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Date:   Sat,  2 Jul 2022 12:09:57 +0800
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Subject: [PATCH v5 2/4] module: panic: Taint the kernel when selftest modules load
From:   David Gow <davidgow@google.com>
To:     Brendan Higgins <brendanhiggins@google.com>,
        Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
        Jonathan Corbet <corbet@lwn.net>,
        Andrew Morton <akpm@linux-foundation.org>,
        Kees Cook <keescook@chromium.org>,
        Shuah Khan <skhan@linuxfoundation.org>,
        Greg KH <gregkh@linuxfoundation.org>,
        Luis Chamberlain <mcgrof@kernel.org>,
        Masahiro Yamada <masahiroy@kernel.org>
Cc:     David Gow <davidgow@google.com>,
        "Guilherme G . Piccoli" <gpiccoli@igalia.com>,
        Sebastian Reichel <sre@kernel.org>,
        John Ogness <john.ogness@linutronix.de>,
        Joe Fradley <joefradley@google.com>,
        Daniel Latypov <dlatypov@google.com>,
        kunit-dev@googlegroups.com, linux-kselftest@vger.kernel.org,
        linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org,
        Jani Nikula <jani.nikula@linux.intel.com>,
        Lucas De Marchi <lucas.demarchi@intel.com>,
        Aaron Tomlin <atomlin@redhat.com>,
        linux-fsdevel@vger.kernel.org, linux-block@vger.kernel.org,
        Michal Marek <michal.lkml@markovi.net>,
        Nick Desaulniers <ndesaulniers@google.com>,
        linux-kbuild@vger.kernel.org
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Precedence: bulk

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@kernel.org>
Signed-off-by: David Gow <davidgow@google.com>
---
 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