From 09dc9cd6528f5b52bcbd3292a6312e762c85260f Mon Sep 17 00:00:00 2001 From: Mike Marciniszyn Date: Thu, 7 Jan 2016 16:44:10 -0500 Subject: [PATCH] IB/qib: fix mcast detach when qp not attached The code produces the following trace: [1750924.419007] general protection fault: 0000 [#3] SMP [1750924.420364] Modules linked in: nfnetlink autofs4 rpcsec_gss_krb5 nfsv4 dcdbas rfcomm bnep bluetooth nfsd auth_rpcgss nfs_acl dm_multipath nfs lockd scsi_dh sunrpc fscache radeon ttm drm_kms_helper drm serio_raw parport_pc ppdev i2c_algo_bit lpc_ich ipmi_si ib_mthca ib_qib dca lp parport ib_ipoib mac_hid ib_cm i3000_edac ib_sa ib_uverbs edac_core ib_umad ib_mad ib_core ib_addr tg3 ptp dm_mirror dm_region_hash dm_log psmouse pps_core [1750924.420364] CPU: 1 PID: 8401 Comm: python Tainted: G D 3.13.0-39-generic #66-Ubuntu [1750924.420364] Hardware name: Dell Computer Corporation PowerEdge 860/0XM089, BIOS A04 07/24/2007 [1750924.420364] task: ffff8800366a9800 ti: ffff88007af1c000 task.ti: ffff88007af1c000 [1750924.420364] RIP: 0010:[] [] qib_mcast_qp_free+0x11/0x50 [ib_qib] [1750924.420364] RSP: 0018:ffff88007af1dd70 EFLAGS: 00010246 [1750924.420364] RAX: 0000000000000001 RBX: ffff88007b822688 RCX: 000000000000000f [1750924.420364] RDX: ffff88007b822688 RSI: ffff8800366c15a0 RDI: 6764697200000000 [1750924.420364] RBP: ffff88007af1dd78 R08: 0000000000000001 R09: 0000000000000000 [1750924.420364] R10: 0000000000000011 R11: 0000000000000246 R12: ffff88007baa1d98 [1750924.420364] R13: ffff88003ecab000 R14: ffff88007b822660 R15: 0000000000000000 [1750924.420364] FS: 00007ffff7fd8740(0000) GS:ffff88007fc80000(0000) knlGS:0000000000000000 [1750924.420364] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [1750924.420364] CR2: 00007ffff597c750 CR3: 000000006860b000 CR4: 00000000000007e0 [1750924.420364] Stack: [1750924.420364] ffff88007b822688 ffff88007af1ddf0 ffffffffa0132429 000000007af1de20 [1750924.420364] ffff88007baa1dc8 ffff88007baa0000 ffff88007af1de70 ffffffffa00cb313 [1750924.420364] 00007fffffffde88 0000000000000000 0000000000000008 ffff88003ecab000 [1750924.420364] Call Trace: [1750924.420364] [] qib_multicast_detach+0x1e9/0x350 [ib_qib] [1750924.568035] [] ? ib_uverbs_modify_qp+0x323/0x3d0 [ib_uverbs] [1750924.568035] [] ib_detach_mcast+0x31/0x50 [ib_core] [1750924.568035] [] ib_uverbs_detach_mcast+0x93/0x170 [ib_uverbs] [1750924.568035] [] ib_uverbs_write+0xc6/0x2c0 [ib_uverbs] [1750924.568035] [] ? apparmor_file_permission+0x18/0x20 [1750924.568035] [] ? security_file_permission+0x23/0xa0 [1750924.568035] [] vfs_write+0xb4/0x1f0 [1750924.568035] [] SyS_write+0x49/0xa0 [1750924.568035] [] system_call_fastpath+0x1a/0x1f [1750924.568035] Code: 66 2e 0f 1f 84 00 00 00 00 00 31 c0 5d c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 0f 1f 44 00 00 55 