[PATCH v5 2/4] module: panic: Taint the kernel when selftest modules load

From: David Gow
Date: Sat Jul 02 2022 - 00:10:19 EST


Taint the kernel with TAINT_TEST whenever a test module loads, by adding
a new "TEST" module property, and setting it for all modules in the
tools/testing directory. This property can also be set manually, for
tests which live outside the tools/testing directory with:
MODULE_INFO(test, "Y");

Reviewed-by: Luis Chamberlain <mcgrof@xxxxxxxxxx>
Signed-off-by: David Gow <davidgow@xxxxxxxxxx>
---
kernel/module/main.c | 7 +++++++
scripts/mod/modpost.c | 3 +++
2 files changed, 10 insertions(+)

diff --git a/kernel/module/main.c b/kernel/module/main.c
index fed58d30725d..730503561eb0 100644
--- a/kernel/module/main.c
+++ b/kernel/module/main.c
@@ -1988,6 +1988,13 @@ static int check_modinfo(struct module *mod, struct load_info *info, int flags)
/* Set up license info based on the info section */
set_license(mod, get_modinfo(info, "license"));

+ if (!get_modinfo(info, "test")) {
+ if (!test_taint(TAINT_TEST))
+ pr_warn_once("%s: loading test module taints kernel.\n",
+ mod->name);
+ add_taint_module(mod, TAINT_TEST, LOCKDEP_STILL_OK);
+ }
+
return 0;
}

diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c
index 29d5a841e215..5937212b4433 100644
--- a/scripts/mod/modpost.c
+++ b/scripts/mod/modpost.c
@@ -2191,6 +2191,9 @@ static void add_header(struct buffer *b, struct module *mod)

if (strstarts(mod->name, "drivers/staging"))
buf_printf(b, "\nMODULE_INFO(staging, \"Y\");\n");
+
+ if (strstarts(mod->name, "tools/testing"))
+ buf_printf(b, "\nMODULE_INFO(test, \"Y\");\n");
}

static void add_exported_symbols(struct buffer *buf, struct module *mod)
--
2.37.0.rc0.161.g10f37bed90-goog