- 09 Jun, 2017 2 commits
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Stephane Grosjean authored
This patch fixes two uninitialized symbol warnings in the new code adding support of the PEAK-System PCAN-PCI Express FD boards, in the socket-CAN network protocol family. Signed-off-by: Stephane Grosjean <s.grosjean@peak-system.com> Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
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Marc Kleine-Budde authored
In OOM situations where no skb can be allocated, can_change_state() may be called with cf == NULL. As this function updates the state and error statistics it's not an option to skip the call to can_change_state() in OOM situations. This patch makes can_change_state() robust, so that it can be called with cf == NULL. Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
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- 08 Jun, 2017 21 commits
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David Ahern authored
Commit 1aa6c4f6 ("net: vrf: Add l3mdev rules on first device create") adds the l3mdev FIB rule the first time a VRF device is created. However, it only creates the rule once and only in the namespace the first device is created - which may not be init_net. Fix by using the net_generic capability to make the add_fib_rules flag per network namespace. Fixes: 1aa6c4f6 ("net: vrf: Add l3mdev rules on first device create") Reported-by: Petr Machata <petrm@mellanox.com> Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
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Daniel Borkmann authored
I noticed that test_l4lb was failing in selftests: # ./test_progs test_pkt_access:PASS:ipv4 77 nsec test_pkt_access:PASS:ipv6 44 nsec test_xdp:PASS:ipv4 2933 nsec test_xdp:PASS:ipv6 1500 nsec test_l4lb:PASS:ipv4 377 nsec test_l4lb:PASS:ipv6 544 nsec test_l4lb:FAIL:stats 6297600000 200000 test_tcp_estats:PASS: 0 nsec Summary: 7 PASSED, 1 FAILED Tracking down the issue actually revealed that endianness selection in bpf_endian.h is broken when compiled with clang with bpf target. test_pkt_access.c, test_l4lb.c is compiled with __BYTE_ORDER as __BIG_ENDIAN, test_xdp.c as __LITTLE_ENDIAN! test_l4lb noticeably fails, because the test accounts bytes via bpf_ntohs(ip6h->payload_len) and bpf_ntohs(iph->tot_len), and compares them against a defined value and given a wrong endianness, the test outcome is different, of course. Turns out that there are actually two bugs: i) when we do __BYTE_ORDER comparison with __LITTLE_ENDIAN/__BIG_ENDIAN, then depending on the include order we see different outcomes. Reason is that __BYTE_ORDER is undefined due to missing endian.h include. Before we include the asm/byteorder.h (e.g. through linux/in.h), then __BYTE_ORDER equals __LITTLE_ENDIAN since both are undefined, after the include which correctly pulls in linux/byteorder/little_endian.h, __LITTLE_ENDIAN is defined, but given __BYTE_ORDER is still undefined, we match on __BYTE_ORDER equals to __BIG_ENDIAN since __BIG_ENDIAN is also undefined at that point, sigh. ii) But even that would be wrong, since when compiling the test cases with clang, one can select between bpfeb and bpfel targets for cross compilation. Hence, we can also not rely on what the system's endian.h provides, but we need to look at the compiler's defined endianness. The compiler defines __BYTE_ORDER__, and we can match __ORDER_LITTLE_ENDIAN__ and __ORDER_BIG_ENDIAN__, which also reflects targets bpf (native), bpfel, bpfeb correctly, thus really only rely on that. After patch: # ./test_progs test_pkt_access:PASS:ipv4 74 nsec test_pkt_access:PASS:ipv6 42 nsec test_xdp:PASS:ipv4 2340 nsec test_xdp:PASS:ipv6 1461 nsec test_l4lb:PASS:ipv4 400 nsec test_l4lb:PASS:ipv6 530 nsec test_tcp_estats:PASS: 0 nsec Summary: 7 PASSED, 0 FAILED Fixes: 43bcf707 ("bpf: fix _htons occurences in test_progs") Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
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Nicolas Dichtel authored
Each time a new speed is added, the bonding 802.3ad isn't updated. Add a comment to remind the developer to update this driver. Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com> Acked-by: Andy Gospodarek <andy@greyhouse.net> Signed-off-by: David S. Miller <davem@davemloft.net>
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Nicolas Dichtel authored
