From: Mike Marciniszyn mike.marciniszyn@intel.com
commit be8638344c70bf492963ace206a9896606b6922d upstream.
Cleaning up a pq can result in the following warning and panic:
WARNING: CPU: 52 PID: 77418 at lib/list_debug.c:53 __list_del_entry+0x63/0xd0 list_del corruption, ffff88cb2c6ac068->next is LIST_POISON1 (dead000000000100) Modules linked in: mmfs26(OE) mmfslinux(OE) tracedev(OE) 8021q garp mrp ib_isert iscsi_target_mod target_core_mod crc_t10dif crct10dif_generic opa_vnic rpcrdma ib_iser libiscsi scsi_transport_iscsi ib_ipoib(OE) bridge stp llc iTCO_wdt iTCO_vendor_support intel_powerclamp coretemp intel_rapl iosf_mbi kvm_intel kvm irqbypass crct10dif_pclmul crct10dif_common crc32_pclmul ghash_clmulni_intel ast aesni_intel ttm lrw gf128mul glue_helper ablk_helper drm_kms_helper cryptd syscopyarea sysfillrect sysimgblt fb_sys_fops drm pcspkr joydev lpc_ich mei_me drm_panel_orientation_quirks i2c_i801 mei wmi ipmi_si ipmi_devintf ipmi_msghandler nfit libnvdimm acpi_power_meter acpi_pad hfi1(OE) rdmavt(OE) rdma_ucm ib_ucm ib_uverbs ib_umad rdma_cm ib_cm iw_cm ib_core binfmt_misc numatools(OE) xpmem(OE) ip_tables nfsv3 nfs_acl nfs lockd grace sunrpc fscache igb ahci i2c_algo_bit libahci dca ptp libata pps_core crc32c_intel [last unloaded: i2c_algo_bit] CPU: 52 PID: 77418 Comm: pvbatch Kdump: loaded Tainted: G OE ------------ 3.10.0-957.38.3.el7.x86_64 #1 Hardware name: HPE.COM HPE SGI 8600-XA730i Gen10/X11DPT-SB-SG007, BIOS SBED1229 01/22/2019 Call Trace: [<ffffffff90365ac0>] dump_stack+0x19/0x1b [<ffffffff8fc98b78>] __warn+0xd8/0x100 [<ffffffff8fc98bff>] warn_slowpath_fmt+0x5f/0x80 [<ffffffff8ff970c3>] __list_del_entry+0x63/0xd0 [<ffffffff8ff9713d>] list_del+0xd/0x30 [<ffffffff8fddda70>] kmem_cache_destroy+0x50/0x110 [<ffffffffc0328130>] hfi1_user_sdma_free_queues+0xf0/0x200 [hfi1] [<ffffffffc02e2350>] hfi1_file_close+0x70/0x1e0 [hfi1] [<ffffffff8fe4519c>] __fput+0xec/0x260 [<ffffffff8fe453fe>] ____fput+0xe/0x10 [<ffffffff8fcbfd1b>] task_work_run+0xbb/0xe0 [<ffffffff8fc2bc65>] do_notify_resume+0xa5/0xc0 [<ffffffff90379134>] int_signal+0x12/0x17 BUG: unable to handle kernel NULL pointer dereference at 0000000000000010 IP: [<ffffffff8fe1f93e>] kmem_cache_close+0x7e/0x300 PGD 2cdab19067 PUD 2f7bfdb067 PMD 0 Oops: 0000 [#1] SMP Modules linked in: mmfs26(OE) mmfslinux(OE) tracedev(OE) 8021q garp mrp ib_isert iscsi_target_mod target_core_mod crc_t10dif crct10dif_generic opa_vnic rpcrdma ib_iser libiscsi scsi_transport_iscsi ib_ipoib(OE) bridge stp llc iTCO_wdt iTCO_vendor_support intel_powerclamp coretemp intel_rapl iosf_mbi kvm_intel kvm irqbypass crct10dif_pclmul