Re: PTRACE_{READ,WRITE}{TEXT,DATA}

From: Benjamin Herrenschmidt
Date: Tue Apr 29 2008 - 01:06:53 EST



On Mon, 2008-04-28 at 21:34 -0700, David Miller wrote:
> From: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
> Date: Tue, 29 Apr 2008 13:54:08 +1000
>
> > I noticed kernel/ptrace.c has ptrace_readdata/writedata functions that
> > are only used by sparc and sparc64 which implements the ptrace requests
> > PTRACE_READ_DATA, PTRACE_WRITE_DATA (and _TEXT variants).
> >
> > Any reason not to make everybody benefit from these and moving the sparc
> > implementation to the generic ptrace_request (&compat) ?
> >
> > It's more efficient than read/writing one word at a time... I thought
> > about it in the light of some work Rik is doing to make
> > access_process_vm useable on video ram mappings done by the X server...
>
> It's kind of pointless because what gdb does these days on Linux is
> use the procfs 'mem' file to directly read in parts of the inferior's
> address space.
>
> See linux_proc_xfer_partial() in gdb/linux-nat.c=

Good point. That still uses access_process_vm() so Rik and I work
is still valid tho.

Thanks,
Ben.


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