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2021-04-27Merge tag 'printk-for-5.13' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux Pull printk updates from Petr Mladek: - Stop synchronizing kernel log buffer readers by logbuf_lock. As a result, the access to the buffer is fully lockless now. Note that printk() itself still uses locks because it tries to flush the messages to the console immediately. Also the per-CPU temporary buffers are still there because they prevent infinite recursion and serialize backtraces from NMI. All this is going to change in the future. - kmsg_dump API rework and cleanup as a side effect of the logbuf_lock removal. - Make bstr_printf() aware that %pf and %pF formats could deference the given pointer. - Show also page flags by %pGp format. - Clarify the documentation for plain pointer printing. - Do not show no_hash_pointers warning multiple times. - Update Senozhatsky email address. - Some clean up. * tag 'printk-for-5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux: (24 commits) lib/vsprintf.c: remove leftover 'f' and 'F' cases from bstr_printf() printk: clarify the documentation for plain pointer printing kernel/printk.c: Fixed mundane typos printk: rename vprintk_func to vprintk vsprintf: dump full information of page flags in pGp mm, slub: don't combine pr_err with INFO mm, slub: use pGp to print page flags MAINTAINERS: update Senozhatsky email address lib/vsprintf: do not show no_hash_pointers message multiple times printk: console: remove unnecessary safe buffer usage printk: kmsg_dump: remove _nolock() variants printk: remove logbuf_lock printk: introduce a kmsg_dump iterator printk: kmsg_dumper: remove @active field printk: add syslog_lock printk: use atomic64_t for devkmsg_user.seq printk: use seqcount_latch for clear_seq printk: introduce CONSOLE_LOG_MAX printk: consolidate kmsg_dump_get_buffer/syslog_print_all code printk: refactor kmsg_dump_get_buffer() ...
2021-04-21drivers: hv: Create a consistent pattern for checking Hyper-V hypercall statusJoseph Salisbury
There is not a consistent pattern for checking Hyper-V hypercall status. Existing code uses a number of variants. The variants work, but a consistent pattern would improve the readability of the code, and be more conformant to what the Hyper-V TLFS says about hypercall status. Implemented new helper functions hv_result(), hv_result_success(), and hv_repcomp(). Changed the places where hv_do_hypercall() and related variants are used to use the helper functions. Signed-off-by: Joseph Salisbury <joseph.salisbury@microsoft.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Link: https://lore.kernel.org/r/1618620183-9967-2-git-send-email-joseph.salisbury@linux.microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
2021-04-20Drivers: hv: vmbus: Increase wait time for VMbus unloadMichael Kelley
When running in Azure, disks may be connected to a Linux VM with read/write caching enabled. If a VM panics and issues a VMbus UNLOAD request to Hyper-V, the response is delayed until all dirty data in the disk cache is flushed. In extreme cases, this flushing can take 10's of seconds, depending on the disk speed and the amount of dirty data. If kdump is configured for the VM, the current 10 second timeout in vmbus_wait_for_unload() may be exceeded, and the UNLOAD complete message may arrive well after the kdump kernel is already running, causing problems. Note that no problem occurs if kdump is not enabled because Hyper-V waits for the cache flush before doing a reboot through the BIOS/UEFI code. Fix this problem by increasing the timeout in vmbus_wait_for_unload() to 100 seconds. Also output periodic messages so that if anyone is watching the serial console, they won't think the VM is completely hung. Fixes: 911e1987efc8 ("Drivers: hv: vmbus: Add timeout to vmbus_wait_for_unload") Signed-off-by: Michael Kelley <mikelley@microsoft.com> Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com> Link: https://lore.kernel.org/r/1618894089-126662-1-git-send-email-mikelley@microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
2021-04-20Drivers: hv: vmbus: Initialize unload_event staticallyAndrea Parri (Microsoft)
If a malicious or compromised Hyper-V sends a spurious message of type CHANNELMSG_UNLOAD_RESPONSE, the function vmbus_unload_response() will call complete() on an uninitialized event, and cause an oops. Reported-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Link: https://lore.kernel.org/r/20210420014350.2002-1-parri.andrea@gmail.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
