[PATCH 6.1 087/197] modpost: Dont let "driver"s reference .exit.*

Greg Kroah-Hartman
2024-02-20T21:02:26Z

From: "Uwe Kleine-König" <u.kleine-koenig@pengutronix.de>

commit f177cd0c15fcc7bdbb68d8d1a3166dead95314c8 upstream.

Drivers must not reference functions marked with __exit as these likely
are not available when the code is built-in.

There are few creative offenders uncovered for example in ARCH=amd64
allmodconfig builds. So only trigger the section mismatch warning for
W=1 builds.

The dual rule that drivers must not reference .init.* is implemented
since commit 0db252452378 ("modpost: don't allow *driver to reference
.init.*") which however missed that .exit.* should be handled in the
same way.

Thanks to Masahiro Yamada and Arnd Bergmann who gave valuable hints to
find this improvement.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Stable-dep-of: 846cfbeed09b ("um: Fix adding '-no-pie' for clang")
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
scripts/mod/modpost.c | 15 +++++++++++++--
1 file changed, 13 insertions(+), 2 deletions(-)

--- a/scripts/mod/modpost.c
+++ b/scripts/mod/modpost.c
@@ -1087,9 +1087,20 @@ static int secref_whitelist(const struct
"*_console")))
return 0;

- /* symbols in data sections that may refer to meminit/exit sections */
+ /* symbols in data sections that may refer to meminit sections */
if (match(fromsec, PATTERNS(DATA_SECTIONS)) &&
- match(tosec, PATTERNS(ALL_XXXINIT_SECTIONS, ALL_EXIT_SECTIONS)) &&
+ match(tosec, PATTERNS(ALL_XXXINIT_SECTIONS, ALL_XXXEXIT_SECTIONS)) &&
+ match(fromsym, PATTERNS("*driver")))
+ return 0;
+
+ /*
+ * symbols in data sections must not refer to .exit.*, but there are
+ * quite a few offenders, so hide these unless for W=1 builds until
+ * these are fixed.
+ */
+ if (!extra_warn &&
+ match(fromsec, PATTERNS(DATA_SECTIONS)) &&
+ match(tosec, PATTERNS(EXIT_SECTIONS)) &&
match(fromsym, PATTERNS("*driver")))
return 0;