48 89 e5 53 48 89 fb 48 8b 7f 10 ff 8f 40 01 00 00 74 0e 48 89 df e8 8e f8 06 e1 5b 5d c3 0f [1750924.568035] RIP [] qib_mcast_qp_free+0x11/0x50 [ib_qib] [1750924.568035] RSP [1750924.650439] ---[ end trace 73d5d4b3f8ad4851 ] The fix is to note the qib_mcast_qp that was found. If none is found, then return EINVAL indicating the error. Cc: Reviewed-by: Dennis Dalessandro Reported-by: Jason Gunthorpe Signed-off-by: Mike Marciniszyn Signed-off-by: Doug Ledford --- drivers/infiniband/hw/qib/qib_verbs_mcast.c | 35 +++++++++------------ 1 file changed, 15 insertions(+), 20 deletions(-) diff --git a/drivers/infiniband/hw/qib/qib_verbs_mcast.c b/drivers/infiniband/hw/qib/qib_verbs_mcast.c index f8ea069a3eaf..b2fb5286dbd9 100644 --- a/drivers/infiniband/hw/qib/qib_verbs_mcast.c +++ b/drivers/infiniband/hw/qib/qib_verbs_mcast.c @@ -286,15 +286,13 @@ int qib_multicast_detach(struct ib_qp *ibqp, union ib_gid *gid, u16 lid) struct qib_ibdev *dev = to_idev(ibqp->device); struct qib_ibport *ibp = to_iport(ibqp->device, qp->port_num); struct qib_mcast *mcast = NULL; - struct qib_mcast_qp *p, *tmp; + struct qib_mcast_qp *p, *tmp, *delp = NULL; struct rb_node *n; int last = 0; int ret; - if (ibqp->qp_num <= 1 || qp->state == IB_QPS_RESET) { - ret = -EINVAL; - goto bail; - } + if (ibqp->qp_num <= 1 || qp->state == IB_QPS_RESET) + return -EINVAL; spin_lock_irq(&ibp->lock); @@ -303,8 +301,7 @@ int qib_multicast_detach(struct ib_qp *ibqp, union ib_gid *gid, u16 lid) while (1) { if (n == NULL) { spin_unlock_irq(&ibp->lock); - ret = -EINVAL; - goto bail; + return -EINVAL; } mcast = rb_entry(n, struct qib_mcast, rb_node); @@ -328,6 +325,7 @@ int qib_multicast_detach(struct ib_qp *ibqp, union ib_gid *gid, u16 lid) */ list_del_rcu(&p->list); mcast->n_attached--; + delp = p; /* If this was the last attached QP, remove the GID too. */ if (list_empty(&mcast->qp_list)) { @@ -338,15 +336,16 @@ int qib_multicast_detach(struct ib_qp *ibqp, union ib_gid *gid, u16 lid) } spin_unlock_irq(&ibp->lock); + /* QP not attached */ + if (!delp) + return -EINVAL; + /* + * Wait for any list walkers to finish before freeing the + * list element. + */ + wait_event(mcast->wait, atomic_read(&mcast->refcount) <= 1); + qib_mcast_qp_free(delp); - if (p) { - /* - * Wait for any list walkers to finish before freeing the - * list element. - */ - wait_event(mcast->wait, atomic_read(&mcast->refcount) <= 1); - qib_mcast_qp_free(p); - } if (last) { atomic_dec(&mcast->refcount); wait_event(mcast->wait, !atomic_read(&mcast->refcount)); @@ -355,11 +354,7 @@ int qib_multicast_detach(struct ib_qp *ibqp, union ib_gid *gid, u16 lid) dev->n_mcast_grps_allocated--; spin_unlock_irq(&dev->n_mcast_grps_lock); } - - ret = 0; - -bail: - return ret; + return 0; } int qib_mcast_tree_empty(struct qib_ibport *ibp) -- 2.20.1