2021-04-18Drivers: hv: vmbus: Check for pending channel interrupts before taking a CPU ↵Andrea Parri (Microsoft)
offline Check that enough time has passed such that the modify channel message has been processed before taking a CPU offline. Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Link: https://lore.kernel.org/r/20210416143449.16185-4-parri.andrea@gmail.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
2021-04-18Drivers: hv: vmbus: Drivers: hv: vmbus: Introduce ↵Andrea Parri (Microsoft)
CHANNELMSG_MODIFYCHANNEL_RESPONSE Introduce the CHANNELMSG_MODIFYCHANNEL_RESPONSE message type, and code to receive and process such a message. Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Link: https://lore.kernel.org/r/20210416143449.16185-3-parri.andrea@gmail.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
2021-04-18Drivers: hv: vmbus: Introduce and negotiate VMBus protocol version 5.3Andrea Parri (Microsoft)
Hyper-V has added VMBus protocol version 5.3. Allow Linux guests to negotiate the new version on version of Hyper-V that support it. Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Link: https://lore.kernel.org/r/20210416143449.16185-2-parri.andrea@gmail.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
2021-04-16Drivers: hv: vmbus: Use after free in __vmbus_open()Dan Carpenter
The "open_info" variable is added to the &vmbus_connection.chn_msg_list, but the error handling frees "open_info" without removing it from the list. This will result in a use after free. First remove it from the list, and then free it. Fixes: 6f3d791f3006 ("Drivers: hv: vmbus: Fix rescind handling issues") Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Reviewed-by: Andrea Parri <parri.andrea@gmail.com> Link: https://lore.kernel.org/r/YHV3XLCot6xBS44r@mwanda Signed-off-by: Wei Liu <wei.liu@kernel.org>
2021-04-14Drivers: hv: vmbus: remove unused functionJiapeng Chong
Fix the following clang warning: drivers/hv/ring_buffer.c:89:1: warning: unused function 'hv_set_next_read_location' [-Wunused-function]. Reported-by: Abaci Robot <abaci@linux.alibaba.com> Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Link: https://lore.kernel.org/r/1618381282-119135-1-git-send-email-jiapeng.chong@linux.alibaba.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
2021-04-02Drivers: hv: vmbus: Remove unused linux/version.h headerQiheng Lin
That file is not needed in hv.c. Reported-by: Hulk Robot <hulkci@huawei.com> Signed-off-by: Qiheng Lin <linqiheng@huawei.com> Link: https://lore.kernel.org/r/20210331060646.2471-1-linqiheng@huawei.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
2021-03-24x86/Hyper-V: Support for free page reportingSunil Muthuswamy
Linux has support for free page reporting now (36e66c554b5c) for virtualized environment. On Hyper-V when virtually backed VMs are configured, Hyper-V will advertise cold memory discard capability, when supported. This patch adds the support to hook into the free page reporting infrastructure and leverage the Hyper-V cold memory discard hint hypercall to report/free these pages back to the host. Signed-off-by: Sunil Muthuswamy <sunilmut@microsoft.com> Tested-by: Matheus Castello <matheus@castello.eng.br> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Tested-by: Nathan Chancellor <nathan@kernel.org> Link: https://lore.kernel.org/r/SN4PR2101MB0880121FA4E2FEC67F35C1DCC0649@SN4PR2101MB0880.namprd21.prod.outlook.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
2021-03-22drivers: hv: Fix EXPORT_SYMBOL and tab spaces issueVasanth
1.Fixed EXPORT_SYMBOL should be follow immediately function/variable. 2.Fixed code tab spaces issue. Signed-off-by: Vasanth M <vasanth3g@gmail.com> Link: https://lore.kernel.org/r/20210310052155.39460-1-vasanth3g@gmail.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
2021-03-22Drivers: hv: vmbus: Drop error message when 'No request id available'Andrea Parri (Microsoft)
