From patchwork Thu Feb 20 13:20:17 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Gustavo A. R. Silva" X-Patchwork-Id: 11394179 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 3B5F9138D for ; Thu, 20 Feb 2020 13:41:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CB5D7222C4 for ; Thu, 20 Feb 2020 13:41:30 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=embeddedor.com header.i=@embeddedor.com header.b="WkfFysgN" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728225AbgBTNla (ORCPT ); Thu, 20 Feb 2020 08:41:30 -0500 Received: from gateway20.websitewelcome.com ([192.185.49.40]:43073 "EHLO gateway20.websitewelcome.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728028AbgBTNl3 (ORCPT ); Thu, 20 Feb 2020 08:41:29 -0500 X-Greylist: delayed 1434 seconds by postgrey-1.27 at vger.kernel.org; Thu, 20 Feb 2020 08:41:29 EST Received: from cm12.websitewelcome.com (cm12.websitewelcome.com [100.42.49.8]) by gateway20.websitewelcome.com (Postfix) with ESMTP id 46501400C76B4 for ; Thu, 20 Feb 2020 06:03:34 -0600 (CST) Received: from gator4166.hostgator.com ([108.167.133.22]) by cmsmtp with SMTP id 4lhujvy4rvBMd4lhvjt417; Thu, 20 Feb 2020 07:17:35 -0600 X-Authority-Reason: nr=8 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=embeddedor.com; s=default; h=Content-Type:MIME-Version:Message-ID:Subject: Cc:To:From:Date:Sender:Reply-To:Content-Transfer-Encoding:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:In-Reply-To:References:List-Id:List-Help:List-Unsubscribe: List-Subscribe:List-Post:List-Owner:List-Archive; bh=z1nik/sLu1rWe1J16Res5lnb/I2LgkK5u9A27nU3ovY=; b=WkfFysgNRAo+UWyPV48G7KJxrr QdENWL2WZlpyux/qZ58g4YNrrdODyN/3/5cURbxev/i8i5y9/fNa5+YyCQqKV2OF1pfuypyeMs6Lw Y92EXY+tFP+JEI7zuhJ9u/F6GFh7jn0iMXQaIrEbM3+gaYf84/xhX9DUaDN6ZeBMHJoz95ht6epCx mwmOwqv+ZxjhNYtjful6ZZFIlk487O59qsgsT0VioFBEeGpH9HBiP4Jg6ntzqB0+xPpRVA0H+Bz77 pcSB4jcakHBCa6z+/lfyyqg19of677C4vhYE8WCxtJPfP7j9vA8WbGR6YsuqF2vp5ilM+33vEmh8f GwMVz72w==; Received: from [201.144.174.47] (port=28175 helo=embeddedor) by gator4166.hostgator.com with esmtpa (Exim 4.92) (envelope-from ) id 1j4lht-003Yvz-1W; Thu, 20 Feb 2020 07:17:33 -0600 Date: Thu, 20 Feb 2020 07:20:17 -0600 From: "Gustavo A. R. Silva" To: Greg Kroah-Hartman , Minas Harutyunyan , Alan Stern , Thierry Reding , Jonathan Hunter , Mathias Nyman , Matthias Brugger , Johan Hovold , Felipe Balbi Cc: linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, linux-tegra@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-mediatek@lists.infradead.org, "Gustavo A. R. Silva" Subject: [PATCH] USB: Replace zero-length array with flexible-array member Message-ID: <20200220132017.GA29262@embeddedor> MIME-Version: 1.0 Content-Disposition: inline User-Agent: Mutt/1.9.4 (2018-02-28) X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - gator4166.hostgator.com X-AntiAbuse: Original Domain - vger.kernel.org X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - embeddedor.com X-BWhitelist: no X-Source-IP: 201.144.174.47 X-Source-L: No X-Exim-ID: 1j4lht-003Yvz-1W X-Source: X-Source-Args: X-Source-Dir: X-Source-Sender: (embeddedor) [201.144.174.47]:28175 X-Source-Auth: gustavo@embeddedor.com X-Email-Count: 10 X-Source-Cap: Z3V6aWRpbmU7Z3V6aWRpbmU7Z2F0b3I0MTY2Lmhvc3RnYXRvci5jb20= X-Local-Domain: yes