- 28 Apr, 2016 36 commits
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Mike Marciniszyn authored
The awkward coding for setting the allowed_ops field was tripping an smatch warning. This patch uses the more appropriate defines from include/rdma to avoid the issue. As part of the patch remove a mask that was duplicated in rdmavt include files and use that mask as appropriate. Fixes: 8bea6b1cfe6f ("IB/rdmavt: Add create queue pair functionality") Reported-by:Dan Carpenter <dan.carpenter@oracle.com> Reviewed-by:
Dennis Dalessandro <dennis.dalessandro@intel.com> Signed-off-by:
Mike Marciniszyn <mike.marciniszyn@intel.com> Signed-off-by:
Doug Ledford <dledford@redhat.com>
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Mike Marciniszyn authored
Remove unreachable code from RC ack handling to fix an smatch error. Fixes: 633d2739 ("staging/rdma/hfi1: use mod_timer when appropriate") Reported-by:
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Dean Luick authored
The function refresh_qsfp_cache() acquires the i2c chain resource, but one caller already holds the resource. Change the acquire so all calls to refresh_qsfp_cache() are covered by the acquire and remove the acquire within refresh_qsfp_cache(). Reviewed-by:
Easwar Hariharan <easwar.hariharan@intel.com> Signed-off-by:
Dean Luick <dean.luick@intel.com> Signed-off-by:
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Dean Luick authored
The discrete ASIC board design makes the two I2C chains not independent of each other. That is, only one chain can safely be accessed at a time. For discrete ASIC devices, adjust the resource locking so that access to one I2C chain will lock both of the chains. Reviewed-by:
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Easwar Hariharan authored
The pre-LNI SerDes and channel tuning algorithm already checks for module presence assertion for the relevant port types. The extraneous check removed in this patch blocks link up for port types for which the module presence assertion is not relevant. Reviewed-by:
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Easwar Hariharan authored
Clock and data recovery mechanisms (CDRs) in active QSFP modules can be turned on or off to improve the bit error rate observed on the channel. Signal integrity and bit error rate requirements require us to always turn on any CDRs present in low power cables (power dissipation 2.5W or lower). However, we adhere to the platform designer's settings (provided in the platform configuration) for higher power cables (dissipation 3.5W or higher) if the platform designer has determined that the platform requires the CDRs to be turned on (or off) and is capable of supplying and cooling the higher power modules. This patch also introduces the get_qsfp_power_class function to centralize the bit twiddling required to determine the QSFP power class across the code. Reusing this function improves the readability of code that depends on knowing the power class of the cable, such as the active and optical channel tuning algorithm. Reviewed-by:
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Sebastian Sanchez authored
Add the P_KEY check for user-context mechanism for both PIO and SDMA. For PIO, the SendCtxtCheckEnable.DisallowKDETHPackets is set by default. When the P_KEY is set, SendCtxtCheckEnable.DisallowKDETHPackets is cleared. For SDMA, a software check was included. This change requires user processes to set the P_KEY before sending any packets, otherwise, the sent packet will fail. The original submission didn't have this check but it's required. Reviewed-by:
Mikto Haralanov <mitko.haralanov@intel.com> Signed-off-by:
Sebastian Sanchez <sebastian.sanchez@intel.com> Signed-off-by:
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Sebastian Sanchez authored
Increasing the default MTU size to 10KB improves performance for PSM. Change the default MTU to 10KB but constrain Verbs MTU to 8KB. Also update default MTU module parameter description to be HFI1_DEFAULT_MAX_MTU. Reviewed-by:
Jubin John <jubin.john@intel.com> Signed-off-by:
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Dean Luick authored
