| Message ID | 1447370023-27793-1-git-send-email-kamal@canonical.com |
|---|---|
| State | New |
| Headers | show |
diff --git a/arch/s390/boot/compressed/Makefile b/arch/s390/boot/compressed/Makefile index f90d1fc..f70b232 100644 --- a/arch/s390/boot/compressed/Makefile +++ b/arch/s390/boot/compressed/Makefile @@ -12,7 +12,7 @@ targets += misc.o piggy.o sizes.h head$(BITS).o KBUILD_CFLAGS := -m$(BITS) -D__KERNEL__ $(LINUX_INCLUDE) -O2 KBUILD_CFLAGS += -DDISABLE_BRANCH_PROFILING -KBUILD_CFLAGS += $(cflags-y) -fno-delete-null-pointer-checks +KBUILD_CFLAGS += $(cflags-y) -fno-delete-null-pointer-checks -msoft-float KBUILD_CFLAGS += $(call cc-option,-mpacked-stack) KBUILD_CFLAGS += $(call cc-option,-ffreestanding)
This is a note to let you know that I have just added a patch titled s390/boot/decompression: disable floating point in decompressor to the linux-3.19.y-queue branch of the 3.19.y-ckt extended stable tree which can be found at: http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-3.19.y-queue This patch is scheduled to be released in version 3.19.8-ckt10. If you, or anyone else, feels it should not be added to this tree, please reply to this email. For more information about the 3.19.y-ckt tree, see https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable Thanks. -Kamal ------ From 16fb2259ad2b96c03a671522774d7baafb0c8b42 Mon Sep 17 00:00:00 2001 From: Christian Borntraeger <borntraeger@de.ibm.com> Date: Mon, 28 Sep 2015 22:47:42 +0200 Subject: [PATCH 009/120] s390/boot/decompression: disable floating point in decompressor commit adc0b7fbf6fe9967505c0254d9535ec7288186ae upstream. 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> Signed-off-by: Kamal Mostafa <kamal@canonical.com> --- arch/s390/boot/compressed/Makefile | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) -- 1.9.1