kernel/linux.git/drivers/hv, branch v4.19.39

Drivers: hv: vmbus: Check for ring when getting debug info

2019-01-31T07:14:36+00:00

commit ba50bf1ce9a51fc97db58b96d01306aa70bc3979 upstream. fc96df16a1ce is good and can already fix the "return stack garbage" issue, but let's also improve hv_ringbuffer_get_debuginfo(), which would silently return stack garbage, if people forget to check channel->state or ring_info->ring_buffer, when using the function in the future. Having an error check in the function would eliminate the potential risk. Add a Fixes tag to indicate the patch depdendency. Fixes: fc96df16a1ce ("Drivers: hv: vmbus: Return -EINVAL for the sys files for unopened channels") Cc: stable@vger.kernel.org Cc: K. Y. Srinivasan Cc: Haiyang Zhang Signed-off-by: Stephen Hemminger Signed-off-by: Dexuan Cui Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

hv_balloon: avoid touching uninitialized struct page during tail onlining

2019-01-31T07:14:36+00:00

commit da8ced360ca8ad72d8f41f5c8fcd5b0e63e1555f upstream. Hyper-V memory hotplug protocol has 2M granularity and in Linux x86 we use 128M. To deal with it we implement partial section onlining by registering custom page onlining callback (hv_online_page()). Later, when more memory arrives we try to online the 'tail' (see hv_bring_pgs_online()). It was found that in some cases this 'tail' onlining causes issues: BUG: Bad page state in process kworker/0:2 pfn:109e3a page:ffffe08344278e80 count:0 mapcount:1 mapping:0000000000000000 index:0x0 flags: 0xfffff80000000() raw: 000fffff80000000 dead000000000100 dead000000000200 0000000000000000 raw: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 page dumped because: nonzero mapcount ... Workqueue: events hot_add_req [hv_balloon] Call Trace: dump_stack+0x5c/0x80 bad_page.cold.112+0x7f/0xb2 free_pcppages_bulk+0x4b8/0x690 free_unref_page+0x54/0x70 hv_page_online_one+0x5c/0x80 [hv_balloon] hot_add_req.cold.24+0x182/0x835 [hv_balloon] ... Turns out that we now have deferred struct page initialization for memory hotplug so e.g. memory_block_action() in drivers/base/memory.c does pages_correctly_probed() check and in that check it avoids inspecting struct pages and checks sections instead. But in Hyper-V balloon driver we do PageReserved(pfn_to_page()) check and this is now wrong. Switch to checking online_section_nr() instead. Signed-off-by: Vitaly Kuznetsov Cc: stable@kernel.org Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

x86, hyperv: remove PCI dependency

2019-01-13T08:51:00+00:00

[ Upstream commit c629421a990033ba539eb8585e73a2e6fa9ea631 ] Need to be able to boot without PCI devices present. Signed-off-by: Sinan Kaya Signed-off-by: Sasha Levin

Drivers: hv: vmbus: Return -EINVAL for the sys files for unopened channels

2018-12-29T12:37:56+00:00

commit fc96df16a1ce80cbb3c316ab7d4dc8cd5c2852ce upstream. Before 98f4c651762c, we returned zeros for unopened channels. With 98f4c651762c, we started to return random on-stack values. We'd better return -EINVAL instead. Fixes: 98f4c651762c ("hv: move ringbuffer bus attributes to dev_groups") Cc: stable@vger.kernel.org Cc: K. Y. Srinivasan Cc: Haiyang Zhang Cc: Stephen Hemminger Signed-off-by: Dexuan Cui Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

Drivers: hv: vmbus: Offload the handling of channels to two workqueues

2018-12-13T08:16:22+00:00

commit 37c2578c0c40e286bc0d30bdc05290b2058cf66e upstream. vmbus_process_offer() mustn't call channel->sc_creation_callback() directly for sub-channels, because sc_creation_callback() -> vmbus_open() may never get the host's response to the OPEN_CHANNEL message (the host may rescind a channel at any time, e.g. in the case of hot removing a NIC), and vmbus_onoffer_rescind() may not wake up the vmbus_open() as it's blocked due to a non-zero vmbus_connection.offer_in_progress, and finally we have a deadlock. The above is also true for primary channels, if the related device drivers use sync probing mode by default. And, usually the handling of primary channels and sub-channels can depend on each other, so we should offload them to different workqueues to avoid possible deadlock, e.g. in sync-probing mode, NIC1's netvsc_subchan_work() can race with NIC2's netvsc_probe() -> rtnl_lock(), and causes deadlock: the former gets the rtnl_lock and waits for all the sub-channels to appear, but the latter can't get the rtnl_lock and this blocks the handling of sub-channels. The patch can fix the multiple-NIC deadlock described above for v3.x kernels (e.g. RHEL 7.x) which don't support async-probing of devices, and v4.4, v4.9, v4.14 and v4.18 which support async-probing but don't enable async-probing for Hyper-V drivers (yet). The patch can also fix the hang issue in sub-channel's handling described above for all versions of kernels, including v4.19 and v4.20-rc4. So actually the patch should be applied to all the existing kernels, not only the kernels that have 8195b1396ec8. Fixes: 8195b1396ec8 ("hv_netvsc: fix deadlock on hotplug") Cc: stable@vger.kernel.org Cc: Stephen Hemminger Cc: K. Y. Srinivasan Cc: Haiyang Zhang Signed-off-by: Dexuan Cui Signed-off-by: K. Y. Srinivasan Signed-off-by: Greg Kroah-Hartman

