On Thu, 2021-06-17 at 11:10 +0200, Jiri Olsa wrote:
On Wed, Jun 16, 2021 at 03:09:13PM -0700, Tony Ambardar wrote:
On Wed, 16 Jun 2021 at 09:38, Jiri Olsa jolsa@redhat.com wrote:
I have no idea how is this handled in libelf (perhaps it's ok), but just that comment above suggests it could be also 64 bits, cc-ing Frank and Mark for more insight
One other area I'd like to confirm is with section compression. Is it safe to ignore this for .BTF_ids? I've done so because include/linux/btf_ids.h appears to define the section with SHF_ALLOC flag set, which is incompatible with compression based on "libelf.h" comments.
not sure what you mean.. where it wouldn't be safe? what workflow/processing
I haven't looked at the code/patch, but Tony is correct that if a section has SHF_ALLOC set it cannot be a compressed section. SHF_COMPRESSED is incompatbile with SHF_ALLOC (or SHF_NOBITS) sections, because it would be unclear what a loader would need to do with them (uncompress the data first, then map it, or map the compressed data as is into memory).
So ignoring whether or not a section is compressed for SHF_ALLOC sections is fine.
Cheers,
Mark