Re: [PATCH v2] Partially revert "build: -no-pie is no functional linker flag"

[Richard Henderson]

On 10/14/21 4:30 PM, Michael Roth wrote:
> Quoting Jessica Clarke (2021-08-05 14:25:45)
> > This partially reverts commit bbd2d5a8120771ec59b86a80a1f51884e0a26e53.
> >
> > This commit was misguided and broke using --disable-pie on any distro
> > that enables PIE by default in their compiler driver, including Debian
> > and its derivatives. Whilst -no-pie is not a linker flag, it is a
> > compiler driver flag that ensures -pie is not automatically passed by it
> > to the linker. Without it, all compile_prog checks will fail as any code
> > built with the explicit -fno-pie will fail to link with the implicit
> > default -pie due to trying to use position-dependent relocations. The
> > only bug that needed fixing was LDFLAGS_NOPIE being used as a flag for
> > the linker itself in pc-bios/optionrom/Makefile.
> >
> > Note this does not reinstate exporting LDFLAGS_NOPIE, as it is unused,
> > since the only previous use was the one that should not have existed. I
> > have also updated the comment for the -fno-pie and -no-pie checks to
> > reflect what they're actually needed for.
> >
> > Fixes: bbd2d5a8120771ec59b86a80a1f51884e0a26e53
> > Cc: Christian Ehrhardt <christian.ehrhardt@canonical.com>
> > Cc: Paolo Bonzini <pbonzini@redhat.com>
> > Cc: qemu-stable@nongnu.org
> > Signed-off-by: Jessica Clarke <jrtc27@jrtc27.com>
>
> Ping. --disable-pie builds are broken on Ubuntu 20.04 without this regression
> fix. Looking to include it for v6.0.1/v6.1.1.

Sorry, missed this the first time around.

I think a better fix is to remove the direct invocation of ld in 
pc-bios/optionrom/Makefile, and instead rely on the compiler driver.  All of the local 
ldflags can be passed through via -Wl, but we'd get no-pie via CFLAGS_NOPIE.


r~