proc_dointvec: write a single value

The commit 00b7c3395aec3df43de5bd02a3c5a099ca51169f
"sysctl: refactor integer handling proc code"
modified the behaviour of writing to /proc.
Before the commit, write("1\n") to /proc/sys/kernel/printk succeeded. But
now it returns EINVAL.

This commit supports writing a single value to a multi-valued entry.

Signed-off-by: J. R. Okajima <hooanon05@yahoo.co.jp>
Reviewed-and-tested-by: WANG Cong <amwang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index b125830..f948f20 100644 (file)
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -2253,6 +2253,8 @@ static int __do_proc_dointvec(void *tbl_data, struct ctl_table *table,
                if (write) {
                        left -= proc_skip_spaces(&kbuf);
 
+                       if (!left)
+                               break;
                        err = proc_get_long(&kbuf, &left, &lval, &neg,
                                             proc_wspace_sep,
                                             sizeof(proc_wspace_sep), NULL);
@@ -2279,7 +2281,7 @@ static int __do_proc_dointvec(void *tbl_data, struct ctl_table *table,
 
        if (!write && !first && left && !err)
                err = proc_put_char(&buffer, &left, '\n');
-       if (write && !err)
+       if (write && !err && left)
                left -= proc_skip_spaces(&kbuf);
 free:
        if (write) {