Sender: linux-usb-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org The current codebase makes use of the zero-length array language extension to the C90 standard, but the preferred mechanism to declare variable-length types such as these ones is a flexible array member[1][2], introduced in C99: struct foo { int stuff; struct boo array[]; }; By making use of the mechanism above, we will get a compiler warning in case the flexible array does not occur last in the structure, which will help us prevent some kind of undefined behavior bugs from being inadvertently introduced[3] to the codebase from now on. Also, notice that, dynamic memory allocations won't be affected by this change: "Flexible array members have incomplete type, and so the sizeof operator may not be applied. As a quirk of the original implementation of zero-length arrays, sizeof evaluates to zero."[1] This issue was found with the help of Coccinelle. [1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html [2] https://github.com/KSPP/linux/issues/21 [3] commit 76497732932f ("cxgb3/l2t: Fix undefined behaviour") Signed-off-by: Gustavo A. R. Silva --- drivers/usb/atm/usbatm.h | 2 +- drivers/usb/dwc2/hcd.h | 2 +- drivers/usb/host/ehci-tegra.c | 2 +- drivers/usb/host/ehci.h | 4 ++-- drivers/usb/host/fotg210.h | 2 +- drivers/usb/host/ohci.h | 4 ++-- drivers/usb/host/xhci-mtk.h | 2 +- drivers/usb/host/xhci.h | 4 ++-- drivers/usb/serial/io_usbvend.h | 4 ++-- drivers/usb/serial/ti_usb_3410_5052.c | 4 ++-- include/linux/usb.h | 4 ++-- include/linux/usb/audio-v2.h | 2 +- include/linux/usb/audio-v3.h | 2 +- include/linux/usb/gadget.h | 2 +- include/linux/usb/hcd.h | 2 +- include/linux/usbdevice_fs.h | 2 +- 16 files changed, 22 insertions(+), 22 deletions(-) diff --git a/drivers/usb/atm/usbatm.h b/drivers/usb/atm/usbatm.h index d3bdc4cc47aa..8725755bd53d 100644 --- a/drivers/usb/atm/usbatm.h +++ b/drivers/usb/atm/usbatm.h @@ -164,7 +164,7 @@ struct usbatm_data { unsigned char *cell_buf; /* holds partial rx cell */ unsigned int buf_usage; - struct urb *urbs[0]; + struct urb *urbs[]; }; static inline void *to_usbatm_driver_data(struct usb_interface *intf) diff --git a/drivers/usb/dwc2/hcd.h b/drivers/usb/dwc2/hcd.h index 8ca6d12a6f57..1224fa9df604 100644 --- a/drivers/usb/dwc2/hcd.h +++ b/drivers/usb/dwc2/hcd.h @@ -199,7 +199,7 @@ struct dwc2_hcd_urb { u32 flags; u16 interval; struct dwc2_hcd_pipe_info pipe_info; - struct dwc2_hcd_iso_packet_desc iso_descs[0]; + struct dwc2_hcd_iso_packet_desc iso_descs[]; }; /* Phases for control transfers */ diff --git a/drivers/usb/host/ehci-tegra.c b/drivers/usb/host/ehci-tegra.c index d6433f206c17..10d51daa6a1b 100644 --- a/drivers/usb/host/ehci-tegra.c +++ b/drivers/usb/host/ehci-tegra.c @@ -282,7 +282,7 @@ static int tegra_ehci_hub_control( struct dma_aligned_buffer { void *kmalloc_ptr; void *old_xfer_buffer; - u8 data[0]; + u8 data[]; }; static void free_dma_aligned_buffer(struct urb *urb) diff --git a/drivers/usb/host/ehci.h b/drivers/usb/host/ehci.h index ac5e967907d1..229b3de319e6 100644 --- a/drivers/usb/host/ehci.h +++ b/drivers/usb/host/ehci.h @@ -255,7 +255,7 @@ struct ehci_hcd { /* one per controller */ struct list_head tt_list; /* platform-specific data -- must come last */ - unsigned long