On Mon, Jan 14, 2019 at 02:59:37PM +0000, Ian Jackson wrote: > CLONE_NEWIPC was introduced in Linux 2.6.19, on the 29th of November > 2006, which was 12 years, 1 month, and 14 days ago. > > Nevertheless apparently some people are trying to build Xen on systems > whose kernel headers are that old. Placate these people by providing > a fallback #define for CLONE_NEWIPC. > > The actual binary value will of course remain constant, because of the > kernel API promise, so this is and will be correct on all platforms > where the CLONE_NEWIPC is supported. (Even if for some reason we miss > the right #includes.) > > Of course at runtime this value will not work on older kernels. It > will be rejected as unknown by anything except some pre-2.6.18 > kernels. On those kernels we do not want to support dm_restrict, and > an attempt to use it will fail. It is OK for the failure to be a > messy EINVAL syscall failure. (The IPC namespace unshare is necessary > to avoid a suborned deprivileged qemu from causing trouble with shm, > sem, etc.) > > On the very old kernels, the feature is totally out of scope. > (We are only interested, here, in making the build work, to avoid > blocking people who aren't using this feature.) > > CC: Wei Liu <wei.l...@citrix.com> > CC: Juergen Gross <jgr...@suse.com> > CC: Jan Beulich <jbeul...@suse.com> > Signed-off-by: Ian Jackson <ian.jack...@eu.citrix.com> >
Acked-by: Wei Liu <wei.l...@citrix.com> _______________________________________________ Xen-devel mailing list Xen-devel@lists.xenproject.org https://lists.xenproject.org/mailman/listinfo/xen-devel
