Re: [PATCH v4 01/13] scripts/gdb: Add infrastructure

[Jan Kiszka <jan.kiszka@siemens.com>]

On 2013-01-23 12:41, Borislav Petkov wrote:
> On Mon, Jan 21, 2013 at 06:06:08PM +0100, Jan Kiszka wrote:
>> This provides the basic infrastructure to load kernel-specific python
>> helper scripts when debugging the kernel in gdb.
>>
>> The loading mechanism is based on gdb loading for <objfile>-gdb.py when
>> opening <objfile>. Therefore, this places a corresponding link to the
>> main helper script into the output directory that contains vmlinux.
>>
>> The main scripts will pull in submodules containing Linux specific gdb
>> commands and functions. To avoid polluting the source directory with
>> compiled python modules, we link to them from the object directory.
>>
>> Due to gdb.parse_and_eval, we depend on gdb >= 7.1. We need to
>> pre-process the version string returned by gdb as some distros tend to
>> prefix it with their name.
>>
>> This feature depends on CONFIG_DEBUG_INFO.
>>
>> CC: Michal Marek <mmarek@suse.cz>
>> CC: linux-kbuild@vger.kernel.org
>> Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
>> ---
>>  Makefile                   |    5 ++++-
>>  scripts/Makefile           |    3 ++-
>>  scripts/gdb/Makefile       |    9 +++++++++
>>  scripts/gdb/utils.py       |   17 +++++++++++++++++
>>  scripts/gdb/vmlinux-gdb.py |   22 ++++++++++++++++++++++
>>  5 files changed, 54 insertions(+), 2 deletions(-)
>>  create mode 100644 scripts/gdb/Makefile
>>  create mode 100644 scripts/gdb/utils.py
>>  create mode 100644 scripts/gdb/vmlinux-gdb.py
>>
>> diff --git a/Makefile b/Makefile
>> index 253a455..fb18794 100644
>> --- a/Makefile
>> +++ b/Makefile
>> @@ -774,6 +774,9 @@ endif
>>  ifdef CONFIG_BUILD_DOCSRC
>>  	$(Q)$(MAKE) $(build)=Documentation
>>  endif
>> +ifdef CONFIG_DEBUG_INFO
>> +	$(Q)ln -fsn $(srctree)/scripts/gdb/vmlinux-gdb.py
>> +endif
> 
> I'm wondering whether it won't be a better idea to make this symlink
> creation in the toplevel directory only when a user requires it.. I.e.,
> not simply when CONFIG_DEBUG_INFO is enabled (it could be enabled for a
> lot and different reasons) but only when user wants to really debug the
> kernel with gdb.
> 
> Then, having a specific make target could arrange for all the setup like
> the symlink, gdb version checking, etc, maybe something like this:
> 
> $ make gdb
> 
> and all is prepared (or errored out with a sensible message).
> 
> Hmm....

I wonder why we should do this, remove the convenience of the automatic
script setup, but I'm open for arguments.

Jan

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