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

From: Glenn Washburn
Date: Sun Feb 26 2023 - 23:06:45 EST


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