cciss: Fix race between disk-adding code and interrupt handler

[safe/jmp/linux-2.6] / drivers / firewire / fw-cdev.c

diff --git a/drivers/firewire/fw-cdev.c b/drivers/firewire/fw-cdev.c
index 46bc197..4a54192 100644 (file)
--- a/drivers/firewire/fw-cdev.c
+++ b/drivers/firewire/fw-cdev.c
@@ -269,21 +269,28 @@ static int ioctl_get_info(struct client *client, void *buffer)
 {
        struct fw_cdev_get_info *get_info = buffer;
        struct fw_cdev_event_bus_reset bus_reset;
+       unsigned long ret = 0;
 
        client->version = get_info->version;
        get_info->version = FW_CDEV_VERSION;
 
+       down_read(&fw_device_rwsem);
+
        if (get_info->rom != 0) {
                void __user *uptr = u64_to_uptr(get_info->rom);
                size_t want = get_info->rom_length;
                size_t have = client->device->config_rom_length * 4;
 
-               if (copy_to_user(uptr, client->device->config_rom,
-                                min(want, have)))
-                       return -EFAULT;
+               ret = copy_to_user(uptr, client->device->config_rom,
+                                  min(want, have));
        }
        get_info->rom_length = client->device->config_rom_length * 4;
 
+       up_read(&fw_device_rwsem);
+
+       if (ret != 0)
+               return -EFAULT;
+
        client->bus_reset_closure = get_info->bus_reset_closure;
        if (get_info->bus_reset != 0) {
                void __user *uptr = u64_to_uptr(get_info->bus_reset);