On Wed, Sep 04, 2019 at 11:37:36AM +0100, Cristian Marussi wrote:
> On 04/09/2019 11:05, Dave Martin wrote:
> > On Fri, Aug 30, 2019 at 03:29:29PM +0100, Cristian Marussi wrote:
> >> Hi
> >>
> >> On 13/08/2019 17:25, Dave Martin wrote:
> >>> On Fri, Aug 02, 2019 at 06:02:55PM +0100, Cristian Marussi wrote:
> >
> > [...]
> >
> >>>> diff --git a/tools/testing/selftests/arm64/signal/testcases/fake_sigreturn_bad_magic.c b/tools/testing/selftests/arm64/signal/testcases/fake_sigreturn_bad_magic.c
> >
> > [...]
> >
> >>>> +static int fake_sigreturn_bad_magic_run(struct tdescr *td,
> >>>> + siginfo_t *si, ucontext_t *uc)
> >>>> +{
> >>>> + size_t resv_sz, offset;
> >>>> + struct _aarch64_ctx *shead = GET_SF_RESV_HEAD(sf), *head;
> >>>> +
> >>>> + /* just to fill the ucontext_t with something real */
> >>>> + if (!get_current_context(td, &sf.uc))
> >>>> + return 1;
> >>>> +
> >>>> + resv_sz = GET_SF_RESV_SIZE(sf);
> >>>> + /*
> >>>> + * find the terminator, preserving existing headers
> >>>> + * and verify amount of spare room in __reserved area.
> >>>> + */
> >>>> + head = get_terminator(shead, resv_sz, &offset);
> >>>> + /*
> >>>> + * try stripping extra_context header when low on space:
> >>>> + * we need at least 2*HDR_SZ space ... one for the KSFT_BAD_MAGIC
> >>>> + * and the other for the usual terminator.
> >>>> + */
> >>>> + if (head && resv_sz - offset < HDR_SZ * 2) {
> >>>
> >>> Can we factor out this logic for finding space in the signal frame?
> >>>
> >>> We do pretty much the same thing in all the fake_sigreturn tests...
> >>
> >> Ok
> >>>
> >>>> + fprintf(stderr, "Low on space:%zd. Discarding extra_context.\n",
> >>>> + resv_sz - offset);
> >>>> + head = get_header(shead, EXTRA_MAGIC, resv_sz, &offset);
> >>>> + }
> >>>> + /* just give up and timeout if still not enough space */
> >>>
> >>> Do we actually time out? I don't see where we actually wait, so doesn't
> >>> test_run() just fail immediately?
> >>>
> >>> The same applies to all the other fake_sigreturn tests too.
> >>>
> >> Right. It is probably a leftover.
> >>
> >> SIGALRM is used as an extreme measure to kill tests gone bad, but this
> >> can happen only once the fake sigframe has been effectively placed on the stack
> >> and sigreturned.
> >
> > OK, so this gets reported as a test failure because with no SIGSEGV,
> > nothing ever sets td->pass?
>
> Yes exactly. End result is based on value on td->pass, in case of abrupt
> termination or timeout nobody sets td->pass ever.
> >
> > This is probably OK for now, though I wonder whether this should be
> > reported as a skipped test instead.
> >
> > In case of doubt, reporting a failure is preferable anyway, since that
> > will encourage people actually to investigate what went wrong.
> >
>
> As of now I never skip a test in fact...also tests for unsupported features
> are built and run expecting a SIGILL, and reported as PASS in that case.
OK, just wanted to check I'd understood correcly.
Cheers
---Dave
