Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752648AbdFQGXX (ORCPT ); Sat, 17 Jun 2017 02:23:23 -0400 Received: from smtprelay0095.hostedemail.com ([216.40.44.95]:42487 "EHLO smtprelay.hostedemail.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1750761AbdFQGXV (ORCPT ); Sat, 17 Jun 2017 02:23:21 -0400 X-Session-Marker: 6A6F6540706572636865732E636F6D X-Spam-Summary: 2,0,0,,d41d8cd98f00b204,joe@perches.com,:::::::::::::::::::::,RULES_HIT:1:41:355:379:541:599:960:973:982:988:989:1260:1277:1311:1313:1314:1345:1359:1373:1437:1515:1516:1518:1593:1594:1605:1730:1747:1777:1792:2194:2198:2199:2200:2393:2553:2559:2562:2639:2691:2828:2898:3138:3139:3140:3141:3142:3622:3653:3865:3866:3867:3868:3870:3871:3872:3873:3874:4250:4321:4362:4384:4605:5007:6119:7903:7904:8957:9040:9108:9121:10848:11026:11232:11473:11657:11658:11783:11914:12043:12050:12296:12438:12679:12740:12895:13138:13231:13255:13439:13894:14659:21080:21324:21433:21434:21611:21627:30003:30009:30012:30054:30055:30070:30079:30090:30091,0,RBL:none,CacheIP:none,Bayesian:0.5,0.5,0.5,Netcheck:none,DomainCache:0,MSF:not bulk,SPF:,MSBL:0,DNSBL:none,Custom_rules:0:1:0,LFtime:2,LUA_SUMMARY:none X-HE-Tag: queen28_56f019a286337 X-Filterd-Recvd-Size: 14558 Message-ID: <1497680595.10546.34.camel@perches.com> Subject: Re: endian bitshift defects [ was: staging: fusb302: don't bitshift __le16 type ] From: Joe Perches To: Julia Lawall Cc: Frans Klaver , Greg Kroah-Hartman , kernel-janitors , Guenter Roeck , Yueyao Zhu , Rui Miguel Silva , Guru Das Srinagesh , Javier Martinez Canillas , devel@driverdev.osuosl.org, linux-kernel@vger.kernel.org Date: Fri, 16 Jun 2017 23:23:15 -0700 In-Reply-To: References: <20170616174556.2358-1-fransklaver@gmail.com> <1497653077.10546.23.camel@perches.com> <1497678601.10546.32.camel@perches.com> Content-Type: text/plain; charset="ISO-8859-1" X-Mailer: Evolution 3.22.6-1ubuntu1 Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 12921 Lines: 335 On Sat, 2017-06-17 at 08:00 +0200, Julia Lawall wrote: > On Fri, 16 Jun 2017, Joe Perches wrote: > > On Sat, 2017-06-17 at 07:23 +0200, Julia Lawall wrote: > > > On Fri, 16 Jun 2017, Joe Perches wrote: > > > > On Fri, 2017-06-16 at 19:45 +0200, Frans Klaver wrote: > > > > > The header field in struct pd_message is declared as an __le16 type. The > > > > > data in the message is supposed to be little endian. This means we don't > > > > > have to go and shift the individual bytes into position when we're > > > > > filling the buffer, we can just copy the contents right away. As an > > > > > added benefit we don't get fishy results on big endian systems anymore. > > > > > > > > Thanks for pointing this out. > > > > > > > > There are several instances of this class of error. > > > > > > > > Here's a cocci script to find them. > > > > > > > > This is best used with cocci's --all-includes option like: > > > > > > > > $ spatch --all-includes --very-quiet --sp-file lebe_bitshifts.cocci . > > > > [ many defects...] > > > > Probably would have been better as [ many possible defects... ] > > OK > > > > > $ cat lebe_bitshifts.cocci > > > > @@ > > > > typedef __le16, __le32, __le64,??