diff mbox series

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

Message ID 20230222093730.1826523-1-suagrfillet@gmail.com
State New
Headers
Series [RESEND] scripts/gdb: add lx_current support for riscv |

Commit Message

Song Shuai Feb. 22, 2023, 9:37 a.m. UTC 
  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@gmail.com>
---
 scripts/gdb/linux/cpus.py | 3 +++
 1 file changed, 3 insertions(+)

Comments

Conor Dooley Feb. 22, 2023, 9:52 a.m. UTC | #1 
Hey Song

On Wed, Feb 22, 2023 at 05:37:30PM +0800, Song Shuai wrote:
> 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.

FYI, there's already been some patches posted for this:
https://lore.kernel.org/all/mhng-bdcd75a5-e6d6-4090-8292-a32eb46e4464@palmer-ri-x1c9a/

That version already has review and ack tags from Palmer and others.
It seems to me that Andrew is the usual applier of patches for this
script, so I'm gonna add him to CC here so he is aware - but as it is
the middle of the merge window the best course of action might just be
reposting that patch, CCing Andrew, after v6.3-rc1.

Cheers,
Conor.

> 
> Signed-off-by: Song Shuai <suagrfillet@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("$tp")
> +         return current_task_addr.cast(task_ptr_type).dereference()
>      else:
>          raise gdb.GdbError("Sorry, obtaining the current task is not yet "
>                             "supported with this arch")
> -- 
> 2.20.1
> 
>
Song Shuai Feb. 22, 2023, 10:13 a.m. UTC | #2 
Conor Dooley <conor.dooley@microchip.com> 于2023年2月22日周三 09:53写道：
>
> Hey Song
>
> On Wed, Feb 22, 2023 at 05:37:30PM +0800, Song Shuai wrote:
> > RISC-V uses the tp register to save the current task_struct address
> > as its current() defines. So lx_current() of riscv just returns the
> > dereference of the address cast via task_ptr_type.
>
> FYI, there's already been some patches posted for this:
> https://lore.kernel.org/all/mhng-bdcd75a5-e6d6-4090-8292-a32eb46e4464@palmer-ri-x1c9a/
>
Deepak's patch is much better than mine, which also takes the
userspace and trap handler into count.
So no need to care about this patch.
> That version already has review and ack tags from Palmer and others.
> It seems to me that Andrew is the usual applier of patches for this
> script, so I'm gonna add him to CC here so he is aware - but as it is
> the middle of the merge window the best course of action might just be
> reposting that patch, CCing Andrew, after v6.3-rc1.
>
> Cheers,
> Conor.
>
> >
> > Signed-off-by: Song Shuai <suagrfillet@gmail.com>
> > ---
> >  scripts/gdb/linux/cpus.py | 3 +++
> >  1 file changed, 3 insertions(+)
> >
> > diff --git a/scripts/gdb/linux/cpus.py b/scripts/gdb/linux/cpus.py
> > index 15fc4626d236..6825a9834394 100644
> > --- a/scripts/gdb/linux/cpus.py
> > +++ b/scripts/gdb/linux/cpus.py
> > @@ -173,6 +173,9 @@ def get_current_task(cpu):
> >           else:
> >               raise gdb.GdbError("Sorry, obtaining the current task is not allowed "
> >                                  "while running in userspace(EL0)")
> > +    elif utils.is_target_arch("riscv"):
> > +         current_task_addr = gdb.parse_and_eval("$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
> >
> >
diff mbox series

Patch

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")