Running out of request IDs on a channel essentially produces the same effect as running out of space in the ring buffer, in that -EAGAIN is returned. The error message in hv_ringbuffer_write() should either be dropped (since we don't output a message when the ring buffer is full) or be made conditional/debug-only. Suggested-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com> Fixes: e8b7db38449ac ("Drivers: hv: vmbus: Add vmbus_requestor data structure for VMBus hardening") Link: https://lore.kernel.org/r/20210301191348.196485-1-parri.andrea@gmail.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
2021-03-08Drivers: hv: vmbus: Move handling of VMbus interruptsMichael Kelley
VMbus interrupts are most naturally modelled as per-cpu IRQs. But because x86/x64 doesn't have per-cpu IRQs, the core VMbus interrupt handling machinery is done in code under arch/x86 and Linux IRQs are not used. Adding support for ARM64 means adding equivalent code using per-cpu IRQs under arch/arm64. A better model is to treat per-cpu IRQs as the normal path (which it is for modern architectures), and the x86/x64 path as the exception. Do this by incorporating standard Linux per-cpu IRQ allocation into the main VMbus driver, and bypassing it in the x86/x64 exception case. For x86/x64, special case code is retained under arch/x86, but no VMbus interrupt handling code is needed under arch/arm64. No functional change. Signed-off-by: Michael Kelley <mikelley@microsoft.com> Reviewed-by: Boqun Feng <boqun.feng@gmail.com> Link: https://lore.kernel.org/r/1614721102-2241-7-git-send-email-mikelley@microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
2021-03-08Drivers: hv: vmbus: Handle auto EOI quirk inlineMichael Kelley
On x86/x64, Hyper-V provides a flag to indicate auto EOI functionality, but it doesn't on ARM64. Handle this quirk inline instead of calling into code under arch/x86 (and coming, under arch/arm64). No functional change. Signed-off-by: Michael Kelley <mikelley@microsoft.com> Reviewed-by: Boqun Feng <boqun.feng@gmail.com> Link: https://lore.kernel.org/r/1614721102-2241-6-git-send-email-mikelley@microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
2021-03-08Drivers: hv: vmbus: Move hyperv_report_panic_msg to arch neutral codeMichael Kelley
With the new Hyper-V MSR set function, hyperv_report_panic_msg() can be architecture neutral, so move it out from under arch/x86 and merge into hv_kmsg_dump(). This move also avoids needing a separate implementation under arch/arm64. No functional change. Signed-off-by: Michael Kelley <mikelley@microsoft.com> Reviewed-by: Boqun Feng <boqun.feng@gmail.com> Link: https://lore.kernel.org/r/1614721102-2241-5-git-send-email-mikelley@microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
2021-03-08Drivers: hv: Redo Hyper-V synthetic MSR get/set functionsMichael Kelley
Current code defines a separate get and set macro for each Hyper-V synthetic MSR used by the VMbus driver. Furthermore, the get macro can't be converted to a standard function because the second argument is modified in place, which is somewhat bad form. Redo this by providing a single get and a single set function that take a parameter specifying the MSR to be operated on. Fixup usage of the get function. Calling locations are no more complex than before, but the code under arch/x86 and the upcoming code under arch/arm64 is significantly simplified. Also standardize the names of Hyper-V synthetic MSRs that are architecture neutral. But keep the old x86-specific names as aliases that can be removed later when all references (particularly in KVM code) have been cleaned up in a separate patch series. No functional change. Signed-off-by: Michael Kelley <mikelley@microsoft.com> Reviewed-by: Boqun Feng <boqun.feng@gmail.com> Link: https://lore.kernel.org/r/1614721102-2241-4-git-send-email-mikelley@microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
2021-03-08Drivers: hv: vmbus: Move Hyper-V page allocator to arch neutral codeMichael Kelley
The Hyper-V page allocator functions are implemented in an architecture neutral way. Move them into the architecture neutral VMbus module so a separate implementation for ARM64 is not needed. No functional change. Signed-off-by: Michael Kelley <mikelley@microsoft.com> Reviewed-by: Boqun Feng <boqun.feng@gmail.com> Link: https://lore.kernel.org/r/1614721102-2241-2-git-send-email-mikelley@microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
2021-03-08drivers: hv: Fix whitespace errorsVasanth
Fixed checkpatch warning and errors on hv driver. Signed-off-by: Vasanth Mathivanan <vasanth3g@gmail.com> Link: https://lore.kernel.org/r/20210219171311.421961-1-vasanth3g@gmail.com Reviewed-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2021-03-08printk: introduce a kmsg_dump iteratorJohn Ogness
