Re: [Qemu-devel] [PATCH] dump-guest-memory.py: fix python 2 support

[Laszlo Ersek <lersek@redhat.com>]

On 01/17/18 12:44, Marc-André Lureau wrote:
> Python GDB support may use Python 2 or 3.
> 
> Inferior.read_memory() may return a buffer with Python 2 or a
> memoryview with Python 3 (see also
> https://sourceware.org/gdb/onlinedocs/gdb/Inferiors-In-Python.html)
> 
> The elf.add_vmcoreinfo_note() method expect a byte string, but Python 2
> buffer doesn't provide the tobyes() method. Wrap the read_memory()
> result to a memoryview, available in Python 2.7. (if the return object
> is already a memoryview, this adds a useless identity view on top)

OOP is awesome.

> 
> Fixes a regression introduced with commit
> d23bfa91b7789534d16ede6cb7d925bfac3f3c4c ("add vmcoreinfo").

Do you want to CC stable? Commit d23bfa91b778 is part of v2.11.0.

> 
> Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
> ---
>  scripts/dump-guest-memory.py | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/scripts/dump-guest-memory.py b/scripts/dump-guest-memory.py
> index 09bec92b50..6f7e1a83b3 100644
> --- a/scripts/dump-guest-memory.py
> +++ b/scripts/dump-guest-memory.py
> @@ -564,7 +564,9 @@ shape and this command should mostly work."""
>  
>          vmcoreinfo = self.phys_memory_read(addr, size)
>          if vmcoreinfo:
> -            self.elf.add_vmcoreinfo_note(vmcoreinfo.tobytes())
> +            # Python 2.7 returns a buffer
> +            vmciview = memoryview(vmcoreinfo)
> +            self.elf.add_vmcoreinfo_note(vmciview.tobytes())
>  
>      def invoke(self, args, from_tty):
>          """Handles command invocation from gdb."""
> 

Reviewed-by: Laszlo Ersek <lersek@redhat.com>

Laszlo