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