Re: [PATCH] Clean up dangling pointers in cgraph_edge (PR ipa/89330).
On 7/30/19 10:36 AM, Richard Biener wrote: > On Tue, Jul 30, 2019 at 9:27 AM Martin Liška wrote: >> >> Hi. >> >> We have to clean up dangling pointers before we call ggc_free for a >> cgraph_edge. >> >> Patch can bootstrap on x86_64-linux-gnu and survives regression tests. >> And it survives --enable-checking=release bootstrap on x86_64-linux-gnu. >> >> Ready to be installed? > > Eh? The only "real" effect I see is that e->indirect_info test is now > never true. Yep, you are right. > > I think it rather means the edge we ggc_free is still referenced to > from somewhere > and _that_ needs to be fixed or we ggc_free the edge wrongly. Yes, that's one another situation IPA CP is touching a dead cgraph_edge. Martin will help me latter. I'm reducing a test-case now.. Martin > > Richard. > >> Thanks, >> Martin >> >> gcc/ChangeLog: >> >> 2019-07-30 Martin Liska >> >> PR ipa/89330 >> * cgraph.c (symbol_table::free_edge): Memset 0 to cgraph_edge >> before we call ggc_free. >> --- >> gcc/cgraph.c | 2 ++ >> 1 file changed, 2 insertions(+) >> >>
Re: [PATCH] Clean up dangling pointers in cgraph_edge (PR ipa/89330).
On Tue, Jul 30, 2019 at 9:27 AM Martin Liška wrote: > > Hi. > > We have to clean up dangling pointers before we call ggc_free for a > cgraph_edge. > > Patch can bootstrap on x86_64-linux-gnu and survives regression tests. > And it survives --enable-checking=release bootstrap on x86_64-linux-gnu. > > Ready to be installed? Eh? The only "real" effect I see is that e->indirect_info test is now never true. I think it rather means the edge we ggc_free is still referenced to from somewhere and _that_ needs to be fixed or we ggc_free the edge wrongly. Richard. > Thanks, > Martin > > gcc/ChangeLog: > > 2019-07-30 Martin Liska > > PR ipa/89330 > * cgraph.c (symbol_table::free_edge): Memset 0 to cgraph_edge > before we call ggc_free. > --- > gcc/cgraph.c | 2 ++ > 1 file changed, 2 insertions(+) > >
[PATCH] Clean up dangling pointers in cgraph_edge (PR ipa/89330).
Hi. We have to clean up dangling pointers before we call ggc_free for a cgraph_edge. Patch can bootstrap on x86_64-linux-gnu and survives regression tests. And it survives --enable-checking=release bootstrap on x86_64-linux-gnu. Ready to be installed? Thanks, Martin gcc/ChangeLog: 2019-07-30 Martin Liska PR ipa/89330 * cgraph.c (symbol_table::free_edge): Memset 0 to cgraph_edge before we call ggc_free. --- gcc/cgraph.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/gcc/cgraph.c b/gcc/cgraph.c index 81250acb70c..372974f12df 100644 --- a/gcc/cgraph.c +++ b/gcc/cgraph.c @@ -1008,6 +1008,8 @@ symbol_table::free_edge (cgraph_edge *e) if (e->m_summary_id != -1) edge_released_summary_ids.safe_push (e->m_summary_id); + /* Clear out the edge so we do not dangle pointers. */ + memset (e, 0, sizeof (*e)); if (e->indirect_info) ggc_free (e->indirect_info); ggc_free (e);