crct10dif_common crc32_pclmul ghash_clmulni_intel ast aesni_intel ttm lrw gf128mul glue_helper ablk_helper drm_kms_helper cryptd syscopyarea sysfillrect sysimgblt fb_sys_fops drm pcspkr joydev lpc_ich mei_me drm_panel_orientation_quirks i2c_i801 mei wmi ipmi_si ipmi_devintf ipmi_msghandler nfit libnvdimm acpi_power_meter acpi_pad hfi1(OE) rdmavt(OE) rdma_ucm ib_ucm ib_uverbs ib_umad rdma_cm ib_cm iw_cm ib_core binfmt_misc numatools(OE) xpmem(OE) ip_tables nfsv3 nfs_acl nfs lockd grace sunrpc fscache igb ahci i2c_algo_bit libahci dca ptp libata pps_core crc32c_intel [last unloaded: i2c_algo_bit] CPU: 52 PID: 77418 Comm: pvbatch Kdump: loaded Tainted: G W OE ------------ 3.10.0-957.38.3.el7.x86_64 #1 Hardware name: HPE.COM HPE SGI 8600-XA730i Gen10/X11DPT-SB-SG007, BIOS SBED1229 01/22/2019 task: ffff88cc26db9040 ti: ffff88b5393a8000 task.ti: ffff88b5393a8000 RIP: 0010:[<ffffffff8fe1f93e>] [<ffffffff8fe1f93e>] kmem_cache_close+0x7e/0x300 RSP: 0018:ffff88b5393abd60 EFLAGS: 00010287 RAX: 0000000000000000 RBX: ffff88cb2c6ac000 RCX: 0000000000000003 RDX: 0000000000000400 RSI: 0000000000000400 RDI: ffffffff9095b800 RBP: ffff88b5393abdb0 R08: ffffffff9095b808 R09: ffffffff8ff77c19 R10: ffff88b73ce1f160 R11: ffffddecddde9800 R12: ffff88cb2c6ac000 R13: 000000000000000c R14: ffff88cf3fdca780 R15: 0000000000000000 FS: 00002aaaaab52500(0000) GS:ffff88b73ce00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000010 CR3: 0000002d27664000 CR4: 00000000007607e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 PKRU: 55555554 Call Trace: [<ffffffff8fe20d44>] __kmem_cache_shutdown+0x14/0x80 [<ffffffff8fddda78>] kmem_cache_destroy+0x58/0x110 [<ffffffffc0328130>] hfi1_user_sdma_free_queues+0xf0/0x200 [hfi1] [<ffffffffc02e2350>] hfi1_file_close+0x70/0x1e0 [hfi1] [<ffffffff8fe4519c>] __fput+0xec/0x260 [<ffffffff8fe453fe>] ____fput+0xe/0x10 [<ffffffff8fcbfd1b>] task_work_run+0xbb/0xe0 [<ffffffff8fc2bc65>] do_notify_resume+0xa5/0xc0 [<ffffffff90379134>] int_signal+0x12/0x17 Code: 00 00 ba 00 04 00 00 0f 4f c2 3d 00 04 00 00 89 45 bc 0f 84 e7 01 00 00 48 63 45 bc 49 8d 04 c4 48 89 45 b0 48 8b 80 c8 00 00 00 <48> 8b 78 10 48 89 45 c0 48 83 c0 10 48 89 45 d0 48 8b 17 48 39 RIP [<ffffffff8fe1f93e>] kmem_cache_close+0x7e/0x300 RSP <ffff88b5393abd60> CR2: 0000000000000010
The panic is the result of slab entries being freed during the destruction of the pq slab.
The code attempts to quiesce the pq, but looking for n_req == 0 doesn't account for new requests.
Fix the issue by using SRCU to get a pq pointer and adjust the pq free logic to NULL the fd pq pointer prior to the quiesce.