__be16, __be32, __be64; > > > > { __le16, __le32, __le64,??__be16, __be32, __be64 } a; > > > > expression b; > > > > @@ > > > > > > > > * a << b > > > > [etc...] > > > > > Is this always a problem? > > > > No, not always. > > > > If the CPU is the equivalent endian, the bitshift is fine. > > It can't be known if the code is only compiled on a > > single cpu type. It is rather odd though to use endian > > notation if the code is compiled for a single cpu type. > > Is there some way to know from the code if it is compiled for a single cou > type? No easy way as far as I can tell. I believe it'd require parsing Kconfig. > > > Would it be useful to add this to the scripts > > > in the kernel? > > > > Maybe. > > If there are a lot of false positives, it could be a nuisance... I believe the most likely false positives would be in arch/ code > > btw: is there a way for the operators to be surrounded by > > some \( \| \) or some other bracket style so it could > > be written with a single test? > > > > Something like: > > > > @@ > > typedef __le16, __le32, __le64,??__be16, __be32, __be64; > > { __le16, __le32, __le64,??__be16, __be32, __be64 } a; > > expression b; > > @@ > > > > * a [<<|<<=|>>|>>=] b > > Partly. You can define > > binary operator bop = {<<,>>}; thanks. btw: After a couple hours with this script, I got a segmentation fault Here's the output I got running $ spatch --all-includes --very-quiet --sp-file lebe_bitshifts.cocci . diff -u -p ./net/dsa/tag_qca.c /tmp/nothing/net/dsa/tag_qca.c --- ./net/dsa/tag_qca.c +++ /tmp/nothing/net/dsa/tag_qca.c @@ -84,7 +84,6 @@ static struct sk_buff *qca_tag_rcv(struc hdr = ntohs(*phdr); /* Make sure the version is correct */ - ver = (hdr & QCA_HDR_RECV_VERSION_MASK) >> QCA_HDR_RECV_VERSION_S; if (unlikely(ver != QCA_HDR_VERSION)) return NULL; diff -u -p ./arch/mips/pci/pci-lantiq.c /tmp/nothing/arch/mips/pci/pci-lantiq.c --- ./arch/mips/pci/pci-lantiq.c +++ /tmp/nothing/arch/mips/pci/pci-lantiq.c @@ -151,7 +151,6 @@ static int ltq_pci_startup(struct platfo /* setup the request mask */ req_mask = of_get_property(node, "req-mask", NULL); if (req_mask) - temp_buffer &= ~((*req_mask & 0xf) << 16); else temp_buffer &= ~0xf0000; /* enable internal arbiter */ diff -u -p ./arch/powerpc/platforms/powernv/opal-lpc.c /tmp/nothing/arch/powerpc/platforms/powernv/opal-lpc.c --- ./arch/powerpc/platforms/powernv/opal-lpc.c +++ /tmp/nothing/arch/powerpc/platforms/powernv/opal-lpc.c @@ -44,7 +44,6 @@ static __le16 __opal_lpc_inw(unsigned lo if (opal_lpc_chip_id < 0 || port > 0xfffe) return 0xffff; if (port & 1) - return (__le16)opal_lpc_inb(port) << 8 | opal_lpc_inb(port + 1); rc = opal_lpc_read(opal_lpc_chip_id, OPAL_LPC_IO, port, &data, 2); return rc ? 