kernel.git/arch/arm/xen, branch linux-4.14.y

arm/xen: fix xen_vcpu_info allocation alignment

2023-12-08T07:41:59Z

[ Upstream commit 7bf9a6b46549852a37e6d07e52c601c3c706b562 ] xen_vcpu_info is a percpu area than needs to be mapped by Xen. Currently, it could cross a page boundary resulting in Xen being unable to map it: [ 0.567318] kernel BUG at arch/arm64/xen/../../arm/xen/enlighten.c:164! [ 0.574002] Internal error: Oops - BUG: 00000000f2000800 [#1] PREEMPT SMP Fix the issue by using __alloc_percpu and requesting alignment for the memory allocation. Signed-off-by: Stefano Stabellini Link: https://lore.kernel.org/r/alpine.DEB.2.22.394.2311221501340.2053963@ubuntu-linux-20-04-desktop Fixes: 24d5373dda7c ("arm/xen: Use alloc_percpu rather than __alloc_percpu") Reviewed-by: Juergen Gross Signed-off-by: Juergen Gross Signed-off-by: Sasha Levin

xen/arm: Fix race in RB-tree based P2M accounting

2022-07-07T15:31:18Z

commit b75cd218274e01d026dc5240e86fdeb44bbed0c8 upstream. During the PV driver life cycle the mappings are added to the RB-tree by set_foreign_p2m_mapping(), which is called from gnttab_map_refs() and are removed by clear_foreign_p2m_mapping() which is called from gnttab_unmap_refs(). As both functions end up calling __set_phys_to_machine_multi() which updates the RB-tree, this function can be called concurrently. There is already a "p2m_lock" to protect against concurrent accesses, but the problem is that the first read of "phys_to_mach.rb_node" in __set_phys_to_machine_multi() is not covered by it, so this might lead to the incorrect mappings update (removing in our case) in RB-tree. In my environment the related issue happens rarely and only when PV net backend is running, the xen_add_phys_to_mach_entry() claims that it cannot add new pfn <-> mfn mapping to the tree since it is already exists which results in a failure when mapping foreign pages. But there might be other bad consequences related to the non-protected root reads such use-after-free, etc. While at it, also fix the similar usage in __pfn_to_mfn(), so initialize "struct rb_node *n" with the "p2m_lock" held in both functions to avoid possible bad consequences. This is CVE-2022-33744 / XSA-406. Signed-off-by: Oleksandr Tyshchenko Reviewed-by: Stefano Stabellini Signed-off-by: Juergen Gross Signed-off-by: Greg Kroah-Hartman

Xen/gnttab: handle p2m update errors on a per-slot basis

2021-03-07T10:27:45Z

commit 8310b77b48c5558c140e7a57a702e7819e62f04e upstream. Bailing immediately from set_foreign_p2m_mapping() upon a p2m updating error leaves the full batch in an ambiguous state as far as the caller is concerned. Instead flags respective slots as bad, unmapping what was mapped there right away. HYPERVISOR_grant_table_op()'s return value and the individual unmap slots' status fields get used only for a one-time - there's not much we can do in case of a failure. Note that there's no GNTST_enomem or alike, so GNTST_general_error gets used. The map ops' handle fields get overwritten just to be on the safe side. This is part of XSA-367. Cc: Signed-off-by: Jan Beulich Reviewed-by: Juergen Gross Link: https://lore.kernel.org/r/96cccf5d-e756-5f53-b91a-ea269bfb9be0@suse.com Signed-off-by: Juergen Gross Signed-off-by: Greg Kroah-Hartman

xen/arm: don't ignore return errors from set_phys_to_machine

2021-02-23T13:00:33Z

commit 36bf1dfb8b266e089afa9b7b984217f17027bf35 upstream. set_phys_to_machine can fail due to lack of memory, see the kzalloc call in arch/arm/xen/p2m.c:__set_phys_to_machine_multi. Don't ignore the potential return error in set_foreign_p2m_mapping, returning it to the caller instead. This is part of XSA-361. Signed-off-by: Stefano Stabellini Cc: stable@vger.kernel.org Reviewed-by: Julien Grall Signed-off-by: Juergen Gross Signed-off-by: Greg Kroah-Hartman

arm/xen: Don't probe xenbus as part of an early initcall

2021-02-23T13:00:31Z

commit c4295ab0b485b8bc50d2264bcae2acd06f25caaf upstream. After Commit 3499ba8198cad ("xen: Fix event channel callback via INTX/GSI"), xenbus_probe() will be called too early on Arm. This will recent to a guest hang during boot. If the hang wasn't there, we would have ended up to call xenbus_probe() twice (the second time is in xenbus_probe_initcall()). We don't need to initialize xenbus_probe() early for Arm guest. Therefore, the call in xen_guest_init() is now removed. After this change, there is no more external caller for xenbus_probe(). So the function is turned to a static one. Interestingly there were two prototypes for it. Cc: stable@vger.kernel.org Fixes: 3499ba8198cad ("xen: Fix event channel callback via INTX/GSI") Reported-by: Ian Jackson Signed-off-by: Julien Grall Reviewed-by: David Woodhouse Reviewed-by: Stefano Stabellini Link: https://lore.kernel.org/r/20210210170654.5377-1-julien@xen.org Signed-off-by: Juergen Gross Signed-off-by: Greg Kroah-Hartman

