On 10/10/22 07:18, Vineet Gupta wrote:

On 8/8/22 06:09, Helge Deller wrote:

quoted

The process program name and command line is now shown in generic code
in dump_stack_print_info(), so drop the arc-specific implementation.

Signed-off-by: Helge Deller <deller@gmx.de>

But that info printing was added back in 2018 by e36df28f532f882.
I don't think arc is using show_regs_print_info -> dump_stack_print_info yet.
Or is there a different code path now which calls here ?

Right.
See patches #1 and #2 of this series which added this
info to dump_stack_print_info().

quoted

---
  arch/arc/kernel/troubleshoot.c | 24 ------------------------
  1 file changed, 24 deletions(-)

diff --git a/arch/arc/kernel/troubleshoot.c b/arch/arc/kernel/troubleshoot.c
index 7654c2e42dc0..9807e590ee55 100644
--- a/arch/arc/kernel/troubleshoot.c
+++ b/arch/arc/kernel/troubleshoot.c

@@ -51,29 +51,6 @@ static void print_regs_callee(struct callee_regs *regs)

          regs->r24, regs->r25);
  }

-static void print_task_path_n_nm(struct task_struct *tsk)
-{
-    char *path_nm = NULL;
-    struct mm_struct *mm;
-    struct file *exe_file;
-    char buf[ARC_PATH_MAX];
-
-    mm = get_task_mm(tsk);
-    if (!mm)
-        goto done;
-
-    exe_file = get_mm_exe_file(mm);
-    mmput(mm);
-
-    if (exe_file) {
-        path_nm = file_path(exe_file, buf, ARC_PATH_MAX-1);
-        fput(exe_file);
-    }
-
-done:
-    pr_info("Path: %s\n", !IS_ERR(path_nm) ? path_nm : "?");
-}
-
  static void show_faulting_vma(unsigned long address)
  {
      struct vm_area_struct *vma;

@@ -176,7 +153,6 @@ void show_regs(struct pt_regs *regs)

       */
      preempt_enable();

Maybe we remove preempt* as well now (perhaps as a follow up patch)
since that was added by f731a8e89f8c78 "ARC: show_regs: lockdep:
re-enable preemption" where show_regs -> print_task_path_n_nm ->
mmput was triggering lockdep splat which is supposedly removed.

The patch series was dropped from Andrew's queue, because the kernel
test robot showed some issues:
https://lore.kernel.org/lkml/Yu59QdVpPgnXUnQC@xsang-OptiPlex-9020/ (local)
Maybe adding preempt_enable() in my patches would fix that -
sadly I haven't had time to follow up on this yet ...

Helge

quoted

-    print_task_path_n_nm(tsk);
      show_regs_print_info(KERN_INFO);

      show_ecr_verbose(regs);