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2019-06-14Merge tag 'v5.2-rc4' into mauroJonathan Corbet1-1/+19
We need to pick up post-rc1 changes to various document files so they don't get lost in Mauro's massive RST conversion push.
2019-06-08docs: fix broken documentation linksMauro Carvalho Chehab1-1/+1
Mostly due to x86 and acpi conversion, several documentation links are still pointing to the old file. Fix them. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Reviewed-by: Wolfram Sang <wsa@the-dreams.de> Reviewed-by: Sven Van Asbroeck <TheSven73@gmail.com> Reviewed-by: Bhupesh Sharma <bhsharma@redhat.com> Acked-by: Mark Brown <broonie@kernel.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-06-05vhost: access vq metadata through kernel virtual addressJason Wang1-3/+512
It was noticed that the copy_to/from_user() friends that was used to access virtqueue metdata tends to be very expensive for dataplane implementation like vhost since it involves lots of software checks, speculation barriers, hardware feature toggling (e.g SMAP). The extra cost will be more obvious when transferring small packets since the time spent on metadata accessing become more significant. This patch tries to eliminate those overheads by accessing them through direct mapping of those pages. Invalidation callbacks is implemented for co-operation with general VM management (swap, KSM, THP or NUMA balancing). We will try to get the direct mapping of vq metadata before each round of packet processing if it doesn't exist. If we fail, we will simplely fallback to copy_to/from_user() friends. This invalidation and direct mapping access are synchronized through spinlock and RCU. All matedata accessing through direct map is protected by RCU, and the setup or invalidation are done under spinlock. This method might does not work for high mem page which requires temporary mapping so we just fallback to normal copy_to/from_user() and may not for arch that has virtual tagged cache since extra cache flushing is needed to eliminate the alias. This will result complex logic and bad performance. For those archs, this patch simply go for copy_to/from_user() friends. This is done by ruling out kernel mapping codes through ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE. Note that this is only done when device IOTLB is not enabled. We could use similar method to optimize IOTLB in the future. Tests shows at most about 23% improvement on TX PPS when using virtio-user + vhost_net + xdp1 + TAP on 2.6GHz Broadwell: SMAP on | SMAP off Before: 5.2Mpps | 7.1Mpps After: 6.4Mpps | 8.2Mpps Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: James Bottomley <James.Bottomley@hansenpartnership.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: David Miller <davem@davemloft.net> Cc: Jerome Glisse <jglisse@redhat.com> Cc: linux-mm@kvack.org Cc: linux-arm-kernel@lists.infradead.org Cc: linux-parisc@vger.kernel.org Signed-off-by: Jason Wang <jasowang@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2019-06-05vhost: factor out setting vring addr and numJason Wang1-74/+103
Factoring vring address and num setting which needs special care for accelerating vq metadata accessing. Signed-off-by: Jason Wang <jasowang@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2019-06-05vhost: introduce helpers to get the size of metadata areaJason Wang1-18/+33
To avoid code duplication since it will be used by kernel VA prefetching. Signed-off-by: Jason Wang <jasowang@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2019-06-05vhost: rename vq_iotlb_prefetch() to vq_meta_prefetch()Jason Wang1-2/+2
Rename the function to be more accurate since it actually tries to prefetch vq metadata address in IOTLB. And this will be used by following patch to prefetch metadata virtual addresses. Signed-off-by: Jason Wang <jasowang@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2019-06-05vhost: fine grain userspace memory accessorsJason Wang1-17/+77
This is used to hide the metadata address from virtqueue helpers. This will allow to implement a vmap based fast accessing to metadata. Signed-off-by: Jason Wang <jasowang@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2019-06-05vhost: generalize adding used elemJason Wang1-10/+1
Use one generic vhost_copy_to_user() instead of two dedicated accessor. This will simplify the conversion to fine grain accessors. About 2% improvement of PPS were seen during vitio-user txonly test. Signed-off-by: Jason Wang <jasowang@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2019-05-27vhost: introduce vhost_exceeds_weight()Jason Wang1-1/+19
We used to have vhost_exceeds_weight() for vhost-net to: - prevent vhost kthread from hogging the cpu - balance the time spent between TX and RX This function could be useful for vsock and scsi as well. So move it to vhost.c. Device must specify a weight which counts the number of requests, or it can also specific a byte_weight which counts the number of bytes that has been processed. Signed-off-by: Jason Wang <jasowang@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2019-05-14mm/gup: change GUP fast to use flags rather than a write 'bool'Ira Weiny1-1/+1
To facilitate additional options to get_user_pages_fast() change the singular write parameter to be gup_flags. This patch does not change any functionality. New functionality will follow in subsequent patches. Some of the get_user_pages_fast() call sites were unchanged because they already passed FOLL_WRITE or 0 for the write parameter. NOTE: It was suggested to change the ordering of the get_user_pages_fast() arguments to ensure that callers were converted. This breaks the current GUP call site convention of having the returned pages be the final parameter. So the suggestion was rejected. Link: http://lkml.kernel.org/r/20190328084422.29911-4-ira.weiny@intel.com Link: http://lkml.kernel.org/r/20190317183438.2057-4-ira.weiny@intel.com Signed-off-by: Ira Weiny <ira.weiny@intel.com> Reviewed-by: Mike Marshall <hubcap@omnibond.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Dan Williams <dan.j.williams@intel.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: James Hogan <jhogan@kernel.org> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: John Hubbard <jhubbard@nvidia.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Rich Felker <dalias@libc.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-04-10vhost: reject zero size iova rangeJason Wang1-1/+5
