The simple attribute files do not accept a negative value since the
commit 488dac0c9237 ("libfs: fix error cast of negative value in
simple_attr_write()"), so we can no longer use DEFINE_SIMPLE_ATTRIBUTE() to
define a file operations for errno value.
Fixes: 488dac0c9237 ("libfs: fix error cast of negative value in simple_attr_write()")
Reported-by: Zhao Gongyi <zhaogongyi@xxxxxxxxxx>
Signed-off-by: Akinobu Mita <akinobu.mita@xxxxxxxxx>
---
v2: Fix Reported-by line
lib/notifier-error-inject.c | 38 ++++++++++++++++++++++++++++++-------
1 file changed, 31 insertions(+), 7 deletions(-)
diff --git a/lib/notifier-error-inject.c b/lib/notifier-error-inject.c
index 21016b32d313..30ec41f58d53 100644
--- a/lib/notifier-error-inject.c
+++ b/lib/notifier-error-inject.c
@@ -3,20 +3,44 @@
#include "notifier-error-inject.h"
-static int debugfs_errno_set(void *data, u64 val)
+static int notifier_err_errno_show(struct seq_file *m, void *data)
{
- *(int *)data = clamp_t(int, val, -MAX_ERRNO, 0);
+ int *value = m->private;
+
+ seq_printf(m, "%d\n", *value);
+
return 0;
}
-static int debugfs_errno_get(void *data, u64 *val)
+static int notifier_err_errno_open(struct inode *inode, struct file *file)
{
- *val = *(int *)data;
- return 0;
+ return single_open(file, notifier_err_errno_show, inode->i_private);
+}
+
+static ssize_t notifier_err_errno_write(struct file *file, const char __user *ubuf, size_t len,
+ loff_t *offp)
+{
+ struct seq_file *m = file->private_data;
+ int *value = m->private;
+ int ret;
+
+ ret = kstrtoint_from_user(ubuf, len, 0, value);
+ if (ret)
+ return ret;
+
+ *value = clamp(*value, -MAX_ERRNO, 0);
+
+ return len;
}
-DEFINE_SIMPLE_ATTRIBUTE(fops_errno, debugfs_errno_get, debugfs_errno_set,
- "%lld\n");
+static const struct file_operations fops_errno = {
+ .owner = THIS_MODULE,
+ .open = notifier_err_errno_open,
+ .read = seq_read,
+ .write = notifier_err_errno_write,
+ .llseek = seq_lseek,
+ .release = single_release,
+};
static struct dentry *debugfs_create_errno(const char *name, umode_t mode,
struct dentry *parent, int *value)
--
2.34.1
