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From:   Aaron Tomlin <atomlin@redhat.com>
To:     mcgrof@kernel.org
Cc:     linux-modules@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH 2/2] module: Show the last unloaded module's taint flag(s)
Date:   Mon, 27 Jun 2022 17:40:52 +0100
Message-Id: <20220627164052.2416485-2-atomlin@redhat.com>
In-Reply-To: <20220627164052.2416485-1-atomlin@redhat.com>
References: <20220627164052.2416485-1-atomlin@redhat.com>
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For diagnostic purposes, this patch, in addition to keeping a record/or
track of the last known unloaded module, we now will include the
module's taint flag(s) too e.g: " [last unloaded: fpga_mgr_mod(OE)]"

Signed-off-by: Aaron Tomlin <atomlin@redhat.com>
---
 kernel/module/main.c | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/kernel/module/main.c b/kernel/module/main.c
index dcb83cf18d84..0ca6fd38b903 100644
--- a/kernel/module/main.c
+++ b/kernel/module/main.c
@@ -524,7 +524,12 @@ static struct module_attribute modinfo_##field = {                    \
 MODINFO_ATTR(version);
 MODINFO_ATTR(srcversion);
 
-static char last_unloaded_module[MODULE_NAME_LEN+1];
+/*
+ * Maximum number of characters written by module_flags()
+ * without a module's state information.
+ */
+#define LAST_UNLOADED_MODULE_NAME_LEN (MODULE_NAME_LEN + MODULE_FLAGS_BUF_SIZE - 2 + 1)
+static char last_unloaded_module[LAST_UNLOADED_MODULE_NAME_LEN];
 
 #ifdef CONFIG_MODULE_UNLOAD
 
@@ -694,6 +699,7 @@ SYSCALL_DEFINE2(delete_module, const char __user *, name_user,
 {
 	struct module *mod;
 	char name[MODULE_NAME_LEN];
+	char buf[LAST_UNLOADED_MODULE_NAME_LEN];
 	int ret, forced = 0;
 
 	if (!capable(CAP_SYS_MODULE) || modules_disabled)
@@ -753,8 +759,8 @@ SYSCALL_DEFINE2(delete_module, const char __user *, name_user,
 
 	async_synchronize_full();
 
-	/* Store the name of the last unloaded module for diagnostic purposes */
 	strlcpy(last_unloaded_module, mod->name, sizeof(last_unloaded_module));
+	strcat(last_unloaded_module, module_flags(mod, buf, false));
 
 	free_module(mod);
 	/* someone could wait for the module in add_unformed_module() */
-- 
2.34.3