We used to accept zero size iova range which will lead a infinite loop in translate_desc(). Fixing this by failing the request in this case. Reported-by: syzbot+d21e6e297322a900c128@syzkaller.appspotmail.com Fixes: 6b1e6cc7 ("vhost: new device IOTLB API") Signed-off-by: Jason Wang <jasowang@redhat.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-03-06vhost: silence an unused-variable warningArnd Bergmann1-1/+1
On some architectures, the MMU can be disabled, leading to access_ok() becoming an empty macro that does not evaluate its size argument, which in turn produces an unused-variable warning: drivers/vhost/vhost.c:1191:9: error: unused variable 's' [-Werror,-Wunused-variable] size_t s = vhost_has_feature(vq, VIRTIO_RING_F_EVENT_IDX) ? 2 : 0; Mark the variable as __maybe_unused to shut up that warning. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2019-02-19vhost: correctly check the return value of translate_desc() in log_used()Jason Wang1-1/+1
When fail, translate_desc() returns negative value, otherwise the number of iovs. So we should fail when the return value is negative instead of a blindly check against zero. Detected by CoverityScan, CID# 1442593: Control flow issues (DEADCODE) Fixes: cc5e71075947 ("vhost: log dirty page correctly") Acked-by: Michael S. Tsirkin <mst@redhat.com> Reported-by: Stephen Hemminger <stephen@networkplumber.org> Signed-off-by: Jason Wang <jasowang@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-01-28vhost: fix OOB in get_rx_bufs()Jason Wang1-3/+4
After batched used ring updating was introduced in commit e2b3b35eb989 ("vhost_net: batch used ring update in rx"). We tend to batch heads in vq->heads for more than one packet. But the quota passed to get_rx_bufs() was not correctly limited, which can result a OOB write in vq->heads. headcount = get_rx_bufs(vq, vq->heads + nvq->done_idx, vhost_len, &in, vq_log, &log, likely(mergeable) ? UIO_MAXIOV : 1); UIO_MAXIOV was still used which is wrong since we could have batched used in vq->heads, this will cause OOB if the next buffer needs more than 960 (1024 (UIO_MAXIOV) - 64 (VHOST_NET_BATCH)) heads after we've batched 64 (VHOST_NET_BATCH) heads: Acked-by: Stefan Hajnoczi <stefanha@redhat.com> ============================================================================= BUG kmalloc-8k (Tainted: G B ): Redzone overwritten ----------------------------------------------------------------------------- INFO: 0x00000000fd93b7a2-0x00000000f0713384. First byte 0xa9 instead of 0xcc INFO: Allocated in alloc_pd+0x22/0x60 age=3933677 cpu=2 pid=2674 kmem_cache_alloc_trace+0xbb/0x140 alloc_pd+0x22/0x60 gen8_ppgtt_create+0x11d/0x5f0 i915_ppgtt_create+0x16/0x80 i915_gem_create_context+0x248/0x390 i915_gem_context_create_ioctl+0x4b/0xe0 drm_ioctl_kernel+0xa5/0xf0 drm_ioctl+0x2ed/0x3a0 do_vfs_ioctl+0x9f/0x620 ksys_ioctl+0x6b/0x80 __x64_sys_ioctl+0x11/0x20 do_syscall_64+0x43/0xf0 entry_SYSCALL_64_after_hwframe+0x44/0xa9 INFO: Slab 0x00000000d13e87af objects=3 used=3 fp=0x (null) flags=0x200000000010201 INFO: Object 0x0000000003278802 @offset=17064 fp=0x00000000e2e6652b Fixing this by allocating UIO_MAXIOV + VHOST_NET_BATCH iovs for vhost-net. This is done through set the limitation through vhost_dev_init(), then set_owner can allocate the number of iov in a per device manner. This fixes CVE-2018-16880. Fixes: e2b3b35eb989 ("vhost_net: batch used ring update in rx") Signed-off-by: Jason Wang <jasowang@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-01-21Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netLinus Torvalds1-14/+83
Pull networking fixes from David Miller: 1) Fix endless loop in nf_tables, from Phil Sutter. 2) Fix cross namespace ip6_gre tunnel hash list corruption, from Olivier Matz. 3) Don't be too strict in phy_start_aneg() otherwise we might not allow restarting auto negotiation. From Heiner Kallweit. 4) Fix various KMSAN uninitialized value cases in tipc, from Ying Xue. 5) Memory leak in act_tunnel_key, from Davide Caratti. 6) Handle chip errata of mv88e6390 PHY, from Andrew Lunn. 7) Remove linear SKB assumption in fou/fou6, from Eric Dumazet. 8) Missing udplite rehash callbacks, from Alexey Kodanev. 9) Log dirty pages properly in vhost, from Jason Wang. 10) Use consume_skb() in neigh_probe() as this is a normal free not a drop, from Yang Wei. Likewise in macvlan_process_broadcast(). 11) Missing device_del() in mdiobus_register() error paths, from Thomas Petazzoni. 12) Fix checksum handling of short packets in mlx5, from Cong Wang. * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (96 commits) bpf: in __bpf_redirect_no_mac pull mac only if present virtio_net: bulk free tx skbs net: phy: phy driver features are mandatory isdn: avm: Fix string plus integer warning from Clang net/mlx5e: Fix cb_ident duplicate in indirect block register net/mlx5e: Fix wrong (zero) TX drop counter indication for representor net/mlx5e: Fix wrong error code return on FEC query failure net/mlx5e: Force CHECKSUM_UNNECESSARY for short ethernet frames tools: bpftool: Cleanup license mess bpf: fix inner map masking to prevent oob under speculation bpf: pull in pkt_sched.h header for tooling to fix bpftool build selftests: forwarding: Add a test case for externally learned FDB entries selftests: mlxsw: Test FDB offload indication mlxsw: spectrum_switchdev: Do not treat static FDB entries as sticky net: bridge: Mark FDB entries that were added by user as such mlxsw: spectrum_fid: Update dummy FID index mlxsw: pci: Return error on PCI reset timeout mlxsw: pci: Increase PCI SW reset timeout mlxsw: pci: Ring CQ's doorbell before RDQ's MAINTAINERS: update email addresses of liquidio driver maintainers ...
