2022-09-01 15:27:46

by Aaron Tomlin

Subject: [PATCH v2 modules-next 0/1] module: Add debugfs interface to view unloaded tainted modules

Hi Luis,

Changes since v1 [1]:

- Replaced the use of module_mutex to instead mark
a RCU read-side critical section (Petr Pavlu)
- Added __acquires() and __releases() to support
sparse context checking

[1]: https://lore.kernel.org/lkml/[email protected]/


Aaron Tomlin (1):
module: Add debugfs interface to view unloaded tainted modules

kernel/module/tracking.c | 68 ++++++++++++++++++++++++++++++++++++++++
1 file changed, 68 insertions(+)


base-commit: 554694ba120b87e39cf732ed632e6a0c52fafb7c
--
2.37.1

2022-09-01 17:09:45

by Aaron Tomlin

Subject: [PATCH v2 modules-next 1/1] module: Add debugfs interface to view unloaded tainted modules

This patch provides debug/modules/unloaded_tainted file to see a
record of unloaded tainted modules.

Signed-off-by: Aaron Tomlin <[email protected]>
---
kernel/module/tracking.c | 68 ++++++++++++++++++++++++++++++++++++++++
1 file changed, 68 insertions(+)

diff --git a/kernel/module/tracking.c b/kernel/module/tracking.c
index 7f8133044d09..a139e63b6f20 100644
--- a/kernel/module/tracking.c
+++ b/kernel/module/tracking.c
@@ -10,6 +10,7 @@
#include <linux/printk.h>
#include <linux/slab.h>
#include <linux/list.h>
+#include <linux/debugfs.h>
#include <linux/rculist.h>
#include "internal.h"

@@ -59,3 +60,70 @@ void print_unloaded_tainted_modules(void)
}
}
}
+
+#ifdef CONFIG_DEBUG_FS
+static void *unloaded_tainted_modules_seq_start(struct seq_file *m, loff_t *pos)
+ __acquires(rcu)
+{
+ rcu_read_lock();
+ return seq_list_start_rcu(&unloaded_tainted_modules, *pos);
+}
+
+static void *unloaded_tainted_modules_seq_next(struct seq_file *m, void *p, loff_t *pos)
+{
+ return seq_list_next_rcu(p, &unloaded_tainted_modules, pos);
+}
+
+static void unloaded_tainted_modules_seq_stop(struct seq_file *m, void *p)
+ __releases(rcu)
+{
+ rcu_read_unlock();
+}
+
+static int unloaded_tainted_modules_seq_show(struct seq_file *m, void *p)
+{
+ struct mod_unload_taint *mod_taint;
+ char buf[MODULE_FLAGS_BUF_SIZE];
+ size_t l;
+
+ mod_taint = list_entry(p, struct mod_unload_taint, list);
+ l = module_flags_taint(mod_taint->taints, buf);
+ buf[l++] = '\0';
+
+ seq_printf(m, "%s (%s) %llu", mod_taint->name, buf, mod_taint->count);
+ seq_puts(m, "\n");
+
+ return 0;
+}
+
+static const struct seq_operations unloaded_tainted_modules_seq_ops = {
+ .start = unloaded_tainted_modules_seq_start,
+ .next = unloaded_tainted_modules_seq_next,
+ .stop = unloaded_tainted_modules_seq_stop,
+ .show = unloaded_tainted_modules_seq_show,
+};
+
+static int unloaded_tainted_modules_open(struct inode *inode, struct file *file)
+{
+ return seq_open(file, &unloaded_tainted_modules_seq_ops);
+}
+
+static const struct file_operations unloaded_tainted_modules_fops = {
+ .open = unloaded_tainted_modules_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = seq_release,
+};
+
+static int __init unloaded_tainted_modules_init(void)
+{
+ struct dentry *dir;
+
+ dir = debugfs_create_dir("modules", NULL);
+ debugfs_create_file("unloaded_tainted", 0444, dir, NULL,
+ &unloaded_tainted_modules_fops);
+
+ return 0;
+}
+module_init(unloaded_tainted_modules_init);
+#endif /* CONFIG_DEBUG_FS */
--
2.37.1

2022-09-09 00:00:43

by Luis Chamberlain

Subject: Re: [PATCH v2 modules-next 0/1] module: Add debugfs interface to view unloaded tainted modules

On Thu, Sep 01, 2022 at 04:24:53PM +0100, Aaron Tomlin wrote:
> Hi Luis,
>
> Changes since v1 [1]:
>
> - Replaced the use of module_mutex to instead mark
> a RCU read-side critical section (Petr Pavlu)
> - Added __acquires() and __releases() to support
> sparse context checking
>
> [1]: https://lore.kernel.org/lkml/[email protected]/

Queued up to modules-testing, thanks!

Luis