Hi YAMAZAKI,
On Fri, Oct 3, 2025 at 8:23 PM YAMAZAKI MASAMITSU(山崎 真光)
<yamazaki-msmt(a)nec.com> wrote:
 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.
 >
 > Signed-off-by: Tao Liu <ltao(a)redhat.com>
 > ---
 >   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;
 Hi Liu
 This problem need to be solve. But I don't know how to reproduce.
 If Your server is running rust program. Or Or is it running as a
 module by rust? Please tell me how to reproduce it. 
Sure
E.g. using the following eppic program: /tmp/test.c:
string test_opt(){return "";}
string test_usage(){return "";}
static void test_showusage(){printf("");}
string test_help(){return "";}
int test()
{
struct task_struct *p;
unsigned long offset;
p = (struct task_struct *)&init_task;
offset = (unsigned long)&(p->tasks) - (unsigned long)p;
do {
printf("%d\n", (int)(p->pid));
p = (struct task_struct *)((unsigned long)(p->tasks.next) - (unsigned long)p);
} while (p != &init_task);
return 1;
}
$ ./makedumpfile --dry-run -d 31 -l
/var/crash/127.0.0.1-2025-06-10-18\:03\:12/vmcore /tmp/out -x
/lib/debug/lib/modules/6.11.8-300.fc41.x86_64/vmlinux --eppic
/tmp/test.c
Segmentation fault (core dumped)
With the patch, no segfault.
The vmcore/vmlinux should contain rust symbols: CONFIG_RUST=y, you can
use the following vmcore 
https://people.redhat.com/~ltao/core/vmcore +
https://kojipkgs.fedoraproject.org//packages/kernel/6.11.8/300.fc41/x86_6...
for vmlinux and vmcore to test.
Thanks,
Tao Liu
 Thanks,
 Masa