slightly reduce idiocy in drivers/staging/bcm/Misc.c

a) vfs_llseek() does *not* access userland pointers of any kind
b) neither does filp_close(), for that matter
c) ... nor filp_open()
d) vfs_read() does, but we do have a wrapper for that (kernel_read()),
so there's no need to reinvent it.
e) passing current->files to filp_close() on something that never
had been in descriptor table is pointless.

ISAGN: voodoo dolls to be used on voodoo programmers...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

drivers/staging/bcm/Misc.c

@@ -157,12 +157,7 @@ static int create_worker_threads(PMINI_ADAPTER psAdapter)
 
 static struct file *open_firmware_file(PMINI_ADAPTER Adapter, const char *path)
 {
-	struct file *flp = NULL;
-	mm_segment_t oldfs;
-	oldfs = get_fs();
-	set_fs(get_ds());
-	flp = filp_open(path, O_RDONLY, S_IRWXU);
-	set_fs(oldfs);
+	struct file *flp = filp_open(path, O_RDONLY, S_IRWXU);
 	if (IS_ERR(flp)) {
 		pr_err(DRV_NAME "Unable To Open File %s, err %ld", path, PTR_ERR(flp));
 		flp = NULL;
@@ -183,14 +178,12 @@ static int BcmFileDownload(PMINI_ADAPTER Adapter, const char *path, unsigned int
 {
 	int errorno = 0;
 	struct file *flp = NULL;
-	mm_segment_t oldfs;
 	struct timeval tv = {0};
 
 	flp = open_firmware_file(Adapter, path);
 	if (!flp) {
-		errorno = -ENOENT;
 		BCM_DEBUG_PRINT(Adapter, DBG_TYPE_INITEXIT, MP_INIT, DBG_LVL_ALL, "Unable to Open %s\n", path);
-		goto exit_download;
+		return -ENOENT;
 	}
 	BCM_DEBUG_PRINT(Adapter, DBG_TYPE_INITEXIT, MP_INIT, DBG_LVL_ALL, "Opened file is = %s and length =0x%lx to be downloaded at =0x%x", path, (unsigned long)flp->f_dentry->d_inode->i_size, loc);
 	do_gettimeofday(&tv);
@@ -201,10 +194,7 @@ static int BcmFileDownload(PMINI_ADAPTER Adapter, const char *path, unsigned int
 		errorno = -EIO;
 		goto exit_download;
 	}
-	oldfs = get_fs();
-	set_fs(get_ds());
 	vfs_llseek(flp, 0, 0);
-	set_fs(oldfs);
 	if (Adapter->bcm_file_readback_from_chip(Adapter->pvInterfaceAdapter, flp, loc)) {
 		BCM_DEBUG_PRINT(Adapter, DBG_TYPE_INITEXIT, MP_INIT, DBG_LVL_ALL, "Failed to read back firmware!");
 		errorno = -EIO;
@@ -212,12 +202,7 @@ static int BcmFileDownload(PMINI_ADAPTER Adapter, const char *path, unsigned int
 	}
 
 exit_download:
-	oldfs = get_fs();
-	set_fs(get_ds());
-	if (flp && !(IS_ERR(flp)))
-		filp_close(flp, current->files);
-	set_fs(oldfs);
-
+	filp_close(flp, NULL);
 	return errorno;
 }
 
@@ -1080,10 +1065,8 @@ OUT:
 static int bcm_parse_target_params(PMINI_ADAPTER Adapter)
 {
 	struct file *flp = NULL;
-	mm_segment_t oldfs = {0};
 	char *buff;
 	int len = 0;
-	loff_t pos = 0;
 
 	buff = kmalloc(BUFFER_1K, GFP_KERNEL);
 	if (!buff)
@@ -1103,20 +1086,16 @@ static int bcm_parse_target_params(PMINI_ADAPTER Adapter)
 		Adapter->pstargetparams = NULL;
 		return -ENOENT;
 	}
-	oldfs = get_fs();
-	set_fs(get_ds());
-	len = vfs_read(flp, (void __user __force *)buff, BUFFER_1K, &pos);
-	set_fs(oldfs);
+	len = kernel_read(flp, 0, buff, BUFFER_1K);
+	filp_close(flp, NULL);
 
 	if (len != sizeof(STARGETPARAMS)) {
 		BCM_DEBUG_PRINT(Adapter, DBG_TYPE_INITEXIT, MP_INIT, DBG_LVL_ALL, "Mismatch in Target Param Structure!\n");
 		kfree(buff);
 		kfree(Adapter->pstargetparams);
 		Adapter->pstargetparams = NULL;
-		filp_close(flp, current->files);
 		return -ENOENT;
 	}
-	filp_close(flp, current->files);
 
 	/* Check for autolink in config params */
 	/*