On Wed, 19 Aug 2020 11:23:42 +0200 Jiri Olsa <jolsa@xxxxxxxxxx> wrote:
> The data of compressed section should be aligned to 4
> (for 32bit) or 8 (for 64 bit) bytes.
>
> The binutils ld sets sh_addralign to 1, which makes libelf
> fail with misaligned section error during the update as
> reported by Jesper:
>
> FAILED elf_update(WRITE): invalid section alignment
>
> While waiting for ld fix, we can fix compressed sections
> sh_addralign value manually.
>
> Adding warning in -vv mode when the fix is triggered:
>
> $ ./tools/bpf/resolve_btfids/resolve_btfids -vv vmlinux
> ...
> section(36) .comment, size 44, link 0, flags 30, type=1
> section(37) .debug_aranges, size 45684, link 0, flags 800, type=1
> - fixing wrong alignment sh_addralign 16, expected 8
> section(38) .debug_info, size 129104957, link 0, flags 800, type=1
> - fixing wrong alignment sh_addralign 1, expected 8
> section(39) .debug_abbrev, size 1152583, link 0, flags 800, type=1
> - fixing wrong alignment sh_addralign 1, expected 8
> section(40) .debug_line, size 7374522, link 0, flags 800, type=1
> - fixing wrong alignment sh_addralign 1, expected 8
> section(41) .debug_frame, size 702463, link 0, flags 800, type=1
> section(42) .debug_str, size 1017571, link 0, flags 830, type=1
> - fixing wrong alignment sh_addralign 1, expected 8
> section(43) .debug_loc, size 3019453, link 0, flags 800, type=1
> - fixing wrong alignment sh_addralign 1, expected 8
> section(44) .debug_ranges, size 1744583, link 0, flags 800, type=1
> - fixing wrong alignment sh_addralign 16, expected 8
> section(45) .symtab, size 2955888, link 46, flags 0, type=2
> section(46) .strtab, size 2613072, link 0, flags 0, type=3
> ...
> update ok for vmlinux
I also works for me:
[...]
section(37) .debug_aranges, size 45684, link 0, flags 800, type=1
- fixing wrong alignment sh_addralign 16, expected 8
section(38) .debug_info, size 129098181, link 0, flags 800, type=1
- fixing wrong alignment sh_addralign 1, expected 8
section(39) .debug_abbrev, size 1152583, link 0, flags 800, type=1
- fixing wrong alignment sh_addralign 1, expected 8
section(40) .debug_line, size 7374522, link 0, flags 800, type=1
- fixing wrong alignment sh_addralign 1, expected 8
section(41) .debug_frame, size 702463, link 0, flags 800, type=1
section(42) .debug_str, size 1017606, link 0, flags 830, type=1
- fixing wrong alignment sh_addralign 1, expected 8
section(43) .debug_loc, size 3019453, link 0, flags 800, type=1
- fixing wrong alignment sh_addralign 1, expected 8
section(44) .debug_ranges, size 1744583, link 0, flags 800, type=1
- fixing wrong alignment sh_addralign 16, expected 8
section(45) .symtab, size 2955888, link 46, flags 0, type=2
section(46) .strtab, size 2613072, link 0, flags 0, type=3
section(47) .shstrtab, size 525, link 0, flags 0, type=3
[...]
update ok for vmlinux.err.bak
>
> Another workaround is to disable compressed debug info data
> CONFIG_DEBUG_INFO_COMPRESSED kernel option.
>
> Fixes: fbbb68de80a4 ("bpf: Add resolve_btfids tool to resolve BTF IDs in ELF object")
> Cc: Mark Wielaard <mjw@xxxxxxxxxx>
> Cc: Nick Clifton <nickc@xxxxxxxxxx>
> Reported-by: Jesper Dangaard Brouer <brouer@xxxxxxxxxx>
> Signed-off-by: Jiri Olsa <jolsa@xxxxxxxxxx>
> ---
Thanks for fixing this!
Acked-by: Jesper Dangaard Brouer <brouer@xxxxxxxxxx>
--
Best regards,
Jesper Dangaard Brouer
MSc.CS, Principal Kernel Engineer at Red Hat
LinkedIn: http://www.linkedin.com/in/brouer
