Re: [tip: objtool/core] objtool/klp: Add .klp.symid for sympos disambiguation

Thank you for your contribution! Sashiko AI review found 1 potential issue(=
s) to consider:
- [Low] The `.exitcall.exit` section is discarded during the final vmlinux =
link, but `klp_create_symid_sections` incorrectly generates `.klp.symid` re=
locations to duplicate static symbols within it.
--

--- Patch [1]: [tip: objtool/core] objtool/klp: Add .klp.symid for sympos d=
isambiguation ---
commit 95a71e72a77916e00e9b21eb4e2fc9a9e4c3258d
Author: Josh Poimboeuf <[email protected]>
Date:   Mon Aug 3 05:49:39 2026 +0000

objtool/klp: Add .klp.symid for sympos disambiguation

Livepatch identifies a duplicate-named symbol by its position (sympos)
among same-named kallsyms entries, which for vmlinux are counted in
ascending address order in the final linked kernel. This commit adds a
new .klp.symid section to bridge the gap and correlate symbols between
vmlinux.o and vmlinux.

Link: https://patch.msgid.link/64d50f077b569f47883c015cdb7079edb068efe8.178=
[email protected]

> diff --git a/tools/objtool/klp-symid.c b/tools/objtool/klp-symid.c
> new file mode 100644
> index 0000000000000..cf188cdfa6079
> --- /dev/null
> +++ b/tools/objtool/klp-symid.c
[ ... ]
> +static const char * const discarded_secs[] =3D {
> +	".discard",
> +	".modinfo",
> +	"__tracepoint_check",
> +};

[Severity: Low]
Does this list need to include ".exitcall.exit"?

When built-in components use module_exit() with identical function
names (like sm4_exit in multiple x86 crypto modules), duplicate static
variables are created in the .exitcall.exit section.

Because this section is missing from discarded_secs[], symid_needed()
generates R_ABS64 relocations in .klp.symid to these symbols.

Since .exitcall.exit is unconditionally discarded by the linker during the
final vmlinux link, this can cause a fatal linker error: ".klp.symid refers
to discarded section .exitcall.exit".

--=20
Sashiko AI review =C2=B7 https://sashiko.dev/#/patchset/178573617913.121094=
5.4137827646322421739.tip-bot2@tip-bot2?part=3D1