Make init_qpmap_table() easier to understand by simplifying the loop indexing and writing each register when it is "full", removing the need for a follow-on register write. Reviewed-by:
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Dean Luick authored
The function hdr2sc was using an unshifted mask to obtain the 5th bit of the service class. Correct the issue by using the shifted mask. Reviewed-by:
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Dean Luick authored
The QOS RSM rule mappings are off by one, referencing a kernel receive context that does not exist. Correctly start the QOS RSM map entries at FIRST_KERNEL_CONTEXT rather than MIN_KERNEL_KCTXTS. Remove the cruft that hid this. Change the QP map table so all traffic not caught by QOS RSM goes to the control context rather than the first QOS context. Correct comments to match the actual code operation and intent. Reviewed-by:
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Dean Luick authored
Remove an invalid compare of the number of QOS RSM map table entries against the number of physical receive contexts. The RSM map table has its own size and has no relation to the number of physical receive contexts. Reviewed-by:
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Dean Luick authored
The bit width for num_vls, n, needs to be calculated based on the pow2 rounded up of the number of vls. Otherwise num_vls of 3, 5, 6, and 7 will have misplaced QOS RSM map entries. Reviewed-by:
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Dean Luick authored
The i2c and qsfp read/write routines should check for the resource reservation of the incoming argument target rather than the implicit target of the hardware HFI. Reviewed-by:
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Dean Luick authored
Two sysfs files do not pay attention to the file offset when reading data. Fix that. Reviewed-by:
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Jubin John authored
rdi->ports has memory allocated in rvt_alloc_device(), but does not get freed because the hfi1 and qib drivers drivers call ib_dealloc_device() directly instead of going through rdmavt. Add a rvt_dealloc_device() that frees rdi->ports and then calls ib_dealloc_device(). Switch hfi1 and qib drivers to calling rvt_dealloc_device() instead of ib_dealloc_device() directly. Reviewed-by:
Brian Welty <brian.welty@intel.com> Signed-off-by:
Leon Romanovsky <leonro@mellanox.com> Signed-off-by:
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Mitko Haralanov authored
There are two possible causes for node/memory corruption both of which are related to the cache eviction algorithm. One way to cause corruption is due to the asynchronous nature of the MMU invalidation and the locking used when invalidating node. The MMU invalidation routine would temporarily release the RB tree lock to avoid a deadlock. However, this would allow the eviction function to take the lock resulting in the removal of cache nodes. If the node being removed by the eviction code is the same as the node being invalidated, the result is use after free. The same is true in the other direction due to the temporary release of the eviction list lock in the eviction loop. Another corner case exists when dealing with the SDMA buffer cache that could cause memory corruption of kernel memory. The most common way, in which this corruption exhibits itself is a linked list node corruption. In that case, the kernel will complain that a node with poisoned pointers is being removed. The fact that the pointers are already poisoned means that the node has already been removed from the list. To root cause of this corruption was a mishandling of the eviction list maintained by the driver. In order for this to happen four conditions need to be satisfied: 1. A node describing a user buffer already exists in the interval RB tree, 2. The beginning of the current user buffer matches that node but is bigger. This will cause the node to be extended. 