0xffff : be32_to_cpu(data); } @@ -61,9 +60,6 @@ static __le32 __opal_lpc_inl(unsigned lo if (opal_lpc_chip_id < 0 || port > 0xfffc) return 0xffffffff; if (port & 3) - return (__le32)opal_lpc_inb(port ) << 24 | - (__le32)opal_lpc_inb(port + 1) << 16 | - (__le32)opal_lpc_inb(port + 2) << 8 | opal_lpc_inb(port + 3); rc = opal_lpc_read(opal_lpc_chip_id, OPAL_LPC_IO, port, &data, 4); return rc ? 0xffffffff : be32_to_cpu(data); @@ -86,7 +82,6 @@ static void __opal_lpc_outw(__le16 val, if (opal_lpc_chip_id < 0 || port > 0xfffe) return; if (port & 1) { - opal_lpc_outb(val >> 8, port); opal_lpc_outb(val , port + 1); return; } @@ -103,9 +98,6 @@ static void __opal_lpc_outl(__le32 val, if (opal_lpc_chip_id < 0 || port > 0xfffc) return; if (port & 3) { - opal_lpc_outb(val >> 24, port); - opal_lpc_outb(val >> 16, port + 1); - opal_lpc_outb(val >> 8, port + 2); opal_lpc_outb(val , port + 3); return; } diff -u -p ./drivers/net/geneve.c /tmp/nothing/drivers/net/geneve.c --- ./drivers/net/geneve.c +++ /tmp/nothing/drivers/net/geneve.c @@ -93,8 +93,6 @@ static __be64 vni_to_tunnel_id(const __u static void tunnel_id_to_vni(__be64 tun_id, __u8 *vni) { #ifdef __BIG_ENDIAN - vni[0] = (__force __u8)(tun_id >> 16); - vni[1] = (__force __u8)(tun_id >> 8); vni[2] = (__force __u8)tun_id; #else vni[0] = (__force __u8)((__force u64)tun_id >> 40); diff -u -p ./drivers/net/ethernet/atheros/atl1c/atl1c_main.c /tmp/nothing/drivers/net/ethernet/atheros/atl1c/atl1c_main.c --- ./drivers/net/ethernet/atheros/atl1c/atl1c_main.c +++ /tmp/nothing/drivers/net/ethernet/atheros/atl1c/atl1c_main.c @@ -1785,7 +1785,6 @@ static void atl1c_clean_rfd(struct atl1c u16 rfd_index; struct atl1c_buffer *buffer_info = rfd_ring->buffer_info; - rfd_index = (rrs->word0 >> RRS_RX_RFD_INDEX_SHIFT) & RRS_RX_RFD_INDEX_MASK; for (i = 0; i < num; i++) { buffer_info[rfd_index].skb = NULL; @@ -1816,7 +1815,6 @@ static void atl1c_clean_rx_irq(struct at break; rrs = ATL1C_RRD_DESC(rrd_ring, rrd_ring->next_to_clean); if (likely(RRS_RXD_IS_VALID(rrs->word3))) { - rfd_num = (rrs->word0 >> RRS_RX_RFD_CNT_SHIFT) & RRS_RX_RFD_CNT_MASK; if (unlikely(rfd_num != 1)) /* TODO support mul rfd*/ @@ -1838,11 +1836,9 @@ rrs_checked: continue; } - length = le16_to_cpu((rrs->word3 >> RRS_PKT_SIZE_SHIFT) & RRS_PKT_SIZE_MASK); /* Good Receive */ if (likely(rfd_num == 1)) { - rfd_index = (rrs->word0 >> RRS_RX_RFD_INDEX_SHIFT) & RRS_RX_RFD_INDEX_MASK; buffer_info = &rfd_ring->buffer_info[rfd_index]; pci_unmap_single(pdev, buffer_info->dma, diff -u -p ./drivers/net/ethernet/atheros/atl1e/atl1e_main.c /tmp/nothing/drivers/net/ethernet/atheros/atl1e/atl1e_main.c --- ./drivers/net/ethernet/atheros/atl1e/atl1e_main.c +++ /tmp/nothing/drivers/net/ethernet/atheros/atl1e/atl1e_main.c @@ -1449,7 +1449,6 @@ static void atl1e_clean_rx_irq(struct at } } - packet_size = ((prrs->word1 >> RRS_PKT_SIZE_SHIFT) & RRS_PKT_SIZE_MASK); if (likely(!