On Mon, Mar 10, 2014 at 5:38 PM, Dave Jones <da...@redhat.com> wrote: > On Mon, Mar 10, 2014 at 05:19:27PM -0700, Andy Lutomirski wrote: > > On Mon, Mar 10, 2014 at 5:13 PM, H. Peter Anvin <h...@linux.intel.com> > wrote: > > > On 03/10/2014 05:12 PM, Andy Lutomirski wrote: > > >> The compat vDSO is a complicated hack that's needed to maintain > > >> compatibility with a small range of never-released glibc versions. > > >> > > >> This removes it and replaces it with a much simpler hack: a config > > >> option to disable the 32-bit vDSO by default. > > >> > > >> Signed-off-by: Andy Lutomirski <l...@amacapital.net> > > > > > > Can we verify this works correctly on the affected distributions? > > > > It works correctly on Fedora 20 32-bit and 64-bit. > > I went and dug through the SRPMs at https://archives.fedoraproject.org > Fedora hasn't ever shipped with COMPAT_VDSO enabled. > Before FC6 (kernel 2.6.18), the option never existed. >
What I mean is: a kernel with this patch can boot Fedora 20. It looks like OpenSUSE 9 is the affected distribution. I bootstrapped a minimal OpenSUSE 9 32-bit chroot (filesystem, glibc, ncurses, readline, bash). If there's a non-compat vDSO, it says: Inconsistency detected by ld.so: rtld.c: 1250: dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed! With 'echo 0 >/proc/sys/abi/vsyscall32', it works. With vdso32=2, it works. With CONFIG_ENABLE_VDSO32_BY_DEFAULT=n, it works. I also checked an unpatched kernel with compat vdso on. That also works. So, the upshot of my patch is that the default becomes sane for everyone except users of OpenSUSE 9 and similar. OpenSUSE 9 users will need to fiddle with their settings or config. And it looks like I need to spruce up virtme a bit to make this kind of testing easier :) I'll respin the patch to note that OpenSUSE 9 is affected. NB: I've only tested a 64-bit kernel. Testing a 32-bit kernel will involve considerably more effort. > Dave > -- Andy Lutomirski AMA Capital Management, LLC -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
