[PATCH v3 0/2] Fix lack of section mismatch warnings with LTO

Nathan Chancellor
2022-12-13T18:35:48Z

Hi all,

Vincent recently reported an issue with lack of section mismatch
warnings with LTO. This is due to commit 6c730bfc894f ("modpost: handle
-ffunction-sections"), which ignores all function sections for modpost.

I believe this is incorrect, as these function sections may still refer
to symbols in other sections and they will ultimately be coalesced into
.text by vmlinux.lds anyways.

The first patch fixes a warning that I see with allmodconfig + ThinLTO
builds after applying the second patch. The second patch moves ".text.*"
into TEXT_SECTIONS so that modpost audits them for mismatches.

I expect this to go via the kbuild tree with an ack from the padata
maintainers.

Cc: Steffen Klassert <steffen.klassert@secunet.com>
Cc: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: linux-crypto@vger.kernel.org

v3:
- Stick a comment above padata_work_init() to explain presence of
__ref (Masahiro, Daniel).
- Expand on problem in first patch's commit message (Masahiro).
- Adjust location of __ref within function definition (Daniel)
- Fix typo in commit message of second patch (Masahiro).
v2: https://lore.kernel.org/20221207191657.2852229-1-nathan@kernel.org/
v1: https://lore.kernel.org/20221129190123.872394-1-nathan@kernel.org/

Nathan Chancellor (2):
padata: Mark padata_work_init() as __ref
modpost: Include '.text.*' in TEXT_SECTIONS

kernel/padata.c | 12 ++++++++++--
scripts/mod/modpost.c | 4 ++--
2 files changed, 12 insertions(+), 4 deletions(-)

base-commit: 830b3c68c1fb1e9176028d02ef86f3cf76aa2476
--
2.39.0