2019-01-17vhost: log dirty page correctlyJason Wang1-14/+83
Vhost dirty page logging API is designed to sync through GPA. But we try to log GIOVA when device IOTLB is enabled. This is wrong and may lead to missing data after migration. To solve this issue, when logging with device IOTLB enabled, we will: 1) reuse the device IOTLB translation result of GIOVA->HVA mapping to get HVA, for writable descriptor, get HVA through iovec. For used ring update, translate its GIOVA to HVA 2) traverse the GPA->HVA mapping to get the possible GPA and log through GPA. Pay attention this reverse mapping is not guaranteed to be unique, so we should log each possible GPA in this case. This fix the failure of scp to guest during migration. In -next, we will probably support passing GIOVA->GPA instead of GIOVA->HVA. Fixes: 6b1e6cc7855b ("vhost: new device IOTLB API") Reported-by: Jintack Lim <jintack@cs.columbia.edu> Cc: Jintack Lim <jintack@cs.columbia.edu> Signed-off-by: Jason Wang <jasowang@redhat.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-01-14vhost: return EINVAL if iovecs size does not match the message sizePavel Tikhomirov1-2/+6
We've failed to copy and process vhost_iotlb_msg so let userspace at least know about it. For instance before these patch the code below runs without any error: int main() { struct vhost_msg msg; struct iovec iov; int fd; fd = open("/dev/vhost-net", O_RDWR); if (fd == -1) { perror("open"); return 1; } iov.iov_base = &msg; iov.iov_len = sizeof(msg)-4; if (writev(fd, &iov,1) == -1) { perror("writev"); return 1; } return 0; } Signed-off-by: Pavel Tikhomirov <ptikhomirov@virtuozzo.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2019-01-03Remove 'type' argument from access_ok() functionLinus Torvalds1-8/+8
Nobody has actually used the type (VERIFY_READ vs VERIFY_WRITE) argument of the user address range verification function since we got rid of the old racy i386-only code to walk page tables by hand. It existed because the original 80386 would not honor the write protect bit when in kernel mode, so you had to do COW by hand before doing any user access. But we haven't supported that in a long time, and these days the 'type' argument is a purely historical artifact. A discussion about extending 'user_access_begin()' to do the range checking resulted this patch, because there is no way we're going to move the old VERIFY_xyz interface to that model. And it's best done at the end of the merge window when I've done most of my merges, so let's just get this done once and for all. This patch was mostly done with a sed-script, with manual fix-ups for the cases that weren't of the trivial 'access_ok(VERIFY_xyz' form. There were a couple of notable cases: - csky still had the old "verify_area()" name as an alias. - the iter_iov code had magical hardcoded knowledge of the actual values of VERIFY_{READ,WRITE} (not that they mattered, since nothing really used it) - microblaze used the type argument for a debug printout but other than those oddities this should be a total no-op patch. I tried to fix up all architectures, did fairly extensive grepping for access_ok() uses, and the changes are trivial, but I may have missed something. Any missed conversion should be trivially fixable, though. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-12-12Revert "net: vhost: lock the vqs one by one"Jason Wang1-4/+17
This reverts commit 78139c94dc8c96a478e67dab3bee84dc6eccb5fd. We don't protect device IOTLB with vq mutex, which will lead e.g use after free for device IOTLB entries. And since we've switched to use mutex_trylock() in previous patch, it's safe to revert it without having deadlock. Fixes: commit 78139c94dc8c ("net: vhost: lock the vqs one by one") Cc: Tonghao Zhang <xiangxia.m.yue@gmail.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Jason Wang <jasowang@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-12-12vhost: make sure used idx is seen before log in vhost_add_used_n()Jason Wang1-0/+2
We miss a write barrier that guarantees used idx is updated and seen before log. This will let userspace sync and copy used ring before used idx is update. Fix this by adding a barrier before log_write(). Fixes: 8dd014adfea6f ("vhost-net: mergeable buffers support") Acked-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Jason Wang <jasowang@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-12-03vhost: fix IOTLB lockingJean-Philippe Brucker1-3/+0
Commit 78139c94dc8c ("net: vhost: lock the vqs one by one") moved the vq lock to improve scalability, but introduced a possible deadlock in vhost-iotlb. vhost_iotlb_notify_vq() now takes vq->mutex while holding the device's IOTLB spinlock. And on the vhost_iotlb_miss() path, the spinlock is taken while holding vq->mutex. Since calling vhost_poll_queue() doesn't require any lock, avoid the deadlock by not taking vq->mutex. Fixes: 78139c94dc8c ("net: vhost: lock the vqs one by one") Acked-by: Jason Wang <jasowang@redhat.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Jean-Philippe Brucker <jean-philippe.brucker@arm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-10-31vhost: Fix Spectre V1 vulnerabilityJason Wang1-0/+2
