PM: Fix PM QOS's user mode interface to work with ASCII input

Make pm_qos_power_write() accept values passed to it in the ASCII hex
format either with or without an ending newline.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Mark Gross <markgross@thegnar.org>

1 files changed, 23 insertions, 10 deletions

diff --git a/kernel/pm_qos_params.c b/kernel/pm_qos_params.c
index 0da058bff8e..68df076fec5 100644
--- a/kernel/pm_qos_params.c
+++ b/kernel/pm_qos_params.c
@@ -40,6 +40,7 @@
 #include <linux/string.h>
 #include <linux/platform_device.h>
 #include <linux/init.h>
+#include <linux/kernel.h>
 
 #include <linux/uaccess.h>
 
@@ -404,24 +405,36 @@ static ssize_t pm_qos_power_write(struct file *filp, const char __user *buf,
                 size_t count, loff_t *f_pos)
 {
         s32 value;
-        int x;
-        char ascii_value[11];
         struct pm_qos_request_list *pm_qos_req;
 
         if (count == sizeof(s32)) {
                 if (copy_from_user(&value, buf, sizeof(s32)))
                         return -EFAULT;
-        } else if (count == 11) { /* len('0x12345678/0') */
-                if (copy_from_user(ascii_value, buf, 11))
+        } else if (count <= 11) { /* ASCII perhaps? */
+                char ascii_value[11];
+                unsigned long int ulval;
+                int ret;
+
+                if (copy_from_user(ascii_value, buf, count))
                         return -EFAULT;
-                if (strlen(ascii_value) != 10)
-                        return -EINVAL;
-                x = sscanf(ascii_value, "%x", &value);
-                if (x != 1)
+
+                if (count > 10) {
+                        if (ascii_value[10] == '\n')
+                                ascii_value[10] = '\0';
+                        else
+                                return -EINVAL;
+                } else {
+                        ascii_value[count] = '\0';
+                }
+                ret = strict_strtoul(ascii_value, 16, &ulval);
+                if (ret) {
+                        pr_debug("%s, 0x%lx, 0x%x\n", ascii_value, ulval, ret);
                         return -EINVAL;
-                pr_debug("%s, %d, 0x%x\n", ascii_value, x, value);
-        } else
+                }
+                value = (s32)lower_32_bits(ulval);
+        } else {
                 return -EINVAL;
+        }
 
         pm_qos_req = filp->private_data;
         pm_qos_update_request(pm_qos_req, value);