Re: [rfc] PR 20569, segv in follow_exec

[Pedro Alves <palves@redhat.com>]

On 10/19/2016 09:19 PM, Luis Machado wrote:

> I was thinking of a way to test this and decided to exercise everything
> against an invalid sysroot (by always passing 'set sysroot
> <something_invalid>' and i noticed quite a few segmentation faults
> ocurring in 10+ tests.
> 
> Now we know things are broken and we know how to show that, but i'm
> wondering if we want to re-run tests with an invalid sysroot or if the
> manual testing with a sysroot override is enough.

I think we should have some representative test that always runs,
without requiring manual testing.

> 
> I could add a loop to each test that is failing, but, though that
> exercises and shows the failure, it sounds like a waste of time to
> repeat those tests.

Yeah.

> 
> I could also pick one candidate and isolate that in a test, but i'm not
> yet sure if all those 10+ failures fail for the same exact reason.
> 
> Suggestions?

I think it is sufficient to have one representative test for
each reasons (or reasons).  Whether that is a new separate testcase
or whether we reuse some existing testcase, I guess depends on how
complicated the test needs to be.  If trivial, maybe go for separate,
focused test.   If a lot of test set up is needed, e.g., to get the
inferior to the state that triggers the bug), might make sense to
reuse some existing testcase.


> 
> These are the failing tests:
> 
> gdb.base/catch-syscall.exp
> gdb.base/execl-update-breakpoints.exp
> gdb.base/foll-exec-mode.exp
> gdb.base/foll-exec.exp
> gdb.base/foll-vfork.exp
> gdb.base/pie-execl.exp
> gdb.linespec/explicit.exp
> gdb.multi/bkpt-multi-exec.exp
> gdb.python/py-finish-breakpoint.exp
> gdb.threads/execl.exp
> gdb.threads/non-ldr-exc-1.exp
> gdb.threads/non-ldr-exc-2.exp
> gdb.threads/non-ldr-exc-3.exp
> gdb.threads/non-ldr-exc-4.exp
> gdb.threads/thread-execl.exp

The obvious pattern here is that these are tests that exec.  :-)

-- 
Thanks,
Pedro Alves