From: Christian Borntraeger <borntraeger@de.ibm.com>
To: Aurelien Jarno <aurelien@aurel32.net>, qemu-devel@nongnu.org
Cc: Cornelia Huck <cornelia.huck@de.ibm.com>, Alexander Graf <agraf@suse.de>
Subject: Re: [Qemu-devel] [PATCH] s390/bios: build with -fdelete-null-pointer-checks
Date: Mon, 15 Jun 2015 12:54:12 +0200 [thread overview]
Message-ID: <557EAED4.8080209@de.ibm.com> (raw)
In-Reply-To: <1434363843-14576-1-git-send-email-aurelien@aurel32.net>
Am 15.06.2015 um 12:24 schrieb Aurelien Jarno:
> Starting with version 4.9, GCC assumes it can't safely dereference null
> pointers, and uses this for some optimizations. On s390, the lowcore
> memory is located at address 0, so this assumption is wrong and breaks
> the s390-ccw firmware. Pass -fdelete-null-pointer-checks to avoid that.
>
> Cc: Cornelia Huck <cornelia.huck@de.ibm.com>
> Cc: Christian Borntraeger <borntraeger@de.ibm.com>
> Cc: Alexander Graf <agraf@suse.de>
> Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
> ---
> pc-bios/s390-ccw/Makefile | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/pc-bios/s390-ccw/Makefile b/pc-bios/s390-ccw/Makefile
> index 009bb8d..746603a 100644
> --- a/pc-bios/s390-ccw/Makefile
> +++ b/pc-bios/s390-ccw/Makefile
> @@ -10,7 +10,7 @@ $(call set-vpath, $(SRC_PATH)/pc-bios/s390-ccw)
> .PHONY : all clean build-all
>
> OBJECTS = start.o main.o bootmap.o sclp-ascii.o virtio.o
> -CFLAGS += -fPIE -fno-stack-protector -ffreestanding
> +CFLAGS += -fPIE -fno-stack-protector -ffreestanding -fno-delete-null-pointer-checks
> LDFLAGS += -Wl,-pie -nostdlib
>
> build-all: s390-ccw.img
>
applied thanks.
prev parent reply other threads:[~2015-06-15 10:54 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-06-15 10:24 [Qemu-devel] [PATCH] s390/bios: build with -fdelete-null-pointer-checks Aurelien Jarno
2015-06-15 10:54 ` Christian Borntraeger [this message]
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