Rather than storing the iterator information in the registered kmsg_dumper structure, create a separate iterator structure. The kmsg_dump_iter structure can reside on the stack of the caller, thus allowing lockless use of the kmsg_dump functions. Update code that accesses the kernel logs using the kmsg_dumper structure to use the new kmsg_dump_iter structure. For kmsg_dumpers, this also means adding a call to kmsg_dump_rewind() to initialize the iterator. All this is in preparation for removal of @logbuf_lock. Signed-off-by: John Ogness <john.ogness@linutronix.de> Reviewed-by: Kees Cook <keescook@chromium.org> # pstore Reviewed-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20210303101528.29901-13-john.ogness@linutronix.de
2021-02-26mm/memory_hotplug: MEMHP_MERGE_RESOURCE -> MHP_MERGE_RESOURCEDavid Hildenbrand
Let's make "MEMHP_MERGE_RESOURCE" consistent with "MHP_NONE", "mhp_t" and "mhp_flags". As discussed recently [1], "mhp" is our internal acronym for memory hotplug now. [1] https://lore.kernel.org/linux-mm/c37de2d0-28a1-4f7d-f944-cfd7d81c334d@redhat.com/ Link: https://lkml.kernel.org/r/20210126115829.10909-1-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Miaohe Lin <linmiaohe@huawei.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Oscar Salvador <osalvador@suse.de> Acked-by: Wei Liu <wei.liu@kernel.org> Reviewed-by: Pankaj Gupta <pankaj.gupta@cloud.ionos.com> Cc: "K. Y. Srinivasan" <kys@microsoft.com> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: Stephen Hemminger <sthemmin@microsoft.com> Cc: Jason Wang <jasowang@redhat.com> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Juergen Gross <jgross@suse.com> Cc: Stefano Stabellini <sstabellini@kernel.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Wei Yang <richard.weiyang@linux.alibaba.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-15Revert "Drivers: hv: vmbus: Copy packets sent by Hyper-V out of the ring buffer"Wei Liu
This reverts commit a8c3209998afb5c4941b49e35b513cea9050cb4a. It is reported that the said commit caused regression in netvsc. Reported-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2021-02-11Drivers: hv: vmbus: skip VMBus initialization if Linux is rootWei Liu
There is no VMBus and the other infrastructures initialized in hv_acpi_init when Linux is running as the root partition. Signed-off-by: Wei Liu <wei.liu@kernel.org> Reviewed-by: Pavel Tatashin <pasha.tatashin@soleen.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Link: https://lore.kernel.org/r/20210203150435.27941-4-wei.liu@kernel.org
2021-02-11Drivers: hv: vmbus: Enforce 'VMBus version >= 5.2' on isolated guestsAndrea Parri (Microsoft)
Restrict the protocol version(s) that will be negotiated with the host to be 5.2 or greater if the guest is running isolated. This reduces the footprint of the code that will be exercised by Confidential VMs and hence the exposure to bugs and vulnerabilities. Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Link: https://lore.kernel.org/r/20210201144814.2701-4-parri.andrea@gmail.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
2021-02-11Drivers: hv: vmbus: Restrict vmbus_devices on isolated guestsAndrea Parri (Microsoft)
Only the VSCs or ICs that have been hardened and that are critical for the successful adoption of Confidential VMs should be allowed if the guest is running isolated. This change reduces the footprint of the code that will be exercised by Confidential VMs and hence the exposure to bugs and vulnerabilities. Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Link: https://lore.kernel.org/r/20210201144814.2701-3-parri.andrea@gmail.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
2021-02-11hv_utils: Fix spelling mistake "Hearbeat" -> "Heartbeat"Colin Ian King
There is a spelling mistake in an error message. Fix it. Signed-off-by: Colin Ian King <colin.king@canonical.com> Link: https://lore.kernel.org/r/20210127233136.623465-1-colin.king@canonical.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
2021-02-11Drivers: hv: vmbus: Add /sys/bus/vmbus/hibernationDexuan Cui
