[PATCH v2 3/3] um: allow static linking for non-glibc implementations

[Ignat Korchagin]

On Wed, Jul 15, 2020 at 9:44 AM Brendan Higgins
<brendanhiggins at google.com> wrote:
>
> On Sat, Jul 4, 2020 at 1:52 AM Ignat Korchagin <ignat at cloudflare.com> wrote:
> >
> > It is possible to produce a statically linked UML binary with UML_NET_VECTOR,
> > UML_NET_VDE and UML_NET_PCAP options enabled using alternative libc
> > implementations, which do not rely on NSS, such as musl.
> >
> > Allow static linking in this case.
> >
> > Signed-off-by: Ignat Korchagin <ignat at cloudflare.com>
>
> One minor issue below. Other than that:
>
> Reviewed-by: Brendan Higgins <brendanhiggins at google.com>
>
> > ---
> >  arch/um/Kconfig         | 2 +-
> >  arch/um/drivers/Kconfig | 3 ---
> >  2 files changed, 1 insertion(+), 4 deletions(-)
> >
> > diff --git a/arch/um/Kconfig b/arch/um/Kconfig
> > index 9318dc6d1a0c..af7ed63f9c74 100644
> > --- a/arch/um/Kconfig
> > +++ b/arch/um/Kconfig
> > @@ -67,7 +67,7 @@ config FORBID_STATIC_LINK
>
> Doesn't look like FORBID_STATIC_LINK is used anymore, so you should
> probably drop it as well.

Right, good catch! I will repost the series with this adjusted as well
cc Masahiro Yamada as mentioned for +1 on the changes to can-link.sh
script.
Seems I also need to rebase now to accommodate changes in
b816b3db15f68690ee72a4a414624f8e82942b25 ("kbuild: fix
CONFIG_CC_CAN_LINK(_STATIC) for cross-compilation with Clang")

> With the preceding changes, in this patchset, you can revert my patch
> like you did in the RFC - or not, your choice. I am not offended by
> people reverting my commits. I just don't like it when people break
> allyesconfig. :-)
>
> >  config STATIC_LINK
> >         bool "Force a static link"
> > -       depends on !FORBID_STATIC_LINK
> > +       depends on CC_CAN_LINK_STATIC_NO_RUNTIME_DEPS || (!UML_NET_VECTOR && !UML_NET_VDE && !UML_NET_PCAP)
> >         help
> >           This option gives you the ability to force a static link of UML.
> >           Normally, UML is linked as a shared binary.  This is inconvenient for
> > diff --git a/arch/um/drivers/Kconfig b/arch/um/drivers/Kconfig
> > index 9160ead56e33..72d417055782 100644
> > --- a/arch/um/drivers/Kconfig
> > +++ b/arch/um/drivers/Kconfig
> > @@ -234,7 +234,6 @@ config UML_NET_DAEMON
> >  config UML_NET_VECTOR
> >         bool "Vector I/O high performance network devices"
> >         depends on UML_NET
> > -       select FORBID_STATIC_LINK
> >         help
> >         This User-Mode Linux network driver uses multi-message send
> >         and receive functions. The host running the UML guest must have
> > @@ -246,7 +245,6 @@ config UML_NET_VECTOR
> >  config UML_NET_VDE
> >         bool "VDE transport (obsolete)"
> >         depends on UML_NET
> > -       select FORBID_STATIC_LINK
> >         help
> >         This User-Mode Linux network transport allows one or more running
> >         UMLs on a single host to communicate with each other and also
> > @@ -294,7 +292,6 @@ config UML_NET_MCAST
> >  config UML_NET_PCAP
> >         bool "pcap transport (obsolete)"
> >         depends on UML_NET
> > -       select FORBID_STATIC_LINK
> >         help
> >         The pcap transport makes a pcap packet stream on the host look
> >         like an ethernet device inside UML.  This is useful for making
> > --
> > 2.20.1
> >