From 6d51363d53db4f5f11a13509ef28e917b97eb2b3 Mon Sep 17 00:00:00 2001 From: Glenn Washburn Date: Sun, 26 Feb 2023 22:06:00 -0600 Subject: scripts/gdb: support getting current task struct in UML A running x86 UML kernel reports with architecture "i386:x86-64" as it is a sub-architecture. However, a difference with bare-metal x86 kernels is in how it manages tasks and the current task struct. To identify that the inferior is a UML kernel and not bare-metal, check for the existence of the UML specific symbol "cpu_tasks" which contains the current task struct. Link: https://lkml.kernel.org/r/b839d611e2906ccef2725c34d8e353fab35fe75e.1677469905.git.development@efficientek.com Signed-off-by: Glenn Washburn Reviewed-by: Jan Kiszka Cc: Anton Ivanov Cc: Johannes Berg Cc: Kieran Bingham Cc: Richard Weinberger Signed-off-by: Andrew Morton --- scripts/gdb/linux/cpus.py | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) (limited to 'scripts') diff --git a/scripts/gdb/linux/cpus.py b/scripts/gdb/linux/cpus.py index e8d2a62ff119..255dc18cb9da 100644 --- a/scripts/gdb/linux/cpus.py +++ b/scripts/gdb/linux/cpus.py @@ -163,8 +163,14 @@ 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("&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 + # differently than other x86 sub architectures + var_ptr = gdb.parse_and_eval("(struct task_struct *)cpu_tasks[0].task") + return var_ptr.dereference() + else: + 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") if (current_task_addr >> 63) != 0: -- cgit v1.2.3