* [PATCH modules-next] module: Add debugfs interface to view unloaded tainted modules
@ 2022-08-23 19:32 Aaron Tomlin
2022-08-29 7:14 ` Petr Pavlu
0 siblings, 1 reply; 3+ messages in thread
From: Aaron Tomlin @ 2022-08-23 19:32 UTC (permalink / raw)
To: mcgrof; +Cc: christophe.leroy, linux-kernel, linux-modules, atomlin
This patch provides debug/modules/unloaded_tainted file to see
a record of unloaded tainted modules.
Signed-off-by: Aaron Tomlin <atomlin@redhat.com>
---
kernel/module/tracking.c | 66 ++++++++++++++++++++++++++++++++++++++++
1 file changed, 66 insertions(+)
diff --git a/kernel/module/tracking.c b/kernel/module/tracking.c
index 7f8133044d09..015e641bc346 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 +60,68 @@ void print_unloaded_tainted_modules(void)
}
}
}
+
+#ifdef CONFIG_DEBUG_FS
+static void *unloaded_tainted_modules_seq_start(struct seq_file *m, loff_t *pos)
+{
+ mutex_lock(&module_mutex);
+ 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)
+{
+ mutex_unlock(&module_mutex);
+}
+
+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 */
base-commit: 554694ba120b87e39cf732ed632e6a0c52fafb7c
--
2.37.1
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH modules-next] module: Add debugfs interface to view unloaded tainted modules
2022-08-23 19:32 [PATCH modules-next] module: Add debugfs interface to view unloaded tainted modules Aaron Tomlin
@ 2022-08-29 7:14 ` Petr Pavlu
2022-08-31 10:19 ` Aaron Tomlin
0 siblings, 1 reply; 3+ messages in thread
From: Petr Pavlu @ 2022-08-29 7:14 UTC (permalink / raw)
To: Aaron Tomlin, mcgrof
Cc: christophe.leroy, linux-kernel, linux-modules, atomlin
On 8/23/22 21:32, Aaron Tomlin wrote:
> [...]
> @@ -59,3 +60,68 @@ void print_unloaded_tainted_modules(void)
> }
> }
> }
> +
> +#ifdef CONFIG_DEBUG_FS
> +static void *unloaded_tainted_modules_seq_start(struct seq_file *m, loff_t *pos)
> +{
> + mutex_lock(&module_mutex);
> + return seq_list_start_rcu(&unloaded_tainted_modules, *pos);
> +}
unloaded_tainted_modules looks to be a proper RCU list which makes me think
this reader could use just rcu_read_lock() instead of
mutex_lock(&module_mutex)?
Thanks,
Petr
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH modules-next] module: Add debugfs interface to view unloaded tainted modules
2022-08-29 7:14 ` Petr Pavlu
@ 2022-08-31 10:19 ` Aaron Tomlin
0 siblings, 0 replies; 3+ messages in thread
From: Aaron Tomlin @ 2022-08-31 10:19 UTC (permalink / raw)
To: Petr Pavlu; +Cc: mcgrof, christophe.leroy, linux-kernel, linux-modules, atomlin
On Mon 2022-08-29 09:14 +0200, Petr Pavlu wrote:
> On 8/23/22 21:32, Aaron Tomlin wrote:
> > [...]
> > @@ -59,3 +60,68 @@ void print_unloaded_tainted_modules(void)
> > }
> > }
> > }
> > +
> > +#ifdef CONFIG_DEBUG_FS
> > +static void *unloaded_tainted_modules_seq_start(struct seq_file *m, loff_t *pos)
> > +{
> > + mutex_lock(&module_mutex);
> > + return seq_list_start_rcu(&unloaded_tainted_modules, *pos);
> > +}
Hi Petr,
> unloaded_tainted_modules looks to be a proper RCU list which makes me think
> this reader could use just rcu_read_lock() instead of
> mutex_lock(&module_mutex)?
If I understand correctly, yes: the use of rcu_read_lock() and
rcu_read_unlock(), respectively, will be sufficient.
I will send a follow up patch.
Kind regards,
--
Aaron Tomlin
^ permalink raw reply [flat|nested] 3+ messages in thread
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2022-08-29 7:14 ` Petr Pavlu
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