The idx in vhost_vring_ioctl() was controlled by userspace, hence a potential exploitation of the Spectre variant 1 vulnerability. Fixing this by sanitizing idx before using it to index d->vqs. Cc: Michael S. Tsirkin <mst@redhat.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Signed-off-by: Jason Wang <jasowang@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-09-26net: vhost: lock the vqs one by oneTonghao Zhang1-17/+7
This patch changes the way that lock all vqs at the same, to lock them one by one. It will be used for next patch to avoid the deadlock. Signed-off-by: Tonghao Zhang <xiangxia.m.yue@gmail.com> Acked-by: Jason Wang <jasowang@redhat.com> Signed-off-by: Jason Wang <jasowang@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-08-25vhost: correctly check the iova range when waking virtqueueJason Wang1-1/+1
We don't wakeup the virtqueue if the first byte of pending iova range is the last byte of the range we just got updated. This will lead a virtqueue to wait for IOTLB updating forever. Fixing by correct the check and wake up the virtqueue in this case. Fixes: 6b1e6cc7855b ("vhost: new device IOTLB API") Reported-by: Peter Xu <peterx@redhat.com> Signed-off-by: Jason Wang <jasowang@redhat.com> Reviewed-by: Peter Xu <peterx@redhat.com> Tested-by: Peter Xu <peterx@redhat.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-08-09Merge ra.kernel.org:/pub/scm/linux/kernel/git/davem/netDavid S. Miller1-3/+6
Overlapping changes in RXRPC, changing to ktime_get_seconds() whilst adding some tracepoints. Signed-off-by: David S. Miller <davem@davemloft.net>
2018-08-08vhost: reset metadata cache when initializing new IOTLBJason Wang1-3/+6
We need to reset metadata cache during new IOTLB initialization, otherwise the stale pointers to previous IOTLB may be still accessed which will lead a use after free. Reported-by: syzbot+c51e6736a1bf614b3272@syzkaller.appspotmail.com Fixes: f88949138058 ("vhost: introduce O(1) vq metadata cache") Signed-off-by: Jason Wang <jasowang@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-08-06vhost: switch to use new message formatJason Wang1-18/+53
We use to have message like: struct vhost_msg { int type; union { struct vhost_iotlb_msg iotlb; __u8 padding[64]; }; }; Unfortunately, there will be a hole of 32bit in 64bit machine because of the alignment. This leads a different formats between 32bit API and 64bit API. What's more it will break 32bit program running on 64bit machine. So fixing this by introducing a new message type with an explicit 32bit reserved field after type like: struct vhost_msg_v2 { __u32 type; __u32 reserved; union { struct vhost_iotlb_msg iotlb; __u8 padding[64]; }; }; We will have a consistent ABI after switching to use this. To enable this capability, introduce a new ioctl (VHOST_SET_BAKCEND_FEATURE) for userspace to enable this feature (VHOST_BACKEND_F_IOTLB_V2). Fixes: 6b1e6cc7855b ("vhost: new device IOTLB API") Signed-off-by: Jason Wang <jasowang@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-06-16Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhostLinus Torvalds1-0/+3
Pull virtio updates from Michael Tsirkin: "virtio, vhost: features, fixes - PCI virtual function support for virtio - DMA barriers for virtio strong barriers - bugfixes" * tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost: virtio: update the comments for transport features virtio_pci: support enabling VFs vhost: fix info leak due to uninitialized memory virtio_ring: switch to dma_XX barriers for rpmsg
2018-06-12treewide: kmalloc() -> kmalloc_array()Kees Cook1-4/+7
The kmalloc() function has a 2-factor argument form, kmalloc_array(). This patch replaces cases of: kmalloc(a * b, gfp) with: kmalloc_array(a * b, gfp) as well as handling cases of: kmalloc(a * b * c, gfp) with: kmalloc(array3_size(a, b, c), gfp) as it's slightly less ugly than: kmalloc_array(array_size(a, b), c, gfp) This does, however, attempt to ignore constant size factors like: kmalloc(4 * 1024, gfp) though any constants defined via macros get caught up in the conversion. Any factors with a sizeof() of "unsigned char", "char", and "u8" were dropped, since they're redundant. The tools/ directory was manually excluded, since it has its own implementation of kmalloc(). The Coccinelle script used for this was: // Fix redundant parens around sizeof(). @@ type TYPE; expression THING, E; @@ ( kmalloc( - (sizeof(TYPE)) * E + sizeof(TYPE) * E , ...) | kmalloc( - (sizeof(THING)) * E + sizeof(THING) * E , ...) ) // Drop single-byte sizes and redundant parens. @@ expression COUNT; typedef u8; typedef __u8; @@ ( kmalloc( - sizeof(u8) * (COUNT) + COUNT , ...) | kmalloc( - sizeof(__u8) * (COUNT) + COUNT , ...) | kmalloc( - sizeof(char) * (COUNT) + COUNT , ...) | kmalloc( - sizeof(unsigned char) * (COUNT) + COUNT , ...) | kmalloc( - sizeof(u8) * COUNT + COUNT , ...) | kmalloc( - sizeof(__u8) * COUNT + COUNT , ...) | kmalloc( - sizeof(char) * COUNT + COUNT , ...) | kmalloc( - sizeof(unsigned char) * COUNT + COUNT , ...) ) // 2-factor product with sizeof(type/expression) and identifier or constant. @@ type TYPE; expression THING; identifier COUNT_ID; constant COUNT_CONST; @@ ( - kmalloc + kmalloc_array ( - sizeof(TYPE) * (COUNT_ID) + COUNT_ID, sizeof(TYPE) , ...) | - kmalloc + kmalloc_array ( - sizeof(TYPE) * COUNT_ID + COUNT_ID, sizeof(TYPE) , ...) | - kmalloc + kmalloc_array ( - sizeof(TYPE) * (COUNT_CONST) + COUNT_CONST, sizeof(TYPE) , ...) | - kmalloc + kmalloc_array ( - sizeof(TYPE) * COUNT_CONST + COUNT_CONST, sizeof(TYPE) , ...) | - kmalloc + kmalloc_array ( - sizeof(THING) * (COUNT_ID) + COUNT_ID, sizeof(THING) , ...) | - kmalloc + kmalloc_array ( - sizeof(THING) * COUNT_ID + COUNT_ID, sizeof(THING) , ...) | - kmalloc + kmalloc_array ( - sizeof(THING) * (COUNT_CONST) + COUNT_CONST, sizeof(THING) , ...) | - kmalloc + kmalloc_array ( - sizeof(THING) * COUNT_CONST + COUNT_CONST, sizeof(THING) , ...) ) // 2-factor product, only identifiers. @@ identifier SIZE, COUNT; @@ - kmalloc + kmalloc_array ( - SIZE * COUNT + COUNT, SIZE , ...) // 3-factor product with 1 sizeof(type) or sizeof(expression), with // redundant parens removed. @@ expression THING; identifier STRIDE, COUNT; type TYPE; @@ ( kmalloc( - sizeof(TYPE) * (COUNT) * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | kmalloc( - sizeof(TYPE) * (COUNT) * STRIDE + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | kmalloc( - sizeof(TYPE) * COUNT * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | kmalloc( - sizeof(TYPE) * COUNT * STRIDE + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | kmalloc( - sizeof(THING) * (COUNT) * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) | kmalloc( - sizeof(THING) * (COUNT) * STRIDE + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) | kmalloc( - sizeof(THING) * COUNT * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) | kmalloc( - sizeof(THING) * COUNT * STRIDE + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) ) // 3-factor product with 2 sizeof(variable), with redundant parens removed. @@ expression THING1, THING2; identifier COUNT; type TYPE1, TYPE2; @@ ( kmalloc( - sizeof(TYPE1) * sizeof(TYPE2) * COUNT + array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2)) , ...) | kmalloc( - sizeof(TYPE1) * sizeof(THING2) * (COUNT) + array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2)) , ...) | kmalloc( - sizeof(THING1) * sizeof(THING2) * COUNT + array3_size(COUNT, sizeof(THING1), sizeof(THING2)) , ...) | kmalloc( - sizeof(THING1) * sizeof(THING2) * (COUNT) + array3_size(COUNT, sizeof(THING1), sizeof(THING2)) , ...) | kmalloc( - sizeof(TYPE1) * sizeof(THING2) * COUNT + array3_size(COUNT, sizeof(TYPE1), sizeof(THING2)) , ...) | kmalloc( - sizeof(TYPE1) * sizeof(THING2) * (COUNT) + array3_size(COUNT, sizeof(TYPE1), sizeof(THING2)) , ...) ) // 3-factor product, only identifiers, with redundant parens removed. @@ identifier STRIDE, SIZE, COUNT; @@ ( kmalloc( - (COUNT) * STRIDE * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) | kmalloc( - COUNT * (STRIDE) * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) | kmalloc( - COUNT * STRIDE * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | kmalloc( - (COUNT) * (STRIDE) * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) | kmalloc( - COUNT * (STRIDE) * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | kmalloc( - (COUNT) * STRIDE * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | kmalloc( - (COUNT) * (STRIDE) * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | kmalloc( - COUNT * STRIDE * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) ) // Any remaining multi-factor products, first at least 3-factor products, // when they're not all constants... @@ expression E1, E2, E3; constant C1, C2, C3; @@ ( kmalloc(C1 * C2 * C3, ...) | kmalloc( - (E1) * E2 * E3 + array3_size(E1, E2, E3) , ...) | kmalloc( - (E1) * (E2) * E3 + array3_size(E1, E2, E3) , ...) | kmalloc( - (E1) * (E2) * (E3) + array3_size(E1, E2, E3) , ...) | kmalloc( - E1 * E2 * E3 + array3_size(E1, E2, E3) , ...) ) // And then all remaining 2 factors products when they're not all constants, // keeping sizeof() as the second factor argument. @@ expression THING, E1, E2; type TYPE; constant C1, C2, C3; @@ ( kmalloc(sizeof(THING) * C2, ...) | kmalloc(sizeof(TYPE) * C2, ...) | kmalloc(C1 * C2 * C3, ...) | kmalloc(C1 * C2, ...) | - kmalloc + kmalloc_array ( - sizeof(TYPE) * (E2) + E2, sizeof(TYPE) , ...) | - kmalloc + kmalloc_array ( - sizeof(TYPE) * E2 + E2, sizeof(TYPE) , ...) | - kmalloc + kmalloc_array ( - sizeof(THING) * (E2) + E2, sizeof(THING) , ...) | - kmalloc + kmalloc_array ( - sizeof(THING) * E2 + E2, sizeof(THING) , ...) | - kmalloc + kmalloc_array ( - (E1) * E2 + E1, E2 , ...) | - kmalloc + kmalloc_array ( - (E1) * (E2) + E1, E2 , ...) | - kmalloc + kmalloc_array ( - E1 * E2 + E1, E2 , ...) ) Signed-off-by: Kees Cook <keescook@chromium.org>
2018-06-12Convert vhost to struct_sizeMatthew Wilcox1-1/+2
Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com> Signed-off-by: Kees Cook <keescook@chromium.org>
2018-06-12vhost: fix info leak due to uninitialized memoryMichael S. Tsirkin1-0/+3
