Remove offline status check, We can query the registers of
each CPU at any time and obtain their stack.

CPU 0: [OFFLINE]
    X0: 0000000000000000   X1: 0000000000000000   X2: 0000000000000000
    X3: 000000000003fcbc   X4: 0000000000000001   X5: 0000000000000000
    X6: 0000000000000000   X7: 0000000000000000   X8: 00000000ffffffff
    X9: ffffffc009e6ae48  X10: ffffffc009e6ae20  X11: 0000000000000000
   X12: 0000000000000002  X13: 0000000000000004  X14: 0000000000000000
   X15: 0000000000004000  X16: 00000000f90f05f6  X17: 00000000f90f05f6
   X18: 0000000000000000  X19: 0000000000000002  X20: ffffffc009e3b008
   X21: ffffffc00a01d020  X22: ffffffc009f798f0  X23: 0000000060001000
   X24: 0000000000000000  X25: 0000000000000000  X26: 0000000000000000
   X27: 0000000000000000  X28: ffffff8111eecb00  X29: ffffffc008003f50
    LR: ffffffc00802df88   SP: ffffffc008003f40   PC: ffffffc00802df94
   PSTATE: 024003c5   FPVALID: 00000000

crash> bt -c 0
PID: 1842     TASK: ffffff8111eecb00  CPU: 0    COMMAND: "android.bg"
 00 [ffffffc008003f50] ipi_handler at ffffffc00802df90
 01 [ffffffc008003f90] handle_percpu_devid_irq at ffffffc008146f50
 02 [ffffffc008003fd0] generic_handle_domain_irq at ffffffc00813f484
 03 [ffffffc008003fe0] gic_handle_irq at ffffffc008010140
--- <IRQ stack> ---
 04 [ffffffc019c3be20] call_on_irq_stack at ffffffc008016ed4
 05 [ffffffc019c3be40] do_interrupt_handler at ffffffc008019cb4
 06 [ffffffc019c3be60] el0_interrupt at ffffffc008f7b848
 07 [ffffffc019c3be90] __el0_irq_handler_common at ffffffc008f7b368
 08 [ffffffc019c3bea0] el0t_64_irq_handler at ffffffc008f7b344
 09 [ffffffc019c3bfe0] el0t_64_irq at ffffffc008011720
     PC: 0000000072415108   LR: 00000000724150d0   SP: 0000007691d2bfa0
    X29: 00000000734f60e0  X28: 000000001a2fa678  X27: 0000000000000063
    X26: 000000001a2fa678  X25: 000000001a2fa678  X24: 000000001a7bb718
    X23: 000000001a7ba198  X22: 000000001a7ba190  X21: b4000076f9a828c8
    X20: 0000000000000000  X19: b4000076f9a82800  X18: 000000768d68a000
    X17: 00000000708f89f8  X16: 00000000000000f0  X15: 0000000000000000
    X14: 0000007691d2bca0  X13: 0000000080100000  X12: 0000000000000000
    X11: 0000000000000000  X10: 0000000000000000   X9: 9636716211228cd4
     X8: 9636716211228cd4   X7: 0000000000000010   X6: 000000001a7bb728
     X5: 0000000070845200   X4: 0000000018a40d38   X3: 00000000707e8f98
     X2: 000000001a2fa678   X1: 000000001a7ba198   X0: 0000000070847aa8
    ORIG_X0: 00000000ffffff9c  SYSCALLNO: ffffffff  PSTATE: 60001000

Signed-off-by: Guanyou.Chen <chenguanyou@xiaomi.com>

---
 netdump.c | 15 +++++----------
 1 file changed, 5 insertions(+), 10 deletions(-)

diff --git a/netdump.c b/netdump.c
index 435793b..455f90e 100644
--- a/netdump.c
+++ b/netdump.c
@@ -101,7 +101,7 @@ map_cpus_to_prstatus(void)
    nrcpus = (kt->kernel_NR_CPUS ? kt->kernel_NR_CPUS : NR_CPUS);

    for (i = 0; i < nrcpus; i++) {
-       if (in_cpu_map(ONLINE_MAP, i) && machdep->is_cpu_prstatus_valid(i)) {
+       if (machdep->is_cpu_prstatus_valid(i)) {
            nd->nt_prstatus_percpu[i] = nt_ptr[i];
            nd->num_prstatus_notes =
                MAX(nd->num_prstatus_notes, i+1);
@@ -2998,15 +2998,10 @@ dump_registers_for_elf_dumpfiles(void)
        return;
    }

-        for (c = 0; c < kt->cpus; c++) {
-       if (check_offline_cpu(c)) {
-           fprintf(fp, "%sCPU %d: [OFFLINE]\n", c ? "\n" : "", c);
-           continue;
-       }
-
-                fprintf(fp, "%sCPU %d:\n", c ? "\n" : "", c);
-                display_regs_from_elf_notes(c, fp);
-        }
+   for (c = 0; c < kt->cpus; c++) {
+       fprintf(fp, "%sCPU %d: %s\n", c ? "\n" : "", c, check_offline_cpu(c) ? "[OFFLINE]" : "[ONLINE]");
+       display_regs_from_elf_notes(c, fp);
+   }
 }

 struct x86_64_user_regs_struct {
--
2.34.1

Guanyou.

Thanks.