[PATCH -repost 19/21] kgr: expose global 'in_progress' state through procfs

From: Jiri Slaby
Date: Wed Jun 25 2014 - 07:08:11 EST


From: Jiri Kosina <jkosina@xxxxxxx>

In addition to having a per-process flag that shows which processess have
already been "migrated", it's useful to have a global-wide flag that will
show whether the patching operation is currently undergoing without having
to traverse all /proc entries.

js: handle error

Reported-by: Libor Pechacek <lpechacek@xxxxxxx>
Signed-off-by: Jiri Kosina <jkosina@xxxxxxx>
Signed-off-by: Jiri Slaby <jslaby@xxxxxxx>
---
kernel/kgraft.c | 24 ++++++++++++++++++++++++
1 file changed, 24 insertions(+)

diff --git a/kernel/kgraft.c b/kernel/kgraft.c
index 5ec0c1abe0d6..1247f1c60b09 100644
--- a/kernel/kgraft.c
+++ b/kernel/kgraft.c
@@ -26,6 +26,8 @@
#include <linux/spinlock.h>
#include <linux/types.h>
#include <linux/workqueue.h>
+#include <linux/seq_file.h>
+#include <linux/proc_fs.h>

static int kgr_patch_code(const struct kgr_patch *patch,
struct kgr_patch_fun *patch_fun, bool final);
@@ -382,6 +384,25 @@ unlock_free:
}
EXPORT_SYMBOL_GPL(kgr_start_patching);

+static int kgr_show(struct seq_file *m, void *v)
+{
+ seq_printf(m, "%d\n", kgr_in_progress);
+ return 0;
+}
+
+static int kgr_open(struct inode *inode, struct file *file)
+{
+ return single_open(file, kgr_show, NULL);
+}
+
+static const struct file_operations kgr_fops = {
+ .owner = THIS_MODULE,
+ .open = kgr_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = single_release,
+};
+
static int __init kgr_init(void)
{
if (ftrace_is_dead()) {
@@ -398,6 +419,9 @@ static int __init kgr_init(void)
kgr_initialized = true;
pr_info("kgr: successfully initialized\n");

+ if (!proc_create("kgr_in_progress", 0, NULL, &kgr_fops))
+ pr_warn("kgr: cannot create kgr_in_progress in procfs\n");
+
return 0;
}
module_init(kgr_init);
--
2.0.0

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