struct vhost_msg within struct vhost_msg_node is copied to userspace. Unfortunately it turns out on 64 bit systems vhost_msg has padding after type which gcc doesn't initialize, leaking 4 uninitialized bytes to userspace. This padding also unfortunately means 32 bit users of this interface are broken on a 64 bit kernel which will need to be fixed separately. Fixes: CVE-2018-1118 Cc: stable@vger.kernel.org Reported-by: Kevin Easton <kevin@guarana.org> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Reported-by: syzbot+87cfa083e727a224754b@syzkaller.appspotmail.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2018-06-04Merge branch 'work.aio-1' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull aio updates from Al Viro: "Majority of AIO stuff this cycle. aio-fsync and aio-poll, mostly. The only thing I'm holding back for a day or so is Adam's aio ioprio - his last-minute fixup is trivial (missing stub in !CONFIG_BLOCK case), but let it sit in -next for decency sake..." * 'work.aio-1' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (46 commits) aio: sanitize the limit checking in io_submit(2) aio: fold do_io_submit() into callers aio: shift copyin of iocb into io_submit_one() aio_read_events_ring(): make a bit more readable aio: all callers of aio_{read,write,fsync,poll} treat 0 and -EIOCBQUEUED the same way aio: take list removal to (some) callers of aio_complete() aio: add missing break for the IOCB_CMD_FDSYNC case random: convert to ->poll_mask timerfd: convert to ->poll_mask eventfd: switch to ->poll_mask pipe: convert to ->poll_mask crypto: af_alg: convert to ->poll_mask net/rxrpc: convert to ->poll_mask net/iucv: convert to ->poll_mask net/phonet: convert to ->poll_mask net/nfc: convert to ->poll_mask net/caif: convert to ->poll_mask net/bluetooth: convert to ->poll_mask net/sctp: convert to ->poll_mask net/tipc: convert to ->poll_mask ...
2018-05-26fs: add new vfs_poll and file_can_poll helpersChristoph Hellwig1-1/+1
These abstract out calls to the poll method in preparation for changes in how we poll. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
2018-05-24vhost: synchronize IOTLB message with dev cleanupJason Wang1-0/+3
DaeRyong Jeong reports a race between vhost_dev_cleanup() and vhost_process_iotlb_msg(): Thread interleaving: CPU0 (vhost_process_iotlb_msg) CPU1 (vhost_dev_cleanup) (In the case of both VHOST_IOTLB_UPDATE and VHOST_IOTLB_INVALIDATE) ===== ===== vhost_umem_clean(dev->iotlb); if (!dev->iotlb) { ret = -EFAULT; break; } dev->iotlb = NULL; The reason is we don't synchronize between them, fixing by protecting vhost_process_iotlb_msg() with dev mutex. Reported-by: DaeRyong Jeong <threeearcat@gmail.com> Fixes: 6b1e6cc7855b0 ("vhost: new device IOTLB API") Signed-off-by: Jason Wang <jasowang@redhat.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-04-11vhost: return bool from *_access_ok() functionsStefan Hajnoczi1-33/+33
Currently vhost *_access_ok() functions return int. This is error-prone because there are two popular conventions: 1. 0 means failure, 1 means success 2. -errno means failure, 0 means success Although vhost mostly uses #1, it does not do so consistently. umem_access_ok() uses #2. This patch changes the return type from int to bool so that false means failure and true means success. This eliminates a potential source of errors. Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-04-11vhost: fix vhost_vq_access_ok() log checkStefan Hajnoczi1-3/+5
Commit d65026c6c62e7d9616c8ceb5a53b68bcdc050525 ("vhost: validate log when IOTLB is enabled") introduced a regression. The logic was originally: if (vq->iotlb) return 1; return A && B; After the patch the short-circuit logic for A was inverted: if (A || vq->iotlb) return A; return B; This patch fixes the regression by rewriting the checks in the obvious way, no longer returning A when vq->iotlb is non-NULL (which is hard to understand). Reported-by: syzbot+65a84dde0214b0387ccd@syzkaller.appspotmail.com Cc: Jason Wang <jasowang@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-04-11vhost: Fix vhost_copy_to_user()Eric Auger1-1/+1
vhost_copy_to_user is used to copy vring used elements to userspace. We should use VHOST_ADDR_USED instead of VHOST_ADDR_DESC. Fixes: f88949138058 ("vhost: introduce O(1) vq metadata cache") Signed-off-by: Eric Auger <eric.auger@redhat.com> Acked-by: Jason Wang <jasowang@redhat.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-04-06Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhostLinus Torvalds1-1/+1
Pull fw_cfg, vhost updates from Michael Tsirkin: "This cleans up the qemu fw cfg device driver. On top of this, vmcore is dumped there on crash to help debugging with kASLR enabled. Also included are some fixes in vhost" * tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost: vhost: add vsock compat ioctl vhost: fix vhost ioctl signature to build with clang fw_cfg: write vmcoreinfo details crash: export paddr_vmcoreinfo_note() fw_cfg: add DMA register fw_cfg: add a public uapi header fw_cfg: handle fw_cfg_read_blob() error fw_cfg: remove inline from fw_cfg_read_blob() fw_cfg: fix sparse warnings around FW_CFG_FILE_DIR read fw_cfg: fix sparse warning reading FW_CFG_ID fw_cfg: fix sparse warnings with fw_cfg_file fw_cfg: fix sparse warnings in fw_cfg_sel_endianness() ptr_ring: fix build
2018-03-29vhost: validate log when IOTLB is enabledJason Wang1-8/+6
