[PATCH v3 0/2] GDB: Support getting current task struct in UML

Glenn Washburn development at efficientek.com
Sun Feb 26 20:05:58 PST 2023


Changes in v3:
  - Rebase onto tip.

Changes in v2:
  - Use cpu_tasks symbols instead of uml_kmalloc when determining if the
    kernel is a UML kernel.
  - Improve formatting.

Glenn

Glenn Washburn (2):
  scripts/gdb: Correct indentation in get_current_task
  scripts/gdb: Support getting current task struct in UML

 scripts/gdb/linux/cpus.py | 24 +++++++++++++++---------
 1 file changed, 15 insertions(+), 9 deletions(-)

Range-diff against v2:
1:  918bc1299bdb ! 1:  2e117b82240d scripts/gdb: Correct indentation in get_current_task
    @@ scripts/gdb/linux/cpus.py: def get_current_task(cpu):
          task_ptr_type = task_type.get_type().pointer()
      
          if utils.is_target_arch("x86"):
    --         var_ptr = gdb.parse_and_eval("&current_task")
    +-         var_ptr = gdb.parse_and_eval("&pcpu_hot.current_task")
     -         return per_cpu(var_ptr, cpu).dereference()
    -+        var_ptr = gdb.parse_and_eval("&current_task")
    ++        var_ptr = gdb.parse_and_eval("&pcpu_hot.current_task")
     +        return per_cpu(var_ptr, cpu).dereference()
          elif utils.is_target_arch("aarch64"):
     -         current_task_addr = gdb.parse_and_eval("$SP_EL0")
2:  93fc6584ea16 ! 2:  b839d611e290 scripts/gdb: Support getting current task struct in UML
    @@ scripts/gdb/linux/cpus.py: def get_current_task(cpu):
          task_ptr_type = task_type.get_type().pointer()
      
          if utils.is_target_arch("x86"):
    --        var_ptr = gdb.parse_and_eval("&current_task")
    +-        var_ptr = gdb.parse_and_eval("&pcpu_hot.current_task")
     -        return per_cpu(var_ptr, cpu).dereference()
     +        if gdb.lookup_global_symbol("cpu_tasks"):
     +            # This is a UML kernel, which stores the current task
    @@ scripts/gdb/linux/cpus.py: def get_current_task(cpu):
     +            var_ptr = gdb.parse_and_eval("(struct task_struct *)cpu_tasks[0].task")
     +            return var_ptr.dereference()
     +        else:
    -+            var_ptr = gdb.parse_and_eval("&current_task")
    ++            var_ptr = gdb.parse_and_eval("&pcpu_hot.current_task")
     +            return per_cpu(var_ptr, cpu).dereference()
          elif utils.is_target_arch("aarch64"):
              current_task_addr = gdb.parse_and_eval("$SP_EL0")
-- 
2.30.2




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