Re: [RFC 0/4] perf tool: Fix non-".text" symbol resolution for kernel modules

[Ravi Bangoria]

Hi Adrian,

On 10-Jan-23 12:05 PM, Adrian Hunter wrote:
> On 10/01/23 07:58, Ravi Bangoria wrote:
>> Kernel module elf contains executable code in non-".text" sections as
>> well, for ex: ".noinstr.text". Plus, kernel module's memory layout
>> differs from it's binary layout because .ko elf does not contain
>> program header table.
> 
> Have you looked at using perf record --kcore option.

Nice! We can also use --kallsyms with perf report and it resolves symbols
fine.

But what about normal perf record/report? Why I'm enforcing on normal perf-
record/report is because, generally user don't specify these options, esp if
he has root privileges, he expects symbol-resolution should just work fine.
But when he sees inconsistency in symbol-resolution of the same kernel module,
he will be clueless of what's missing. This patchset is trying to solve it,
although I too feel adding section specific maps to perf.data is overkill as
--kcore or --kallsyms can also resolve those symbols.

Thanks for your feedback,
Ravi