How to change executing thread in gdb?

Question

I'm currently debugging kernel code using KGDB. Whenever I break in I naturally jump to the interrupt handler for kgdb. Under GDB I ran the following command.

info threads 

and the output would be

7 Thread 7 (rcu_sched) 0x0000000000000000 in irq_stack_union ()

6 Thread 5 (kworker/0:0H) 0x0000000000000000 in irq_stack_union ()

5 Thread 3 (ksoftirqd/0) 0x0000000000000000 in irq_stack_union ()

4 Thread 2 (kthreadd) 0x0000000000000000 in irq_stack_union ()

3 Thread 1 (init) 0x0000000000000000 in irq_stack_union ()

2 Thread 3754 (Xorg) 0x0000000000000000 in irq_stack_union ()

• 1 Thread 4294967294 (shadowCPU0) kgdb_breakpoint ()

  at kernel/debug/debug_core.c:1042

I would then jump through the code expecting to end up in a different thread (I'm interested in Xorg) however after i step through the code the next executing thread becomes cpu idle.

info thread

• 1 Thread 4294967294 (shadowCPU0) cpu_idle_loop () at kernel/cpu/idle.c:116

How can I switch my debug context to Xorg or any other thread, additionally what does irq_stack_union () mean. Thread is idle pending interrupts?

Answer 1

根据官方文档，只是thread threadno https://sourceware.org/gdb/onlinedocs/gdb/Threads.html