gdb-script: updated lx_current for riscv

Message ID 20221111195938.1499148-2-debug@rivosinc.com
State New
Headers
Series gdb-script: updated lx_current for riscv |

Commit Message

Deepak Gupta Nov. 11, 2022, 7:59 p.m. UTC
  From: Deepak Gupta <debug@rivosinc.com>

lx_current python gdb command defined in scripts/gdb/cpus.py updated
to support riscv architecture.

Signed-off-by: Deepak Gupta <debug@rivosinc.com>
---
 scripts/gdb/linux/cpus.py | 8 ++++++++
 1 file changed, 8 insertions(+)
  

Comments

Conor Dooley Nov. 13, 2022, 12:13 a.m. UTC | #1
On Fri, Nov 11, 2022 at 11:59:38AM -0800, debug@rivosinc.com wrote:
> From: Deepak Gupta <debug@rivosinc.com>
> 
> lx_current python gdb command defined in scripts/gdb/cpus.py updated
> to support riscv architecture.

The commit which added support for arm64 gave an explanation of why
SP_EL0 needed to be checked. Would be nice if you could do the same here
for RISC-V. See 526940e39626 ("scripts/gdb: add lx_current support for
arm64") for what I mean.

While you're at it, "scripts/gdb: add support for RISC-V" would appear
to be a more standard $subject for this file.

Thanks,
Conor.

> 
> Signed-off-by: Deepak Gupta <debug@rivosinc.com>
> ---
>  scripts/gdb/linux/cpus.py | 8 ++++++++
>  1 file changed, 8 insertions(+)
> 
> diff --git a/scripts/gdb/linux/cpus.py b/scripts/gdb/linux/cpus.py
> index 15fc4626d236..ce6703f1e35a 100644
> --- a/scripts/gdb/linux/cpus.py
> +++ b/scripts/gdb/linux/cpus.py
> @@ -173,6 +173,14 @@ 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")
> +         if((current_task_addr.cast(utils.get_long_type()) >> 63) != 0):
> +             current_task = current_task_addr.cast(task_ptr_type)
> +             return current_task.dereference()
> +         else:
> +             raise gdb.GdbError("Sorry, obtaining the current task is not allowed "
> +                                "while running in userspace")
>      else:
>          raise gdb.GdbError("Sorry, obtaining the current task is not yet "
>                             "supported with this arch")
> -- 
> 2.25.1
>
  
Andrew Jones Nov. 13, 2022, 11:06 a.m. UTC | #2
On Fri, Nov 11, 2022 at 11:59:38AM -0800, debug@rivosinc.com wrote:
> From: Deepak Gupta <debug@rivosinc.com>
> 
> lx_current python gdb command defined in scripts/gdb/cpus.py updated
> to support riscv architecture.
> 
> Signed-off-by: Deepak Gupta <debug@rivosinc.com>
> ---
>  scripts/gdb/linux/cpus.py | 8 ++++++++
>  1 file changed, 8 insertions(+)
> 
> diff --git a/scripts/gdb/linux/cpus.py b/scripts/gdb/linux/cpus.py
> index 15fc4626d236..ce6703f1e35a 100644
> --- a/scripts/gdb/linux/cpus.py
> +++ b/scripts/gdb/linux/cpus.py
> @@ -173,6 +173,14 @@ 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")
> +         if((current_task_addr.cast(utils.get_long_type()) >> 63) != 0):

Shouldn't there be a get_long_type().sizeof == 8 check somewhere before
shifting by 63? Or are 32-bit targets not supported at all for some
reason?

Thanks,
drew

> +             current_task = current_task_addr.cast(task_ptr_type)
> +             return current_task.dereference()
> +         else:
> +             raise gdb.GdbError("Sorry, obtaining the current task is not allowed "
> +                                "while running in userspace")
>      else:
>          raise gdb.GdbError("Sorry, obtaining the current task is not yet "
>                             "supported with this arch")
> -- 
> 2.25.1
> 
> 
> _______________________________________________
> linux-riscv mailing list
> linux-riscv@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-riscv
  
Conor Dooley Nov. 13, 2022, 2:14 p.m. UTC | #3
On Sun, Nov 13, 2022 at 12:13:40AM +0000, Conor Dooley wrote:
> On Fri, Nov 11, 2022 at 11:59:38AM -0800, debug@rivosinc.com wrote:
> > From: Deepak Gupta <debug@rivosinc.com>
> > 
> > lx_current python gdb command defined in scripts/gdb/cpus.py updated
> > to support riscv architecture.
> 
> The commit which added support for arm64 gave an explanation of why
> SP_EL0 needed to be checked. Would be nice if you could do the same here
> for RISC-V. See 526940e39626 ("scripts/gdb: add lx_current support for
> arm64") for what I mean.
> 
> While you're at it, "scripts/gdb: add support for RISC-V" would appear

Realised I omitted a word there, sorry: s/add support/add lx_current support/

> to be a more standard $subject for this file.
> 
> Thanks,
> Conor.
> 
> > 
> > Signed-off-by: Deepak Gupta <debug@rivosinc.com>
> > ---
> >  scripts/gdb/linux/cpus.py | 8 ++++++++
> >  1 file changed, 8 insertions(+)
> > 
> > diff --git a/scripts/gdb/linux/cpus.py b/scripts/gdb/linux/cpus.py
> > index 15fc4626d236..ce6703f1e35a 100644
> > --- a/scripts/gdb/linux/cpus.py
> > +++ b/scripts/gdb/linux/cpus.py
> > @@ -173,6 +173,14 @@ def get_current_task(cpu):
> >           else:
> >               raise gdb.GdbError("Sorry, obtaining the current task is not allowed "
> >                                  "while running in userspace(EL0)")
> > +    elif utils.is_target_arch("riscv"):
> > +         current_task_addr = gdb.parse_and_eval("$tp")
> > +         if((current_task_addr.cast(utils.get_long_type()) >> 63) != 0):
> > +             current_task = current_task_addr.cast(task_ptr_type)
> > +             return current_task.dereference()
> > +         else:
> > +             raise gdb.GdbError("Sorry, obtaining the current task is not allowed "
> > +                                "while running in userspace")
> >      else:
> >          raise gdb.GdbError("Sorry, obtaining the current task is not yet "
> >                             "supported with this arch")
> > -- 
> > 2.25.1
> >
  

Patch

diff --git a/scripts/gdb/linux/cpus.py b/scripts/gdb/linux/cpus.py
index 15fc4626d236..ce6703f1e35a 100644
--- a/scripts/gdb/linux/cpus.py
+++ b/scripts/gdb/linux/cpus.py
@@ -173,6 +173,14 @@  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")
+         if((current_task_addr.cast(utils.get_long_type()) >> 63) != 0):
+             current_task = current_task_addr.cast(task_ptr_type)
+             return current_task.dereference()
+         else:
+             raise gdb.GdbError("Sorry, obtaining the current task is not allowed "
+                                "while running in userspace")
     else:
         raise gdb.GdbError("Sorry, obtaining the current task is not yet "
                            "supported with this arch")