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path: root/drivers/misc/vmw_vmci/vmci_doorbell.c
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2019-08-28VMCI: Release resource if the work is already queuedNadav Amit1-2/+4
Francois reported that VMware balloon gets stuck after a balloon reset, when the VMCI doorbell is removed. A similar error can occur when the balloon driver is removed with the following splat: [ 1088.622000] INFO: task modprobe:3565 blocked for more than 120 seconds. [ 1088.622035] Tainted: G W 5.2.0 #4 [ 1088.622087] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 1088.622205] modprobe D 0 3565 1450 0x00000000 [ 1088.622210] Call Trace: [ 1088.622246] __schedule+0x2a8/0x690 [ 1088.622248] schedule+0x2d/0x90 [ 1088.622250] schedule_timeout+0x1d3/0x2f0 [ 1088.622252] wait_for_completion+0xba/0x140 [ 1088.622320] ? wake_up_q+0x80/0x80 [ 1088.622370] vmci_resource_remove+0xb9/0xc0 [vmw_vmci] [ 1088.622373] vmci_doorbell_destroy+0x9e/0xd0 [vmw_vmci] [ 1088.622379] vmballoon_vmci_cleanup+0x6e/0xf0 [vmw_balloon] [ 1088.622381] vmballoon_exit+0x18/0xcc8 [vmw_balloon] [ 1088.622394] __x64_sys_delete_module+0x146/0x280 [ 1088.622408] do_syscall_64+0x5a/0x130 [ 1088.622410] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 1088.622415] RIP: 0033:0x7f54f62791b7 [ 1088.622421] Code: Bad RIP value. [ 1088.622421] RSP: 002b:00007fff2a949008 EFLAGS: 00000206 ORIG_RAX: 00000000000000b0 [ 1088.622426] RAX: ffffffffffffffda RBX: 000055dff8b55d00 RCX: 00007f54f62791b7 [ 1088.622426] RDX: 0000000000000000 RSI: 0000000000000800 RDI: 000055dff8b55d68 [ 1088.622427] RBP: 000055dff8b55d00 R08: 00007fff2a947fb1 R09: 0000000000000000 [ 1088.622427] R10: 00007f54f62f5cc0 R11: 0000000000000206 R12: 000055dff8b55d68 [ 1088.622428] R13: 0000000000000001 R14: 000055dff8b55d68 R15: 00007fff2a94a3f0 The cause for the bug is that when the "delayed" doorbell is invoked, it takes a reference on the doorbell entry and schedules work that is supposed to run the appropriate code and drop the doorbell entry reference. The code ignores the fact that if the work is already queued, it will not be scheduled to run one more time. As a result one of the references would not be dropped. When the code waits for the reference to get to zero, during balloon reset or module removal, it gets stuck. Fix it. Drop the reference if schedule_work() indicates that the work is already queued. Note that this bug got more apparent (or apparent at all) due to commit ce664331b248 ("vmw_balloon: VMCI_DOORBELL_SET does not check status"). Fixes: 83e2ec765be03 ("VMCI: doorbell implementation.") Reported-by: Francois Rigault <rigault.francois@gmail.com> Cc: Jorgen Hansen <jhansen@vmware.com> Cc: Adit Ranadive <aditr@vmware.com> Cc: Alexios Zavras <alexios.zavras@intel.com> Cc: Vishnu DASA <vdasa@vmware.com> Cc: stable@vger.kernel.org Signed-off-by: Nadav Amit <namit@vmware.com> Reviewed-by: Vishnu Dasa <vdasa@vmware.com> Link: https://lore.kernel.org/r/20190820202638.49003-1-namit@vmware.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-05treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 321Thomas Gleixner1-9/+1
Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation version 2 and no later version this program is distributed in the hope that it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 33 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Alexios Zavras <alexios.zavras@intel.com> Reviewed-by: Allison Randal <allison@lohutok.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190530000435.345978407@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-26VMCI: Support upto 64-bit PPNsVishnu DASA1-3/+6
Add support in the VMCI driver to handle upto 64-bit PPNs when the VMCI device exposes the capability for 64-bit PPNs. Reviewed-by: Adit Ranadive <aditr@vmware.com> Reviewed-by: Jorgen Hansen <jhansen@vmware.com> Signed-off-by: Vishnu Dasa <vdasa@vmware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-10-28VMCI: Doorbell create and destroy fixesJorgen Hansen1-1/+7
