From: Paolo Bonzini <pbonzini@redhat.com>
To: Vineet Gupta <vineetg@rivosinc.com>, qemu-devel@nongnu.org
Cc: Alistair Francis <alistair.francis@wdc.com>,
Palmer Dabbelt <palmer@dabbelt.com>,
qemu-riscv@nongnu.org, gnu-toolchain@rivosinc.com
Subject: Re: [PATCH] build: fix build failure with gcc 11.2 by disabling -fcf-protection
Date: Fri, 18 Feb 2022 16:47:27 +0100 [thread overview]
Message-ID: <335a7af3-b5af-3117-2647-783a217d75a2@redhat.com> (raw)
In-Reply-To: <20220208211937.79580-1-vineetg@rivosinc.com>
On 2/8/22 22:19, Vineet Gupta wrote:
> When doing RV qemu builds with host gcc 11.2, ran into following build failure
>
> | cc -MMD -MP -MT linuxboot_dma.o -MF ./linuxboot_dma.d -O2 -g -march=i486 -Wall \
> | -Wstrict-prototypes -Wredundant-decls -Wundef -Wwrite-strings -Wmissing-prototypes \
> | -Wold-style-declaration -Wold-style-definition -Wtype-limits -Wformat-security \
> | -Wformat-y2k -Winit-self -Wignored-qualifiers -Wempty-body -Wnested-externs \
> | -Wendif-labels -Wexpansion-to-defined -Wimplicit-fallthrough=2 -Wno-missing-include-dirs \
> | -Wno-shift-negative-value -Wno-psabi -fno-pie -ffreestanding -IQEMU/include \
> | -fno-stack-protector -m16 -Wa,-32 \
> | -c QEMU/pc-bios/optionrom/linuxboot_dma.c -o linuxboot_dma.o
> |cc1: error: ‘-fcf-protection’ is not compatible with this target
>
> Signed-off-by: Vineet Gupta <vineetg@rivosinc.com>
> ---
> This might be a crude fix to the problem
> ---
> pc-bios/optionrom/Makefile | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/pc-bios/optionrom/Makefile b/pc-bios/optionrom/Makefile
> index 5d55d25acca2..8f843ee803c1 100644
> --- a/pc-bios/optionrom/Makefile
> +++ b/pc-bios/optionrom/Makefile
> @@ -22,6 +22,9 @@ override CFLAGS += $(CFLAGS_NOPIE) -ffreestanding -I$(TOPSRC_DIR)/include
> override CFLAGS += $(call cc-option, -fno-stack-protector)
> override CFLAGS += $(call cc-option, -m16)
>
> +# issue with gcc 11.2
> +override CFLAGS += $(call cc-option, -fcf-protection=none)
> +
> ifeq ($(filter -m16, $(CFLAGS)),)
> # Attempt to work around compilers that lack -m16 (GCC <= 4.8, clang <= ??)
> # On GCC we add -fno-toplevel-reorder to keep the order of asm blocks with
This is a problem in the Ubuntu compiler that you're using. If
-fcf-protection is not compatible with -m16, Ubuntu should not enable it
instead of breaking -m16.
Besides, QEMU is not at all compatible with -fcf-protection, not just
the ROMs. So it should be added to QEMU_CFLAGS in configure as well.
Paolo
prev parent reply other threads:[~2022-02-18 15:48 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-02-08 21:19 [PATCH] build: fix build failure with gcc 11.2 by disabling -fcf-protection Vineet Gupta
2022-02-18 13:13 ` Peter Maydell
2022-02-18 15:47 ` Paolo Bonzini [this message]
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