When a Linux VM runs on Hyper-V, if the host toolstack doesn't support hibernation for the VM (this happens on old Hyper-V hosts like Windows Server 2016, or new Hyper-V hosts if the admin or user doesn't declare the hibernation intent for the VM), the VM is discouraged from trying hibernation (because the host doesn't guarantee that the VM's virtual hardware configuration will remain exactly the same across hibernation), i.e. the VM should not try to set up the swap partition/file for hibernation, etc. x86 Hyper-V uses the presence of the virtual ACPI S4 state as the indication of the host toolstack support for a VM. Currently there is no easy and reliable way for the userspace to detect the presence of the state (see https://lkml.org/lkml/2020/12/11/1097). Add /sys/bus/vmbus/hibernation for this purpose. Signed-off-by: Dexuan Cui <decui@microsoft.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Link: https://lore.kernel.org/r/20210107014552.14234-1-decui@microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
2021-02-05Drivers: hv: vmbus: Resolve race condition in vmbus_onoffer_rescind()Andrea Parri (Microsoft)
An erroneous or malicious host could send multiple rescind messages for a same channel. In vmbus_onoffer_rescind(), the guest maps the channel ID to obtain a pointer to the channel object and it eventually releases such object and associated data. The host could time rescind messages and lead to an use-after-free. Add a new flag to the channel structure to make sure that only one instance of vmbus_onoffer_rescind() can get the reference to the channel object. Reported-by: Juan Vazquez <juvazq@microsoft.com> Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Link: https://lore.kernel.org/r/20201209070827.29335-6-parri.andrea@gmail.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
2021-02-05Drivers: hv: vmbus: Avoid use-after-free in vmbus_onoffer_rescind()Andrea Parri (Microsoft)
When channel->device_obj is non-NULL, vmbus_onoffer_rescind() could invoke put_device(), that will eventually release the device and free the channel object (cf. vmbus_device_release()). However, a pointer to the object is dereferenced again later to load the primary_channel. The use-after-free can be avoided by noticing that this load/check is redundant if device_obj is non-NULL: primary_channel must be NULL if device_obj is non-NULL, cf. vmbus_add_channel_work(). Fixes: 54a66265d6754b ("Drivers: hv: vmbus: Fix rescind handling") Reported-by: Juan Vazquez <juvazq@microsoft.com> Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Link: https://lore.kernel.org/r/20201209070827.29335-5-parri.andrea@gmail.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
2021-02-05Drivers: hv: vmbus: Copy the hv_message in vmbus_on_msg_dpc()Andrea Parri (Microsoft)
Since the message is in memory shared with the host, an erroneous or a malicious Hyper-V could 'corrupt' the message while vmbus_on_msg_dpc() or individual message handlers are executing. To prevent it, copy the message into private memory. Reported-by: Juan Vazquez <juvazq@microsoft.com> Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Link: https://lore.kernel.org/r/20201209070827.29335-4-parri.andrea@gmail.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
2021-02-05Drivers: hv: vmbus: Reduce number of references to message in vmbus_on_msg_dpc()Andrea Parri (Microsoft)
Simplify the function by removing various references to the hv_message 'msg', introduce local variables 'msgtype' and 'payload_size'. Suggested-by: Juan Vazquez <juvazq@microsoft.com> Suggested-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Link: https://lore.kernel.org/r/20201209070827.29335-3-parri.andrea@gmail.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
2021-02-05Drivers: hv: vmbus: Initialize memory to be sent to the hostAndrea Parri (Microsoft)
__vmbus_open() and vmbus_teardown_gpadl() do not inizialite the memory for the vmbus_channel_open_channel and the vmbus_channel_gpadl_teardown objects they allocate respectively. These objects contain padding bytes and fields that are left uninitialized and that are later sent to the host, potentially leaking guest data. Zero initialize such fields to avoid leaking sensitive information to the host. Reported-by: Juan Vazquez <juvazq@microsoft.com> Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Link: https://lore.kernel.org/r/20201209070827.29335-2-parri.andrea@gmail.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
2021-02-05hv_utils: Add validation for untrusted Hyper-V valuesAndres Beltran
