Re: [PATCH] analyzer: fix ICE casued by dup2 in sm-fd.cc[PR106551]

[Mir Immad <mirimnan017@gmail.com>]

Thanks. I've added few testcases that use uninitialized ints in dup, dup2,
and dup3.

Immad.

On Tue, Aug 9, 2022 at 8:43 PM David Malcolm <dmalcolm@redhat.com> wrote:

> On Tue, 2022-08-09 at 13:16 +0530, Immad Mir wrote:
> > This patch fixes the ICE caused by valid_to_unchecked_state,
> > at analyzer/sm-fd.cc by handling the m_start state in
> > check_for_dup.
> >
> > Tested lightly on x86_64.
> >
> > gcc/analyzer/ChangeLog:
> >         PR analyzer/106551
> >         * sm-fd.cc (check_for_dup): handle the m_start
> >         state when transitioning the state of LHS
> >         of dup, dup2 and dup3 call.
> >
> > Signed-off-by: Immad Mir <mirimmad@outlook.com>
> > ---
> >  gcc/analyzer/sm-fd.cc | 4 ++--
> >  1 file changed, 2 insertions(+), 2 deletions(-)
> >
> > diff --git a/gcc/analyzer/sm-fd.cc b/gcc/analyzer/sm-fd.cc
> > index 8bb76d72b05..c8b9930a7b6 100644
> > --- a/gcc/analyzer/sm-fd.cc
> > +++ b/gcc/analyzer/sm-fd.cc
> > @@ -983,7 +983,7 @@ fd_state_machine::check_for_dup (sm_context
> > *sm_ctxt, const supernode *node,
> >      case DUP_1:
> >        if (lhs)
> >         {
> > -         if (is_constant_fd_p (state_arg_1))
> > +         if (is_constant_fd_p (state_arg_1) || state_arg_1 ==
> > m_start)
> >             sm_ctxt->set_next_state (stmt, lhs,
> > m_unchecked_read_write);
> >           else
> >             sm_ctxt->set_next_state (stmt, lhs,
> > @@ -1011,7 +1011,7 @@ fd_state_machine::check_for_dup (sm_context
> > *sm_ctxt, const supernode *node,
> >        file descriptor i.e the first argument.  */
> >        if (lhs)
> >         {
> > -         if (is_constant_fd_p (state_arg_1))
> > +         if (is_constant_fd_p (state_arg_1) || state_arg_1 ==
> > m_start)
> >             sm_ctxt->set_next_state (stmt, lhs,
> > m_unchecked_read_write);
> >           else
> >             sm_ctxt->set_next_state (stmt, lhs,
>
> Thanks.  The fix looks reasonable, but please can the patch also add a
> reproducer to the test suite, covering each of the three dup/dup2/dup3
> entrypoints - presumably the one from the bug can be used/adapted.
>
> Dave
>
>