Vq log_base is the userspace address of bitmap which has nothing to do with IOTLB. So it needs to be validated unconditionally otherwise we may try use 0 as log_base which may lead to pin pages that will lead unexpected result (e.g trigger BUG_ON() in set_bit_to_user()). Fixes: 6b1e6cc7855b0 ("vhost: new device IOTLB API") Reported-by: syzbot+6304bf97ef436580fede@syzkaller.appspotmail.com Signed-off-by: Jason Wang <jasowang@redhat.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-27vhost: correctly remove wait queue during poll failureJason Wang1-2/+1
We tried to remove vq poll from wait queue, but do not check whether or not it was in a list before. This will lead double free. Fixing this by switching to use vhost_poll_stop() which zeros poll->wqh after removing poll from waitqueue to make sure it won't be freed twice. Cc: Darren Kenny <darren.kenny@oracle.com> Reported-by: syzbot+c0272972b01b872e604a@syzkaller.appspotmail.com Fixes: 2b8b328b61c79 ("vhost_net: handle polling errors when setting backend") Signed-off-by: Jason Wang <jasowang@redhat.com> Reviewed-by: Darren Kenny <darren.kenny@oracle.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-20vhost: fix vhost ioctl signature to build with clangSonny Rao1-1/+1
Clang is particularly anal about signed vs unsigned comparisons and doesn't like the fact that some ioctl numbers set the MSB, so we get this error when trying to build vhost on aarch64: drivers/vhost/vhost.c:1400:7: error: overflow converting case value to switch condition type (3221794578 to 18446744072636378898) [-Werror, -Wswitch] case VHOST_GET_VRING_BASE: 3221794578 is 0xC008AF12 in hex 18446744072636378898 is 0xFFFFFFFFC008AF12 in hex Fix this by using unsigned ints in the function signature for vhost_vring_ioctl(). Signed-off-by: Sonny Rao <sonnyrao@chromium.org> Reviewed-by: Darren Kenny <darren.kenny@oracle.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2018-02-11vfs: do bulk POLL* -> EPOLL* replacementLinus Torvalds1-5/+5
This is the mindless scripted replacement of kernel use of POLL* variables as described by Al, done by this script: for V in IN OUT PRI ERR RDNORM RDBAND WRNORM WRBAND HUP RDHUP NVAL MSG; do L=`git grep -l -w POLL$V | grep -v '^t' | grep -v /um/ | grep -v '^sa' | grep -v '/poll.h$'|grep -v '^D'` for f in $L; do sed -i "-es/^\([^\"]*\)\(\<POLL$V\>\)/\\1E\\2/" $f; done done with de-mangling cleanups yet to come. NOTE! On almost all architectures, the EPOLL* constants have the same values as the POLL* constants do. But they keyword here is "almost". For various bad reasons they aren't the same, and epoll() doesn't actually work quite correctly in some cases due to this on Sparc et al. The next patch from Al will sort out the final differences, and we should be all done. Scripted-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-02-08Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhostLinus Torvalds1-52/+16
Pull virtio/vhost updates from Michael Tsirkin: "virtio, vhost: fixes, cleanups, features This includes the disk/cache memory stats for for the virtio balloon, as well as multiple fixes and cleanups" * tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost: vhost: don't hold onto file pointer for VHOST_SET_LOG_FD vhost: don't hold onto file pointer for VHOST_SET_VRING_ERR vhost: don't hold onto file pointer for VHOST_SET_VRING_CALL ringtest: ring.c malloc & memset to calloc virtio_vop: don't kfree device on register failure virtio_pci: don't kfree device on register failure virtio: split device_register into device_initialize and device_add vhost: remove unused lock check flag in vhost_dev_cleanup() vhost: Remove the unused variable. virtio_blk: print capacity at probe time virtio: make VIRTIO a menuconfig to ease disabling it all virtio/ringtest: virtio_ring: fix up need_event math virtio/ringtest: fix up need_event math virtio: virtio_mmio: make of_device_ids const. firmware: Use PTR_ERR_OR_ZERO() virtio-mmio: Use PTR_ERR_OR_ZERO() vhost/scsi: Improve a size determination in four functions virtio_balloon: include disk/file caches memory statistics
2018-02-01vhost: don't hold onto file pointer for VHOST_SET_LOG_FDEric Biggers1-19/+5
We already hold a reference to the eventfd_ctx, which is sufficient; there's no need to hold a reference to the struct file as well. So get rid of vhost_dev->log_file. Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Jason Wang <jasowang@redhat.com>
2018-02-01vhost: don't hold onto file pointer for VHOST_SET_VRING_ERREric Biggers1-14/+4
We already hold a reference to the eventfd_ctx, which is sufficient; there's no need to hold a reference to the struct file as well. So get rid of vhost_virtqueue->error. Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Jason Wang <jasowang@redhat.com>
2018-02-01vhost: don't hold onto file pointer for VHOST_SET_VRING_CALLEric Biggers1-15/+5
We already hold a reference to the eventfd_ctx, which is sufficient; there's no need to hold a reference to the struct file as well. So get rid of vhost_virtqueue->call. Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Jason Wang <jasowang@redhat.com>