priv[0] __aligned(sizeof(s64)); + unsigned long priv[] __aligned(sizeof(s64)); }; /* convert between an HCD pointer and the corresponding EHCI_HCD */ @@ -460,7 +460,7 @@ struct ehci_iso_sched { struct list_head td_list; unsigned span; unsigned first_packet; - struct ehci_iso_packet packet[0]; + struct ehci_iso_packet packet[]; }; /* diff --git a/drivers/usb/host/fotg210.h b/drivers/usb/host/fotg210.h index 1b4db95e5c43..6cee40ec65b4 100644 --- a/drivers/usb/host/fotg210.h +++ b/drivers/usb/host/fotg210.h @@ -490,7 +490,7 @@ struct fotg210_iso_packet { struct fotg210_iso_sched { struct list_head td_list; unsigned span; - struct fotg210_iso_packet packet[0]; + struct fotg210_iso_packet packet[]; }; /* diff --git a/drivers/usb/host/ohci.h b/drivers/usb/host/ohci.h index b015b00774b2..27c26ca10bfd 100644 --- a/drivers/usb/host/ohci.h +++ b/drivers/usb/host/ohci.h @@ -337,7 +337,7 @@ typedef struct urb_priv { u16 length; // # tds in this request u16 td_cnt; // tds already serviced struct list_head pending; - struct td *td [0]; // all TDs in this request + struct td *td[]; // all TDs in this request } urb_priv_t; @@ -435,7 +435,7 @@ struct ohci_hcd { struct dentry *debug_dir; /* platform-specific data -- must come last */ - unsigned long priv[0] __aligned(sizeof(s64)); + unsigned long priv[] __aligned(sizeof(s64)); }; diff --git a/drivers/usb/host/xhci-mtk.h b/drivers/usb/host/xhci-mtk.h index 5ac458b7d2e0..acd56517215a 100644 --- a/drivers/usb/host/xhci-mtk.h +++ b/drivers/usb/host/xhci-mtk.h @@ -95,7 +95,7 @@ struct mu3h_sch_ep_info { u32 pkts; u32 cs_count; u32 burst_mode; - u32 bw_budget_table[0]; + u32 bw_budget_table[]; }; #define MU3C_U3_PORT_MAX 4 diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h index 3ecee10fdcdc..685180e1b98a 100644 --- a/drivers/usb/host/xhci.h +++ b/drivers/usb/host/xhci.h @@ -1642,7 +1642,7 @@ struct xhci_scratchpad { struct urb_priv { int num_tds; int num_tds_done; - struct xhci_td td[0]; + struct xhci_td td[]; }; /* @@ -1901,7 +1901,7 @@ struct xhci_hcd { void *dbc; /* platform-specific data -- must come last */ - unsigned long priv[0] __aligned(sizeof(s64)); + unsigned long priv[] __aligned(sizeof(s64)); }; /* Platform specific overrides to generic XHCI hc_driver ops */ diff --git a/drivers/usb/serial/io_usbvend.h b/drivers/usb/serial/io_usbvend.h index c38e87ac5ea9..0d1a5bb4636e 100644 --- a/drivers/usb/serial/io_usbvend.h +++ b/drivers/usb/serial/io_usbvend.h @@ -593,7 +593,7 @@ struct ti_i2c_desc { __u8 Type; // Type of descriptor __le16 Size; // Size of data only not including header __u8 CheckSum; // Checksum (8 bit sum of data only) - __u8 Data[0]; // Data starts here + __u8 Data[]; // Data starts here } __attribute__((packed)); // for 5152 devices only (type 2 record) @@ -601,7 +601,7 @@ struct ti_i2c_desc { struct ti_i2c_firmware_rec { __u8 Ver_Major; // Firmware Major version number __u8 Ver_Minor; // Firmware Minor version number - __u8 Data[0]; // Download starts here + __u8 Data[]; // Download starts here } __attribute__((packed)); diff --git a/drivers/usb/serial/ti_usb_3410_5052.c b/drivers/usb/serial/ti_usb_3410_5052.c index ef23acc9b9ce..73075b9351c5 100644 --- a/drivers/usb/serial/ti_usb_3410_5052.c +++ b/drivers/usb/serial/ti_usb_3410_5052.c @@ -219,7 +219,7 @@ struct ti_write_data_bytes { u8 bDataCounter; __be16 wBaseAddrHi; __be16 wBaseAddrLo; - u8 bData[0]; + u8 bData[]; } __packed; struct ti_read_data_request { @@ -234,7 +234,7 @@ struct ti_read_data_bytes { __u8 bCmdCode; __u8 bModuleId; __u8 bErrorCode; - __u8 bData[0]; + __u8 bData[]; } __packed; /* Interrupt struct */ diff --git a/include/linux/usb.h b/include/linux/usb.h index ca1a5f1e1c5e..9f3c721c70dc 100644 --- a/include/linux/usb.h +++ b/include/linux/usb.h @@ -325,7 +325,7 @@ struct usb_interface_cache { /* variable-length array of alternate settings for this interface, * stored in no particular order */ - struct usb_host_interface altsetting[0]; + struct usb_host_interface altsetting[]; }; #define ref_to_usb_interface_cache(r) \ container_of(r, struct usb_interface_cache, ref) @@ -1589,7 +1589,7 @@ struct urb { int error_count; /* (return) number of ISO errors */ void *context; /* (in) context for completion */ usb_complete_t complete; /* (in) completion routine */ - struct usb_iso_packet_descriptor iso_frame_desc[0]; + struct usb_iso_packet_descriptor iso_frame_desc[]; /* (in) ISO ONLY */ }; diff --git a/include/linux/usb/audio-v2.h b/include/linux/usb/audio-v2.h index cb9900b34b67..ead8c9a47c6a 100644 --- a/include/linux/usb/audio-v2.h +++ b/include/linux/usb/audio-v2.h @@ -153,7 +153,7 @@ struct uac2_feature_unit_descriptor { __u8 bSourceID; /* bmaControls is actually u32, * but u8 is needed for the hybrid parser */ - __u8 bmaControls[0]; /* variable length */ + __u8 bmaControls[]; /* variable length */ } __attribute__((packed)); /* 4.7.2.10 Effect Unit Descriptor */ diff --git a/include/linux/usb/audio-v3.h b/include/linux/usb/audio-v3.h index 6b708434b7f9..c69a6f2e6837 100644 --- a/include/linux/usb/audio-v3.h +++ b/include/linux/usb/audio-v3.h @@ -109,7 +109,7 @@ struct uac3_feature_unit_descriptor { __u8 bSourceID; /* bmaControls is actually u32, * but u8 is needed for the hybrid parser */ - __u8 bmaControls[0]; /* variable length */ + __u8 bmaControls[]; /* variable length */ /* wFeatureDescrStr omitted */ } __attribute__((packed)); diff --git a/include/linux/usb/gadget.h b/include/linux/usb/gadget.h index 124462d65eac..9411c08a5c7e 100644 --- a/include/linux/usb/gadget.h +++ b/include/linux/usb/gadget.h @@ -767,7 +767,7 @@ struct usb_gadget_strings { struct usb_gadget_string_container { struct list_head list; - u8 *stash[0]; + u8 *stash[]; }; /* put descriptor for string with that id into buf (buflen >= 256) */ diff --git a/include/linux/usb/hcd.h b/include/linux/usb/hcd.h index 712b2a603645..e12105ed3834 100644 --- a/include/linux/usb/hcd.h +++ b/include/linux/usb/hcd.h @@ -228,7 +228,7 @@ struct usb_hcd { /* The HC driver's private data is stored at the end of * this structure. */ - unsigned long hcd_priv[0] + unsigned long hcd_priv[] __attribute__ ((aligned(sizeof(s64)))); }; diff --git a/include/linux/usbdevice_fs.h b/include/linux/usbdevice_fs.h index 79aab0065ec8..14ea197ce37f 100644 --- a/include/linux/usbdevice_fs.h +++ b/include/linux/usbdevice_fs.h @@ -69,7 +69,7 @@ struct usbdevfs_urb32 { compat_int_t error_count; compat_uint_t signr; compat_caddr_t usercontext; /* unused */ - struct usbdevfs_iso_packet_desc iso_frame_desc[0]; + struct usbdevfs_iso_packet_desc iso_frame_desc[]; }; struct usbdevfs_ioctl32 {