This change consists of two changes: 1) If vmci_doorbell_create is called when neither guest nor host personality as been initialized, vmci_get_context_id will return VMCI_INVALID_ID. In that case, we should fail the create call. 2) In doorbell destroy, we assume that vmci_guest_code_active() has the same return value on create and destroy. That may not be the case, so we may end up with the wrong refcount. Instead, destroy should check explicitly whether the doorbell is in the index table as an indicator of whether the guest code was active at create time. Reviewed-by: Adit Ranadive <aditr@vmware.com> Signed-off-by: Jorgen Hansen <jhansen@vmware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-02-28hlist: drop the node parameter from iteratorsSasha Levin1-5/+2
I'm not sure why, but the hlist for each entry iterators were conceived list_for_each_entry(pos, head, member) The hlist ones were greedy and wanted an extra parameter: hlist_for_each_entry(tpos, pos, head, member) Why did they need an extra pos parameter? I'm not quite sure. Not only they don't really need it, it also prevents the iterator from looking exactly like the list iterator, which is unfortunate. Besides the semantic patch, there was some manual work required: - Fix up the actual hlist iterators in linux/list.h - Fix up the declaration of other iterators based on the hlist ones. - A very small amount of places were using the 'node' parameter, this was modified to use 'obj->member' instead. - Coccinelle didn't handle the hlist_for_each_entry_safe iterator properly, so those had to be fixed up manually. The semantic patch which is mostly the work of Peter Senna Tschudin is here: @@ iterator name hlist_for_each_entry, hlist_for_each_entry_continue, hlist_for_each_entry_from, hlist_for_each_entry_rcu, hlist_for_each_entry_rcu_bh, hlist_for_each_entry_continue_rcu_bh, for_each_busy_worker, ax25_uid_for_each, ax25_for_each, inet_bind_bucket_for_each, sctp_for_each_hentry, sk_for_each, sk_for_each_rcu, sk_for_each_from, sk_for_each_safe, sk_for_each_bound, hlist_for_each_entry_safe, hlist_for_each_entry_continue_rcu, nr_neigh_for_each, nr_neigh_for_each_safe, nr_node_for_each, nr_node_for_each_safe, for_each_gfn_indirect_valid_sp, for_each_gfn_sp, for_each_host; type T; expression a,c,d,e; identifier b; statement S; @@ -T b; <+... when != b ( hlist_for_each_entry(a, - b, c, d) S | hlist_for_each_entry_continue(a, - b, c) S | hlist_for_each_entry_from(a, - b, c) S | hlist_for_each_entry_rcu(a, - b, c, d) S | hlist_for_each_entry_rcu_bh(a, - b, c, d) S | hlist_for_each_entry_continue_rcu_bh(a, - b, c) S | for_each_busy_worker(a, c, - b, d) S | ax25_uid_for_each(a, - b, c) S | ax25_for_each(a, - b, c) S | inet_bind_bucket_for_each(a, - b, c) S | sctp_for_each_hentry(a, - b, c) S | sk_for_each(a, - b, c) S | sk_for_each_rcu(a, - b, c) S | sk_for_each_from -(a, b) +(a) S + sk_for_each_from(a) S | sk_for_each_safe(a, - b, c, d) S | sk_for_each_bound(a, - b, c) S | hlist_for_each_entry_safe(a, - b, c, d, e) S | hlist_for_each_entry_continue_rcu(a, - b, c) S | nr_neigh_for_each(a, - b, c) S | nr_neigh_for_each_safe(a, - b, c, d) S | nr_node_for_each(a, - b, c) S | nr_node_for_each_safe(a, - b, c, d) S | - for_each_gfn_sp(a, c, d, b) S + for_each_gfn_sp(a, c, d) S | - for_each_gfn_indirect_valid_sp(a, c, d, b) S + for_each_gfn_indirect_valid_sp(a, c, d) S | for_each_host(a, - b, c) S | for_each_host_safe(a, - b, c, d) S | for_each_mesh_entry(a, - b, c, d) S ) ...+> [akpm@linux-foundation.org: drop bogus change from net/ipv4/raw.c] [akpm@linux-foundation.org: drop bogus hunk from net/ipv6/raw.c] [akpm@linux-foundation.org: checkpatch fixes] [akpm@linux-foundation.org: fix warnings] [akpm@linux-foudnation.org: redo intrusive kvm changes] Tested-by: Peter Senna Tschudin <peter.senna@gmail.com> Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Sasha Levin <sasha.levin@oracle.com> Cc: Wu Fengguang <fengguang.wu@intel.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Gleb Natapov <gleb@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-01-09VMCI: doorbell implementation.George Zhang1-0/+604
VMCI doorbell code allows for notifcations between host and guest. Signed-off-by: George Zhang <georgezhang@vmware.com> Acked-by: Andy king <acking@vmware.com> Acked-by: Dmitry Torokhov <dtor@vmware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>