Fixes: e87473bc1b6c ("IB/hfi1: Only set fd pointer when base context is completely initialized") Link: https://lore.kernel.org/r/20200210131033.87408.81174.stgit@awfm-01.aw.intel.... Reviewed-by: Kaike Wan kaike.wan@intel.com Signed-off-by: Mike Marciniszyn mike.marciniszyn@intel.com Signed-off-by: Dennis Dalessandro dennis.dalessandro@intel.com Signed-off-by: Jason Gunthorpe jgg@mellanox.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/infiniband/hw/hfi1/file_ops.c | 52 ++++++++++++++++++------------ drivers/infiniband/hw/hfi1/hfi.h | 5 ++ drivers/infiniband/hw/hfi1/user_exp_rcv.c | 3 - drivers/infiniband/hw/hfi1/user_sdma.c | 17 ++++++--- 4 files changed, 48 insertions(+), 29 deletions(-)
--- a/drivers/infiniband/hw/hfi1/file_ops.c +++ b/drivers/infiniband/hw/hfi1/file_ops.c @@ -200,23 +200,24 @@ static int hfi1_file_open(struct inode *
fd = kzalloc(sizeof(*fd), GFP_KERNEL);
- if (fd) { - fd->rec_cpu_num = -1; /* no cpu affinity by default */ - fd->mm = current->mm; - mmgrab(fd->mm); - fd->dd = dd; - kobject_get(&fd->dd->kobj); - fp->private_data = fd; - } else { - fp->private_data = NULL; - - if (atomic_dec_and_test(&dd->user_refcount)) - complete(&dd->user_comp); - - return -ENOMEM; - } - + if (!fd || init_srcu_struct(&fd->pq_srcu)) + goto nomem; + spin_lock_init(&fd->pq_rcu_lock); + spin_lock_init(&fd->tid_lock); + spin_lock_init(&fd->invalid_lock); + fd->rec_cpu_num = -1; /* no cpu affinity by default */ + fd->mm = current->mm; + mmgrab(fd->mm); + fd->dd = dd; + kobject_get(&fd->dd->kobj); + fp->private_data = fd; return 0; +nomem: + kfree(fd); + fp->private_data = NULL; + if (atomic_dec_and_test(&dd->user_refcount)) + complete(&dd->user_comp); + return -ENOMEM; }
static long hfi1_file_ioctl(struct file *fp, unsigned int cmd, @@ -301,21 +302,30 @@ static long hfi1_file_ioctl(struct file static ssize_t hfi1_write_iter(struct kiocb *kiocb, struct iov_iter *from) { struct hfi1_filedata *fd = kiocb->ki_filp->private_data; - struct hfi1_user_sdma_pkt_q *pq = fd->pq; + struct hfi1_user_sdma_pkt_q *pq; struct hfi1_user_sdma_comp_q *cq = fd->cq; int done = 0, reqs = 0; unsigned long dim = from->nr_segs; + int idx;
- if (!cq || !pq) + idx = srcu_read_lock(&fd->pq_srcu); + pq = srcu_dereference(fd->pq, &fd->pq_srcu); + if (!cq || !pq) { + srcu_read_unlock(&fd->pq_srcu, idx); return -EIO; + }
- if (!iter_is_iovec(from) || !dim) + if (!iter_is_iovec(from) || !dim) { + srcu_read_unlock(&fd->pq_srcu, idx); return -EINVAL; + }
trace_hfi1_sdma_request(fd->dd, fd->uctxt->ctxt, fd->subctxt, dim);
- if (atomic_read(&pq->n_reqs) == pq->n_max_reqs) + if (atomic_read(&pq->n_reqs) == pq->n_max_reqs) { + srcu_read_unlock(&fd->pq_srcu, idx); return -ENOSPC; + }