For additional robustness in the face of Hyper-V errors or malicious behavior, validate all values that originate from packets that Hyper-V has sent to the guest in the host-to-guest ring buffer. Ensure that invalid values cannot cause indexing off the end of the icversion_data array in vmbus_prep_negotiate_resp(). Signed-off-by: Andres Beltran <lkmlabelt@gmail.com> Co-developed-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com> Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Link: https://lore.kernel.org/r/20201109100704.9152-1-parri.andrea@gmail.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
2021-02-05Drivers: hv: vmbus: Copy packets sent by Hyper-V out of the ring bufferAndres Beltran
Pointers to ring-buffer packets sent by Hyper-V are used within the guest VM. Hyper-V can send packets with erroneous values or modify packet fields after they are processed by the guest. To defend against these scenarios, return a copy of the incoming VMBus packet after validating its length and offset fields in hv_pkt_iter_first(). In this way, the packet can no longer be modified by the host. Signed-off-by: Andres Beltran <lkmlabelt@gmail.com> Co-developed-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com> Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Jakub Kicinski <kuba@kernel.org> Cc: "James E.J. Bottomley" <jejb@linux.ibm.com> Cc: "Martin K. Petersen" <martin.petersen@oracle.com> Cc: netdev@vger.kernel.org Cc: linux-scsi@vger.kernel.org Reviewed-by: Michael Kelley <mikelley@microsoft.com> Link: https://lore.kernel.org/r/20201208045311.10244-1-parri.andrea@gmail.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
2021-01-05x86/hyperv: Fix kexec panic/hang issuesDexuan Cui
Currently the kexec kernel can panic or hang due to 2 causes: 1) hv_cpu_die() is not called upon kexec, so the hypervisor corrupts the old VP Assist Pages when the kexec kernel runs. The same issue is fixed for hibernation in commit 421f090c819d ("x86/hyperv: Suspend/resume the VP assist page for hibernation"). Now fix it for kexec. 2) hyperv_cleanup() is called too early. In the kexec path, the other CPUs are stopped in hv_machine_shutdown() -> native_machine_shutdown(), so between hv_kexec_handler() and native_machine_shutdown(), the other CPUs can still try to access the hypercall page and cause panic. The workaround "hv_hypercall_pg = NULL;" in hyperv_cleanup() is unreliabe. Move hyperv_cleanup() to a better place. Signed-off-by: Dexuan Cui <decui@microsoft.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Link: https://lore.kernel.org/r/20201222065541.24312-1-decui@microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-12-16Merge tag 'hyperv-next-signed-20201214' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux Pull Hyper-V updates from Wei Liu: - harden VMBus (Andres Beltran) - clean up VMBus driver (Matheus Castello) - fix hv_balloon reporting (Vitaly Kuznetsov) - fix a potential OOB issue (Andrea Parri) - remove an obsolete TODO item (Stefan Eschenbacher) * tag 'hyperv-next-signed-20201214' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux: hv_balloon: do adjust_managed_page_count() when ballooning/un-ballooning hv_balloon: simplify math in alloc_balloon_pages() drivers/hv: remove obsolete TODO and fix misleading typo in comment drivers: hv: vmbus: Fix checkpatch SPLIT_STRING hv_netvsc: Validate number of allocated sub-channels drivers: hv: vmbus: Fix call msleep using < 20ms drivers: hv: vmbus: Fix checkpatch LINE_SPACING drivers: hv: vmbus: Replace symbolic permissions by octal permissions drivers: hv: Fix hyperv_record_panic_msg path on comment hv_netvsc: Use vmbus_requestor to generate transaction IDs for VMBus hardening scsi: storvsc: Use vmbus_requestor to generate transaction IDs for VMBus hardening Drivers: hv: vmbus: Add vmbus_requestor data structure for VMBus hardening
2020-12-13hv_balloon: do adjust_managed_page_count() when ballooning/un-ballooningVitaly Kuznetsov
Unlike virtio_balloon/virtio_mem/xen balloon drivers, Hyper-V balloon driver does not adjust managed pages count when ballooning/un-ballooning and this leads to incorrect stats being reported, e.g. unexpected 'free' output. Note, the calculation in post_status() seems to remain correct: ballooned out pages are never 'available' and we manually add dm->num_pages_ballooned to 'commited'. Suggested-by: David Hildenbrand <david@redhat.com> Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Reviewed-by: David Hildenbrand <david@redhat.com> Link: https://lore.kernel.org/r/20201202161245.2406143-3-vkuznets@redhat.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-12-13hv_balloon: simplify math in alloc_balloon_pages()Vitaly Kuznetsov
