[PATCH v2 1/2] padata: Mark padata_work_init() as __ref

Nathan Chancellor
2022-12-07T19:17:43Z

When building arm64 allmodconfig + ThinLTO with clang and a proposed
modpost update to account for -ffuncton-sections, the following warning
appears:

WARNING: modpost: vmlinux.o: section mismatch in reference: padata_work_init (section: .text.padata_work_init) -> padata_mt_helper (section: .init.text)
WARNING: modpost: vmlinux.o: section mismatch in reference: padata_work_init (section: .text.padata_work_init) -> padata_mt_helper (section: .init.text)

LLVM has optimized padata_work_init() to include the address of
padata_mt_helper() directly, which causes modpost to complain since
padata_work_init() is not __init, whereas padata_mt_helper() is. In
reality, padata_work_init() is only called with padata_mt_helper() as
the work_fn argument in code that is __init, so this warning will not
result in any problems. Silence it with __ref, which makes it clear to
modpost that padata_work_init() can only use padata_mt_helper() in
__init code.

Suggested-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
---
Cc: Steffen Klassert <steffen.klassert@secunet.com>
Cc: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: linux-crypto@vger.kernel.org
---
kernel/padata.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/kernel/padata.c b/kernel/padata.c
index e5819bb8bd1d..4c3137fe8449 100644
--- a/kernel/padata.c
+++ b/kernel/padata.c
@@ -83,8 +83,8 @@ static struct padata_work *padata_work_alloc(void)
return pw;
}

-static void padata_work_init(struct padata_work *pw, work_func_t work_fn,
- void *data, int flags)
+static __ref void padata_work_init(struct padata_work *pw, work_func_t work_fn,
+ void *data, int flags)
{
if (flags & PADATA_WORK_ONSTACK)
INIT_WORK_ONSTACK(&pw->pw_work, work_fn);

base-commit: 76dcd734eca23168cb008912c0f69ff408905235
--
2.38.1