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path: root/drivers/input/evdev.c
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Diffstat (limited to 'drivers/input/evdev.c')
-rw-r--r--drivers/input/evdev.c63
1 files changed, 43 insertions, 20 deletions
diff --git a/drivers/input/evdev.c b/drivers/input/evdev.c
index 2d65411f6763..3524bef62be6 100644
--- a/drivers/input/evdev.c
+++ b/drivers/input/evdev.c
@@ -647,6 +647,47 @@ static int str_to_user(const char *str, unsigned int maxlen, void __user *p)
return copy_to_user(p, str, len) ? -EFAULT : len;
}
+#define OLD_KEY_MAX 0x1ff
+static int handle_eviocgbit(struct input_dev *dev, unsigned int cmd, void __user *p, int compat_mode)
+{
+ static unsigned long keymax_warn_time;
+ unsigned long *bits;
+ int len;
+
+ switch (_IOC_NR(cmd) & EV_MAX) {
+
+ case 0: bits = dev->evbit; len = EV_MAX; break;
+ case EV_KEY: bits = dev->keybit; len = KEY_MAX; break;
+ case EV_REL: bits = dev->relbit; len = REL_MAX; break;
+ case EV_ABS: bits = dev->absbit; len = ABS_MAX; break;
+ case EV_MSC: bits = dev->mscbit; len = MSC_MAX; break;
+ case EV_LED: bits = dev->ledbit; len = LED_MAX; break;
+ case EV_SND: bits = dev->sndbit; len = SND_MAX; break;
+ case EV_FF: bits = dev->ffbit; len = FF_MAX; break;
+ case EV_SW: bits = dev->swbit; len = SW_MAX; break;
+ default: return -EINVAL;
+ }
+
+ /*
+ * Work around bugs in userspace programs that like to do
+ * EVIOCGBIT(EV_KEY, KEY_MAX) and not realize that 'len'
+ * should be in bytes, not in bits.
+ */
+ if ((_IOC_NR(cmd) & EV_MAX) == EV_KEY && _IOC_SIZE(cmd) == OLD_KEY_MAX) {
+ len = OLD_KEY_MAX;
+ if (printk_timed_ratelimit(&keymax_warn_time, 10 * 1000))
+ printk(KERN_WARNING
+ "evdev.c(EVIOCGBIT): Suspicious buffer size %u, "
+ "limiting output to %zu bytes. See "
+ "http://userweb.kernel.org/~dtor/eviocgbit-bug.html\n",
+ OLD_KEY_MAX,
+ BITS_TO_LONGS(OLD_KEY_MAX) * sizeof(long));
+ }
+
+ return bits_to_user(bits, len, _IOC_SIZE(cmd), p, compat_mode);
+}
+#undef OLD_KEY_MAX
+
static long evdev_do_ioctl(struct file *file, unsigned int cmd,
void __user *p, int compat_mode)
{
@@ -733,26 +774,8 @@ static long evdev_do_ioctl(struct file *file, unsigned int cmd,
if (_IOC_DIR(cmd) == _IOC_READ) {
- if ((_IOC_NR(cmd) & ~EV_MAX) == _IOC_NR(EVIOCGBIT(0, 0))) {
-
- unsigned long *bits;
- int len;
-
- switch (_IOC_NR(cmd) & EV_MAX) {
-
- case 0: bits = dev->evbit; len = EV_MAX; break;
- case EV_KEY: bits = dev->keybit; len = KEY_MAX; break;
- case EV_REL: bits = dev->relbit; len = REL_MAX; break;
- case EV_ABS: bits = dev->absbit; len = ABS_MAX; break;
- case EV_MSC: bits = dev->mscbit; len = MSC_MAX; break;
- case EV_LED: bits = dev->ledbit; len = LED_MAX; break;
- case EV_SND: bits = dev->sndbit; len = SND_MAX; break;
- case EV_FF: bits = dev->ffbit; len = FF_MAX; break;
- case EV_SW: bits = dev->swbit; len = SW_MAX; break;
- default: return -EINVAL;
- }
- return bits_to_user(bits, len, _IOC_SIZE(cmd), p, compat_mode);
- }
+ if ((_IOC_NR(cmd) & ~EV_MAX) == _IOC_NR(EVIOCGBIT(0, 0)))
+ return handle_eviocgbit(dev, cmd, p, compat_mode);
if (_IOC_NR(cmd) == _IOC_NR(EVIOCGKEY(0)))
return bits_to_user(dev->key, KEY_MAX, _IOC_SIZE(cmd),