WSL2-Linux-Kernel

The source for the Linux kernel used in Windows Subsystem for Linux 2 (WSL2)

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Souptick Joarder 8d1502f629 xen/gntdev.c: Replace vm_map_pages() with vm_map_pages_zero() 'commit `df9bde015a` ("xen/gntdev.c: convert to use vm_map_pages()")' breaks gntdev driver. If vma->vm_pgoff > 0, vm_map_pages() will: - use map->pages starting at vma->vm_pgoff instead of 0 - verify map->count against vma_pages()+vma->vm_pgoff instead of just vma_pages(). In practice, this breaks using a single gntdev FD for mapping multiple grants. relevant strace output: [pid 857] ioctl(7, IOCTL_GNTDEV_MAP_GRANT_REF, 0x7ffd3407b6d0) = 0 [pid 857] mmap(NULL, 4096, PROT_READ\|PROT_WRITE, MAP_SHARED, 7, 0) = 0x777f1211b000 [pid 857] ioctl(7, IOCTL_GNTDEV_SET_UNMAP_NOTIFY, 0x7ffd3407b710) = 0 [pid 857] ioctl(7, IOCTL_GNTDEV_MAP_GRANT_REF, 0x7ffd3407b6d0) = 0 [pid 857] mmap(NULL, 4096, PROT_READ\|PROT_WRITE, MAP_SHARED, 7, 0x1000) = -1 ENXIO (No such device or address) details here: https://github.com/QubesOS/qubes-issues/issues/5199 The reason is -> ( copying Marek's word from discussion) vma->vm_pgoff is used as index passed to gntdev_find_map_index. It's basically using this parameter for "which grant reference to map". map struct returned by gntdev_find_map_index() describes just the pages to be mapped. Specifically map->pages[0] should be mapped at vma->vm_start, not vma->vm_start+vma->vm_pgoff*PAGE_SIZE. When trying to map grant with index (aka vma->vm_pgoff) > 1, __vm_map_pages() will refuse to map it because it will expect map->count to be at least vma_pages(vma)+vma->vm_pgoff, while it is exactly vma_pages(vma). Converting vm_map_pages() to use vm_map_pages_zero() will fix the problem. Marek has tested and confirmed the same. Cc: stable@vger.kernel.org # v5.2+ Fixes: `df9bde015a` ("xen/gntdev.c: convert to use vm_map_pages()") Reported-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com> Signed-off-by: Souptick Joarder <jrdr.linux@gmail.com> Tested-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Juergen Gross <jgross@suse.com>		2019-07-31 08:13:59 +02:00
Documentation	xen: Map "xen_nopv" parameter to "nopv" and mark it obsolete	2019-07-17 08:09:58 +02:00
LICENSES	…
arch	xen/pv: Fix a boot up hang revealed by int3 self test	2019-07-17 08:09:59 +02:00
block	…
certs	…
crypto	…
drivers	xen/gntdev.c: Replace vm_map_pages() with vm_map_pages_zero()	2019-07-31 08:13:59 +02:00
fs	for-linus-20190715	2019-07-15 21:20:52 -07:00
include	xen: remove tmem driver	2019-07-17 08:09:58 +02:00
init	…
ipc	…
kernel	pci-v5.3-changes	2019-07-15 20:44:49 -07:00
lib	5.3 Merge window RDMA pull request	2019-07-15 20:38:15 -07:00
mm	…
net	pci-v5.3-changes	2019-07-15 20:44:49 -07:00
samples	…
scripts	…
security	…
sound	…
tools	pci-v5.3-changes	2019-07-15 20:44:49 -07:00
usr	…
virt	…
.clang-format	…
.cocciconfig	…
.get_maintainer.ignore	…
.gitattributes	…
.gitignore	…
.mailmap	…
COPYING	…
CREDITS	…
Kbuild	…
Kconfig	…
MAINTAINERS	for-linus-20190715	2019-07-15 21:20:52 -07:00
Makefile	…
README	…

README

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.