[PATCH RFC 01/22] alpha: srm_env: let procfs copy in writes

[Christian Brauner]

Implement ->proc_write_buf() so procfs copies in what is written to
/proc/srm_environment/* before it pins the entry, and hand that copy to
the console callback through the page it used before.

Signed-off-by: Christian Brauner (Amutable) <brauner@xxxxxxxxxx>
---
 arch/alpha/kernel/srm_env.c | 12 +++---------
 1 file changed, 3 insertions(+), 9 deletions(-)

diff --git a/arch/alpha/kernel/srm_env.c b/arch/alpha/kernel/srm_env.c
index faafc2df7886..6a1742b09a82 100644
--- a/arch/alpha/kernel/srm_env.c
+++ b/arch/alpha/kernel/srm_env.c
@@ -81,7 +81,7 @@ static int srm_env_proc_show(struct seq_file *m, void *v)
 	return ret;
 }
 
-static ssize_t srm_env_proc_write(struct file *file, const char __user *buffer,
+static ssize_t srm_env_proc_write(struct file *file, char *buffer,
 				  size_t count, loff_t *pos)
 {
 	int res;
@@ -92,13 +92,8 @@ static ssize_t srm_env_proc_write(struct file *file, const char __user *buffer,
 	if (!buf)
 		return -ENOMEM;
 
-	res = -EINVAL;
-	if (count >= PAGE_SIZE)
-		goto out;
-
 	res = -EFAULT;
-	if (copy_from_user(buf, buffer, count))
-		goto out;
+	memcpy(buf, buffer, count);
 	buf[count] = '\0';
 
 	ret1 = callback_setenv(id, buf, count);
@@ -109,14 +104,13 @@ static ssize_t srm_env_proc_write(struct file *file, const char __user *buffer,
 		res = (int) ret1;
 	}
 
- out:
 	free_page((unsigned long)buf);
 	return res;
 }
 
 static const struct proc_ops srm_env_proc_ops = {
 	.proc_show	= srm_env_proc_show,
-	.proc_write	= srm_env_proc_write,
+	.proc_write_buf	= srm_env_proc_write,
 };
 
 static int __init

-- 
2.53.0