'alloc_unit' in alloc_balloon_pages() is either '512' for 2M allocations or '1' for 4k allocations. So 1 << get_order(alloc_unit << PAGE_SHIFT) equals to 'alloc_unit' and the for loop basically sets all them offline. Simplify the math to improve the readability. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Reviewed-by: David Hildenbrand <david@redhat.com> Link: https://lore.kernel.org/r/20201202161245.2406143-2-vkuznets@redhat.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-12-07drivers/hv: remove obsolete TODO and fix misleading typo in commentStefan Eschenbacher
Removes an obsolete TODO in the VMBus module and fixes a misleading typo in the comment for the macro MAX_NUM_CHANNELS, where two digits have been twisted. Signed-off-by: Stefan Eschenbacher <stefan.eschenbacher@fau.de> Co-developed-by: Max Stolze <max.stolze@fau.de> Signed-off-by: Max Stolze <max.stolze@fau.de> Link: https://lore.kernel.org/r/20201206104850.24843-1-stefan.eschenbacher@fau.de Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-12-02drivers: hv: vmbus: Fix checkpatch SPLIT_STRINGMatheus Castello
Checkpatch emits WARNING: quoted string split across lines. To keep the code clean and with the 80 column length indentation the check and registration code for kmsg_dump_register has been transferred to a new function hv_kmsg_dump_register. Signed-off-by: Matheus Castello <matheus@castello.eng.br> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Link: https://lore.kernel.org/r/20201125032926.17002-1-matheus@castello.eng.br Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-11-17drivers: hv: vmbus: Fix call msleep using < 20msMatheus Castello
Fixed checkpatch warning: MSLEEP: msleep < 20ms can sleep for up to 20ms; see Documentation/timers/timers-howto.rst Signed-off-by: Matheus Castello <matheus@castello.eng.br> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Link: https://lore.kernel.org/r/20201115195734.8338-7-matheus@castello.eng.br Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-11-17drivers: hv: vmbus: Fix checkpatch LINE_SPACINGMatheus Castello
Fixed checkpatch warning: Missing a blank line after declarations checkpatch(LINE_SPACING) Signed-off-by: Matheus Castello <matheus@castello.eng.br> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Link: https://lore.kernel.org/r/20201115195734.8338-4-matheus@castello.eng.br Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-11-17drivers: hv: vmbus: Replace symbolic permissions by octal permissionsMatheus Castello
This fixed the below checkpatch issue: WARNING: Symbolic permissions 'S_IRUGO' are not preferred. Consider using octal permissions '0444'. Signed-off-by: Matheus Castello <matheus@castello.eng.br> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Link: https://lore.kernel.org/r/20201115195734.8338-3-matheus@castello.eng.br Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-11-17drivers: hv: Fix hyperv_record_panic_msg path on commentMatheus Castello
Fix the kernel parameter path in the comment, in the documentation the parameter is correct but if someone who is studying the code and see this first can get confused and try to access the wrong path/parameter Signed-off-by: Matheus Castello <matheus@castello.eng.br> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Link: https://lore.kernel.org/r/20201115195734.8338-2-matheus@castello.eng.br Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-11-17Drivers: hv: vmbus: Add vmbus_requestor data structure for VMBus hardeningAndres Beltran
Currently, VMbus drivers use pointers into guest memory as request IDs for interactions with Hyper-V. To be more robust in the face of errors or malicious behavior from a compromised Hyper-V, avoid exposing guest memory addresses to Hyper-V. Also avoid Hyper-V giving back a bad request ID that is then treated as the address of a guest data structure with no validation. Instead, encapsulate these memory addresses and provide small integers as request IDs. Signed-off-by: Andres Beltran <lkmlabelt@gmail.com> Co-developed-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com> Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Reviewed-by: Wei Liu <wei.liu@kernel.org> Link: https://lore.kernel.org/r/20201109100402.8946-2-parri.andrea@gmail.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-11-16Merge tag 'hyperv-fixes-signed' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux Pull Hyper-V fix from Wei Liu: "One patch from Chris to fix kexec on Hyper-V" * tag 'hyperv-fixes-signed' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux: Drivers: hv: vmbus: Allow cleanup of VMBUS_CONNECT_CPU if disconnected