This patch adds 14 Gbps enum definition, and fixes aggregated bandwidth calculation based on above slave links. Fixes: 0d7e2d21 ("IB/ipoib: add get_link_ksettings in ethtool") Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com> Acked-by: Andy Gospodarek <andy@greyhouse.net> Signed-off-by: David S. Miller <davem@davemloft.net>
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Thibaut Collet authored
This patch adds [5|50] Gbps enum definition, and fixes aggregated bandwidth calculation based on above slave links. Fixes: c9a70d43 ("net-next: ethtool: Added port speed macros.") Signed-off-by: Thibaut Collet <thibaut.collet@6wind.com> Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com> Acked-by: Andy Gospodarek <andy@greyhouse.net> Signed-off-by: David S. Miller <davem@davemloft.net>
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Nicolas Dichtel authored
The first netlink attribute (value 0) must always be defined as none/unspec. Because we cannot change an existing UAPI, I add a comment to point the mistake and avoid to propagate it in a new ovs API in the future. Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com> Signed-off-by: David S. Miller <davem@davemloft.net>
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Arnd Bergmann authored
While discussing the possible merits of clang warning about unused initialized functions, I found one function that was clearly meant to be called but never actually is. __ila_hash_secret_init() initializes the hash value for the ila locator, apparently this is intended to prevent hash collision attacks, but this ends up being a read-only zero constant since there is no caller. I could find no indication of why it was never called, the earliest patch submission for the module already was like this. If my interpretation is right, we certainly want to backport the patch to stable kernels as well. I considered adding it to the ila_xlat_init callback, but for best effect the random data is read as late as possible, just before it is first used. The underlying net_get_random_once() is already highly optimized to avoid overhead when called frequently. Fixes: 7f00feaf ("ila: Add generic ILA translation facility") Cc: stable@vger.kernel.org Link: https://www.spinics.net/lists/kernel/msg2527243.htmlSigned-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: David S. Miller <davem@davemloft.net>
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David S. Miller authored
drivers/staging/rtl8723bs/os_dep/ioctl_cfg80211.c: In function ‘rtw_cfg80211_add_monitor_if’: drivers/staging/rtl8723bs/os_dep/ioctl_cfg80211.c:2670:10: error: ‘struct net_device’ has no member named ‘destructor’ mon_ndev->destructor = rtw_ndev_destructor; ^ Signed-off-by: David S. Miller <davem@davemloft.net>
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David S. Miller authored
Stephen Hemminger says: ==================== netvsc: bug fixes These are bugfixes for netvsc driver in 4.12. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
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stephen hemminger authored
The work queue and handling of network filter parameters should be in rndis_device. This gets rid of warning from RCU checks, eliminates a race and cleans up code. Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com> Signed-off-by: David S. Miller <davem@davemloft.net>
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stephen hemminger authored
The ndo_poll_controller function needs to schedule NAPI to pick up arriving packets and send completions. Otherwise no data will ever be received. For simple case of netconsole, it also will allow send completions to happen. Without this netpoll will eventually get stuck. Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com> Signed-off-by: David S. Miller <davem@davemloft.net>
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stephen hemminger authored
The ethtool info command calls the netvsc get_sset_count with RTNL but not with RCU. Which causes warning: drivers/net/hyperv/netvsc_drv.c:1010 suspicious rcu_dereference_check() usage! Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com> Signed-off-by: David S. Miller <davem@davemloft.net>
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David Ahern authored
Roopa reported attempts to delete a bond device that is referenced in a multipath route is hanging: $ ifdown bond2 # ifupdown2 command that deletes virtual devices unregister_netdevice: waiting for bond2 to become free. Usage count = 2 Steps to reproduce: echo 1 > /proc/sys/net/ipv6/conf/all/ignore_routes_with_linkdown ip link add dev bond12 type bond ip link add dev bond13 type bond ip addr add 2001:db8:2::0/64 dev bond12 ip addr add 2001:db8:3::0/64 dev bond13 ip route add 2001:db8:33::0/64 nexthop via 2001:db8:2::2 nexthop via 2001:db8:3::2 ip link del dev bond12 ip link del dev bond13 The root cause is the recent change to keep routes on a linkdown. Update the check to detect when the device is unregistering and release the route for that case. Fixes: a1a22c12 ("net: ipv6: Keep nexthop of multipath route on admin down") Reported-by: Roopa Prabhu <roopa@cumulusnetworks.com> Signed-off-by: David Ahern <dsahern@gmail.com> Acked-by: Roopa Prabhu <roopa@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
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Mintz, Yuval authored
Some of the structure's fields are not initialized by the rtnetlink. If driver doesn't set those in ndo_get_vf_config(), they'd leak memory to user. Signed-off-by: Yuval Mintz <Yuval.Mintz@cavium.com> CC: Michal Schmidt <mschmidt@redhat.com> Reviewed-by: Greg Rose <gvrose8192@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
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Mateusz Jurczyk authored
Verify that the length of the socket buffer is sufficient to cover the nlmsghdr structure before accessing the nlh->nlmsg_len field for further input sanitization. If the client only supplies 1-3 bytes of data in sk_buff, then nlh->nlmsg_len remains partially uninitialized and contains leftover memory from the corresponding kernel allocation. Operating on such data may result in indeterminate evaluation of the nlmsg_len < sizeof(*nlh) expression. The bug was discovered by a runtime instrumentation designed to detect use of uninitialized memory in the kernel. The patch prevents this and other similar tools (e.g. KMSAN) from flagging this behavior in the future. Signed-off-by: Mateusz Jurczyk <mjurczyk@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
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David S. Miller authored
This reverts commit 85eac2ba. There is an updated version of this fix which we should use instead. Signed-off-by: David S. Miller <davem@davemloft.net>
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Christian Lamparter authored
emac_mdio_read_link() was not copying the requested phy settings back into the emac driver's own phy api. This has caused a link speed mismatch issue for the AR8035 as the emac driver kept trying to connect with 10/100MBps on a 1GBit/s link. This patch also unifies shared code between emac_setup_aneg() and emac_mdio_setup_forced(). And furthermore it removes a chunk of emac_mdio_init_phy(), that was copying the same data into itself. Signed-off-by: Christian Lamparter <chunkeey@googlemail.com> Reviewed-by: Andrew Lunn <andrew@lunn.ch> Signed-off-by: David S. Miller <davem@davemloft.net>
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Christian Lamparter authored
This patch fixes a problem where the AR8035 PHY can't be detected on an Cisco Meraki MR24, if the ethernet cable is not connected on boot. Russell Senior provided steps to reproduce the issue: |Disconnect ethernet cable, apply power, wait until device has booted, |plug in ethernet, check for interfaces, no eth0 is listed. | |This appears to be a problem during probing of the AR8035 Phy chip. |When ethernet has no link, the phy detection fails, and eth0 is not |created. Plugging ethernet later has no effect, because there is no |interface as far as the kernel is concerned. The relevant part of |the boot log looks like this: |this is the failing case: | |[ 0.876611] /plb/opb/emac-rgmii@ef601500: input 0 in RGMII mode |[ 0.882532] /plb/opb/ethernet@ef600c00: reset timeout |[ 0.888546] /plb/opb/ethernet@ef600c00: can't find PHY! |and the succeeding case: | |[ 0.876672] /plb/opb/emac-rgmii@ef601500: input 0 in RGMII mode |[ 0.883952] eth0: EMAC-0 /plb/opb/ethernet@ef600c00, MAC 00:01:.. |[ 0.890822] eth0: found Atheros 8035 Gigabit Ethernet PHY (0x01) Based on the comment and the commit message of commit 23fbb5a8 ("emac: Fix EMAC soft reset on 460EX/GT"). This is because the AR8035 PHY doesn't provide the TX Clock, if the ethernet cable is not attached. This causes the reset to timeout and the PHY detection code in emac_init_phy() is unable to detect the AR8035 PHY. As a result, the emac driver bails out early and the user left with no ethernet. In order to stay compatible with existing configurations, the driver tries the current reset approach at first. Only if the first attempt timed out, it does perform one more retry with the clock temporarily switched to the internal source for just the duration of the reset. LEDE-Bug: #687 <https://bugs.lede-project.org/index.php?do=details&task_id=687> Cc: Chris Blake <chrisrblake93@gmail.com> Reported-by: Russell Senior <russell@personaltelco.net> Fixes: 23fbb5a8 ("emac: Fix EMAC soft reset on 460EX/GT") Signed-off-by: Christian Lamparter <chunkeey@googlemail.com> Reviewed-by: Andrew Lunn <andrew@lunn.ch> Signed-off-by: David S. Miller <davem@davemloft.net>
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Mateusz Jurczyk authored
Verify that the length of the socket buffer is sufficient to cover the entire nlh->nlmsg_len field before accessing that field for further input sanitization. If the client only supplies 1-3 bytes of data in sk_buff, then nlh->nlmsg_len remains partially uninitialized and contains leftover memory from the corresponding kernel allocation. Operating on such data may result in indeterminate evaluation of the nlmsg_len < sizeof(*nlh) expression. The bug was discovered by a runtime instrumentation designed to detect use of uninitialized memory in the kernel. The patch prevents this and other similar tools (e.g. KMSAN) from flagging this behavior in the future. Signed-off-by: Mateusz Jurczyk <mjurczyk@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
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David S. Miller authored
> ../drivers/hsi/clients/ssi_protocol.c:1069:5: error: 'struct net_device' has no member named 'destructor' Reported-by: Mark Brown <broonie@kernel.org> Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
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Stephen Rothwell authored
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
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- 07 Jun, 2017 7 commits
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David S. Miller authored
Network devices can allocate reasources and private memory using netdev_ops->ndo_init(). However, the release of these resources can occur in one of two different places. Either netdev_ops->ndo_uninit() or netdev->destructor(). The decision of which operation frees the resources depends upon whether it is necessary for all netdev refs to be released before it is safe to perform the freeing. netdev_ops->ndo_uninit() presumably can occur right after the NETDEV_UNREGISTER notifier completes and the unicast and multicast address lists are flushed. netdev->destructor(), on the other hand, does not run until the netdev references all go away. Further complicating the situation is that netdev->destructor() almost universally does also a free_netdev(). This creates a problem for the logic in register_netdevice(). Because all callers of register_netdevice() manage the freeing of the netdev, and invoke free_netdev(dev) if register_netdevice() fails. If netdev_ops->ndo_init() succeeds, but something else fails inside of register_netdevice(), it does call ndo_ops->ndo_uninit(). But it is not able to invoke netdev->destructor(). This is because netdev->destructor() will do a free_netdev() and then the caller of register_netdevice() will do the same. However, this means that the resources that would normally be released by netdev->destructor() will not be. Over the years drivers have added local hacks to deal with this, by invoking their destructor parts by hand when register_netdevice() fails. Many drivers do not try to deal with this, and instead we have leaks. Let's close this hole by formalizing the distinction between what private things need to be freed up by netdev->destructor() and whether the driver needs unregister_netdevice() to perform the free_netdev(). netdev->priv_destructor() performs all actions to free up the private resources that used to be freed by netdev->destructor(), except for free_netdev(). netdev->needs_free_netdev is a boolean that indicates whether free_netdev() should be done at the end of unregister_netdevice(). Now, register_netdevice() can sanely release all resources after ndo_ops->ndo_init() succeeds, by invoking both ndo_ops->ndo_uninit() and netdev->priv_destructor(). And at the end of unregister_netdevice(), we invoke netdev->priv_destructor() and optionally call free_netdev(). Signed-off-by: David S. Miller <davem@davemloft.net>
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Daniel Borkmann authored
Will reported that in BPF_XADD we must use a different register in stxr instruction for the status flag due to otherwise CONSTRAINED UNPREDICTABLE behavior per architecture. Reference manual says [1]: If s == t, then one of the following behaviors must occur: * The instruction is UNDEFINED. * The instruction executes as a NOP. * The instruction performs the store to the specified address, but the value stored is UNKNOWN. Thus, use a different temporary register for the status flag to fix it. Disassembly extract from test 226/STX_XADD_DW from test_bpf.ko: [...] 0000003c: c85f7d4b ldxr x11, [x10] 00000040: 8b07016b add x11, x11, x7 00000044: c80c7d4b stxr w12, x11, [x10] 00000048: 35ffffac cbnz w12, 0x0000003c [...] [1] https://static.docs.arm.com/ddi0487/b/DDI0487B_a_armv8_arm.pdf, p.6132 Fixes: 85f68fe8 ("bpf, arm64: implement jiting of BPF_XADD") Reported-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
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Antoine Ténart authored
The mvpp22_port_mii_set() function was added by 26975821, but the function directly returns without doing anything. This return was used when debugging and wasn't removed before sending the patch. Fix this. Fixes: 26975821 ("net: mvpp2: handle misc PPv2.1/PPv2.2 differences") Signed-off-by: Antoine Tenart <antoine.tenart@free-electrons.com> Acked-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com> Signed-off-by: David S. Miller <davem@davemloft.net>
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John Allen authored
Changing the mtu is currently not supported in the ibmvnic driver. Implement .ndo_change_mtu in the driver so that attempting to use ifconfig to change the mtu will fail and present the user with an error message. Signed-off-by: John Allen <jallen@linux.vnet.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
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Michael S. Tsirkin authored
commit 61b905da ("net: Rename skb->rxhash to skb->hash") didn't update the documentation, fix this up. Cc: Tom Herbert <therbert@google.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
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Michal Schmidt authored
When freeing VF's DMA mappings, an already NULLed pointer was checked again due to an apparent copy&paste error. Consequently, the pf2vf bulletin DMA mapping was not freed. Signed-off-by: Michal Schmidt <mschmidt@redhat.com> Acked-by: Yuval Mintz <Yuval.Mintz@cavium.com> Signed-off-by: David S. Miller <davem@davemloft.net>
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Alexander Potapenko authored
KMSAN reported a use of uninitialized memory in dev_set_alias(), which was caused by calling strlcpy() (which in turn called strlen()) on the user-supplied non-terminated string. Signed-off-by: Alexander Potapenko <glider@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
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- 06 Jun, 2017 10 commits
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git://git.kernel.org/pub/scm/linux/kernel/git/davem/netLinus Torvalds authored
Pull networking fixes from David Miller: 1) Made TCP congestion control documentation match current reality, from Anmol Sarma. 2) Various build warning and failure fixes from Arnd Bergmann. 3) Fix SKB list leak in ipv6_gso_segment(). 4) Use after free in ravb driver, from Eugeniu Rosca. 5) Don't use udp_poll() in ping protocol driver, from Eric Dumazet. 6) Don't crash in PCI error recovery of cxgb4 driver, from Guilherme Piccoli. 7) _SRC_NAT_DONE_BIT needs to be cleared using atomics, from Liping Zhang. 8) Use after free in vxlan deletion, from Mark Bloch. 9) Fix ordering of NAPI poll enabled in ethoc driver, from Max Filippov. 10) Fix stmmac hangs with TSO, from Niklas Cassel. 11) Fix crash in CALIPSO ipv6, from Richard Haines. 12) Clear nh_flags properly on mpls link up. From Roopa Prabhu. 13) Fix regression in sk_err socket error queue handling, noticed by ping applications. From Soheil Hassas Yeganeh. 14) Update mlx4/mlx5 MAINTAINERS information. * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (78 commits) net: stmmac: fix a broken u32 less than zero check net: stmmac: fix completely hung TX when using TSO net: ethoc: enable NAPI before poll may be scheduled net: bridge: fix a null pointer dereference in br_afspec ravb: Fix use-after-free on `ifconfig eth0 down` net/ipv6: Fix CALIPSO causing GPF with datagram support net: stmmac: ensure jumbo_frm error return is correctly checked for -ve value Revert "sit: reload iphdr in ipip6_rcv" i40e/i40evf: proper update of the page_offset field i40e: Fix state flags for bit set and clean operations of PF iwlwifi: fix host command memory leaks iwlwifi: fix min API version for 7265D, 3168, 8000 and 8265 iwlwifi: mvm: clear new beacon command template struct iwlwifi: mvm: don't fail when removing a key from an inexisting sta iwlwifi: pcie: only use d0i3 in suspend/resume if system_pm is set to d0i3 iwlwifi: mvm: fix firmware debug restart recording iwlwifi: tt: move ucode_loaded check under mutex iwlwifi: mvm: support ibss in dqa mode iwlwifi: mvm: Fix command queue number on d0i3 flow iwlwifi: mvm: rs: start using LQ command color ...
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git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparcLinus Torvalds authored
Pull sparc fixes from David Miller: 1) Fix TLB context wrap races, from Pavel Tatashin. 2) Cure some gcc-7 build issues. 3) Handle invalid setup_hugepagesz command line values properly, from Liam R Howlett. 4) Copy TSB using the correct address shift for the huge TSB, from Mike Kravetz. * git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc: sparc64: delete old wrap code sparc64: new context wrap sparc64: add per-cpu mm of secondary contexts sparc64: redefine first version sparc64: combine activate_mm and switch_mm sparc64: reset mm cpumask after wrap sparc/mm/hugepages: Fix setup_hugepagesz for invalid values. sparc: Machine description indices can vary sparc64: mm: fix copy_tsb to correctly copy huge page TSBs arch/sparc: support NR_CPUS = 4096 sparc64: Add __multi3 for gcc 7.x and later. sparc64: Fix build warnings with gcc 7. arch/sparc: increase CONFIG_NODES_SHIFT on SPARC64 to 5
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David Rientjes authored
GCC explicitly does not warn for unused static inline functions for -Wunused-function. The manual states: Warn whenever a static function is declared but not defined or a non-inline static function is unused. Clang does warn for static inline functions that are unused. It turns out that suppressing the warnings avoids potentially complex #ifdef directives, which also reduces LOC. Suppress the warning for clang. Signed-off-by: David Rientjes <rientjes@google.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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David S. Miller authored
Pavel Tatashin says: ==================== sparc64: context wrap fixes This patch series contains fixes for context wrap: when we are out of context ids, and need to get a new version. It fixes memory corruption issues which happen when more than number of context ids (currently set to 8K) number of processes are started simultaneously, and processes can get a wrong context. sparc64: new context wrap: - contains explanation of new wrap method, and also explanation of races that it solves sparc64: reset mm cpumask after wrap - explains issue of not reseting cpu mask on a wrap ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
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Pavel Tatashin authored
The old method that is using xcall and softint to get new context id is deleted, as it is replaced by a method of using per_cpu_secondary_mm without xcall to perform the context wrap. Signed-off-by: Pavel Tatashin <pasha.tatashin@oracle.com> Reviewed-by: Bob Picco <bob.picco@oracle.com> Reviewed-by: Steven Sistare <steven.sistare@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
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Pavel Tatashin authored
The current wrap implementation has a race issue: it is called outside of the ctx_alloc_lock, and also does not wait for all CPUs to complete the wrap. This means that a thread can get a new context with a new version and another thread might still be running with the same context. The problem is especially severe on CPUs with shared TLBs, like sun4v. I used the following test to very quickly reproduce the problem: - start over 8K processes (must be more than context IDs) - write and read values at a memory location in every process. Very quickly memory corruptions start happening, and what we read back does not equal what we wrote. Several approaches were explored before settling on this one: Approach 1: Move smp_new_mmu_context_version() inside ctx_alloc_lock, and wait for every process to complete the wrap. (Note: every CPU must WAIT before leaving smp_new_mmu_context_version_client() until every one arrives). This approach ends up with deadlocks, as some threads own locks which other threads are waiting for, and they never receive softint until these threads exit smp_new_mmu_context_version_client(). Since we do not allow the exit, deadlock happens. Approach 2: Handle wrap right during mondo interrupt. Use etrap/rtrap to enter into into C code, and issue new versions to every CPU. This approach adds some overhead to runtime: in switch_mm() we must add some checks to make sure that versions have not changed due to wrap while we were loading the new secondary context. (could be protected by PSTATE_IE but that degrades performance as on M7 and older CPUs as it takes 50 cycles for each access). Also, we still need a global per-cpu array of MMs to know where we need to load new contexts, otherwise we can change context to a thread that is going way (if we received mondo between switch_mm() and switch_to() time). Finally, there are some issues with window registers in rtrap() when context IDs are changed during CPU mondo time. The approach in this patch is the simplest and has almost no impact on runtime. We use the array with mm's where last secondary contexts were loaded onto CPUs and bump their versions to the new generation without changing context IDs. If a new process comes in to get a context ID, it will go through get_new_mmu_context() because of version mismatch. But the running processes do not need to be interrupted. And wrap is quicker as we do not need to xcall and wait for everyone to receive and complete wrap. Signed-off-by: Pavel Tatashin <pasha.tatashin@oracle.com> Reviewed-by: Bob Picco <bob.picco@oracle.com> Reviewed-by: Steven Sistare <steven.sistare@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
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Pavel Tatashin authored
The new wrap is going to use information from this array to figure out mm's that currently have valid secondary contexts setup. Signed-off-by: Pavel Tatashin <pasha.tatashin@oracle.com> Reviewed-by: Bob Picco <bob.picco@oracle.com> Reviewed-by: Steven Sistare <steven.sistare@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
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Pavel Tatashin authored
CTX_FIRST_VERSION defines the first context version, but also it defines first context. This patch redefines it to only include the first context version. Signed-off-by: Pavel Tatashin <pasha.tatashin@oracle.com> Reviewed-by: Bob Picco <bob.picco@oracle.com> Reviewed-by: Steven Sistare <steven.sistare@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
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Pavel Tatashin authored
The only difference between these two functions is that in activate_mm we unconditionally flush context. However, there is no need to keep this difference after fixing a bug where cpumask was not reset on a wrap. So, in this patch we combine these. Signed-off-by: Pavel Tatashin <pasha.tatashin@oracle.com> Reviewed-by: Bob Picco <bob.picco@oracle.com> Reviewed-by: Steven Sistare <steven.sistare@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
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Pavel Tatashin authored
After a wrap (getting a new context version) a process must get a new context id, which means that we would need to flush the context id from the TLB before running for the first time with this ID on every CPU. But, we use mm_cpumask to determine if this process has been running on this CPU before, and this mask is not reset after a wrap. So, there are two possible fixes for this issue: 1. Clear mm cpumask whenever mm gets a new context id 2. Unconditionally flush context every time process is running on a CPU This patch implements the first solution Signed-off-by: Pavel Tatashin <pasha.tatashin@oracle.com> Reviewed-by: Bob Picco <bob.picco@oracle.com> Reviewed-by: Steven Sistare <steven.sistare@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
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