
setup-y += video-vga.o
setup-y += video-vesa.o
setup-y += video-bios.o
targets += $(setup-y)
hostprogs-y := tools/build
hostprogs-$(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
$(obj)/cpustr.h: $(obj)/mkcpustr FORCE
$(call if_changed,cpustr)
endif
clean-files += cpustr.h
# ---------------------------------------------------------------------------
KBUILD_CFLAGS := $(USERINCLUDE) $(REALMODE_CFLAGS) -D_SETUP
KBUILD_AFLAGS := $(KBUILD_CFLAGS) -D__ASSEMBLY__
GCOV_PROFILE := n
UBSAN_SANITIZE := n
$(obj)/bzImage: asflags-y := $(SVGA_MODE)
quiet_cmd_image = BUILD $@
cmd_image = $(obj)/tools/build $(obj)/setup.bin $(obj)/vmlinux.bin \
$(obj)/zoffset.h $@
$(obj)/bzImage: $(obj)/setup.bin $(obj)/vmlinux.bin $(obj)/tools/build FORCE
$(call if_changed,image)
@echo 'Kernel: $@ is ready' ' (#'`cat .version`')'
OBJCOPYFLAGS_vmlinux.bin := -O binary -R .note -R .comment -S
$(obj)/vmlinux.bin: $(obj)/compressed/vmlinux FORCE
$(call if_changed,objcopy)
SETUP_OBJS = $(addprefix $(obj)/,$(setup-y))
sed-voffset := -e 's/^\([0-9a-fA-F]*\) [ABCDGRSTVW] \(_text\|_end\)$$/\#define VO_\2 0x\1/p'
quiet_cmd_voffset = VOFFSET $@
cmd_voffset = $(NM) $< | sed -n $(sed-voffset) > $@
targets += voffset.h
$(obj)/voffset.h: vmlinux FORCE
$(call if_changed,voffset)
sed-zoffset := -e 's/^\([0-9a-fA-F]*\) [ABCDGRSTVW] \(startup_32\|startup_64\|efi32_stub_entry\|efi64_stub_entry\|efi_pe_entry\|input_data\|_end\|_ehead\|_text\|z_.*\)$$/\#define ZO_\2 0x\1/p'
quiet_cmd_zoffset = ZOFFSET $@
cmd_zoffset = $(NM) $< | sed -n $(sed-zoffset) > $@
targets += zoffset.h
$(obj)/zoffset.h: $(obj)/compressed/vmlinux FORCE
$(call if_changed,zoffset)
AFLAGS_header.o += -I$(obj)
$(obj)/header.o: $(obj)/voffset.h $(obj)/zoffset.h
LDFLAGS_setup.elf := -T
$(obj)/setup.elf: $(src)/setup.ld $(SETUP_OBJS) FORCE
$(call if_changed,ld)
OBJCOPYFLAGS_setup.bin := -O binary
$(obj)/setup.bin: $(obj)/setup.elf FORCE
$(call if_changed,objcopy)
$(obj)/compressed/vmlinux: FORCE
$(Q)$(MAKE) $(build)=$(obj)/compressed $@
# Set this if you want to pass append arguments to the
# bzdisk/fdimage/isoimage kernel
FDARGS =
# Set this if you want an initrd included with the
# bzdisk/fdimage/isoimage kernel
FDINITRD =
image_cmdline = default linux $(FDARGS) $(if $(FDINITRD),initrd=initrd.img,)
$(obj)/mtools.conf: $(src)/mtools.conf.in
sed -e 's|@OBJ@|$(obj)|g' < $< > $@
# This requires write access to /dev/fd0
bzdisk: $(obj)/bzImage $(obj)/mtools.conf
MTOOLSRC=$(obj)/mtools.conf mformat a: ; sync
syslinux /dev/fd0 ; sync
echo '$(image_cmdline)' | \
MTOOLSRC=$(src)/mtools.conf mcopy - a:syslinux.cfg
if [ -f '$(FDINITRD)' ] ; then \
MTOOLSRC=$(obj)/mtools.conf mcopy '$(FDINITRD)' a:initrd.img ; \
fi
MTOOLSRC=$(obj)/mtools.conf mcopy $(obj)/bzImage a:linux ; sync
# These require being root or having syslinux 2.02 or higher installed
fdimage fdimage144: $(obj)/bzImage $(obj)/mtools.conf
dd if=/dev/zero of=$(obj)/fdimage bs=1024 count=1440
MTOOLSRC=$(obj)/mtools.conf mformat v: ; sync
syslinux $(obj)/fdimage ; sync
echo '$(image_cmdline)' | \
MTOOLSRC=$(obj)/mtools.conf mcopy - v:syslinux.cfg
if [ -f '$(FDINITRD)' ] ; then \
MTOOLSRC=$(obj)/mtools.conf mcopy '$(FDINITRD)' v:initrd.img ; \
fi
MTOOLSRC=$(obj)/mtools.conf mcopy $(obj)/bzImage v:linux ; sync
fdimage288: $(obj)/bzImage $(obj)/mtools.conf
dd if=/dev/zero of=$(obj)/fdimage bs=1024 count=2880
MTOOLSRC=$(obj)/mtools.conf mformat w: ; sync
syslinux $(obj)/fdimage ; sync
echo '$(image_cmdline)' | \
MTOOLSRC=$(obj)/mtools.conf mcopy - w:syslinux.cfg
if [ -f '$(FDINITRD)' ] ; then \
MTOOLSRC=$(obj)/mtools.conf mcopy '$(FDINITRD)' w:initrd.img ; \
fi
MTOOLSRC=$(obj)/mtools.conf mcopy $(obj)/bzImage w:linux ; sync
isoimage: $(obj)/bzImage
-rm -rf $(obj)/isoimage
mkdir $(obj)/isoimage
for i in lib lib64 share end ; do \
if [ -f /usr/$$i/syslinux/isolinux.bin ] ; then \
cp /usr/$$i/syslinux/isolinux.bin $(obj)/isoimage ; \
break ; \
fi ; \
if [ $$i = end ] ; then exit 1 ; fi ; \
done
cp $(obj)/bzImage $(obj)/isoimage/linux
echo '$(image_cmdline)' > $(obj)/isoimage/isolinux.cfg
if [ -f '$(FDINITRD)' ] ; then \
cp '$(FDINITRD)' $(obj)/isoimage/initrd.img ; \
fi
mkisofs -J -r -o $(obj)/image.iso -b isolinux.bin -c boot.cat \
-no-emul-boot -boot-load-size 4 -boot-info-table \
$(obj)/isoimage
isohybrid $(obj)/image.iso 2>/dev/null || true
rm -rf $(obj)/isoimage
bzlilo: $(obj)/bzImage
if [ -f $(INSTALL_PATH)/vmlinuz ]; then mv $(INSTALL_PATH)/vmlinuz $(INSTALL_PATH)/vmlinuz.old; fi
if [ -f $(INSTALL_PATH)/System.map ]; then mv $(INSTALL_PATH)/System.map $(INSTALL_PATH)/System.old; fi
cat $(obj)/bzImage > $(INSTALL_PATH)/vmlinuz
cp System.map $(INSTALL_PATH)/
if [ -x /sbin/lilo ]; then /sbin/lilo; else /etc/lilo/install; fi
install:
sh $(srctree)/$(src)/install.sh $(KERNELRELEASE) $(obj)/bzImage \
System.map "$(INSTALL_PATH)"