[Crash-utility] Re: [PATCH RFC][makedumpfile 02/10] dwarf_info: Fix a infinite recursion bug for search_domain

Hi Tao, thank you for the fix. On 2025/06/10 18:57, Tao Liu wrote: > There is an infinite recursion bug noticed in rust symbols. The root cause is > unclear to me. This patch will avoid the bug by skip the recursion of rust > symbols, since currently we don't need to deal with those. I confirmed that the recursive dwarf_child() calls result in a loop, and I'm also not sure how we can avoid it correctly. I think for now there is no demand for eppic + Rust with makedumpfile, so I can agree about skipping Rust DIEs. I think that probably you tried to support them as much as possible, so the patch has the lang check in search_domain(). but a halfway support may be confusing, i.e. maybe a user cannot determine whether it's not supported or a bug.

So could we skip it in get_debug_info() like below and describe that the eppic extension does not support Rust's debug information in the man page?

@@ -1007,6 +1010,12 @@ get_debug_info(void) ERRMSG("Can't get CU die.\n"); goto out; } + + /* NOTE: currently Rust is not supported. */ + if (dwarf_srclang(&cu_die) == DW_LANG_Rust) + continue; +

search_die_tree(&cu_die, &found); if (found) break; Thanks, Kazu > > Signed-off-by: Tao Liu <ltao(a)redhat.com&gt; > --- > dwarf_info.c | 15 ++++++++------- > 1 file changed, 8 insertions(+), 7 deletions(-) > > diff --git a/dwarf_info.c b/dwarf_info.c > index a3a2fd6..73842ab 100644 > --- a/dwarf_info.c > +++ b/dwarf_info.c > @@ -837,7 +837,7 @@ search_symbol(Dwarf_Die *die, int *found) > } > > static void > -search_domain(Dwarf_Die *die, int *found) > +search_domain(Dwarf_Die *die, int *found, int lang) > { > int tag; > const char *name; > @@ -859,10 +859,11 @@ search_domain(Dwarf_Die *die, int *found) > if (is_container(&die_type)) { > Dwarf_Die child; > > - if (dwarf_child(&die_type, &child) != 0) > + if (dwarf_child(&die_type, &child) != 0 || > + lang == DW_LANG_Rust) > continue; > > - search_domain(&child, found); > + search_domain(&child, found, lang); > > if (*found) > return; > @@ -924,7 +925,7 @@ search_die(Dwarf_Die *die, int *found) > } > > static void > -search_die_tree(Dwarf_Die *die, int *found) > +search_die_tree(Dwarf_Die *die, int *found, int lang) > { > Dwarf_Die child; > > @@ -932,7 +933,7 @@ search_die_tree(Dwarf_Die *die, int *found) > * start by looking at the children > */ > if (dwarf_child(die, &child) == 0) > - search_die_tree(&child, found); > + search_die_tree(&child, found, lang); > > if (*found) > return; > @@ -950,7 +951,7 @@ search_die_tree(Dwarf_Die *die, int *found) > search_typedef(die, found); > > else if (is_search_domain(dwarf_info.cmd)) > - search_domain(die, found); > + search_domain(die, found, lang); > > else if (is_search_die(dwarf_info.cmd)) > search_die(die, found); > @@ -1007,7 +1008,7 @@ get_debug_info(void) > ERRMSG("Can't get CU die.\n"); > goto out; > } > - search_die_tree(&cu_die, &found); > + search_die_tree(&cu_die, &found, dwarf_srclang(&cu_die)); > if (found) > break; > off = next_off;