On 17.09.22 09:14, Akinobu Mita wrote:
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@huawei.com Signed-off-by: Akinobu Mita akinobu.mita@gmail.com
But shouldn't we fix simple_attr_write() instead?
I mean, simple_attr_read() might use attr->fmt to print a signed value, but simple_attr_write() fails on signed values now?
I might be wrong, but there is a disconnect. I feel like simple_attr_write() should similarly make decisions based on attr->fmt.
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)