Re: [PATCH 1/2] kallsyms: add symbol size for kallsyms symbols that can change size

[Geert Uytterhoeven]

Hi André,

On Tue, 28 Jul 2026 at 14:52, André Draszik <andre.draszik@xxxxxxxxxx> wrote:
> Add symbol size for kallsyms symbols that can change size so that sizes
> can be determined easily without having to manually calculate them
> when inspecting the object files (.tmp_vmlinux?.kallsyms.o or
> .tmp_vmlinux?). Without, the assembler records the symbol size as 0.
>
> This is primarily useful as a debugging aid in case of linker errors as
> part of link-vmlinux.sh, and because symbol size doesn't have to align
> with the offset to the next symbol due to padding/alignment.
>
> Signed-off-by: André Draszik <andre.draszik@xxxxxxxxxx>

Thanks for your patch, which is now commit d6bf11a7e8a86135 ("kallsyms:
add symbol size for kallsyms symbols that can change size") upstream.

FTR, this commit has a huge impact on kernel size, according to
bloat-o-meter:

    $ bloat-o-meter vmlinux.{old,}
    add/remove: 4/0 grow/shrink: 0/0 up/down: 440264/0 (440264)
    Function                                     old     new   delta
    kallsyms_names                                 -  324543 +324543
    kallsyms_offsets                               -  114424 +114424
    kallsyms_token_table                           -     849    +849
    kallsyms_markers                               -     448    +448
    Total: Before=5085496, After=5525760, chg +8.66%

However, this seems to be totally bogus, and thus a false-positive:

    $ size vmlinux.{old,}
       text   data    bss    dec    hex filename
    4520823 1507876 154960 6183659 5e5aeb /tmp/vmlinux.old
    4520823 1507876 154960 6183659 5e5aeb /tmp/vmlinux
    $ ls -l vmlinux.{old,}
    -rwxrwxr-x 1 geert geert 7922796 aug 24 14:18 /tmp/vmlinux.old*
    -rwxrwxr-x 1 geert geert 7922796 aug 24 14:19 /tmp/vmlinux*

I also see no change in memory consumption after boot-up, so everything
is good...

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds