user/sven/linux.git/include, branch v3.12.49

iio: Add inverse unit conversion macros

2015-09-30T08:59:50Z

commit c689a923c867eac40ed3826c1d9328edea8b6bc7 upstream. Add inverse unit conversion macro to convert from standard IIO units to units that might be used by some devices. Those are useful in combination with scale factors that are specified as IIO_VAL_FRACTIONAL. Typically the denominator for those specifications will contain the maximum raw value the sensor will generate and the numerator the value it maps to in a specific unit. Sometimes datasheets specify those in different units than the standard IIO units (e.g. degree/s instead of rad/s) and so we need to do a unit conversion. From a mathematical point of view it does not make a difference whether we apply the unit conversion to the numerator or the inverse unit conversion to the denominator since (x / y) / z = x / (y * z). But as the denominator is typically a larger value and we are rounding both the numerator and denominator to integer values using the later method gives us a better precision (E.g. the relative error is smaller if we round 8000.3 to 8000 rather than rounding 8.3 to 8). This is where in inverse unit conversion macros will be used. Marked for stable as used by some upcoming fixes. Signed-off-by: Lars-Peter Clausen Signed-off-by: Jonathan Cameron Signed-off-by: Jiri Slaby

PCI: Add dev_flags bit to access VPD through function 0

2015-09-18T07:26:29Z

commit 932c435caba8a2ce473a91753bad0173269ef334 upstream. Add a dev_flags bit, PCI_DEV_FLAGS_VPD_REF_F0, to access VPD through function 0 to provide VPD access on other functions. This is for hardware devices that provide copies of the same VPD capability registers in multiple functions. Because the kernel expects that each function has its own registers, both the locking and the state tracking are affected by VPD accesses to different functions. On such devices for example, if a VPD write is performed on function 0, *any* later attempt to read VPD from any other function of that device will hang. This has to do with how the kernel tracks the expected value of the F bit per function. Concurrent accesses to different functions of the same device can not only hang but also corrupt both read and write VPD data. When hangs occur, typically the error message: vpd r/w failed. This is likely a firmware bug on this device. will be seen. Never set this bit on function 0 or there will be an infinite recursion. Signed-off-by: Mark Rustad Signed-off-by: Bjorn Helgaas Acked-by: Alexander Duyck Signed-off-by: Jiri Slaby

netfilter: nf_conntrack: don't release a conntrack with non-zero refcnt

2015-09-14T14:28:42Z

[ Upstream commit e53376bef2cd97d3e3f61fdc677fb8da7d03d0da ] With this patch, the conntrack refcount is initially set to zero and it is bumped once it is added to any of the list, so we fulfill Eric's golden rule which is that all released objects always have a refcount that equals zero. Andrey Vagin reports that nf_conntrack_free can't be called for a conntrack with non-zero ref-counter, because it can race with nf_conntrack_find_get(). A conntrack slab is created with SLAB_DESTROY_BY_RCU. Non-zero ref-counter says that this conntrack is used. So when we release a conntrack with non-zero counter, we break this assumption. CPU1 CPU2 ____nf_conntrack_find() nf_ct_put() destroy_conntrack() ... init_conntrack __nf_conntrack_alloc (set use = 1) atomic_inc_not_zero(&ct->use) (use = 2) if (!l4proto->new(ct, skb, dataoff, timeouts)) nf_conntrack_free(ct); (use = 2 !!!) ... __nf_conntrack_alloc (set use = 1) if (!nf_ct_key_equal(h, tuple, zone)) nf_ct_put(ct); (use = 0) destroy_conntrack() /* continue to work with CT */ After applying the path "[PATCH] netfilter: nf_conntrack: fix RCU race in nf_conntrack_find_get" another bug was triggered in destroy_conntrack(): <4>[67096.759334] ------------[ cut here ]------------ <2>[67096.759353] kernel BUG at net/netfilter/nf_conntrack_core.c:211! ... <4>[67096.759837] Pid: 498649, comm: atdd veid: 666 Tainted: G C --------------- 2.6.32-042stab084.18 #1 042stab084_18 /DQ45CB <4>[67096.759932] RIP: 0010:[] [] destroy_conntrack+0x15c/0x190 [nf_conntrack] <4>[67096.760255] Call Trace: <4>[67096.760255] [] nf_conntrack_destroy+0x17/0x30 <4>[67096.760255] [] nf_conntrack_find_get+0x85/0x130 [nf_conntrack] <4>[67096.760255] [] nf_conntrack_in+0x352/0xb60 [nf_conntrack] <4>[67096.760255] [] ipv4_conntrack_local+0x51/0x60 [nf_conntrack_ipv4] <4>[67096.760255] [] nf_iterate+0x69/0xb0 <4>[67096.760255] [] ? dst_output+0x0/0x20 <4>[67096.760255] [] nf_hook_slow+0x74/0x110 <4>[67096.760255] [] ? dst_output+0x0/0x20 <4>[67096.760255] [] raw_sendmsg+0x775/0x910 <4>[67096.760255] [] ? flush_tlb_others_ipi+0x128/0x130 <4>[67096.760255] [] ? apic_timer_interrupt+0xe/0x20 <4>[67096.760255] [] ? apic_timer_interrupt+0xe/0x20 <4>[67096.760255] [] inet_sendmsg+0x4a/0xb0 <4>[67096.760255] [] ? sock_sendmsg+0x13/0x140 <4>[67096.760255] [] sock_sendmsg+0x117/0x140 <4>[67096.760255] [] ? native_smp_send_reschedule+0x49/0x60 <4>[67096.760255] [] ? _spin_unlock_bh+0x1b/0x20 <4>[67096.760255] [] ? autoremove_wake_function+0x0/0x40 <4>[67096.760255] [] ? do_ip_setsockopt+0x90/0xd80 <4>[67096.760255] [] ? apic_timer_interrupt+0xe/0x20 <4>[67096.760255] [] ? apic_timer_interrupt+0xe/0x20 <4>[67096.760255] [] sys_sendto+0x139/0x190 <4>[67096.760255] [] ? audit_syscall_entry+0x1d7/0x200 <4>[67096.760255] [] ? __audit_syscall_exit+0x265/0x290 <4>[67096.760255] [] compat_sys_socketcall+0x13f/0x210 <4>[67096.760255] [] ia32_sysret+0x0/0x5 I have reused the original title for the RFC patch that Andrey posted and most of the original patch description. Cc: Eric Dumazet Cc: Andrew Vagin Cc: Florian Westphal Reported-by: Andrew Vagin Signed-off-by: Pablo Neira Ayuso Reviewed-by: Eric Dumazet Acked-by: Andrew Vagin Signed-off-by: Jiri Slaby

ipv6: lock socket in ip6_datagram_connect()

2015-08-27T07:27:01Z

[ Upstream commit 03645a11a570d52e70631838cb786eb4253eb463 ] ip6_datagram_connect() is doing a lot of socket changes without socket being locked. This looks wrong, at least for udp_lib_rehash() which could corrupt lists because of concurrent udp_sk(sk)->udp_portaddr_hash accesses. Signed-off-by: Eric Dumazet Acked-by: Herbert Xu Signed-off-by: David S. Miller Signed-off-by: Jiri Slaby

drm/radeon: add new OLAND pci id

2015-08-25T14:57:10Z

commit e037239e5e7b61007763984aa35a8329596d8c88 upstream. Signed-off-by: Alex Deucher Signed-off-by: Jiri Slaby

rcu: Move lockless_dereference() out of rcupdate.h

2015-08-25T14:57:00Z

commit 0a04b0166929405cd833c1cc40f99e862b965ddc upstream. I want to use lockless_dereference() from seqlock.h, which would mean including rcupdate.h from it, however rcupdate.h already includes seqlock.h. Avoid this by moving lockless_dereference() into compiler.h. This is somewhat tricky since it uses smp_read_barrier_depends() which isn't available there, but its a CPP macro so we can get away with it. The alternative would be moving it into asm/barrier.h, but that would be updating each arch (I can do if people feel that is more appropriate). Cc: Paul McKenney Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Rusty Russell Signed-off-by: Jiri Slaby

rcu: Provide counterpart to rcu_dereference() for non-RCU situations

2015-08-25T14:56:59Z

commit 54ef6df3f3f1353d99c80c437259d317b2cd1cbd upstream. Although rcu_dereference() and friends can be used in situations where object lifetimes are being managed by something other than RCU, the resulting sparse and lockdep-RCU noise can be annoying. This commit therefore supplies a lockless_dereference(), which provides the protection for dereferences without the RCU-related debugging noise. Reported-by: Al Viro Signed-off-by: Paul E. McKenney Signed-off-by: Al Viro Signed-off-by: Jiri Slaby

arch: Introduce smp_load_acquire(), smp_store_release()

2015-08-25T14:56:59Z

commit 47933ad41a86a4a9b50bed7c9b9bd2ba242aac63 upstream. A number of situations currently require the heavyweight smp_mb(), even though there is no need to order prior stores against later loads. Many architectures have much cheaper ways to handle these situations, but the Linux kernel currently has no portable way to make use of them. This commit therefore supplies smp_load_acquire() and smp_store_release() to remedy this situation. The new smp_load_acquire() primitive orders the specified load against any subsequent reads or writes, while the new smp_store_release() primitive orders the specifed store against any prior reads or writes. These primitives allow array-based circular FIFOs to be implemented without an smp_mb(), and also allow a theoretical hole in rcu_assign_pointer() to be closed at no additional expense on most architectures. In addition, the RCU experience transitioning from explicit smp_read_barrier_depends() and smp_wmb() to rcu_dereference() and rcu_assign_pointer(), respectively resulted in substantial improvements in readability. It therefore seems likely that replacing other explicit barriers with smp_load_acquire() and smp_store_release() will provide similar benefits. It appears that roughly half of the explicit barriers in core kernel code might be so replaced. [Changelog by PaulMck] Reviewed-by: "Paul E. McKenney" Signed-off-by: Peter Zijlstra Acked-by: Will Deacon Cc: Benjamin Herrenschmidt Cc: Frederic Weisbecker Cc: Mathieu Desnoyers Cc: Michael Ellerman Cc: Michael Neuling Cc: Russell King Cc: Geert Uytterhoeven Cc: Heiko Carstens Cc: Linus Torvalds Cc: Martin Schwidefsky Cc: Victor Kaplansky Cc: Tony Luck Cc: Oleg Nesterov Link: http://lkml.kernel.org/r/20131213150640.908486364@infradead.org Signed-off-by: Ingo Molnar Signed-off-by: Jiri Slaby

nfs: increase size of EXCHANGE_ID name string buffer

2015-08-04T14:52:33Z

commit 764ad8ba8cd4c6f836fca9378f8c5121aece0842 upstream. The current buffer is much too small if you have a relatively long hostname. Bring it up to the size of the one that SETCLIENTID has. Reported-by: Michael Skralivetsky Signed-off-by: Jeff Layton Signed-off-by: Trond Myklebust Signed-off-by: Jiri Slaby

USB: usbfs: allow URBs to be reaped after disconnection

2015-08-04T14:52:31Z

commit 3f2cee73b650921b2e214bf487b2061a1c266504 upstream. The usbfs API has a peculiar hole: Users are not allowed to reap their URBs after the device has been disconnected. There doesn't seem to be any good reason for this; it is an ad-hoc inconsistency. The patch allows users to issue the USBDEVFS_REAPURB and USBDEVFS_REAPURBNDELAY ioctls (together with their 32-bit counterparts on 64-bit systems) even after the device is gone. If no URBs are pending for a disconnected device then the ioctls will return -ENODEV rather than -EAGAIN, because obviously no new URBs will ever be able to complete. The patch also adds a new capability flag for USBDEVFS_GET_CAPABILITIES to indicate that the reap-after-disconnect feature is supported. Signed-off-by: Alan Stern Tested-by: Chris Dickens Acked-by: Hans de Goede Signed-off-by: Jiri Slaby