[PATCH RESEND] scripts/gdb: add lx_current support for riscv

[Song Shuai]

RISC-V uses the tp register to save the current task_struct address
as its current() defines. So lx_current() of riscv just returns the
dereference of the address cast via task_ptr_type.

Signed-off-by: Song Shuai <suagrfillet at gmail.com>
---
 scripts/gdb/linux/cpus.py | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/scripts/gdb/linux/cpus.py b/scripts/gdb/linux/cpus.py
index 15fc4626d236..6825a9834394 100644
--- a/scripts/gdb/linux/cpus.py
+++ b/scripts/gdb/linux/cpus.py
@@ -173,6 +173,9 @@ def get_current_task(cpu):
          else:
              raise gdb.GdbError("Sorry, obtaining the current task is not allowed "
                                 "while running in userspace(EL0)")
+    elif utils.is_target_arch("riscv"):
+         current_task_addr = gdb.parse_and_eval("$tp")
+         return current_task_addr.cast(task_ptr_type).dereference()
     else:
         raise gdb.GdbError("Sorry, obtaining the current task is not yet "
                            "supported with this arch")
-- 
2.20.1