kernel/linux.git/drivers/xen, branch v4.19.112

xen: Enable interrupts when calling _cond_resched()

2020-02-28T15:39:00+00:00

commit 8645e56a4ad6dcbf504872db7f14a2f67db88ef2 upstream. xen_maybe_preempt_hcall() is called from the exception entry point xen_do_hypervisor_callback with interrupts disabled. _cond_resched() evades the might_sleep() check in cond_resched() which would have caught that and schedule_debug() unfortunately lacks a check for irqs_disabled(). Enable interrupts around the call and use cond_resched() to catch future issues. Fixes: fdfd811ddde3 ("x86/xen: allow privcmd hypercalls to be preempted") Signed-off-by: Thomas Gleixner Link: https://lore.kernel.org/r/878skypjrh.fsf@nanos.tec.linutronix.de Reviewed-by: Juergen Gross Signed-off-by: Boris Ostrovsky Signed-off-by: Greg Kroah-Hartman

xen/balloon: Support xend-based toolstack take two

2020-02-11T12:34:08+00:00

commit eda4eabf86fd6806eaabc23fb90dd056fdac037b upstream. Commit 3aa6c19d2f38be ("xen/balloon: Support xend-based toolstack") tried to fix a regression with running on rather ancient Xen versions. Unfortunately the fix was based on the assumption that xend would just use another Xenstore node, but in reality only some downstream versions of xend are doing that. The upstream xend does not write that Xenstore node at all, so the problem must be fixed in another way. The easiest way to achieve that is to fall back to the behavior before commit 96edd61dcf4436 ("xen/balloon: don't online new memory initially") in case the static memory maximum can't be read. This is achieved by setting static_max to the current number of memory pages known by the system resulting in target_diff becoming zero. Fixes: 3aa6c19d2f38be ("xen/balloon: Support xend-based toolstack") Signed-off-by: Juergen Gross Reviewed-by: Boris Ostrovsky Cc: # 4.13 Signed-off-by: Boris Ostrovsky Signed-off-by: Greg Kroah-Hartman

net: add {READ|WRITE}_ONCE() annotations on ->rskq_accept_head

2020-01-27T13:51:18+00:00

[ Upstream commit 60b173ca3d1cd1782bd0096dc17298ec242f6fb1 ] reqsk_queue_empty() is called from inet_csk_listen_poll() while other cpus might write ->rskq_accept_head value. Use {READ|WRITE}_ONCE() to avoid compiler tricks and potential KCSAN splats. Fixes: fff1f3001cc5 ("tcp: add a spinlock to protect struct request_sock_queue") Signed-off-by: Eric Dumazet Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

xen, cpu_hotplug: Prevent an out of bounds access

2020-01-27T13:50:31+00:00

[ Upstream commit 201676095dda7e5b31a5e1d116d10fc22985075e ] The "cpu" variable comes from the sscanf() so Smatch marks it as untrusted data. We can't pass a higher value than "nr_cpu_ids" to cpu_possible() or it results in an out of bounds access. Fixes: d68d82afd4c8 ("xen: implement CPU hotplugging") Signed-off-by: Dan Carpenter Reviewed-by: Juergen Gross Signed-off-by: Juergen Gross Signed-off-by: Sasha Levin

xen/balloon: fix ballooned page accounting without hotplug enabled

2020-01-09T09:18:58+00:00

[ Upstream commit c673ec61ade89bf2f417960f986bc25671762efb ] When CONFIG_XEN_BALLOON_MEMORY_HOTPLUG is not defined reserve_additional_memory() will set balloon_stats.target_pages to a wrong value in case there are still some ballooned pages allocated via alloc_xenballooned_pages(). This will result in balloon_process() no longer be triggered when ballooned pages are freed in batches. Reported-by: Nicholas Tsirakis Signed-off-by: Juergen Gross Reviewed-by: Boris Ostrovsky Signed-off-by: Juergen Gross Signed-off-by: Sasha Levin

xen/gntdev: Use select for DMA_SHARED_BUFFER

2019-12-31T15:35:50+00:00

[ Upstream commit fa6614d8ef13c63aac52ad7c07c5e69ce4aba3dd ] DMA_SHARED_BUFFER can not be enabled by the user (it represents a library set in the kernel). The kconfig convention is to use select for such symbols so they are turned on implicitly when the user enables a kconfig that needs them. Otherwise the XEN_GNTDEV_DMABUF kconfig is overly difficult to enable. Fixes: 932d6562179e ("xen/gntdev: Add initial support for dma-buf UAPI") Cc: Oleksandr Andrushchenko Cc: Boris Ostrovsky Cc: xen-devel@lists.xenproject.org Cc: Juergen Gross Cc: Stefano Stabellini Reviewed-by: Juergen Gross Reviewed-by: Oleksandr Andrushchenko Signed-off-by: Jason Gunthorpe Signed-off-by: Juergen Gross Signed-off-by: Sasha Levin

