From e72e7ac583ee8adddbc668cdefde7d7d3021be79 Mon Sep 17 00:00:00 2001 From: Vitaly Kuznetsov Date: Fri, 27 Feb 2015 11:25:55 -0800 Subject: [PATCH] drivers: hv: vmbus: Teardown synthetic interrupt controllers on module unload SynIC has to be switched off when we unload the module, otherwise registered memory pages can get corrupted after (as Hyper-V host still writes there) and we see the following crashes for random processes: [ 89.116774] BUG: Bad page map in process sh pte:4989c716 pmd:36f81067 [ 89.159454] addr:0000000000437000 vm_flags:00000875 anon_vma: (null) mapping:ffff88007bba55a0 index:37 [ 89.226146] vma->vm_ops->fault: filemap_fault+0x0/0x410 [ 89.257776] vma->vm_file->f_op->mmap: generic_file_mmap+0x0/0x60 [ 89.297570] CPU: 0 PID: 215 Comm: sh Tainted: G B 3.19.0-rc5_bug923184+ #488 [ 89.353738] Hardware name: Microsoft Corporation Virtual Machine/Virtual Machine, BIOS 090006 05/23/2012 [ 89.409138] 0000000000000000 000000004e083d7b ffff880036e9fa18 ffffffff81a68d31 [ 89.468724] 0000000000000000 0000000000437000 ffff880036e9fa68 ffffffff811a1e3a [ 89.519233] 000000004989c716 0000000000000037 ffffea0001edc340 0000000000437000 [ 89.575751] Call Trace: [ 89.591060] [] dump_stack+0x45/0x57 [ 89.625164] [] print_bad_pte+0x1aa/0x250 [ 89.667234] [] vm_normal_page+0x55/0xa0 [ 89.703818] [] unmap_page_range+0x425/0x8a0 [ 89.737982] [] unmap_single_vma+0x81/0xf0 [ 89.780385] [] ? lru_deactivate_fn+0x190/0x190 [ 89.820130] [] unmap_vmas+0x51/0xa0 [ 89.860168] [] exit_mmap+0xac/0x1a0 [ 89.890588] [] mmput+0x63/0x100 [ 89.919205] [] flush_old_exec+0x3f8/0x8b0 [ 89.962135] [] load_elf_binary+0x32b/0x1260 [ 89.998581] [] ? get_user_pages+0x52/0x60 hv_synic_cleanup() function exists but noone calls it now. Do the following: - call hv_synic_cleanup() on each cpu from vmbus_exit(); - write global disable bit through MSR; - use hv_synic_free_cpu() to avoid memory leask and code duplication. Signed-off-by: Vitaly Kuznetsov Signed-off-by: K. Y. Srinivasan Signed-off-by: Greg Kroah-Hartman --- drivers/hv/hv.c | 9 +++++++-- drivers/hv/vmbus_drv.c | 4 ++++ 2 files changed, 11 insertions(+), 2 deletions(-) diff --git a/drivers/hv/hv.c b/drivers/hv/hv.c index 50e51a51ff8b..39531dcf582f 100644 --- a/drivers/hv/hv.c +++ b/drivers/hv/hv.c @@ -477,6 +477,7 @@ void hv_synic_cleanup(void *arg) union hv_synic_sint shared_sint; union hv_synic_simp simp; union hv_synic_siefp siefp; + union hv_synic_scontrol sctrl; int cpu = smp_processor_id(); if (!hv_context.synic_initialized) @@ -502,6 +503,10 @@ void hv_synic_cleanup(void *arg) wrmsrl(HV_X64_MSR_SIEFP, siefp.as_uint64); - free_page((unsigned long)hv_context.synic_message_page[cpu]); - free_page((unsigned long)hv_context.synic_event_page[cpu]); + /* Disable the global synic bit */ + rdmsrl(HV_X64_MSR_SCONTROL, sctrl.as_uint64); + sctrl.enable = 0; + wrmsrl(HV_X64_MSR_SCONTROL, sctrl.as_uint64); + + hv_synic_free_cpu(cpu); } diff --git a/drivers/hv/vmbus_drv.c b/drivers/hv/vmbus_drv.c index 76db97de09fd..d8233d4513a5 100644 --- a/drivers/hv/vmbus_drv.c +++ b/drivers/hv/vmbus_drv.c @@ -1029,11 +1029,15 @@ cleanup: static void __exit vmbus_exit(void) { + int cpu; + vmbus_connection.conn_state = DISCONNECTED; hv_remove_vmbus_irq(); vmbus_free_channels(); bus_unregister(&hv_bus); hv_cleanup(); + for_each_online_cpu(cpu) + smp_call_function_single(cpu, hv_synic_cleanup, NULL, 1); acpi_bus_unregister_driver(&vmbus_acpi_driver); hv_cpu_hotplug_quirk(false); vmbus_disconnect(); -- 2.20.1