3. The amount of cached buffers is close or at the limit of the buffer cache size. 4. The node has dropped close to the end of the eviction list. This will cause the node to be considered for eviction. If all of the above conditions have been satisfied, it is possible for the eviction algorithm to evict the current node, which will free the node without the driver knowing. To solve both issues described above: - the locking around the MMU invalidation loop and cache eviction loop has been improved so locks are not released in the loop body, - a new RB function is introduced which will "atomically" find and remove the matching node from the RB tree, preventing the MMU invalidation loop from touching it, and - the node being extended by the pin_vector_pages() function is removed from the eviction list prior to calling the eviction function. Reviewed-by: -
Mitko Haralanov authored
The page pinning function, which also maintains the pin cache, behaves one of two ways when an exact buffer match is not found: 1. If no node is not found (a buffer with the same starting address is not found in the cache), a new node is created, the buffer pages are pinned, and the node is inserted into the RB tree, or 2. If a node is found but the buffer in that node is a subset of the new user buffer, the node is extended with the new buffer pages. Both modes of operation require (re-)insertion into the interval RB tree. When the node being inserted is a new node, the operations are pretty simple. However, when the node is already existing and is being extended, special care must be taken. First, we want to guard against an asynchronous attempt to delete the node by the MMU invalidation notifier. The simplest way to do this is to remove the node from the RB tree, preventing the search algorithm from finding it. Second, the node needs to be re-inserted so it lands in the proper place in the tree and the tree is correctly re-balanced. This also requires the node to be removed from the RB tree. This commit adds the hfi1_mmu_rb_extract() function, which will search for a node in the interval RB tree matching an address and length and remove it from the RB tree if found. This allows for both of the above special cases be handled in a single step. Reviewed-by: -
Mitko Haralanov authored
The computation of the interval of an interval RB node was incorrect leading to data corruption due to the RB search algorithm not properly finding the all RB nodes in an MMU invalidation interval. The problem stemmed from the fact that the beginning address of the node's range was being aligned to a page boundary. For certain buffer sizes, this would lead to a end address calculation that was off by 1 page. An important aspect of keeping the RB same is also updating the node's range in the case it's being extended. Reviewed-by:
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Mitko Haralanov authored
The current implementation of the clean up function for the interval RB trees has two flaws which may cause problems in cases of concurrent executing of the function and MMU notifier. The flaws were due to the fact that deregistration of the MMU callbacks was done after the tree was emptied and, furthermore, the tree was not being locked. This commit fixes both of these flaws by, first, switch the order of operations, and, second, locking the tree while traversing it to prevent any other operations. Reviewed-by:
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Mitko Haralanov authored
The driver had two memory leaks - one in the user expected receive code and one in SDMA buffer cache. The leak in the expected receive code only showed up when the user/admin had set ulimit sufficiently low and the driver did not have enough room in the cache before hitting the limit of allowed cachable memory. When this condition occurred, the driver returned early signaling userland that it needed to free some buffers to free up room in the cache. The bug was that the driver was not cleaning up allocated memory prior to returning early. The leak in the SDMA buffer cache could occur (even though it never did), when the insertion of a buffer node in the interval RB tree failed. In this case, the driver failed to unpin the pages of the node instead erroneously returning success. Reviewed-by:
