kernel/git/stable/linux.git/drivers/xen/privcmd.c, branch linux-5.4.y

xen/privcmd: Fix a possible warning in privcmd_ioctl_mmap_resource()

2023-01-18T10:40:57+00:00

[ Upstream commit 8b997b2bb2c53b76a6db6c195930e9ab8e4b0c79 ] As 'kdata.num' is user-controlled data, if user tries to allocate memory larger than(>=) MAX_ORDER, then kcalloc() will fail, it creates a stack trace and messes up dmesg with a warning. Call trace: -> privcmd_ioctl --> privcmd_ioctl_mmap_resource Add __GFP_NOWARN in order to avoid too large allocation warning. This is detected by static analysis using smatch. Fixes: 3ad0876554ca ("xen/privcmd: add IOCTL_PRIVCMD_MMAP_RESOURCE") Signed-off-by: Harshit Mogalapalli Reviewed-by: Juergen Gross Link: https://lore.kernel.org/r/20221126050745.778967-1-harshit.m.mogalapalli@oracle.com Signed-off-by: Juergen Gross Signed-off-by: Sasha Levin

xen/privcmd: fix error handling in mmap-resource processing

2021-10-13T08:08:16+00:00

commit e11423d6721dd63b23fb41ade5e8d0b448b17780 upstream. xen_pfn_t is the same size as int only on 32-bit builds (and not even on Arm32). Hence pfns[] can't be used directly to read individual error values returned from xen_remap_domain_mfn_array(); every other error indicator would be skipped/ignored on 64-bit. Fixes: 3ad0876554ca ("xen/privcmd: add IOCTL_PRIVCMD_MMAP_RESOURCE") Cc: stable@vger.kernel.org Signed-off-by: Jan Beulich Reviewed-by: Boris Ostrovsky Signed-off-by: Greg Kroah-Hartman Link: https://lore.kernel.org/r/aa6d6a67-6889-338a-a910-51e889f792d5@suse.com Signed-off-by: Juergen Gross

xen/privcmd: allow fetching resource sizes

2021-01-23T14:57:55+00:00

commit ef3a575baf53571dc405ee4028e26f50856898e7 upstream. Allow issuing an IOCTL_PRIVCMD_MMAP_RESOURCE ioctl with num = 0 and addr = 0 in order to fetch the size of a specific resource. Add a shortcut to the default map resource path, since fetching the size requires no address to be passed in, and thus no VMA to setup. This is missing from the initial implementation, and causes issues when mapping resources that don't have fixed or known sizes. Signed-off-by: Roger Pau Monné Reviewed-by: Juergen Gross Tested-by: Andrew Cooper Cc: stable@vger.kernel.org # >= 4.18 Link: https://lore.kernel.org/r/20210112115358.23346-1-roger.pau@citrix.com Signed-off-by: Juergen Gross Signed-off-by: Greg Kroah-Hartman

xen: avoid link error on ARM

2019-07-31T06:14:12+00:00

Building the privcmd code as a loadable module on ARM, we get a link error due to the private cache management functions: ERROR: "__sync_icache_dcache" [drivers/xen/xen-privcmd.ko] undefined! Move the code into a new that is always built in when Xen is enabled, as suggested by Juergen Gross and Boris Ostrovsky. Signed-off-by: Arnd Bergmann Reviewed-by: Stefano Stabellini Signed-off-by: Juergen Gross

mm/pgtable: drop pgtable_t variable from pte_fn_t functions

2019-07-12T18:05:46+00:00

Drop the pgtable_t variable from all implementation for pte_fn_t as none of them use it. apply_to_pte_range() should stop computing it as well. Should help us save some cycles. Link: http://lkml.kernel.org/r/1556803126-26596-1-git-send-email-anshuman.khandual@arm.com Signed-off-by: Anshuman Khandual Acked-by: Matthew Wilcox Cc: Ard Biesheuvel Cc: Russell King Cc: Catalin Marinas Cc: Will Deacon Cc: Thomas Gleixner Cc: Ingo Molnar Cc: Michal Hocko Cc: Logan Gunthorpe Cc: "Kirill A. Shutemov" Cc: Dan Williams Cc: Cc: Mike Rapoport Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