(netdev->features & NETIF_F_RXFCS))) packet_size -= 4; /* CRC */ @@ -1477,7 +1476,6 @@ static void atl1e_clean_rx_irq(struct at skip_pkt: /* skip current packet whether it's ok or not. */ rx_page->read_offset += - (((u32)((prrs->word1 >> RRS_PKT_SIZE_SHIFT) & RRS_PKT_SIZE_MASK) + sizeof(struct atl1e_recv_ret_status) + 31) & 0xFFFFFFE0); @@ -1716,7 +1714,6 @@ static int atl1e_tx_map(struct atl1e_ada int ring_end; nr_frags = skb_shinfo(skb)->nr_frags; - segment = (tpd->word3 >> TPD_SEGMENT_EN_SHIFT) & TPD_SEGMENT_EN_MASK; if (segment) { /* TSO */ map_len = hdr_len = skb_transport_offset(skb) + tcp_hdrlen(skb); @@ -1831,7 +1828,6 @@ static int atl1e_tx_map(struct atl1e_ada } } - if ((tpd->word3 >> TPD_SEGMENT_EN_SHIFT) & TPD_SEGMENT_EN_MASK) /* note this one is a tcp header */ tpd->word3 |= 1 << TPD_HDRFLAG_SHIFT; /* The last tpd */ diff -u -p ./drivers/net/ethernet/atheros/atlx/atl1.c /tmp/nothing/drivers/net/ethernet/atheros/atlx/atl1.c --- ./drivers/net/ethernet/atheros/atlx/atl1.c +++ /tmp/nothing/drivers/net/ethernet/atheros/atlx/atl1.c @@ -2224,7 +2224,6 @@ static void atl1_tx_map(struct atl1_adap /* put skb in last TPD */ buffer_info->skb = NULL; - retval = (ptpd->word3 >> TPD_SEGMENT_EN_SHIFT) & TPD_SEGMENT_EN_MASK; if (retval) { /* TSO */ hdr_len = skb_transport_offset(skb) + tcp_hdrlen(skb); @@ -2328,7 +2327,6 @@ static void atl1_tx_queue(struct atl1_ad * if this is the first packet in a TSO chain, set * TPD_HDRFLAG, otherwise, clear it. */ - val = (tpd->word3 >> TPD_SEGMENT_EN_SHIFT) & TPD_SEGMENT_EN_MASK; if (val) { if (!j) diff -u -p ./drivers/net/ethernet/3com/3c509.c /tmp/nothing/drivers/net/ethernet/3com/3c509.c --- ./drivers/net/ethernet/3com/3c509.c +++ /tmp/nothing/drivers/net/ethernet/3com/3c509.c @@ -255,9 +255,6 @@ static int el3_isa_id_sequence(__be16 *p ether_addr_equal((u8 *)phys_addr, el3_devs[i]->dev_addr)) { if (el3_debug > 3) pr_debug("3c509 with address %02x %02x %02x %02x %02x %02x was found by ISAPnP\n", - phys_addr[0] & 0xff, phys_addr[0] >> 8, - phys_addr[1] & 0xff, phys_addr[1] >> 8, - phys_addr[2] & 0xff, phys_addr[2] >> 8); /* Set the adaptor tag so that the next card can be found. */ outb(0xd0 + ++current_tag, id_port); return 2; diff -u -p ./drivers/net/ethernet/qualcomm/qca_7k_common.c /tmp/nothing/drivers/net/ethernet/qualcomm/qca_7k_common.c --- ./drivers/net/ethernet/qualcomm/qca_7k_common.c +++ /tmp/nothing/drivers/net/ethernet/qualcomm/qca_7k_common.c @@ -42,7 +42,6 @@ qcafrm_create_header(u8 *buf, u16 length buf[2] = 0xAA; buf[3] = 0xAA; buf[4] = len & 0xff; - buf[5] = (len >> 8) & 0xff; buf[6] = 0; buf[7] = 0; diff -u -p ./drivers/net/ethernet/qlogic/netxen/netxen_nic_init.c /tmp/nothing/drivers/net/ethernet/qlogic/netxen/netxen_nic_init.c --- ./drivers/net/ethernet/qlogic/netxen/netxen_nic_init.c +++ /tmp/nothing/drivers/net/ethernet/qlogic/netxen/netxen_nic_init.c @@ -862,7 +862,6 @@ nx_get_fw_version(struct netxen_adapter if (ret != 3) return 0; - return major + (minor << 8) + (sub << 16); } else return cpu_to_le32(*(u32 *)&fw->data[NX_FW_VERSION_OFFSET]); @@ -877,8 +876,6 @@ nx_get_bios_version(struct netxen_adapte if (adapter->fw_type == NX_UNIFIED_ROMIMAGE) { bios_ver = cpu_to_le32(*((u32 *) (&fw->data[prd_off]) + NX_UNI_BIOS_VERSION_OFF)); - return (bios_ver << 16) + ((bios_ver >> 8) & 0xff00) + - (bios_ver >> 24); } else return cpu_to_le32(*(u32 *)&fw->data[NX_BIOS_VERSION_OFFSET]); diff -u -p ./drivers/net/ethernet/intel/e100.c /tmp/nothing/drivers/net/ethernet/intel/e100.c --- ./drivers/net/ethernet/intel/e100.c +++ /tmp/nothing/drivers/net/ethernet/intel/e100.c @@ -1423,7 +1423,6 @@ static int e100_phy_check_without_mii(st u8 phy_type; int without_mii; - phy_type = (nic->eeprom[eeprom_phy_iface] >> 8) & 0x0f; switch (phy_type) { case NoSuchPhy: /* Non-MII PHY; UNTESTED! */ diff -u -p ./drivers/crypto/sunxi-ss/sun4i-ss-hash.c /tmp/nothing/drivers/crypto/sunxi-ss/sun4i-ss-hash.c --- ./drivers/crypto/sunxi-ss/sun4i-ss-hash.c +++ /tmp/nothing/drivers/crypto/sunxi-ss/sun4i-ss-hash.c @@ -434,7 +434,6 @@ hash_final: if (op->mode == SS_OP_SHA1) { bits = cpu_to_be64(op->byte_count << 3); bf[j++] = bits & 0xffffffff; - bf[j++] = (bits >> 32) & 0xffffffff; } else { bf[j++] = (op->byte_count << 3) & 0xffffffff; bf[j++] = (op->byte_count >> 29) & 0xffffffff; diff -u -p ./drivers/staging/rtl8723bs/core/rtw_wlan_util.c /tmp/nothing/drivers/staging/rtl8723bs/core/rtw_wlan_util.c --- ./drivers/staging/rtl8723bs/core/rtw_wlan_util.c +++ /tmp/nothing/drivers/staging/rtl8723bs/core/rtw_wlan_util.c @@ -2258,9 +2258,6 @@ void rtw_get_current_ip_address(struct a struct in_ifaddr *my_ifa_list = my_ip_ptr->ifa_list; if (my_ifa_list != NULL) { ipaddress[0] = my_ifa_list->ifa_address & 0xFF; - ipaddress[1] = (my_ifa_list->ifa_address >> 8) & 0xFF; - ipaddress[2] = (my_ifa_list->ifa_address >> 16) & 0xFF; - ipaddress[3] = my_ifa_list->ifa_address >> 24; DBG_871X("%s: %d.%d.%d.%d ==========\n", __func__, ipaddress[0], ipaddress[1], ipaddress[2], ipaddress[3]); memcpy(pcurrentip, ipaddress, 4); diff -u -p ./drivers/staging/typec/fusb302/fusb302.c /tmp/nothing/drivers/staging/typec/fusb302/fusb302.c --- ./drivers/staging/typec/fusb302/fusb302.c +++ /tmp/nothing/drivers/staging/typec/fusb302/fusb302.c @@ -1040,7 +1040,6 @@ static int fusb302_pd_send_message(struc /* packsym tells the FUSB302 chip that the next X bytes are payload */ buf[pos++] = FUSB302_TKN_PACKSYM | (len & 0x1F); buf[pos++] = msg->header & 0xFF; - buf[pos++] = (msg->header >> 8) & 0xFF; len -= 2; memcpy(&buf[pos], msg->payload, len); Segmentation fault (core dumped)