pvcalls-front: don't return error when the ring is full

2019-12-17T19:35:32+00:00

[ Upstream commit d90a1ca60a1eccb4383fe203c76223ab4c0799ed ] When the ring is full, size == array_size. It is not an error condition, so simply return 0 instead of an error. Signed-off-by: Stefano Stabellini Reviewed-by: Boris Ostrovsky Signed-off-by: Boris Ostrovsky Signed-off-by: Sasha Levin

xen/pciback: Check dev_data before using it

2019-12-05T08:20:26+00:00

[ Upstream commit 1669907e3d1abfa3f7586e2d55dbbc117b5adba2 ] If pcistub_init_device fails, the release function will be called with dev_data set to NULL. Check it before using it to avoid a NULL pointer dereference. Signed-off-by: Ross Lagerwall Reviewed-by: Boris Ostrovsky Signed-off-by: Boris Ostrovsky Signed-off-by: Sasha Levin

mm/memory_hotplug: make add_memory() take the device_hotplug_lock

2019-12-01T08:17:10+00:00

[ Upstream commit 8df1d0e4a265f25dc1e7e7624ccdbcb4a6630c89 ] add_memory() currently does not take the device_hotplug_lock, however is aleady called under the lock from arch/powerpc/platforms/pseries/hotplug-memory.c drivers/acpi/acpi_memhotplug.c to synchronize against CPU hot-remove and similar. In general, we should hold the device_hotplug_lock when adding memory to synchronize against online/offline request (e.g. from user space) - which already resulted in lock inversions due to device_lock() and mem_hotplug_lock - see 30467e0b3be ("mm, hotplug: fix concurrent memory hot-add deadlock"). add_memory()/add_memory_resource() will create memory block devices, so this really feels like the right thing to do. Holding the device_hotplug_lock makes sure that a memory block device can really only be accessed (e.g. via .online/.state) from user space, once the memory has been fully added to the system. The lock is not held yet in drivers/xen/balloon.c arch/powerpc/platforms/powernv/memtrace.c drivers/s390/char/sclp_cmd.c drivers/hv/hv_balloon.c So, let's either use the locked variants or take the lock. Don't export add_memory_resource(), as it once was exported to be used by XEN, which is never built as a module. If somebody requires it, we also have to export a locked variant (as device_hotplug_lock is never exported). Link: http://lkml.kernel.org/r/20180925091457.28651-3-david@redhat.com Signed-off-by: David Hildenbrand Reviewed-by: Pavel Tatashin Reviewed-by: Rafael J. Wysocki Reviewed-by: Rashmica Gupta Reviewed-by: Oscar Salvador Cc: Benjamin Herrenschmidt Cc: Paul Mackerras Cc: Michael Ellerman Cc: "Rafael J. Wysocki" Cc: Len Brown Cc: Greg Kroah-Hartman Cc: Boris Ostrovsky Cc: Juergen Gross Cc: Nathan Fontenot Cc: John Allen Cc: Michal Hocko Cc: Dan Williams Cc: Joonsoo Kim Cc: Vlastimil Babka Cc: Mathieu Malaterre Cc: Pavel Tatashin Cc: YASUAKI ISHIMATSU Cc: Balbir Singh Cc: Haiyang Zhang Cc: Heiko Carstens Cc: Jonathan Corbet Cc: Kate Stewart Cc: "K. Y. Srinivasan" Cc: Martin Schwidefsky Cc: Michael Neuling Cc: Philippe Ombredanne Cc: Stephen Hemminger Cc: Thomas Gleixner Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Sasha Levin

xen/pci: reserve MCFG areas earlier

2019-10-11T16:21:13+00:00

[ Upstream commit a4098bc6eed5e31e0391bcc068e61804c98138df ] If MCFG area is not reserved in E820, Xen by default will defer its usage until Dom0 registers it explicitly after ACPI parser recognizes it as a reserved resource in DSDT. Having it reserved in E820 is not mandatory according to "PCI Firmware Specification, rev 3.2" (par. 4.1.2) and firmware is free to keep a hole in E820 in that place. Xen doesn't know what exactly is inside this hole since it lacks full ACPI view of the platform therefore it's potentially harmful to access MCFG region without additional checks as some machines are known to provide inconsistent information on the size of the region. Now xen_mcfg_late() runs after acpi_init() which is too late as some basic PCI enumeration starts exactly there as well. Trying to register a device prior to MCFG reservation causes multiple problems with PCIe extended capability initializations in Xen (e.g. SR-IOV VF BAR sizing). There are no convenient hooks for us to subscribe to so register MCFG areas earlier upon the first invocation of xen_add_device(). It should be safe to do once since all the boot time buses must have their MCFG areas in MCFG table already and we don't support PCI bus hot-plug. Signed-off-by: Igor Druzhinin Reviewed-by: Boris Ostrovsky Signed-off-by: Boris Ostrovsky Signed-off-by: Sasha Levin