Implement ->proc_write_buf() so procfs copies in what is written to the
alignment files before it pins the entry, and take the mode from that
copy. Writes larger than PAGE_SIZE - 1 bytes fail with -EINVAL now.
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
---
arch/sh/mm/alignment.c | 7 +++----
1 file changed, 3 insertions(+), 4 deletions(-)
diff --git a/arch/sh/mm/alignment.c b/arch/sh/mm/alignment.c
index 2198c6f2ea63..d832249a8e18 100644
--- a/arch/sh/mm/alignment.c
+++ b/arch/sh/mm/alignment.c
@@ -133,14 +133,13 @@ static int alignment_proc_show(struct seq_file *m, void *v)
}
static ssize_t alignment_proc_write(struct file *file,
- const char __user *buffer, size_t count, loff_t *pos)
+ char *buffer, size_t count, loff_t *pos)
{
int *data = pde_data(file_inode(file));
char mode;
if (count > 0) {
- if (get_user(mode, buffer))
- return -EFAULT;
+ mode = buffer[0];
if (mode >= '0' && mode <= '5')
*data = mode - '0';
}@@ -149,7 +148,7 @@ static ssize_t alignment_proc_write(struct file *file,
static const struct proc_ops alignment_proc_ops = {
.proc_show = alignment_proc_show,
- .proc_write = alignment_proc_write,
+ .proc_write_buf = alignment_proc_write,
};
/*
--
2.53.0