treewide: Add SPDX license identifier for more missed files

2019-05-21T08:50:45+00:00

Add SPDX license identifiers to all files which: - Have no license information of any form - Have MODULE_LICENCE("GPL*") inside which was used in the initial scan/conversion to ignore the file These files fall under the project license, GPL v2 only. The resulting SPDX license identifier is: GPL-2.0-only Signed-off-by: Thomas Gleixner Signed-off-by: Greg Kroah-Hartman

Remove 'type' argument from access_ok() function

2019-01-04T02:57:57+00:00

Nobody has actually used the type (VERIFY_READ vs VERIFY_WRITE) argument of the user address range verification function since we got rid of the old racy i386-only code to walk page tables by hand. It existed because the original 80386 would not honor the write protect bit when in kernel mode, so you had to do COW by hand before doing any user access. But we haven't supported that in a long time, and these days the 'type' argument is a purely historical artifact. A discussion about extending 'user_access_begin()' to do the range checking resulted this patch, because there is no way we're going to move the old VERIFY_xyz interface to that model. And it's best done at the end of the merge window when I've done most of my merges, so let's just get this done once and for all. This patch was mostly done with a sed-script, with manual fix-ups for the cases that weren't of the trivial 'access_ok(VERIFY_xyz' form. There were a couple of notable cases: - csky still had the old "verify_area()" name as an alias. - the iter_iov code had magical hardcoded knowledge of the actual values of VERIFY_{READ,WRITE} (not that they mattered, since nothing really used it) - microblaze used the type argument for a debug printout but other than those oddities this should be a total no-op patch. I tried to fix up all architectures, did fairly extensive grepping for access_ok() uses, and the changes are trivial, but I may have missed something. Any missed conversion should be trivially fixable, though. Signed-off-by: Linus Torvalds

xen: add new hypercall buffer mapping device

2018-06-22T06:26:42+00:00

For passing arbitrary data from user land to the Xen hypervisor the Xen tools today are using mlock()ed buffers. Unfortunately the kernel might change access rights of such buffers for brief periods of time e.g. for page migration or compaction, leading to access faults in the hypervisor, as the hypervisor can't use the locks of the kernel. In order to solve this problem add a new device node to the Xen privcmd driver to easily allocate hypercall buffers via mmap(). The memory is allocated in the kernel and just mapped into user space. Marked as VM_IO the user mapping will not be subject to page migration et al. Signed-off-by: Juergen Gross Reviewed-by: Boris Ostrovsky Signed-off-by: Juergen Gross

xen/privcmd: add IOCTL_PRIVCMD_MMAP_RESOURCE

2018-05-14T13:25:37+00:00

My recent Xen patch series introduces a new HYPERVISOR_memory_op to support direct priv-mapping of certain guest resources (such as ioreq pages, used by emulators) by a tools domain, rather than having to access such resources via the guest P2M. This patch adds the necessary infrastructure to the privcmd driver and Xen MMU code to support direct resource mapping. NOTE: The adjustment in the MMU code is partially cosmetic. Xen will now allow a PV tools domain to map guest pages either by GFN or MFN, thus the term 'mfn' has been swapped for 'pfn' in the lower layers of the remap code. Signed-off-by: Paul Durrant Reviewed-by: Boris Ostrovsky Signed-off-by: Juergen Gross

xen: Change return type to vm_fault_t

2018-05-14T12:41:34+00:00

Use new return type vm_fault_t for fault handler in struct vm_operations_struct. Signed-off-by: Souptick Joarder Reviewed-by: Matthew Wilcox Reviewed-by: Juergen Gross Signed-off-by: Juergen Gross