while (dim) { int ret; @@ -333,6 +343,7 @@ static ssize_t hfi1_write_iter(struct ki reqs++; }
+ srcu_read_unlock(&fd->pq_srcu, idx); return reqs; }
@@ -707,6 +718,7 @@ done: if (atomic_dec_and_test(&dd->user_refcount)) complete(&dd->user_comp);
+ cleanup_srcu_struct(&fdata->pq_srcu); kfree(fdata); return 0; } --- a/drivers/infiniband/hw/hfi1/hfi.h +++ b/drivers/infiniband/hw/hfi1/hfi.h @@ -1436,10 +1436,13 @@ struct mmu_rb_handler;
/* Private data for file operations */ struct hfi1_filedata { + struct srcu_struct pq_srcu; struct hfi1_devdata *dd; struct hfi1_ctxtdata *uctxt; struct hfi1_user_sdma_comp_q *cq; - struct hfi1_user_sdma_pkt_q *pq; + /* update side lock for SRCU */ + spinlock_t pq_rcu_lock; + struct hfi1_user_sdma_pkt_q __rcu *pq; u16 subctxt; /* for cpu affinity; -1 if none */ int rec_cpu_num; --- a/drivers/infiniband/hw/hfi1/user_exp_rcv.c +++ b/drivers/infiniband/hw/hfi1/user_exp_rcv.c @@ -87,9 +87,6 @@ int hfi1_user_exp_rcv_init(struct hfi1_f { int ret = 0;
- spin_lock_init(&fd->tid_lock); - spin_lock_init(&fd->invalid_lock); - fd->entry_to_rb = kcalloc(uctxt->expected_count, sizeof(struct rb_node *), GFP_KERNEL); --- a/drivers/infiniband/hw/hfi1/user_sdma.c +++ b/drivers/infiniband/hw/hfi1/user_sdma.c @@ -179,7 +179,6 @@ int hfi1_user_sdma_alloc_queues(struct h pq = kzalloc(sizeof(*pq), GFP_KERNEL); if (!pq) return -ENOMEM; - pq->dd = dd; pq->ctxt = uctxt->ctxt; pq->subctxt = fd->subctxt; @@ -236,7 +235,7 @@ int hfi1_user_sdma_alloc_queues(struct h goto pq_mmu_fail; }
- fd->pq = pq; + rcu_assign_pointer(fd->pq, pq); fd->cq = cq;
return 0; @@ -264,8 +263,14 @@ int hfi1_user_sdma_free_queues(struct hf
trace_hfi1_sdma_user_free_queues(uctxt->dd, uctxt->ctxt, fd->subctxt);
- pq = fd->pq; + spin_lock(&fd->pq_rcu_lock); + pq = srcu_dereference_check(fd->pq, &fd->pq_srcu, + lockdep_is_held(&fd->pq_rcu_lock)); if (pq) { + rcu_assign_pointer(fd->pq, NULL); + spin_unlock(&fd->pq_rcu_lock); + synchronize_srcu(&fd->pq_srcu); + /* at this point there can be no more new requests */ if (pq->handler) hfi1_mmu_rb_unregister(pq->handler); iowait_sdma_drain(&pq->busy); @@ -277,7 +282,8 @@ int hfi1_user_sdma_free_queues(struct hf kfree(pq->req_in_use); kmem_cache_destroy(pq->txreq_cache); kfree(pq); - fd->pq = NULL; + } else { + spin_unlock(&fd->pq_rcu_lock); } if (fd->cq) { vfree(fd->cq->comps); @@ -321,7 +327,8 @@ int hfi1_user_sdma_process_request(struc { int ret = 0, i; struct hfi1_ctxtdata *uctxt = fd->uctxt; - struct hfi1_user_sdma_pkt_q *pq = fd->pq; + struct hfi1_user_sdma_pkt_q *pq = + srcu_dereference(fd->pq, &fd->pq_srcu); struct hfi1_user_sdma_comp_q *cq = fd->cq; struct hfi1_devdata *dd = pq->dd; unsigned long idx = 0;