On 18/06/2023 14:07, Jiri Olsa wrote:
> On Fri, Jun 16, 2023 at 06:17:24PM +0100, Alan Maguire wrote:
>> Generate BTF kind layout information, crcs for kernel and module BTF
>> if support is available in pahole.
>>
>> Signed-off-by: Alan Maguire <alan.maguire@xxxxxxxxxx>
>> ---
>> scripts/pahole-flags.sh | 7 +++++++
>> 1 file changed, 7 insertions(+)
>>
>> diff --git a/scripts/pahole-flags.sh b/scripts/pahole-flags.sh
>> index 728d55190d97..cb304e0a4434 100755
>> --- a/scripts/pahole-flags.sh
>> +++ b/scripts/pahole-flags.sh
>> @@ -25,6 +25,13 @@ if [ "${pahole_ver}" -ge "124" ]; then
>> fi
>> if [ "${pahole_ver}" -ge "125" ]; then
>> extra_paholeopt="${extra_paholeopt} --skip_encoding_btf_inconsistent_proto --btf_gen_optimized"
>> + pahole_help="$(${PAHOLE} --help)"
>
> nice ;-)
>
>> + if [[ "$pahole_help" =~ "btf_gen_kind_layout" ]]; then
>> + extra_paholeopt="${extra_paholeopt} --btf_gen_kind_layout"
>> + fi
>> + if [[ "$pahole_help" =~ "btf_gen_crc" ]]; then
>> + extra_paholeopt="${extra_paholeopt} --btf_gen_crc"
>> + fi
>
> do we need to have an option to enable crc? could it be by default?
>
> it's sort of related to the layout changes and I wonder we will want
> 'not to have it' if there's support for it in BTF
>
I'm reluctant to enable by default yet because without CRC and kind
layout the new header format will work on older kernels too. With
the kind layout len/offset 0 and CRCs 0, the header is just slightly
larger than the original.
I originally combined the two in the metadata section header, but
I think as separate concepts it makes sense to have separate
flags.
Thanks!
Alan
> jirka
>
>> fi
>>
>> echo ${extra_paholeopt}
>> --
>> 2.39.3
>>
