linux-kernel - [PATCH] scripts/gdb: fix aarch64 userspace detection in get_current

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Message-ID: <dcd2fabc-9131-4b48-8419-6444e2d67454@siemens.com>
Date: Fri, 10 Jan 2025 11:36:33 +0100
From: Jan Kiszka <jan.kiszka@...mens.com>
To: Andrew Morton <akpm@...ux-foundation.org>,
 Linux Kernel Mailing List <linux-kernel@...r.kernel.org>
Cc: Kieran Bingham <kbingham@...nel.org>, Barry Song <baohua@...nel.org>
Subject: [PATCH] scripts/gdb: fix aarch64 userspace detection in
 get_current_task

From: Jan Kiszka <jan.kiszka@...mens.com>

At least recent gdb releases (seen with 14.2) return SP_EL0 as signed
long which lets the right-shift always return 0.

Signed-off-by: Jan Kiszka <jan.kiszka@...mens.com>
---
 scripts/gdb/linux/cpus.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/scripts/gdb/linux/cpus.py b/scripts/gdb/linux/cpus.py
index 2f11c4f9c345..13eb8b3901b8 100644
--- a/scripts/gdb/linux/cpus.py
+++ b/scripts/gdb/linux/cpus.py
@@ -167,7 +167,7 @@ def get_current_task(cpu):
             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("$SP_EL0")
+        current_task_addr = gdb.parse_and_eval("(unsigned long)$SP_EL0")
         if (current_task_addr >> 63) != 0:
             current_task = current_task_addr.cast(task_ptr_type)
             return current_task.dereference()
-- 
2.43.0