xen: Fix event channel callback via INTX/GSI

2021-01-30T12:31:13Z

[ Upstream commit 3499ba8198cad47b731792e5e56b9ec2a78a83a2 ] For a while, event channel notification via the PCI platform device has been broken, because we attempt to communicate with xenstore before we even have notifications working, with the xs_reset_watches() call in xs_init(). We tend to get away with this on Xen versions below 4.0 because we avoid calling xs_reset_watches() anyway, because xenstore might not cope with reading a non-existent key. And newer Xen *does* have the vector callback support, so we rarely fall back to INTX/GSI delivery. To fix it, clean up a bit of the mess of xs_init() and xenbus_probe() startup. Call xs_init() directly from xenbus_init() only in the !XS_HVM case, deferring it to be called from xenbus_probe() in the XS_HVM case instead. Then fix up the invocation of xenbus_probe() to happen either from its device_initcall if the callback is available early enough, or when the callback is finally set up. This means that the hack of calling xenbus_probe() from a workqueue after the first interrupt, or directly from the PCI platform device setup, is no longer needed. Signed-off-by: David Woodhouse Reviewed-by: Boris Ostrovsky Link: https://lore.kernel.org/r/20210113132606.422794-2-dwmw2@infradead.org Signed-off-by: Juergen Gross Signed-off-by: Sasha Levin

xen/efi: Set nonblocking callbacks

2019-10-29T08:16:56Z

[ Upstream commit df359f0d09dc029829b66322707a2f558cb720f7 ] Other parts of the kernel expect these nonblocking EFI callbacks to exist and crash when running under Xen. Since the implementations of xen_efi_set_variable() and xen_efi_query_variable_info() do not take any locks, use them for the nonblocking callbacks too. Signed-off-by: Ross Lagerwall Reviewed-by: Juergen Gross Signed-off-by: Juergen Gross Signed-off-by: Sasha Levin

arm/xen: don't inclide rwlock.h directly.

2017-10-26T20:58:17Z

rwlock.h should not be included directly. Instead linux/splinlock.h should be included. One thing it does is to break the RT build. Cc: Stefano Stabellini Cc: xen-devel@lists.xenproject.org Cc: linux-arm-kernel@lists.infradead.org Signed-off-by: Sebastian Andrzej Siewior Reviewed-by: Stefano Stabellini Signed-off-by: Boris Ostrovsky

Merge tag 'dma-mapping-4.13' of git://git.infradead.org/users/hch/dma-mapping

2017-07-07T02:20:54Z

Pull dma-mapping infrastructure from Christoph Hellwig: "This is the first pull request for the new dma-mapping subsystem In this new subsystem we'll try to properly maintain all the generic code related to dma-mapping, and will further consolidate arch code into common helpers. This pull request contains: - removal of the DMA_ERROR_CODE macro, replacing it with calls to ->mapping_error so that the dma_map_ops instances are more self contained and can be shared across architectures (me) - removal of the ->set_dma_mask method, which duplicates the ->dma_capable one in terms of functionality, but requires more duplicate code. - various updates for the coherent dma pool and related arm code (Vladimir) - various smaller cleanups (me)" * tag 'dma-mapping-4.13' of git://git.infradead.org/users/hch/dma-mapping: (56 commits) ARM: dma-mapping: Remove traces of NOMMU code ARM: NOMMU: Set ARM_DMA_MEM_BUFFERABLE for M-class cpus ARM: NOMMU: Introduce dma operations for noMMU drivers: dma-mapping: allow dma_common_mmap() for NOMMU drivers: dma-coherent: Introduce default DMA pool drivers: dma-coherent: Account dma_pfn_offset when used with device tree dma: Take into account dma_pfn_offset dma-mapping: replace dmam_alloc_noncoherent with dmam_alloc_attrs dma-mapping: remove dmam_free_noncoherent crypto: qat - avoid an uninitialized variable warning au1100fb: remove a bogus dma_free_nonconsistent call MAINTAINERS: add entry for dma mapping helpers powerpc: merge __dma_set_mask into dma_set_mask dma-mapping: remove the set_dma_mask method powerpc/cell: use the dma_supported method for ops switching powerpc/cell: clean up fixed mapping dma_ops initialization tile: remove dma_supported and mapping_error methods xen-swiotlb: remove xen_swiotlb_set_dma_mask arm: implement ->dma_supported instead of ->set_dma_mask mips/loongson64: implement ->dma_supported instead of ->set_dma_mask ...

xen-swiotlb: consolidate xen_swiotlb_dma_ops

2017-06-20T09:12:59Z

ARM and x86 had duplicated versions of the dma_ops structure, the only difference is that x86 hasn't wired up the set_dma_mask, mmap, and get_sgtable ops yet. On x86 all of them are identical to the generic version, so they aren't needed but harmless. All the symbols used only for xen_swiotlb_dma_ops can now be marked static as well. Signed-off-by: Christoph Hellwig Reviewed-by: Konrad Rzeszutek Wilk