Re: [PATCHv8 resend 2/2] selftest/x86: add mremap vdso test

[Dmitry Safonov]

On 05/16/2016 09:25 PM, Andy Lutomirski wrote:
> On Mon, May 16, 2016 at 9:24 AM, Dmitry Safonov <dsafonov@xxxxxxxxxxxxx> wrote:
> > On 05/16/2016 04:54 PM, Ingo Molnar wrote:
> > > * Dmitry Safonov <dsafonov@xxxxxxxxxxxxx> wrote:
> > >
> > > > Should print on success:
> > > > [root@localhost ~]# ./test_mremap_vdso_32
> > > >         AT_SYSINFO_EHDR is 0xf773f000
> > > > [NOTE]  Moving vDSO: [f773f000, f7740000] -> [a000000, a001000]
> > > > [OK]
> > > > Or segfault if landing was bad (before patches):
> > > > [root@localhost ~]# ./test_mremap_vdso_32
> > > >         AT_SYSINFO_EHDR is 0xf774f000
> > > > [NOTE]  Moving vDSO: [f774f000, f7750000] -> [a000000, a001000]
> > > > Segmentation fault (core dumped)
> > >
> > >
> > > Can the segfault be caught and recovered from, to print a proper failure
> > > message?
> >
> >
> > Will add segfault handler, thanks.
>
> It may be more complicated that that.  Glibc is likely to explode if
> this happens, and the headers are sufficiently screwed up that it's
> awkward to bypass glibc and call rt_sigaction directly.  I have a test
> that does the latter, though, so it's at least possible, but I'm
> unconvinced it's worth it just for an error message.

Oh, I didn't know that, thanks, Andy.
I'll leave it as is for simplicity.

--
Regards,
Dmitry Safonov