kernel.git/arch/arm/xen, branch linux-5.10.y

arm/xen: fix xen_vcpu_info allocation alignment

2023-12-08T07:46:08Z

[ 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

arm64/arm: xen: enlighten: Fix KPTI checks

2023-11-20T10:06:49Z

[ Upstream commit 20f3b8eafe0ba5d3c69d5011a9b07739e9645132 ] When KPTI is in use, we cannot register a runstate region as XEN requires that this is always a valid VA, which we cannot guarantee. Due to this, xen_starting_cpu() must avoid registering each CPU's runstate region, and xen_guest_init() must avoid setting up features that depend upon it. We tried to ensure that in commit: f88af7229f6f22ce (" xen/arm: do not setup the runstate info page if kpti is enabled") ... where we added checks for xen_kernel_unmapped_at_usr(), which wraps arm64_kernel_unmapped_at_el0() on arm64 and is always false on 32-bit arm. Unfortunately, as xen_guest_init() is an early_initcall, this happens before secondary CPUs are booted and arm64 has finalized the ARM64_UNMAP_KERNEL_AT_EL0 cpucap which backs arm64_kernel_unmapped_at_el0(), and so this can subsequently be set as secondary CPUs are onlined. On a big.LITTLE system where the boot CPU does not require KPTI but some secondary CPUs do, this will result in xen_guest_init() intializing features that depend on the runstate region, and xen_starting_cpu() registering the runstate region on some CPUs before KPTI is subsequent enabled, resulting the the problems the aforementioned commit tried to avoid. Handle this more robsutly by deferring the initialization of the runstate region until secondary CPUs have been initialized and the ARM64_UNMAP_KERNEL_AT_EL0 cpucap has been finalized. The per-cpu work is moved into a new hotplug starting function which is registered later when we're certain that KPTI will not be used. Fixes: f88af7229f6f ("xen/arm: do not setup the runstate info page if kpti is enabled") Signed-off-by: Mark Rutland Cc: Bertrand Marquis Cc: Boris Ostrovsky Cc: Juergen Gross Cc: Stefano Stabellini Cc: Suzuki K Poulose Cc: Will Deacon Signed-off-by: Catalin Marinas Signed-off-by: Sasha Levin

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

2022-07-07T15:52:23Z

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

2021-03-07T11:34:15Z

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

2021-02-23T14:53:24Z

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

2021-02-17T10:02:21Z

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

2021-01-27T10:55:00Z

[ 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

Merge tag 'dma-mapping-5.10' of git://git.infradead.org/users/hch/dma-mapping

2020-10-15T21:43:29Z

Pull dma-mapping updates from Christoph Hellwig: - rework the non-coherent DMA allocator - move private definitions out of - lower CMA_ALIGNMENT (Paul Cercueil) - remove the omap1 dma address translation in favor of the common code - make dma-direct aware of multiple dma offset ranges (Jim Quinlan) - support per-node DMA CMA areas (Barry Song) - increase the default seg boundary limit (Nicolin Chen) - misc fixes (Robin Murphy, Thomas Tai, Xu Wang) - various cleanups * tag 'dma-mapping-5.10' of git://git.infradead.org/users/hch/dma-mapping: (63 commits) ARM/ixp4xx: add a missing include of dma-map-ops.h dma-direct: simplify the DMA_ATTR_NO_KERNEL_MAPPING handling dma-direct: factor out a dma_direct_alloc_from_pool helper dma-direct check for highmem pages in dma_direct_alloc_pages dma-mapping: merge into dma-mapping: move large parts of to kernel/dma dma-mapping: move dma-debug.h to kernel/dma/ dma-mapping: remove dma-mapping: merge into dma-contiguous: remove dma_contiguous_set_default dma-contiguous: remove dev_set_cma_area dma-contiguous: remove dma_declare_contiguous dma-mapping: split cma: decrease CMA_ALIGNMENT lower limit to 2 firewire-ohci: use dma_alloc_pages dma-iommu: implement ->alloc_noncoherent dma-mapping: add new {alloc,free}_noncoherent dma_map_ops methods dma-mapping: add a new dma_alloc_pages API dma-mapping: remove dma_cache_sync 53c700: convert to dma_alloc_noncoherent ...

Merge tag 'for-linus-5.10b-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip

2020-10-14T17:34:45Z

Pull xen updates from Juergen Gross: - two small cleanup patches - avoid error messages when initializing MCA banks in a Xen dom0 - a small series for converting the Xen gntdev driver to use pin_user_pages*() instead of get_user_pages*() - intermediate fix for running as a Xen guest on Arm with KPTI enabled (the final solution will need new Xen functionality) * tag 'for-linus-5.10b-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: x86/xen: Fix typo in xen_pagetable_p2m_free() x86/xen: disable Firmware First mode for correctable memory errors xen/arm: do not setup the runstate info page if kpti is enabled xen: remove redundant initialization of variable ret xen/gntdev.c: Convert get_user_pages*() to pin_user_pages*() xen/gntdev.c: Mark pages as dirty

arch, drivers: replace for_each_membock() with for_each_mem_range()

2020-10-14T01:38:35Z

There are several occurrences of the following pattern: for_each_memblock(memory, reg) { start = __pfn_to_phys(memblock_region_memory_base_pfn(reg); end = __pfn_to_phys(memblock_region_memory_end_pfn(reg)); /* do something with start and end */ } Using for_each_mem_range() iterator is more appropriate in such cases and allows simpler and cleaner code. [akpm@linux-foundation.org: fix arch/arm/mm/pmsa-v7.c build] [rppt@linux.ibm.com: mips: fix cavium-octeon build caused by memblock refactoring] Link: http://lkml.kernel.org/r/20200827124549.GD167163@linux.ibm.com Signed-off-by: Mike Rapoport Signed-off-by: Andrew Morton Cc: Andy Lutomirski Cc: Baoquan He Cc: Benjamin Herrenschmidt Cc: Borislav Petkov Cc: Catalin Marinas Cc: Christoph Hellwig Cc: Daniel Axtens Cc: Dave Hansen Cc: Emil Renner Berthing Cc: Hari Bathini Cc: Ingo Molnar Cc: Ingo Molnar Cc: Jonathan Cameron Cc: Marek Szyprowski Cc: Max Filippov Cc: Michael Ellerman Cc: Michal Simek Cc: Miguel Ojeda Cc: Palmer Dabbelt Cc: Paul Mackerras Cc: Paul Walmsley Cc: Peter Zijlstra Cc: Russell King Cc: Stafford Horne Cc: Thomas Bogendoerfer Cc: Thomas Gleixner Cc: Will Deacon Cc: Yoshinori Sato Link: https://lkml.kernel.org/r/20200818151634.14343-13-rppt@kernel.org Signed-off-by: Linus Torvalds