2020-11-11Drivers: hv: vmbus: Allow cleanup of VMBUS_CONNECT_CPU if disconnectedChris Co
When invoking kexec() on a Linux guest running on a Hyper-V host, the kernel panics. RIP: 0010:cpuhp_issue_call+0x137/0x140 Call Trace: __cpuhp_remove_state_cpuslocked+0x99/0x100 __cpuhp_remove_state+0x1c/0x30 hv_kexec_handler+0x23/0x30 [hv_vmbus] hv_machine_shutdown+0x1e/0x30 machine_shutdown+0x10/0x20 kernel_kexec+0x6d/0x96 __do_sys_reboot+0x1ef/0x230 __x64_sys_reboot+0x1d/0x20 do_syscall_64+0x6b/0x3d8 entry_SYSCALL_64_after_hwframe+0x44/0xa9 This was due to hv_synic_cleanup() callback returning -EBUSY to cpuhp_issue_call() when tearing down the VMBUS_CONNECT_CPU, even if the vmbus_connection.conn_state = DISCONNECTED. hv_synic_cleanup() should succeed in the case where vmbus_connection.conn_state is DISCONNECTED. Fix is to add an extra condition to test for vmbus_connection.conn_state == CONNECTED on the VMBUS_CONNECT_CPU and only return early if true. This way the kexec() path can still shut everything down while preserving the initial behavior of preventing CPU offlining on the VMBUS_CONNECT_CPU while the VM is running. Fixes: 8a857c55420f29 ("Drivers: hv: vmbus: Always handle the VMBus messages on CPU0") Signed-off-by: Chris Co <chrco@microsoft.com> Reviewed-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20201110190118.15596-1-chrco@linux.microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-11-05Merge tag 'hyperv-fixes-signed' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux Pull hyperv fixes from Wei Liu: - clarify a comment (Michael Kelley) - change a pr_warn() to pr_info() (Olaf Hering) * tag 'hyperv-fixes-signed' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux: x86/hyperv: Clarify comment on x2apic mode hv_balloon: disable warning when floor reached
2020-10-19hv_balloon: disable warning when floor reachedOlaf Hering
It is not an error if the host requests to balloon down, but the VM refuses to do so. Without this change a warning is logged in dmesg every five minutes. Fixes: b3bb97b8a49f3 ("Drivers: hv: balloon: Add logging for dynamic memory operations") Signed-off-by: Olaf Hering <olaf@aepfle.de> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Link: https://lore.kernel.org/r/20201008071216.16554-1-olaf@aepfle.de Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-10-16Merge branch 'akpm' (patches from Andrew)Linus Torvalds
Merge more updates from Andrew Morton: "155 patches. Subsystems affected by this patch series: mm (dax, debug, thp, readahead, page-poison, util, memory-hotplug, zram, cleanups), misc, core-kernel, get_maintainer, MAINTAINERS, lib, bitops, checkpatch, binfmt, ramfs, autofs, nilfs, rapidio, panic, relay, kgdb, ubsan, romfs, and fault-injection" * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (155 commits) lib, uaccess: add failure injection to usercopy functions lib, include/linux: add usercopy failure capability ROMFS: support inode blocks calculation ubsan: introduce CONFIG_UBSAN_LOCAL_BOUNDS for Clang sched.h: drop in_ubsan field when UBSAN is in trap mode scripts/gdb/tasks: add headers and improve spacing format scripts/gdb/proc: add struct mount & struct super_block addr in lx-mounts command kernel/relay.c: drop unneeded initialization panic: dump registers on panic_on_warn rapidio: fix the missed put_device() for rio_mport_add_riodev rapidio: fix error handling path nilfs2: fix some kernel-doc warnings for nilfs2 autofs: harden ioctl table ramfs: fix nommu mmap with gaps in the page cache mm: remove the now-unnecessary mmget_still_valid() hack mm/gup: take mmap_lock in get_dump_page() binfmt_elf, binfmt_elf_fdpic: use a VMA list snapshot coredump: rework elf/elf_fdpic vma_dump_size() into common helper coredump: refactor page range dumping into common helper coredump: let dump_emit() bail out on short writes ...
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