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Mitko Haralanov authored
The SDMA cache logic maintains an eviction list which is ordered by most recently used user buffers. Upon errors or buffer freeing, the list nodes were unconditionally being deleted. This would lead to list corruption warnings if the nodes were never inserted in the eviction list to begin with. This commit prevents this by checking that the nodes are already part of the eviction list. Reviewed-by:
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Mike Marciniszyn authored
The dual lock patch moved locking around and missed an issue with handling irq flags when processing UD loopback packets. This issue was revealed by smatch. Fix for both qib and hfi1 to pass the saved flags to the UD request builder and handle the changes correctly. Fixes: 46a80d62 ("IB/qib, staging/rdma/hfi1: add s_hlock for use in post send") Reported-by:
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Mike Marciniszyn authored
The RVT_S_WAIT_PIO_DRAIN flag was missing from the set of flags indicating a qp is waiting on a resource. This caused the sleep/wakeup for adaptive pio drain to lose a wakeup "hanging" a QP. Reviewed-by:
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Doug Ledford authored
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Doug Ledford authored
Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux into testing/4.6
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Jason Gunthorpe authored
The drivers/infiniband stack uses write() as a replacement for bi-directional ioctl(). This is not safe. There are ways to trigger write calls that result in the return structure that is normally written to user space being shunted off to user specified kernel memory instead. For the immediate repair, detect and deny suspicious accesses to the write API. For long term, update the user space libraries and the kernel API to something that doesn't present the same security vulnerabilities (likely a structured ioctl() interface). The impacted uAPI interfaces are generally only available if hardware from drivers/infiniband is installed in the system. Reported-by:
Jann Horn <jann@thejh.net> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by:
Jason Gunthorpe <jgunthorpe@obsidianresearch.com> [ Expanded check to all known write() entry points ] Cc: stable@vger.kernel.org Signed-off-by:
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Dean Luick authored
The ui device llseek had a mistake with SEEK_END and did not fully follow seek semantics. Correct all this by using a kernel supplied function for fixed size devices. Cc: Al Viro <viro@ZenIV.linux.org.uk> Reviewed-by:
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Mitko Haralanov authored
Attempting to free resources which have not been allocated and initialized properly led to the following kernel backtrace: BUG: unable to handle kernel NULL pointer dereference at (null) IP: [<ffffffffa09658fe>] unlock_exp_tids.isra.8+0x2e/0x120 [hfi1] PGD 852a43067 PUD 85d4a6067 PMD 0 Oops: 0000 [#1] SMP CPU: 0 PID: 2831 Comm: osu_bw Tainted: G IO 3.12.18-wfr+ #1 task: ffff88085b15b540 ti: ffff8808588fe000 task.ti: ffff8808588fe000 RIP: 0010:[<ffffffffa09658fe>] [<ffffffffa09658fe>] unlock_exp_tids.isra.8+0x2e/0x120 [hfi1] RSP: 0018:ffff8808588ffde0 EFLAGS: 00010282 RAX: 0000000000000000 RBX: ffff880858a31800 RCX: 0000000000000000 RDX: ffff88085d971bc0 RSI: ffff880858a318f8 RDI: ffff880858a318c0 RBP: ffff8808588ffe20 R08: 0000000000000000 R09: 0000000000000000 R10: ffff88087ffd6f40 R11: 0000000001100348 R12: ffff880852900000 R13: ffff880858a318c0 R14: 0000000000000000 R15: ffff88085d971be8 FS: 00007f4674e83740(0000) GS:ffff88087f400000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 000000085c377000 CR4: 00000000001407f0 Stack: ffffffffa0941a71 ffff880858a318f8 ffff88085d971bc0 ffff880858a31800 ffff880852900000 ffff880858a31800 00000000003ffff7 ffff88085d971bc0 ffff8808588ffe60 ffffffffa09663fc ffff8808588ffe60 ffff880858a31800 Call Trace: [<ffffffffa0941a71>] ? find_mmu_handler+0x51/0x70 [hfi1] [<ffffffffa09663fc>] hfi1_user_exp_rcv_free+0x6c/0x120 [hfi1] [<ffffffffa0932809>] hfi1_file_close+0x1a9/0x340 [hfi1] [<ffffffff8116c189>] __fput+0xe9/0x270 [<ffffffff8116c35e>] ____fput+0xe/0x10 [<ffffffff81065707>] task_work_run+0xa7/0xe0 [<ffffffff81002969>] do_notify_resume+0x59/0x80 [<ffffffff814ffc1a>] int_signal+0x12/0x17 This commit re-arranges the context initialization code in a way that would allow for context event flags to be used to determine whether the context has been successfully initialized. In turn, this can be used to skip the resource de-allocation if they were never allocated in the first place. Fixes: 3abb33ac ("staging/hfi1: Add TID cache receive init and free funcs") Reviewed-by: -
Mike Marciniszyn authored
The iowait_sdma_drained() callback lacked locking to protect the qp s_flags field. This causes the s_flags to be out of sync on multiple CPUs, potentially corrupting the s_flags. Fixes: a545f530 ("staging/rdma/hfi: fix CQ completion order issue") Reviewed-by:
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Jubin John authored
call_send is used to determine whether to send immediately or schedule a send for later. The current logic in rdmavt is inverted and has a negative impact on the latency of the hfi1 and qib drivers. Fix this regression by correctly calling send immediately when call_send is set. Reviewed-by:
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Mitko Haralanov authored
The routine used by the SDMA cache to handle already cached nodes can extend an already existing node. In its error handling code, the routine will unpin pages when not all pages of the buffer extension were pinned. There was a bug in that part of the routine, which would mistakenly unpin pages from the original set rather than the newly pinned pages. This commit fixes that bug by offsetting the page array to the proper place pointing at the beginning of the newly pinned pages. Reviewed-by:
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Mitko Haralanov authored
The locking around the interval RB tree is designed to prevent access to the tree while it's being modified. The locking in its current form is too overzealous, which is causing a deadlock in certain cases with the following backtrace: Kernel panic - not syncing: Watchdog detected hard LOCKUP on cpu 0 CPU: 0 PID: 5836 Comm: IMB-MPI1 Tainted: G O 3.12.18-wfr+ #1 0000000000000000 ffff88087f206c50 ffffffff814f1caa ffffffff817b53f0 ffff88087f206cc8 ffffffff814ecd56 0000000000000010 ffff88087f206cd8 ffff88087f206c78 0000000000000000 0000000000000000 0000000000001662 Call Trace: <NMI> [<ffffffff814f1caa>] dump_stack+0x45/0x56 [<ffffffff814ecd56>] panic+0xc2/0x1cb [<ffffffff810d4370>] ? restart_watchdog_hrtimer+0x50/0x50 [<ffffffff810d4432>] watchdog_overflow_callback+0xc2/0xd0 [<ffffffff81109b4e>] __perf_event_overflow+0x8e/0x2b0 [<ffffffff8110a714>] perf_event_overflow+0x14/0x20 [<ffffffff8101c906>] intel_pmu_handle_irq+0x1b6/0x390 [<ffffffff814f927b>] perf_event_nmi_handler+0x2b/0x50 [<ffffffff814f8ad8>] nmi_handle.isra.3+0x88/0x180 [<ffffffff814f8d39>] do_nmi+0x169/0x310 [<ffffffff814f8177>] end_repeat_nmi+0x1e/0x2e [<ffffffff81272600>] ? unmap_single+0x30/0x30 [<ffffffff814f780d>] ? _raw_spin_lock_irqsave+0x2d/0x40 [<ffffffff814f780d>] ? _raw_spin_lock_irqsave+0x2d/0x40 [<ffffffff814f780d>] ? _raw_spin_lock_irqsave+0x2d/0x40 <<EOE>> <IRQ> [<ffffffffa056c4a8>] hfi1_mmu_rb_search+0x38/0x70 [hfi1] [<ffffffffa05919cb>] user_sdma_free_request+0xcb/0x120 [hfi1] [<ffffffffa0593393>] user_sdma_txreq_cb+0x263/0x350 [hfi1] [<ffffffffa057fad7>] ? sdma_txclean+0x27/0x1c0 [hfi1] [<ffffffffa0593130>] ? user_sdma_send_pkts+0x1710/0x1710 [hfi1] [<ffffffffa057fdd6>] sdma_make_progress+0x166/0x480 [hfi1] [<ffffffff810762c9>] ? ttwu_do_wakeup+0x19/0xd0 [<ffffffffa0581c7e>] sdma_engine_interrupt+0x8e/0x100 [hfi1] [<ffffffffa0546bdd>] sdma_interrupt+0x5d/0xa0 [hfi1] [<ffffffff81097e57>] handle_irq_event_percpu+0x47/0x1d0 [<ffffffff81098017>] handle_irq_event+0x37/0x60 [<ffffffff8109aa5f>] handle_edge_irq+0x6f/0x120 [<ffffffff810044af>] handle_irq+0xbf/0x150 [<ffffffff8104c9b7>] ? irq_enter+0x17/0x80 [<ffffffff8150168d>] do_IRQ+0x4d/0xc0 [<ffffffff814f7c6a>] common_interrupt+0x6a/0x6a <EOI> [<ffffffff81073524>] ? finish_task_switch+0x54/0xe0 [<ffffffff814f56c6>] __schedule+0x3b6/0x7e0 [<ffffffff810763a6>] __cond_resched+0x26/0x30 [<ffffffff814f5eda>] _cond_resched+0x3a/0x50 [<ffffffff814f4f82>] down_write+0x12/0x30 [<ffffffffa0591619>] hfi1_release_user_pages+0x69/0x90 [hfi1] [<ffffffffa059173a>] sdma_rb_remove+0x9a/0xc0 [hfi1] [<ffffffffa056c00d>] __mmu_rb_remove.isra.5+0x5d/0x70 [hfi1] [<ffffffffa056c536>] hfi1_mmu_rb_remove+0x56/0x70 [hfi1] [<ffffffffa059427b>] hfi1_user_sdma_process_request+0x74b/0x1160 [hfi1] [<ffffffffa055c763>] hfi1_aio_write+0xc3/0x100 [hfi1] [<ffffffff8116a14c>] do_sync_readv_writev+0x4c/0x80 [<ffffffff8116b58b>] do_readv_writev+0xbb/0x230 [<ffffffff811a9da1>] ? fsnotify+0x241/0x320 [<ffffffff81073524>] ? finish_task_switch+0x54/0xe0 [<ffffffff8116b795>] vfs_writev+0x35/0x60 [<ffffffff8116b8c9>] SyS_writev+0x49/0xc0 [<ffffffff810cd876>] ? __audit_syscall_exit+0x1f6/0x2a0 [<ffffffff814ff992>] system_call_fastpath+0x16/0x1b As evident from the backtrace above, the process was being put to sleep while holding the lock. Limiting the scope of the lock only to the RB tree operation fixes the above error allowing for proper locking and the process being put to sleep when needed. Reviewed-by: -
Mitko Haralanov authored
There is a potential kernel crash when the MMU notifier calls the invalidation routines in the hfi1 pinned page caching code for sdma. The invalidation routine could call the remove callback for the node, which in turn ends up dereferencing the current task_struct to get a pointer to the mm_struct. However, the mm_struct pointer could be NULL resulting in the following backtrace: BUG: unable to handle kernel NULL pointer dereference at 00000000000000a8 IP: [<ffffffffa041f75a>] sdma_rb_remove+0xaa/0x100 [hfi1] 15 task: ffff88085e66e080 ti: ffff88085c244000 task.ti: ffff88085c244000 RIP: 0010:[<ffffffffa041f75a>] [<ffffffffa041f75a>] sdma_rb_remove+0xaa/0x100 [hfi1] RSP: 0000:ffff88085c245878 EFLAGS: 00010002 RAX: 0000000000000000 RBX: ffff88105b9bbd40 RCX: ffffea003931a830 RDX: 0000000000000004 RSI: ffff88105754a9c0 RDI: ffff88105754a9c0 RBP: ffff88085c245890 R08: ffff88105b9bbd70 R09: 00000000fffffffb R10: ffff88105b9bbd58 R11: 0000000000000013 R12: ffff88105754a9c0 R13: 0000000000000001 R14: 0000000000000001 R15: ffff88105b9bbd40 FS: 0000000000000000(0000) GS:ffff88107ef40000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000000000a8 CR3: 0000000001a0b000 CR4: 00000000001407e0 Stack: ffff88105b9bbd40 ffff88080ec481a8 ffff88080ec481b8 ffff88085c2458c0 ffffffffa03fa00e ffff88080ec48190 ffff88080ed9cd00 0000000001024000 0000000000000000 ffff88085c245920 ffffffffa03fa0e7 0000000000000282 Call Trace: [<ffffffffa03fa00e>] __mmu_rb_remove.isra.5+0x5e/0x70 [hfi1] [<ffffffffa03fa0e7>] mmu_notifier_mem_invalidate+0xc7/0xf0 [hfi1] [<ffffffffa03fa143>] mmu_notifier_page+0x13/0x20 [hfi1] [<ffffffff81156dd0>] __mmu_notifier_invalidate_page+0x50/0x70 [<ffffffff81140bbb>] try_to_unmap_one+0x20b/0x470 [<ffffffff81141ee7>] try_to_unmap_anon+0xa7/0x120 [<ffffffff81141fad>] try_to_unmap+0x4d/0x60 [<ffffffff8111fd7b>] shrink_page_list+0x2eb/0x9d0 [<ffffffff81120ab3>] shrink_inactive_list+0x243/0x490 [<ffffffff81121491>] shrink_lruvec+0x4c1/0x640 [<ffffffff81121641>] shrink_zone+0x31/0x100 [<ffffffff81121b0f>] kswapd_shrink_zone.constprop.62+0xef/0x1c0 [<ffffffff811229e3>] kswapd+0x403/0x7e0 [<ffffffff811225e0>] ? shrink_all_memory+0xf0/0xf0 [<ffffffff81068ac0>] kthread+0xc0/0xd0 [<ffffffff81068a00>] ? insert_kthread_work+0x40/0x40 [<ffffffff814ff8ec>] ret_from_fork+0x7c/0xb0 [<ffffffff81068a00>] ? insert_kthread_work+0x40/0x40 To correct this, the mm_struct passed to us by the MMU notifier is used (which is what should have been done to begin with). This avoids the broken derefences and ensures that the correct mm_struct is used. Reviewed-by: -
Sagi Grimberg authored
Signed-off-by:
Sagi Grimberg <sagi@grimberg.me> Acked-by:
Nicholas Bellinger <nab@linux-iscsi.org> Signed-off-by:
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Sagi Grimberg authored
