Re: Target sim crashes when recording for reverse debugging; find_inferior_ptid returns null

[William Tambe <tambewilliam@gmail.com>]

On Sun, May 17, 2020 at 10:09 AM William Tambe <tambewilliam@gmail.com> wrote:
>
> On Sun, May 17, 2020 at 4:12 AM Andrew Burgess
> <andrew.burgess@embecosm.com> wrote:
> >
> > * William Tambe via Gdb <gdb@sourceware.org> [2020-05-16 08:56:20 -0400]:
> >
> > > ../../iron-toolchain/binutils/gdb/process-stratum-target.c:47:
> > > internal-error: virtual gdbarch*
> > > process_stratum_target::thread_architecture(ptid_t): Assertion `inf !=
> > > NULL' failed.
> > >
> > > Above is the crash that occur after issuing following gdb commands:
> > > target sim
> > > load
> > > record
> > > si
> > >
> > > The crash occurs because find_inferior_ptid() returns NULL.
> > > From below backtrace, is it possible to determine what could be the
> > > cause of find_inferior_ptid() returning NULL ?
> >
> > I've been running with the patch below in place for doing reverse
> > debugging on a simulator.
>
> Should I revert this change if I need to use "target exec" ?

In other words, is this change ok for both "target sim" and "target exec" ?

>
> >
> > I need to clean this up and get it merged at some point.
> >
> > Hope this helps,
> > Thanks,
> > Andrew
> >
> >
> > ---
> >
> > commit ecc84c55f926c5a3d7c0dd16b8f46df597ed3f5f
> > Author: Andrew Burgess <andrew.burgess@embecosm.com>
> > Date:   Mon Oct 21 21:17:00 2019 +0100
> >
> >     gdb: Avoid target_thread_architecture
> >
> >     Don't call target_thread_architecture, get gdbarch from regcache
> >     instead.
> >
> > diff --git a/gdb/record-full.c b/gdb/record-full.c
> > index 51b7beabf66..8c83b017b26 100644
> > --- a/gdb/record-full.c
> > +++ b/gdb/record-full.c
> > @@ -1074,9 +1074,10 @@ record_full_target::resume (ptid_t ptid, int step, enum gdb_signal signal)
> >
> >    if (!RECORD_FULL_IS_REPLAY)
> >      {
> > -      struct gdbarch *gdbarch = target_thread_architecture (ptid);
> > +      struct regcache *regcache = get_current_regcache ();
> > +      struct gdbarch *gdbarch = regcache->arch ();
> >
> > -      record_full_message (get_current_regcache (), signal);
> > +      record_full_message (regcache, signal);
> >
> >        if (!step)
> >          {
> >
> >
> >