2018-02-01vhost: remove unused lock check flag in vhost_dev_cleanup()夷则(Caspar)1-3/+2
In commit ea5d404655ba ("vhost: fix release path lockdep checks"), Michael added a flag to check whether we should hold a lock in vhost_dev_cleanup(), however, in commit 47283bef7ed3 ("vhost: move memory pointer to VQs"), RCU operations have been replaced by mutex, we can remove the no-longer-used `locked' parameter now. Signed-off-by: Caspar Zhang <jinli.zjl@alibaba-inc.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2018-02-01vhost: Remove the unused variable.Tonghao Zhang1-1/+0
The patch (7235acdb1) changed the way of the work flushing in which the queued seq, done seq, and the flushing are not used anymore. Then remove them now. Fixes: 7235acdb1 ("vhost: simplify work flushing") Cc: Jason Wang <jasowang@redhat.com> Signed-off-by: Tonghao Zhang <xiangxia.m.yue@gmail.com> Acked-by: Jason Wang <jasowang@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2018-01-30Merge branch 'misc.poll' of ↵Linus Torvalds1-6/+6
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull poll annotations from Al Viro: "This introduces a __bitwise type for POLL### bitmap, and propagates the annotations through the tree. Most of that stuff is as simple as 'make ->poll() instances return __poll_t and do the same to local variables used to hold the future return value'. Some of the obvious brainos found in process are fixed (e.g. POLLIN misspelled as POLL_IN). At that point the amount of sparse warnings is low and most of them are for genuine bugs - e.g. ->poll() instance deciding to return -EINVAL instead of a bitmap. I hadn't touched those in this series - it's large enough as it is. Another problem it has caught was eventpoll() ABI mess; select.c and eventpoll.c assumed that corresponding POLL### and EPOLL### were equal. That's true for some, but not all of them - EPOLL### are arch-independent, but POLL### are not. The last commit in this series separates userland POLL### values from the (now arch-independent) kernel-side ones, converting between them in the few places where they are copied to/from userland. AFAICS, this is the least disruptive fix preserving poll(2) ABI and making epoll() work on all architectures. As it is, it's simply broken on sparc - try to give it EPOLLWRNORM and it will trigger only on what would've triggered EPOLLWRBAND on other architectures. EPOLLWRBAND and EPOLLRDHUP, OTOH, are never triggered at all on sparc. With this patch they should work consistently on all architectures" * 'misc.poll' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (37 commits) make kernel-side POLL... arch-independent eventpoll: no need to mask the result of epi_item_poll() again eventpoll: constify struct epoll_event pointers debugging printk in sg_poll() uses %x to print POLL... bitmap annotate poll(2) guts 9p: untangle ->poll() mess ->si_band gets POLL... bitmap stored into a user-visible long field ring_buffer_poll_wait() return value used as return value of ->poll() the rest of drivers/*: annotate ->poll() instances media: annotate ->poll() instances fs: annotate ->poll() instances ipc, kernel, mm: annotate ->poll() instances net: annotate ->poll() instances apparmor: annotate ->poll() instances tomoyo: annotate ->poll() instances sound: annotate ->poll() instances acpi: annotate ->poll() instances crypto: annotate ->poll() instances block: annotate ->poll() instances x86: annotate ->poll() instances ...
2018-01-30Merge branch 'core-rcu-for-linus' of ↵Linus Torvalds1-6/+1
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull RCU updates from Ingo Molnar: "The main RCU changes in this cycle were: - Updates to use cond_resched() instead of cond_resched_rcu_qs() where feasible (currently everywhere except in kernel/rcu and in kernel/torture.c). Also a couple of fixes to avoid sending IPIs to offline CPUs. - Updates to simplify RCU's dyntick-idle handling. - Updates to remove almost all uses of smp_read_barrier_depends() and read_barrier_depends(). - Torture-test updates. - Miscellaneous fixes" * 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (72 commits) torture: Save a line in stutter_wait(): while -> for torture: Eliminate torture_runnable and perf_runnable torture: Make stutter less vulnerable to compilers and races locking/locktorture: Fix num reader/writer corner cases locking/locktorture: Fix rwsem reader_delay torture: Place all torture-test modules in one MAINTAINERS group rcutorture/kvm-build.sh: Skip build directory check rcutorture: Simplify functions.sh include path rcutorture: Simplify logging rcutorture/kvm-recheck-*: Improve result directory readability check rcutorture/kvm.sh: Support execution from any directory rcutorture/kvm.sh: Use consistent help text for --qemu-args rcutorture/kvm.sh: Remove unused variable, `alldone` rcutorture: Remove unused script, config2frag.sh rcutorture/configinit: Fix build directory error message rcutorture: Preempt RCU-preempt readers more vigorously torture: Reduce #ifdefs for preempt_schedule() rcu: Remove have_rcu_nocb_mask from tree_plugin.h rcu: Add comment giving debug strategy for double call_rcu() tracing, rcu: Hide trace event rcu_nocb_wake when not used ...