[PATCH] _proc_do_string(): fix short reads

[powerpc.git] / kernel / sysctl.c

diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index 84cab0c..e0ac6cd 100644 (file)
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -1686,13 +1686,12 @@ static int _proc_do_string(void* data, int maxlen, int write,
        size_t len;
        char __user *p;
        char c;
-       
-       if (!data || !maxlen || !*lenp ||
-           (*ppos && !write)) {
+
+       if (!data || !maxlen || !*lenp) {
                *lenp = 0;
                return 0;
        }
-       
+
        if (write) {
                len = 0;
                p = buffer;
@@ -1713,6 +1712,15 @@ static int _proc_do_string(void* data, int maxlen, int write,
                len = strlen(data);
                if (len > maxlen)
                        len = maxlen;
+
+               if (*ppos > len) {
+                       *lenp = 0;
+                       return 0;
+               }
+
+               data += *ppos;
+               len  -= *ppos;
+
                if (len > *lenp)
                        len = *lenp;
                if (len)