mlx5 devices (Connect-IB, ConnectX-4, ConnectX-4-LX) has a limitation where rdma read work queue entries cannot exceed 512 bytes. A rdma_read wqe needs to fit in 512 bytes: - wqe control segment (16 bytes) - rdma segment (16 bytes) - scatter elements (16 bytes each) So max_sge_rd should be: (512 - 16 - 16) / 16 = 30. Cc: linux-stable@vger.kernel.org Reported-by:
Christoph Hellwig <hch@lst.de> Tested-by:
Sagi Grimberg <sagig@grimberg.me> Signed-off-by:
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- 27 Apr, 2016 4 commits
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git://git.kernel.org/pub/scm/linux/kernel/git/tj/wqLinus Torvalds authored
Pull workqueue fix from Tejun Heo: "So, it turns out we had a silly bug in the most fundamental part of workqueue for a very long time. AFAICS, this dates back to pre-git era and has quite likely been there from the time workqueue was first introduced. A work item uses its PENDING bit to synchronize multiple queuers. Anyone who wins the PENDING bit owns the pending state of the work item. Whether a queuer wins or loses the race, one thing should be guaranteed - there will soon be at least one execution of the work item - where "after" means that the execution instance would be able to see all the changes that the queuer has made prior to the queueing attempt. Unfortunately, we were missing a smp_mb() after clearing PENDING for execution, so nothing guaranteed visibility of the changes that a queueing loser has made, which manifested as a reproducible blk-mq stall. Lots of kudos to Roman for debugging the problem. The patch for -stable is the minimal one. For v3.7, Peter is working on a patch to make the code path slightly more efficient and less fragile" * 'for-4.6-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq: workqueue: fix ghost PENDING flag while doing MQ IO
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git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroupLinus Torvalds authored
Pull cgroup fixes from Tejun Heo: "Two patches to fix a deadlock which can be easily triggered if memcg charge moving is used. This bug was introduced while converting threadgroup locking to a global percpu_rwsem and is caused by cgroup controller task migration path depending on the ability to create new kthreads. cpuset had a similar issue which was fixed by performing heavy-lifting operations asynchronous to task migration. The two patches fix the same issue in memcg in a similar way. The first patch makes the mechanism generic and the second relocates memcg charge moving outside the migration path. Given that we don't want to perform heavy operations while writelocking threadgroup lock anyway, moving them out of the way is a desirable solution. One thing to note is that the problem was difficult to debug because lockdep couldn't figure out the deadlock condition. Looking into how to improve that" * 'for-4.6-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: memcg: relocate charge moving from ->attach to ->post_attach cgroup, cpuset: replace cpuset_post_attach_flush() with cgroup_subsys->post_attach callback
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git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linuxLinus Torvalds authored
Pull i2c fixes from Wolfram Sang: "I2C has one buildfix, one ABBA deadlock fix, and three simple 'add ID' patches" * 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: i2c: exynos5: Fix possible ABBA deadlock by keeping I2C clock prepared i2c: cpm: Fix build break due to incompatible pointer types i2c: ismt: Add Intel DNV PCI ID i2c: xlp9xx: add support for Broadcom Vulcan i2c: rk3x: add support for rk3228
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git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arcLinus Torvalds authored
Pull ARC fixes from Vineet Gupta: - lockdep now works for ARCv2 builds - enable DT reserved-memory binding (for forthcoming HDMI driver) * tag 'arc-4.6-rc6-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc: ARC: add support for reserved memory defined by device tree ARC: support generic per-device coherent dma mem Documentation: dt: arc: fix spelling mistakes ARCv2: Enable LOCKDEP
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