Drivers: hv: vmbus: check the creation_status in vmbus_establish_gpadl()

2018-12-05T18:32:14+00:00

commit eceb05965489784f24bbf4d61ba60e475a983016 upstream. This is a longstanding issue: if the vmbus upper-layer drivers try to consume too many GPADLs, the host may return with an error 0xC0000044 (STATUS_QUOTA_EXCEEDED), but currently we forget to check the creation_status, and hence we can pass an invalid GPADL handle into the OPEN_CHANNEL message, and get an error code 0xc0000225 in open_info->response.open_result.status, and finally we hang in vmbus_open() -> "goto error_free_info" -> vmbus_teardown_gpadl(). With this patch, we can exit gracefully on STATUS_QUOTA_EXCEEDED. Cc: Stephen Hemminger Cc: K. Y. Srinivasan Cc: Haiyang Zhang Cc: stable@vger.kernel.org Signed-off-by: Dexuan Cui Signed-off-by: K. Y. Srinivasan Signed-off-by: Greg Kroah-Hartman

Drivers: hv: vmbus: Use cpumask_var_t for on-stack cpu mask

2018-11-13T19:08:34+00:00

[ Upstream commit 25355252607ca288f329ee033f387764883393f6 ] A cpumask structure on the stack can cause a warning with CONFIG_NR_CPUS=8192 (e.g. Ubuntu 16.04 and 18.04 use this): drivers/hv//channel_mgmt.c: In function ‘init_vp_index’: drivers/hv//channel_mgmt.c:702:1: warning: the frame size of 1032 bytes is larger than 1024 bytes [-Wframe-larger-than=] Nowadays it looks most distros enable CONFIG_CPUMASK_OFFSTACK=y, and hence we can work around the warning by using cpumask_var_t. Signed-off-by: Dexuan Cui Cc: K. Y. Srinivasan Cc: Haiyang Zhang Cc: Stephen Hemminger Cc: Signed-off-by: K. Y. Srinivasan Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

Drivers: hv: vmbus: Use get/put_cpu() in vmbus_connect()

2018-09-30T15:49:55+00:00

With CONFIG_DEBUG_PREEMPT=y, I always see this warning: BUG: using smp_processor_id() in preemptible [00000000] Fix the false warning by using get/put_cpu(). Here vmbus_connect() sends a message to the host and waits for the host's response. The host will deliver the response message and an interrupt on CPU msg->target_vcpu, and later the interrupt handler will wake up vmbus_connect(). vmbus_connect() doesn't really have to run on the same cpu as CPU msg->target_vcpu, so it's safe to call put_cpu() just here. Signed-off-by: Dexuan Cui Cc: stable@vger.kernel.org Cc: K. Y. Srinivasan Cc: Haiyang Zhang Cc: Stephen Hemminger Signed-off-by: K. Y. Srinivasan Signed-off-by: Greg Kroah-Hartman

vmbus: don't return values for uninitalized channels

2018-09-12T07:31:00+00:00

For unsupported device types, the vmbus channel ringbuffer is never initialized, and therefore reading the sysfs files will return garbage or cause a kernel OOPS. Fixes: c2e5df616e1a ("vmbus: add per-channel sysfs info") Signed-off-by: Stephen Hemminger Signed-off-by: K. Y. Srinivasan Cc: # 4.15 Signed-off-by: Greg Kroah-Hartman

Drivers: hv: vmbus: Cleanup synic memory free path

2018-08-02T08:20:59+00:00

clk_evt memory is not being freed when the synic is shutdown or when there is an allocation error. Add the appropriate kfree() call, along with a comment to clarify how the memory gets freed after an allocation error. Make the free path consistent by removing checks for NULL since kfree() and free_page() already do the check. Signed-off-by: Michael Kelley Reported-by: Dan Carpenter Signed-off-by: K. Y. Srinivasan Signed-off-by: Greg Kroah-Hartman