linux/arch/s390/boot/compressed/Makefile
Christian Borntraeger adc0b7fbf6 s390/boot/decompression: disable floating point in decompressor
my gcc 5.1 used an ldgr instruction with a register != 0,2,4,6 for
spilling/filling into a floating point register in our decompressor.

This will cause an AFP-register data exception as the decompressor
did not setup the additional floating point registers via cr0.
That causes a program check loop that looked like a hang with
one "Uncompressing Linux... " message (directly booted via kvm)
or a loop of "Uncompressing Linux... " messages (when booted via
zipl boot loader).

The offending code in my build was

   48e400:       e3 c0 af ff ff 71       lay     %r12,-1(%r10)
-->48e406:       b3 c1 00 1c             ldgr    %f1,%r12
   48e40a:       ec 6c 01 22 02 7f       clij    %r6,2,12,0x48e64e

but gcc could do spilling into an fpr at any function. We can
simply disable floating point support at that early stage.

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: stable@vger.kernel.org
2015-09-29 14:45:10 +02:00

70 lines
2.1 KiB
Makefile

#
# linux/arch/s390/boot/compressed/Makefile
#
# create a compressed vmlinux image from the original vmlinux
#
targets := vmlinux.lds vmlinux vmlinux.bin vmlinux.bin.gz vmlinux.bin.bz2
targets += vmlinux.bin.xz vmlinux.bin.lzma vmlinux.bin.lzo vmlinux.bin.lz4
targets += misc.o piggy.o sizes.h head.o
KBUILD_CFLAGS := -m64 -D__KERNEL__ $(LINUX_INCLUDE) -O2
KBUILD_CFLAGS += -DDISABLE_BRANCH_PROFILING
KBUILD_CFLAGS += $(cflags-y) -fno-delete-null-pointer-checks -msoft-float
KBUILD_CFLAGS += $(call cc-option,-mpacked-stack)
KBUILD_CFLAGS += $(call cc-option,-ffreestanding)
GCOV_PROFILE := n
OBJECTS := $(addprefix $(objtree)/arch/s390/kernel/, head.o sclp.o ebcdic.o)
OBJECTS += $(obj)/head.o $(obj)/misc.o $(obj)/piggy.o
LDFLAGS_vmlinux := --oformat $(LD_BFD) -e startup -T
$(obj)/vmlinux: $(obj)/vmlinux.lds $(OBJECTS)
$(call if_changed,ld)
@:
sed-sizes := -e 's/^\([0-9a-fA-F]*\) . \(__bss_start\|_end\)$$/\#define SZ\2 0x\1/p'
quiet_cmd_sizes = GEN $@
cmd_sizes = $(NM) $< | sed -n $(sed-sizes) > $@
$(obj)/sizes.h: vmlinux
$(call if_changed,sizes)
AFLAGS_head.o += -I$(obj)
$(obj)/head.o: $(obj)/sizes.h
CFLAGS_misc.o += -I$(obj)
$(obj)/misc.o: $(obj)/sizes.h
OBJCOPYFLAGS_vmlinux.bin := -R .comment -S
$(obj)/vmlinux.bin: vmlinux
$(call if_changed,objcopy)
vmlinux.bin.all-y := $(obj)/vmlinux.bin
suffix-$(CONFIG_KERNEL_GZIP) := gz
suffix-$(CONFIG_KERNEL_BZIP2) := bz2
suffix-$(CONFIG_KERNEL_LZ4) := lz4
suffix-$(CONFIG_KERNEL_LZMA) := lzma
suffix-$(CONFIG_KERNEL_LZO) := lzo
suffix-$(CONFIG_KERNEL_XZ) := xz
$(obj)/vmlinux.bin.gz: $(vmlinux.bin.all-y)
$(call if_changed,gzip)
$(obj)/vmlinux.bin.bz2: $(vmlinux.bin.all-y)
$(call if_changed,bzip2)
$(obj)/vmlinux.bin.lz4: $(vmlinux.bin.all-y)
$(call if_changed,lz4)
$(obj)/vmlinux.bin.lzma: $(vmlinux.bin.all-y)
$(call if_changed,lzma)
$(obj)/vmlinux.bin.lzo: $(vmlinux.bin.all-y)
$(call if_changed,lzo)
$(obj)/vmlinux.bin.xz: $(vmlinux.bin.all-y)
$(call if_changed,xzkern)
LDFLAGS_piggy.o := -r --format binary --oformat $(LD_BFD) -T
$(obj)/piggy.o: $(obj)/vmlinux.scr $(obj)/vmlinux.bin.$(suffix-y)
$(call if_changed,ld)